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Graham Nelson f530783708 Fix for Jira bug I7-2084
2022-05-07 13:11:24 +01:00

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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
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<title>Inform 6 Code</title>
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<main role="main">
<!--Weave of 'Inform 6 Code' generated by Inweb-->
<div class="breadcrumbs">
<ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="../intern.html">Inter Modules</a></li><li><a href="index.html">final</a></li><li><a href="index.html#4">Chapter 4: Inform 6</a></li><li><b>Inform 6 Code</b></li></ul></div>
<p class="purpose">To generate I6 routines of imperative code.</p>
<ul class="toc"><li><a href="4-i6c2.html#SP2">&#167;2. Functions</a></li><li><a href="4-i6c2.html#SP3">&#167;3. Labels</a></li><li><a href="4-i6c2.html#SP4">&#167;4. Function invocations</a></li><li><a href="4-i6c2.html#SP5">&#167;5. Assembly language</a></li><li><a href="4-i6c2.html#SP6">&#167;6. Primitives</a></li><li><a href="4-i6c2.html#SP7">&#167;7. Support code for property accesses</a></li><li><a href="4-i6c2.html#SP9">&#167;9. The final functions</a></li></ul><hr class="tocbar">
<p class="commentary firstcommentary"><a id="SP1" class="paragraph-anchor"></a><b>&#167;1. </b></p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::create_generator</span><button class="popup" onclick="togglePopup('usagePopup1')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup1">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::create_generator</span></span>:<br/>Generating Inform 6 - <a href="4-fi6.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generator</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">METHOD_ADD</span><span class="plain-syntax">(</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="constant-syntax">DECLARE_FUNCTION_MTID</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP2" class="function-link"><span class="function-syntax">I6TargetCode::declare_function</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">METHOD_ADD</span><span class="plain-syntax">(</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="constant-syntax">PLACE_LABEL_MTID</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP3" class="function-link"><span class="function-syntax">I6TargetCode::place_label</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">METHOD_ADD</span><span class="plain-syntax">(</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="constant-syntax">EVALUATE_LABEL_MTID</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP3" class="function-link"><span class="function-syntax">I6TargetCode::evaluate_label</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">METHOD_ADD</span><span class="plain-syntax">(</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="constant-syntax">INVOKE_PRIMITIVE_MTID</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP6" class="function-link"><span class="function-syntax">I6TargetCode::invoke_primitive</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">METHOD_ADD</span><span class="plain-syntax">(</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="constant-syntax">INVOKE_FUNCTION_MTID</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP4" class="function-link"><span class="function-syntax">I6TargetCode::invoke_function</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">METHOD_ADD</span><span class="plain-syntax">(</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="constant-syntax">INVOKE_OPCODE_MTID</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP5" class="function-link"><span class="function-syntax">I6TargetCode::invoke_opcode</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">METHOD_ADD</span><span class="plain-syntax">(</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="constant-syntax">ASSEMBLY_MARKER_MTID</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP5" class="function-link"><span class="function-syntax">I6TargetCode::assembly_marker</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP2" class="paragraph-anchor"></a><b>&#167;2. Functions. </b>Inform 6 originated as an assembler briefly called "zass", and its assembly-language
character can still be seen in the way functions are declared:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax">[ </span><span class="identifier-syntax">FunctionName</span><span class="plain-syntax"> </span><span class="identifier-syntax">local1</span><span class="plain-syntax"> </span><span class="identifier-syntax">local2</span><span class="plain-syntax"> </span><span class="identifier-syntax">local3</span><span class="plain-syntax"> ... </span><span class="identifier-syntax">localn</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> ...</span>
<span class="plain-syntax">];</span>
</pre>
<p class="commentary">Here <span class="extract"><span class="extract-syntax">local1</span></span>, <span class="extract"><span class="extract-syntax">local2</span></span>, ..., <span class="extract"><span class="extract-syntax">localn</span></span> are all of the local variables accessible
from the function; the earliest will be used as call parameters, all subsequent
ones being initially zero.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::declare_function</span><button class="popup" onclick="togglePopup('usagePopup2')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup2">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::declare_function</span></span>:<br/><a href="4-i6c2.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generator</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">vanilla_function</span><span class="plain-syntax"> *</span><span class="identifier-syntax">vf</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">segmentation_pos</span><span class="plain-syntax"> </span><span class="identifier-syntax">saved</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP12" class="function-link"><span class="function-syntax">CodeGen::select</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="constant-syntax">functions_I7CGS</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">vf</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"no vg"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">fn_name</span><span class="plain-syntax"> = </span><span class="identifier-syntax">vf</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">identifier</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP14" class="function-link"><span class="function-syntax">CodeGen::current</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP2_1" class="named-paragraph-link"><span class="named-paragraph">Open the function</span><span class="named-paragraph-number">2.1</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::eq</span><span class="plain-syntax">(</span><span class="identifier-syntax">fn_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">I</span><span class="string-syntax">"Main"</span><span class="plain-syntax">)) </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP2_3" class="named-paragraph-link"><span class="named-paragraph">Inject code at the top of Main</span><span class="named-paragraph-number">2.3</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::eq</span><span class="plain-syntax">(</span><span class="identifier-syntax">fn_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">I</span><span class="string-syntax">"DebugAction"</span><span class="plain-syntax">)) </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP2_4" class="named-paragraph-link"><span class="named-paragraph">Inject code at the top of DebugAction</span><span class="named-paragraph-number">2.4</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::eq</span><span class="plain-syntax">(</span><span class="identifier-syntax">fn_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">I</span><span class="string-syntax">"DebugAttribute"</span><span class="plain-syntax">)) </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP2_5" class="named-paragraph-link"><span class="named-paragraph">Inject code at the top of DebugAttribute</span><span class="named-paragraph-number">2.5</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::eq</span><span class="plain-syntax">(</span><span class="identifier-syntax">fn_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">I</span><span class="string-syntax">"DebugProperty"</span><span class="plain-syntax">)) </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP2_6" class="named-paragraph-link"><span class="named-paragraph">Inject code at the top of DebugProperty</span><span class="named-paragraph-number">2.6</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::eq</span><span class="plain-syntax">(</span><span class="identifier-syntax">fn_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">I</span><span class="string-syntax">"FINAL_CODE_STARTUP_R"</span><span class="plain-syntax">)) </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP2_7" class="named-paragraph-link"><span class="named-paragraph">Inject code at the top of FINAL_CODE_STARTUP_R</span><span class="named-paragraph-number">2.7</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">vf</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">function_body</span><span class="plain-syntax">); </span><span class="comment-syntax"> This compiles the body of the function</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP2_2" class="named-paragraph-link"><span class="named-paragraph">Close the function</span><span class="named-paragraph-number">2.2</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><a href="2-cg.html#SP12" class="function-link"><span class="function-syntax">CodeGen::deselect</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">saved</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP2_1" class="paragraph-anchor"></a><b>&#167;2.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Open the function</span><span class="named-paragraph-number">2.1</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ %S"</span><span class="plain-syntax">, </span><span class="identifier-syntax">fn_name</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">var_name</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_OVER_LINKED_LIST</span><span class="plain-syntax">(</span><span class="identifier-syntax">var_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax">, </span><span class="identifier-syntax">vf</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">locals</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" %S"</span><span class="plain-syntax">, </span><span class="identifier-syntax">var_name</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">";\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP2">&#167;2</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP2_2" class="paragraph-anchor"></a><b>&#167;2.2. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Close the function</span><span class="named-paragraph-number">2.2</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP2">&#167;2</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP2_3" class="paragraph-anchor"></a><b>&#167;2.3. </b>A few functions will be sneakily rewritten in passing. This is done to handle
specific features of the Z or Glulx virtual machines which do not meaningfully
exist in any wider cross-platform way. Although this could all be done by having
a slightly more elaborate linker and then including the code below in kits
(as was indeed done during 2020), it's really better that the Inter tree not
have to refer to eldritch Z-only symbols like <span class="extract"><span class="extract-syntax">#largest_object</span></span> or Glulx-only
symbols like <span class="extract"><span class="extract-syntax">#g$self</span></span>.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Inject code at the top of Main</span><span class="named-paragraph-number">2.3</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef TARGET_ZCODE; max_z_object = #largest_object - 255; #endif;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP2">&#167;2</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP2_4" class="paragraph-anchor"></a><b>&#167;2.4. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Inject code at the top of DebugAction</span><span class="named-paragraph-number">2.4</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef TARGET_GLULX;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"if (a &lt; 4096) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (a &lt; 0 || a &gt;= #identifiers_table--&gt;7) print \"&lt;invalid action \", a, \"&gt;\";\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" str = #identifiers_table--&gt;6;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" str = str--&gt;a;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (str) print (string) str; else print \"&lt;unnamed action \", a, \"&gt;\";\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef TARGET_ZCODE;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"if (a &lt; 4096) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" anames = #identifiers_table;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" anames = anames + 2*(anames--&gt;0) + 2*48;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" print (string) anames--&gt;a;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP2">&#167;2</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP2_5" class="paragraph-anchor"></a><b>&#167;2.5. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Inject code at the top of DebugAttribute</span><span class="named-paragraph-number">2.5</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">I6_GEN_DATA</span><span class="plain-syntax">(</span><span class="identifier-syntax">DebugAttribute_seen</span><span class="plain-syntax">) = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef TARGET_GLULX;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"if (a &lt; 0 || a &gt;= NUM_ATTR_BYTES*8) print \"&lt;invalid attribute \", a, \"&gt;\";\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" str = #identifiers_table--&gt;4;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" str = str--&gt;a;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (str) print (string) str; else print \"&lt;unnamed attribute \", a, \"&gt;\";\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"return;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef TARGET_ZCODE;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"if (a &lt; 0 || a &gt;= 48) print \"&lt;invalid attribute \", a, \"&gt;\";\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" anames = #identifiers_table; anames = anames + 2*(anames--&gt;0);\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" print (string) anames--&gt;a;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"return;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP2">&#167;2</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP2_6" class="paragraph-anchor"></a><b>&#167;2.6. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Inject code at the top of DebugProperty</span><span class="named-paragraph-number">2.6</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"print (property) p;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"return;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP2">&#167;2</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP2_7" class="paragraph-anchor"></a><b>&#167;2.7. </b>This enables a speed optimisation in the Glulx virtual machine which
reimplements some of the veneer functions in "hardware". If it weren't here,
or if the Gestalt said that the VM didn't support this after all, no harm would
be done except for a slight slowdown.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Inject code at the top of FINAL_CODE_STARTUP_R</span><span class="named-paragraph-number">2.7</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef TARGET_GLULX;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@gestalt 9 0 res;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"if (res == 0) rfalse;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"addr = #classes_table;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelparam 0 addr;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelparam 1 INDIV_PROP_START;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelparam 2 Class;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelparam 3 Object;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelparam 4 Routine;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelparam 5 String;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"addr = #globals_array + WORDSIZE * #g$self;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelparam 6 addr;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelparam 7 NUM_ATTR_BYTES;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"addr = #cpv__start;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelparam 8 addr;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelfunc 1 Z__Region;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelfunc 2 CP__Tab;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelfunc 3 RA__Pr;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelfunc 4 RL__Pr;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelfunc 5 OC__Cl;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelfunc 6 RV__Pr;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@accelfunc 7 OP__Pr;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"rfalse;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP2">&#167;2</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP3" class="paragraph-anchor"></a><b>&#167;3. Labels. </b>Labels in Inform 6 are <span class="extract"><span class="extract-syntax">jump</span></span> destinations, much as in C they are <span class="extract"><span class="extract-syntax">goto</span></span> destinations.
A full stop indicates where they are positioned:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">whatever</span><span class="plain-syntax">) </span><span class="reserved-syntax">jump</span><span class="plain-syntax"> </span><span class="identifier-syntax">Catastrophe</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> ...</span>
<span class="plain-syntax"> .</span><span class="identifier-syntax">Catastrophe</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> ...</span>
</pre>
<p class="commentary">Inter identifiers for labels also start with full stops. So:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::place_label</span><button class="popup" onclick="togglePopup('usagePopup3')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup3">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::place_label</span></span>:<br/><a href="4-i6c2.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generator</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">label_name</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP14" class="function-link"><span class="function-syntax">CodeGen::current</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"%S;\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">label_name</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::evaluate_label</span><button class="popup" onclick="togglePopup('usagePopup4')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup4">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::evaluate_label</span></span>:<br/><a href="4-i6c2.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generator</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">label_name</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP14" class="function-link"><span class="function-syntax">CodeGen::current</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_THROUGH_TEXT</span><span class="plain-syntax">(</span><span class="identifier-syntax">pos</span><span class="plain-syntax">, </span><span class="identifier-syntax">label_name</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::get</span><span class="plain-syntax">(</span><span class="identifier-syntax">pos</span><span class="plain-syntax">) != </span><span class="character-syntax">'.'</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PUT</span><span class="plain-syntax">(</span><span class="identifier-syntax">Str::get</span><span class="plain-syntax">(</span><span class="identifier-syntax">pos</span><span class="plain-syntax">));</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP4" class="paragraph-anchor"></a><b>&#167;4. Function invocations. </b>Or in other words, function calls. These are easy: the syntax is exactly what
it would be for C.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::invoke_function</span><button class="popup" onclick="togglePopup('usagePopup5')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup5">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::invoke_function</span></span>:<br/><a href="4-i6c2.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generator</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">P</span><span class="plain-syntax">, </span><span class="reserved-syntax">vanilla_function</span><span class="plain-syntax"> *</span><span class="identifier-syntax">vf</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">void_context</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP14" class="function-link"><span class="function-syntax">CodeGen::current</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"%S("</span><span class="plain-syntax">, </span><span class="identifier-syntax">vf</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">identifier</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">c</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_THROUGH_INTER_CHILDREN</span><span class="plain-syntax">(</span><span class="identifier-syntax">F</span><span class="plain-syntax">, </span><span class="identifier-syntax">P</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">c</span><span class="plain-syntax">++ &gt; </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">F</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">void_context</span><span class="plain-syntax">) </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">";\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP5" class="paragraph-anchor"></a><b>&#167;5. Assembly language. </b>In general, we make no attempt to police the supposedly valid assembly language
given to us here. Glulx has one set, Z another. Any assembly language in the Inter
tree results from kit material; and if the author of such a kit tries to use an
invalid opcode, then the result won't compile under I6, but none of that is our
business here.
</p>
<p class="commentary">The <span class="extract"><span class="extract-syntax">@aread</span></span> opcode is a valid Z-machine opcode, but owing to the way I6 handles
the irreconcilable change in syntax for the same opcode in V3 and V4-5 of the
Z-machine specification, there is no good way to assemble it using <span class="extract"><span class="extract-syntax">@</span></span> notation
unless we want to save the result. (See the Z-Machine Standards Document.)
As a dodge, we use the Inform 6 statement <span class="extract"><span class="extract-syntax">read X Y</span></span> instead.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::invoke_opcode</span><button class="popup" onclick="togglePopup('usagePopup6')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup6">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::invoke_opcode</span></span>:<br/><a href="4-i6c2.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generator</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">opcode</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">operand_count</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> **</span><span class="identifier-syntax">operands</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">label</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">label_sense</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP14" class="function-link"><span class="function-syntax">CodeGen::current</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::eq</span><span class="plain-syntax">(</span><span class="identifier-syntax">opcode</span><span class="plain-syntax">, </span><span class="identifier-syntax">I</span><span class="string-syntax">"@aread"</span><span class="plain-syntax">)) </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"read"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"%S"</span><span class="plain-syntax">, </span><span class="identifier-syntax">opcode</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">opc</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">opc</span><span class="plain-syntax"> &lt; </span><span class="identifier-syntax">operand_count</span><span class="plain-syntax">; </span><span class="identifier-syntax">opc</span><span class="plain-syntax">++) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">operands</span><span class="plain-syntax">[</span><span class="identifier-syntax">opc</span><span class="plain-syntax">]);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">label</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ?"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">label_sense</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">) </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"~"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">label</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">";\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::assembly_marker</span><button class="popup" onclick="togglePopup('usagePopup7')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup7">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::assembly_marker</span></span>:<br/><a href="4-i6c2.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generator</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_ti</span><span class="plain-syntax"> </span><span class="identifier-syntax">marker</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP14" class="function-link"><span class="function-syntax">CodeGen::current</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">marker</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ASM_ARROW_ASMMARKER:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"-&gt;"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ASM_SP_ASMMARKER:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"sp"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ASM_RTRUE_ASMMARKER:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"?rtrue"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ASM_RFALSE_ASMMARKER:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"?rfalse"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ASM_NEG_ASMMARKER:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"~"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ASM_NEG_RTRUE_ASMMARKER:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"?~rtrue"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ASM_NEG_RFALSE_ASMMARKER:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"?~rfalse"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">default:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE_TO</span><span class="plain-syntax">(</span><span class="identifier-syntax">STDERR</span><span class="plain-syntax">, </span><span class="string-syntax">"Unimplemented assembly marker is '%d'\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">marker</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"unimplemented assembly marker"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP6" class="paragraph-anchor"></a><b>&#167;6. Primitives. </b></p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::invoke_primitive</span><button class="popup" onclick="togglePopup('usagePopup8')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup8">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::invoke_primitive</span></span>:<br/><a href="4-i6c2.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generator</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prim_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">P</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">void_context</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree</span><span class="plain-syntax"> *</span><span class="identifier-syntax">I</span><span class="plain-syntax"> = </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">from</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP14" class="function-link"><span class="function-syntax">CodeGen::current</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_ti</span><span class="plain-syntax"> </span><span class="identifier-syntax">bip</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Primitives::to_BIP</span><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="plain-syntax">, </span><span class="identifier-syntax">prim_name</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">void_context</span><span class="plain-syntax">)?</span><span class="identifier-syntax">FALSE:TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">bip</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_1" class="named-paragraph-link"><span class="named-paragraph">Basic arithmetic and logical operations</span><span class="named-paragraph-number">6.1</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2" class="named-paragraph-link"><span class="named-paragraph">Storing or otherwise changing values</span><span class="named-paragraph-number">6.2</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_5" class="named-paragraph-link"><span class="named-paragraph">VM stack access</span><span class="named-paragraph-number">6.5</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6" class="named-paragraph-link"><span class="named-paragraph">Control structures</span><span class="named-paragraph-number">6.6</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_7" class="named-paragraph-link"><span class="named-paragraph">Indirect function calls</span><span class="named-paragraph-number">6.7</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_8" class="named-paragraph-link"><span class="named-paragraph">Method calls</span><span class="named-paragraph-number">6.8</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_3" class="named-paragraph-link"><span class="named-paragraph">Property value access</span><span class="named-paragraph-number">6.3</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_9" class="named-paragraph-link"><span class="named-paragraph">Textual output</span><span class="named-paragraph-number">6.9</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_10" class="named-paragraph-link"><span class="named-paragraph">The VM object tree</span><span class="named-paragraph-number">6.10</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">default:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE_TO</span><span class="plain-syntax">(</span><span class="identifier-syntax">STDERR</span><span class="plain-syntax">, </span><span class="string-syntax">"Unimplemented primitive is '%S'\n"</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">InterSymbol::identifier</span><span class="plain-syntax">(</span><span class="identifier-syntax">prim_name</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"unimplemented prim"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">) </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">";\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP6_1" class="paragraph-anchor"></a><b>&#167;6.1. </b>Mostly easy, because the Inter primitives here were so closely modelled on
their Inform 6 analogues in the first place.
</p>
<p class="commentary">For example, although <span class="extract"><span class="extract-syntax">!alternative</span></span> is a very unusual linguistic feature &mdash;
it allows alternatives in several conditions, e.g., <span class="extract"><span class="extract-syntax">if (x == 1 or 2 or 3) ...</span></span> &mdash;
it corresponds directly to the <span class="extract"><span class="extract-syntax">or</span></span> keyword of Inform 6, so generating it is trivial.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Basic arithmetic and logical operations</span><span class="named-paragraph-number">6.1</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PLUS_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" + "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">MINUS_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" - "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">UNARYMINUS_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(-("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">TIMES_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"*"</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">DIVIDE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"/"</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">MODULO_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"%%"</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">BITWISEAND_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")&amp;("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">BITWISEOR_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")|("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">BITWISENOT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(~("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">NOT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(~~("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">AND_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") &amp;&amp; ("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">OR_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") || ("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">EQ_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" == "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">NE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ~= "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">GT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" &gt; "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">GE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" &gt;= "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">LT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" &lt; "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">LE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" &lt;= "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">OFCLASS_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ofclass "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">IN_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" in "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">NOTIN_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" notin "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">LOOKUP_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"--&gt;("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">LOOKUPBYTE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"-&gt;("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ALTERNATIVE_BIP:</span><span class="plain-syntax"> </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" or "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">SEQUENTIAL_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">TERNARYSEQUENTIAL_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_1_1" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for ternarysequential</span><span class="named-paragraph-number">6.1.1</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">RANDOM_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"random("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6">&#167;6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_1_1" class="paragraph-anchor"></a><b>&#167;6.1.1. </b>But the unfortunate <span class="extract"><span class="extract-syntax">!ternarysequential a b c</span></span> needs some gymnastics. It
would be trivial to generate to C with the serial comma operator: <span class="extract"><span class="extract-syntax">(a, b, c)</span></span>
evaluates <span class="extract"><span class="extract-syntax">a</span></span>, then throws that away and evaluates <span class="extract"><span class="extract-syntax">b</span></span>, then throws that away
too and returns the value of <span class="extract"><span class="extract-syntax">c</span></span>.
</p>
<p class="commentary">The same effect is annoyingly difficult to get out of the sometimes shaky I6
compiler's expression parser. I6 does support the comma operator, so at first
sight <span class="extract"><span class="extract-syntax">(a, b, c)</span></span> ought to work in I6, too. And it does, right up to the point
where some of the token values themselves include invocations of functions. It
is a known infelicity of the I6 syntax analyser that it won't always allow the
serial comma to be mixed in the same expression with the function argument
comma: for example in the case <span class="extract"><span class="extract-syntax">(a(b, c), d)</span></span>, where the first comma constructs
a list of arguments and the second is the operator. (Many such expressions work
fine in I6 &mdash; but not all.)
</p>
<p class="commentary">That being so, we use the following circumlocution:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> (</span><span class="identifier-syntax">c</span><span class="plain-syntax">) + </span><span class="constant-syntax">0</span><span class="plain-syntax">*((</span><span class="identifier-syntax">b</span><span class="plain-syntax">) + (</span><span class="identifier-syntax">a</span><span class="plain-syntax">))</span>
</pre>
<p class="commentary">Because I6 evaluates the leaves in an expression tree right-to-left, not
left-to-right, the parameter assignments happen first, then the conditions,
then the result.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for ternarysequential</span><span class="named-paragraph-number">6.1.1</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"! This evaluates last\n"</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"+\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"0*(\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"! This evaluates second\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"((\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"\n))\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"+\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"! This evaluate first\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_1">&#167;6.1</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_2" class="paragraph-anchor"></a><b>&#167;6.2. </b>These are the seven primitives which change a storage item given by a
reference, which is always the first child of the primitive node. It might,
for example, be a global variable, or a memory location.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Storing or otherwise changing values</span><span class="named-paragraph-number">6.2</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">STORE_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2_1" class="named-paragraph-link"><span class="named-paragraph">Perform a store</span><span class="named-paragraph-number">6.2.1</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PREINCREMENT_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2_1" class="named-paragraph-link"><span class="named-paragraph">Perform a store</span><span class="named-paragraph-number">6.2.1</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">POSTINCREMENT_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2_1" class="named-paragraph-link"><span class="named-paragraph">Perform a store</span><span class="named-paragraph-number">6.2.1</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PREDECREMENT_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2_1" class="named-paragraph-link"><span class="named-paragraph">Perform a store</span><span class="named-paragraph-number">6.2.1</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">POSTDECREMENT_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2_1" class="named-paragraph-link"><span class="named-paragraph">Perform a store</span><span class="named-paragraph-number">6.2.1</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">SETBIT_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2_1" class="named-paragraph-link"><span class="named-paragraph">Perform a store</span><span class="named-paragraph-number">6.2.1</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">CLEARBIT_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2_1" class="named-paragraph-link"><span class="named-paragraph">Perform a store</span><span class="named-paragraph-number">6.2.1</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6">&#167;6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_2_1" class="paragraph-anchor"></a><b>&#167;6.2.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Perform a store</span><span class="named-paragraph-number">6.2.1</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">W</span><span class="plain-syntax">.</span><span class="identifier-syntax">instruction</span><span class="plain-syntax">[0] == </span><span class="identifier-syntax">REFERENCE_IST</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">ReferenceInstruction::node_is_ref_to</span><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">from</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">),</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PROPERTYVALUE_BIP</span><span class="plain-syntax">)) &amp;&amp;</span>
<span class="plain-syntax"> (</span><a href="4-i6c2.html#SP8" class="function-link"><span class="function-syntax">I6TargetCode::pval_case</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">) != </span><span class="constant-syntax">I6G_CAN_PROVE_IS_OBJ_PROPERTY</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2_1_2" class="named-paragraph-link"><span class="named-paragraph">Alter a property value</span><span class="named-paragraph-number">6.2.1.2</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_2_1_1" class="named-paragraph-link"><span class="named-paragraph">Alter some other storage</span><span class="named-paragraph-number">6.2.1.1</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_2">&#167;6.2</a> (7 times).</li></ul>
<p class="commentary firstcommentary"><a id="SP6_2_1_1" class="paragraph-anchor"></a><b>&#167;6.2.1.1. </b>The easy case first: here, whatever the storage is (for example, a variable),
it's one that we can simply treat as an lvalue in Inform 6 (for example, by giving
its variable name). For example, the memory location <span class="extract"><span class="extract-syntax">A--&gt;3</span></span> can be assigned to,
or can have <span class="extract"><span class="extract-syntax">++</span></span> or <span class="extract"><span class="extract-syntax">--</span></span> applied to it in I6.
</p>
<p class="commentary">Note that this case even includes some property values: if we can see that <span class="extract"><span class="extract-syntax">P</span></span>
is the explicit name of a property we are storing in a VM-property, then we can
use <span class="extract"><span class="extract-syntax">O.P</span></span> as an Inform 6 lvalue, and all is well, and we then end up with code
such as <span class="extract"><span class="extract-syntax">++(O.P)</span></span>.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Alter some other storage</span><span class="named-paragraph-number">6.2.1.1</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">bip</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PREINCREMENT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"++("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">POSTINCREMENT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")++"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PREDECREMENT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"--("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">POSTDECREMENT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")--"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">STORE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" = "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">SETBIT_BIP:</span><span class="plain-syntax"> </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" = "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" | "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">CLEARBIT_BIP:</span><span class="plain-syntax"> </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" = "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" &amp;~ ("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_2_1">&#167;6.2.1</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_2_1_2" class="paragraph-anchor"></a><b>&#167;6.2.1.2. </b>But not all property values can be written as Inform 6 lvalues. If the I7
property P is being stored as a VM-attribute A, then there is no lvalue which
expresses the value of A for an object O: instead one must use <span class="extract"><span class="extract-syntax">give O A</span></span> to
set it, <span class="extract"><span class="extract-syntax">give O ~A</span></span> to unset it, and <span class="extract"><span class="extract-syntax">(O has A)</span></span> to test it. And there will
also be cases where P cannot be identified at compile-time, so that we have no
way to know whether it will be stored as a VM-attribute or not.
</p>
<p class="commentary">To handle these two cases, then, we will compile an attempt to store or modify
a property value either as a <span class="extract"><span class="extract-syntax">give</span></span> statement &mdash; if we can prove P is being
stored in a VM-attribute &mdash; or else as a function call to a general-purpose
function called <span class="extract"><span class="extract-syntax">_final_change_property</span></span>.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Alter a property value</span><span class="named-paragraph-number">6.2.1.2</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">VP</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::second_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">set</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NOT_APPLICABLE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">VP</span><span class="plain-syntax">, </span><span class="identifier-syntax">VAL_IST</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_pair</span><span class="plain-syntax"> </span><span class="identifier-syntax">val</span><span class="plain-syntax"> = </span><span class="identifier-syntax">ValInstruction::value</span><span class="plain-syntax">(</span><span class="identifier-syntax">VP</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::is_number</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::is_zero</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">)) </span><span class="identifier-syntax">set</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::is_one</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">)) </span><span class="identifier-syntax">set</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">c</span><span class="plain-syntax"> = </span><a href="4-i6c2.html#SP8" class="function-link"><span class="function-syntax">I6TargetCode::pval_case</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">c</span><span class="plain-syntax"> == </span><span class="constant-syntax">I6G_CAN_PROVE_IS_OBJ_ATTRIBUTE</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">bip</span><span class="plain-syntax"> == </span><span class="identifier-syntax">STORE_BIP</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">set</span><span class="plain-syntax"> == </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"give "</span><span class="plain-syntax">); </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::second_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" %S"</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP7" class="function-link"><span class="function-syntax">I6TargetCode::inner_name</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::third_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">)));</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">c</span><span class="plain-syntax"> == </span><span class="constant-syntax">I6G_CAN_PROVE_IS_OBJ_ATTRIBUTE</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">bip</span><span class="plain-syntax"> == </span><span class="identifier-syntax">STORE_BIP</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">set</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"give "</span><span class="plain-syntax">); </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::second_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ~%S"</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP7" class="function-link"><span class="function-syntax">I6TargetCode::inner_name</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::third_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">)));</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">bip</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">STORE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_store_property"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PREINCREMENT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_preinc_property"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">POSTINCREMENT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_postinc_property"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PREDECREMENT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_predec_property"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">POSTDECREMENT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_postdec_property"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">SETBIT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_setbit_property"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">CLEARBIT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_clearbit_property"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::second_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::third_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">storage_ref</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">bip</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">STORE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">SETBIT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">CLEARBIT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_2_1">&#167;6.2.1</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_3" class="paragraph-anchor"></a><b>&#167;6.3. </b>Reading property values is easier. The general case, similarly, is to call a
function for this, but an important optimisation collapses this to the use of
the <span class="extract"><span class="extract-syntax">has</span></span> or <span class="extract"><span class="extract-syntax">.</span></span> operators in I6 where we can prove at compile-time that the
property in question is stored as a VM-attribute (resp., a VM-property) of
what is definitely a VM-object. This optimisation results in faster code.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Property value access</span><span class="named-paragraph-number">6.3</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PROPERTYEXISTS_BIP:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">I6_GEN_DATA</span><span class="plain-syntax">(</span><span class="identifier-syntax">value_ranges_needed</span><span class="plain-syntax">) = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">I6_GEN_DATA</span><span class="plain-syntax">(</span><span class="identifier-syntax">value_property_holders_needed</span><span class="plain-syntax">) = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(_final_propertyexists("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PROPERTYARRAY_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(_final_propertyarray("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PROPERTYLENGTH_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(_final_propertylength("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"))"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PROPERTYVALUE_BIP:</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">KP</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OP</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::second_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">PP</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::third_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><a href="4-i6c2.html#SP8" class="function-link"><span class="function-syntax">I6TargetCode::pval_case</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">I6G_CAN_PROVE_IS_OBJ_ATTRIBUTE:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" has %S"</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP7" class="function-link"><span class="function-syntax">I6TargetCode::inner_name</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">PP</span><span class="plain-syntax">)); </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">I6G_CAN_PROVE_IS_OBJ_PROPERTY:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">".%S"</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP7" class="function-link"><span class="function-syntax">I6TargetCode::inner_name</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">PP</span><span class="plain-syntax">)); </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">I6G_CANNOT_PROVE:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">I6_GEN_DATA</span><span class="plain-syntax">(</span><span class="identifier-syntax">value_property_holders_needed</span><span class="plain-syntax">) = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><a href="4-i6c2.html#SP6_4" class="function-link"><span class="function-syntax">I6TargetCode::eval_property_list</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">KP</span><span class="plain-syntax">, </span><span class="identifier-syntax">OP</span><span class="plain-syntax">, </span><span class="identifier-syntax">PP</span><span class="plain-syntax">, </span><span class="constant-syntax">0</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6">&#167;6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_4" class="paragraph-anchor"></a><b>&#167;6.4. </b>In the most general case of <span class="extract"><span class="extract-syntax">!propertyvalue</span></span>, we will end up calling the function
<span class="extract"><span class="extract-syntax">_final_propertyvalue</span></span>. But we don't do so right away because, annoyingly, <span class="extract"><span class="extract-syntax">!propertyvalue</span></span>
can have <span class="extract"><span class="extract-syntax">!alternative</span></span> children supplied. We might find this, for example:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">inv</span><span class="plain-syntax"> </span><span class="function-syntax">!if</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">inv</span><span class="plain-syntax"> </span><span class="function-syntax">!propertyvalue</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">val</span><span class="plain-syntax"> </span><span class="identifier-syntax">K_object</span><span class="plain-syntax"> harmonium</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">inv</span><span class="plain-syntax"> </span><span class="function-syntax">!alternative</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">val</span><span class="plain-syntax"> </span><span class="identifier-syntax">K_value</span><span class="plain-syntax"> </span><span class="identifier-syntax">P_sonorous</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">val</span><span class="plain-syntax"> </span><span class="identifier-syntax">K_value</span><span class="plain-syntax"> </span><span class="identifier-syntax">P_muted</span>
</pre>
<p class="commentary">...arising from kit code such as <span class="extract"><span class="extract-syntax">if (harmonium has sonorous or muted) ...</span></span>.
This only seldom arises, so perhaps we can be given for handling it less than
optimally in all cases. We turn it into:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">or_tmp_var</span><span class="plain-syntax"> = </span><span class="identifier-syntax">harmonium</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">or_tmp_var</span><span class="plain-syntax"> </span><span class="reserved-syntax">has</span><span class="plain-syntax"> </span><span class="identifier-syntax">sonorous</span><span class="plain-syntax">)) ||</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">or_tmp_var</span><span class="plain-syntax"> </span><span class="reserved-syntax">has</span><span class="plain-syntax"> </span><span class="identifier-syntax">muted</span><span class="plain-syntax">))</span>
</pre>
<p class="commentary">Note that <span class="extract"><span class="extract-syntax">or_tmp_var</span></span> is used here so that the left operand, i.e., the object,
is evaluated only once &mdash; in case there are side-effects of the evaluation.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::eval_property_list</span><button class="popup" onclick="togglePopup('usagePopup9')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup9">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::eval_property_list</span></span>:<br/><a href="4-i6c2.html#SP6_3">&#167;6.3</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">K</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">X</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">Y</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">depth</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP14" class="function-link"><span class="function-syntax">CodeGen::current</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">Y</span><span class="plain-syntax">, </span><span class="identifier-syntax">INV_IST</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">InvInstruction::method</span><span class="plain-syntax">(</span><span class="identifier-syntax">Y</span><span class="plain-syntax">) == </span><span class="identifier-syntax">PRIMITIVE_INVMETH</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prim</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InvInstruction::primitive</span><span class="plain-syntax">(</span><span class="identifier-syntax">Y</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_ti</span><span class="plain-syntax"> </span><span class="identifier-syntax">ybip</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Primitives::to_BIP</span><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">from</span><span class="plain-syntax">, </span><span class="identifier-syntax">prim</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">ybip</span><span class="plain-syntax"> == </span><span class="identifier-syntax">ALTERNATIVE_BIP</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">depth</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) { </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"((or_tmp_var = "</span><span class="plain-syntax">); </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">X</span><span class="plain-syntax">); </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") &amp;&amp; (("</span><span class="plain-syntax">); }</span>
<span class="plain-syntax"> </span><a href="4-i6c2.html#SP6_4" class="function-link"><span class="function-syntax">I6TargetCode::eval_property_list</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">K</span><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">Y</span><span class="plain-syntax">), </span><span class="identifier-syntax">depth</span><span class="plain-syntax">+1);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") || ("</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="4-i6c2.html#SP6_4" class="function-link"><span class="function-syntax">I6TargetCode::eval_property_list</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">K</span><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">, </span><span class="identifier-syntax">InterTree::second_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">Y</span><span class="plain-syntax">), </span><span class="identifier-syntax">depth</span><span class="plain-syntax">+1);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">depth</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) { </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")))"</span><span class="plain-syntax">); }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><a href="4-i6c2.html#SP8" class="function-link"><span class="function-syntax">I6TargetCode::pval_case_inner</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">K</span><span class="plain-syntax">, </span><span class="identifier-syntax">Y</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">I6G_CAN_PROVE_IS_OBJ_ATTRIBUTE:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">X</span><span class="plain-syntax">) </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">X</span><span class="plain-syntax">); </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"or_tmp_var"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" has %S"</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP7" class="function-link"><span class="function-syntax">I6TargetCode::inner_name</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">Y</span><span class="plain-syntax">)); </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">I6G_CAN_PROVE_IS_OBJ_PROPERTY:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">X</span><span class="plain-syntax">) </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">X</span><span class="plain-syntax">); </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"or_tmp_var"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">".%S"</span><span class="plain-syntax">, </span><a href="4-i6c2.html#SP7" class="function-link"><span class="function-syntax">I6TargetCode::inner_name</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">Y</span><span class="plain-syntax">)); </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">I6G_CANNOT_PROVE:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_propertyvalue("</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">K</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">X</span><span class="plain-syntax">) </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">X</span><span class="plain-syntax">); </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"or_tmp_var"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">Y</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP6_5" class="paragraph-anchor"></a><b>&#167;6.5. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">VM stack access</span><span class="named-paragraph-number">6.5</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PUSH_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@push "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PULL_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@pull "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6">&#167;6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6" class="paragraph-anchor"></a><b>&#167;6.6. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Control structures</span><span class="named-paragraph-number">6.6</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">BREAK_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"break"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">CONTINUE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"continue"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">RETURN_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_1" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for return</span><span class="named-paragraph-number">6.6.1</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">JUMP_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"jump "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">QUIT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"quit"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">RESTORE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"restore "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">IF_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_2" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for if</span><span class="named-paragraph-number">6.6.2</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">IFDEBUG_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_3" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for ifdebug</span><span class="named-paragraph-number">6.6.3</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">IFSTRICT_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_4" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for ifstrict</span><span class="named-paragraph-number">6.6.4</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">IFELSE_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_5" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for ifelse</span><span class="named-paragraph-number">6.6.5</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">WHILE_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_6" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for while</span><span class="named-paragraph-number">6.6.6</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">DO_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_7" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for do</span><span class="named-paragraph-number">6.6.7</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">FOR_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_8" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for for</span><span class="named-paragraph-number">6.6.8</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">OBJECTLOOP_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_9" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for objectloop</span><span class="named-paragraph-number">6.6.9</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">OBJECTLOOPX_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_10" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for objectloopx</span><span class="named-paragraph-number">6.6.10</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">SWITCH_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_11" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for switch</span><span class="named-paragraph-number">6.6.11</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">CASE_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_12" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for case</span><span class="named-paragraph-number">6.6.12</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ALTERNATIVECASE_BIP:</span><span class="plain-syntax"> </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">DEFAULT_BIP:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP6_6_13" class="named-paragraph-link"><span class="named-paragraph">Generate primitive for default</span><span class="named-paragraph-number">6.6.13</span></a></span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6">&#167;6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_1" class="paragraph-anchor"></a><b>&#167;6.6.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for return</span><span class="named-paragraph-number">6.6.1</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">rboolean</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NOT_APPLICABLE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">V</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">V</span><span class="plain-syntax">, </span><span class="identifier-syntax">VAL_IST</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_pair</span><span class="plain-syntax"> </span><span class="identifier-syntax">val</span><span class="plain-syntax"> = </span><span class="identifier-syntax">ValInstruction::value</span><span class="plain-syntax">(</span><span class="identifier-syntax">V</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::is_zero</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">)) </span><span class="identifier-syntax">rboolean</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::is_one</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">)) </span><span class="identifier-syntax">rboolean</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">rboolean</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">FALSE:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"rfalse"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"rtrue"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">NOT_APPLICABLE:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"return "</span><span class="plain-syntax">); </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">V</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_2" class="paragraph-anchor"></a><b>&#167;6.6.2. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for if</span><span class="named-paragraph-number">6.6.2</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"if ("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") {\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_3" class="paragraph-anchor"></a><b>&#167;6.6.3. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for ifdebug</span><span class="named-paragraph-number">6.6.3</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef DEBUG;\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_4" class="paragraph-anchor"></a><b>&#167;6.6.4. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for ifstrict</span><span class="named-paragraph-number">6.6.4</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef STRICT_MODE;\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_5" class="paragraph-anchor"></a><b>&#167;6.6.5. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for ifelse</span><span class="named-paragraph-number">6.6.5</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"if ("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") {\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"} else {\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_6" class="paragraph-anchor"></a><b>&#167;6.6.6. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for while</span><span class="named-paragraph-number">6.6.6</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"while ("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") {\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_7" class="paragraph-anchor"></a><b>&#167;6.6.7. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for do</span><span class="named-paragraph-number">6.6.7</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"do {"</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"} until (\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_8" class="paragraph-anchor"></a><b>&#167;6.6.8. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for for</span><span class="named-paragraph-number">6.6.8</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"for ("</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">INIT</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!((</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">INIT</span><span class="plain-syntax">, </span><span class="identifier-syntax">VAL_IST</span><span class="plain-syntax">)) &amp;&amp;</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::is_number</span><span class="plain-syntax">(</span><span class="identifier-syntax">ValInstruction::value</span><span class="plain-syntax">(</span><span class="identifier-syntax">INIT</span><span class="plain-syntax">))) &amp;&amp;</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::to_number</span><span class="plain-syntax">(</span><span class="identifier-syntax">ValInstruction::value</span><span class="plain-syntax">(</span><span class="identifier-syntax">INIT</span><span class="plain-syntax">)) == </span><span class="constant-syntax">1</span><span class="plain-syntax">)))</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">":"</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">":"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">U</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::third_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Inode::isnt</span><span class="plain-syntax">(</span><span class="identifier-syntax">U</span><span class="plain-syntax">, </span><span class="identifier-syntax">VAL_IST</span><span class="plain-syntax">))</span>
<span class="plain-syntax"> </span><a href="2-vnl.html#SP3" class="function-link"><span class="function-syntax">Vanilla::node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">U</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") {\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_4C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_9" class="paragraph-anchor"></a><b>&#167;6.6.9. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for objectloop</span><span class="named-paragraph-number">6.6.9</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">in_flag</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">U</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::third_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">U</span><span class="plain-syntax">, </span><span class="identifier-syntax">INV_IST</span><span class="plain-syntax">)) &amp;&amp;</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">InvInstruction::method</span><span class="plain-syntax">(</span><span class="identifier-syntax">U</span><span class="plain-syntax">) == </span><span class="identifier-syntax">PRIMITIVE_INVMETH</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prim</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InvInstruction::primitive</span><span class="plain-syntax">(</span><span class="identifier-syntax">U</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">prim</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">Primitives::to_BIP</span><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="plain-syntax">, </span><span class="identifier-syntax">prim</span><span class="plain-syntax">) == </span><span class="identifier-syntax">IN_BIP</span><span class="plain-syntax">)) </span><span class="identifier-syntax">in_flag</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"objectloop "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">in_flag</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ofclass "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" &amp;&amp; "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> } </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">in_flag</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" {\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_4C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_10" class="paragraph-anchor"></a><b>&#167;6.6.10. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for objectloopx</span><span class="named-paragraph-number">6.6.10</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"objectloop ("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ofclass "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") {\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_11" class="paragraph-anchor"></a><b>&#167;6.6.11. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for switch</span><span class="named-paragraph-number">6.6.11</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"switch ("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") {\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_12" class="paragraph-anchor"></a><b>&#167;6.6.12. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for case</span><span class="named-paragraph-number">6.6.12</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">":\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">";\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_6_13" class="paragraph-anchor"></a><b>&#167;6.6.13. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Generate primitive for default</span><span class="named-paragraph-number">6.6.13</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"default:\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">INDENT</span><span class="plain-syntax">; </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">";\n"</span><span class="plain-syntax">); </span><span class="identifier-syntax">OUTDENT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6_6">&#167;6.6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_7" class="paragraph-anchor"></a><b>&#167;6.7. </b>In Inform 6, as in C, a function which returns a value can be called in a void
context (in which case its return value is thrown away); the syntax for calling
a void function is identical to that for calling a value-returning function, so
we can treat <span class="extract"><span class="extract-syntax">INDIRECT0V_BIP</span></span> as the same as <span class="extract"><span class="extract-syntax">INDIRECT0_BIP</span></span>, and so on.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Indirect function calls</span><span class="named-paragraph-number">6.7</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT0_BIP:</span><span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT0V_BIP:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")()"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT1_BIP:</span><span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT1V_BIP:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT2_BIP:</span><span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT2V_BIP:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT3_BIP:</span><span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT3V_BIP:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_4C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT4_BIP:</span><span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT4V_BIP:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_4C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_5C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT5_BIP:</span><span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INDIRECT5V_BIP:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_4C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_5C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_6C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">EXTERNALCALL_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"external calls impossible in Inform 6"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6">&#167;6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_8" class="paragraph-anchor"></a><b>&#167;6.8. </b>Message calls are handled with functions (see below) in case the user is trying
to send a message to a property stored in an attribute, or something like that.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Method calls</span><span class="named-paragraph-number">6.8</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">MESSAGE0_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_message0("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">MESSAGE1_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_message1("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">MESSAGE2_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_message2("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_4C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">MESSAGE3_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"_final_message3("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">", "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_3C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_4C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">","</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_5C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6">&#167;6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_9" class="paragraph-anchor"></a><b>&#167;6.9. </b>Note that the only styles permitted are those from the original Z-machine, which
is about the level of technology of a 1970s teletype. The <span class="extract"><span class="extract-syntax">!style</span></span> number must be
a constant 1, 2 or 3, or else plain roman is all you get.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Textual output</span><span class="named-paragraph-number">6.9</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PRINT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"print "</span><span class="plain-syntax">); </span><a href="2-cg.html#SP7" class="function-link"><span class="function-syntax">CodeGen::lt_mode</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="constant-syntax">PRINTING_LTM</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><a href="2-cg.html#SP7" class="function-link"><span class="function-syntax">CodeGen::lt_mode</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="constant-syntax">REGULAR_LTM</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PRINTCHAR_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"print (char) "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PRINTNL_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"new_line"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PRINTOBJ_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"print (object) "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PRINTNUMBER_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"print "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PRINTDWORD_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"print (address) "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PRINTSTRING_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"print (string) "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">BOX_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"box "</span><span class="plain-syntax">); </span><a href="2-cg.html#SP7" class="function-link"><span class="function-syntax">CodeGen::lt_mode</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="constant-syntax">BOX_LTM</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><a href="2-cg.html#SP7" class="function-link"><span class="function-syntax">CodeGen::lt_mode</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="constant-syntax">REGULAR_LTM</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">SPACES_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"spaces "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">FONT_BIP:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"if ("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">") { font on; } else { font off; }"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">suppress_terminal_semicolon</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">STYLE_BIP:</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">N</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_pair</span><span class="plain-syntax"> </span><span class="identifier-syntax">pair</span><span class="plain-syntax"> = </span><span class="identifier-syntax">ValInstruction::value</span><span class="plain-syntax">(</span><span class="identifier-syntax">N</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_ti</span><span class="plain-syntax"> </span><span class="identifier-syntax">style</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterValuePairs::to_number</span><span class="plain-syntax">(</span><span class="identifier-syntax">pair</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">style</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">1</span><span class="plain-syntax">: </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"style bold"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">2</span><span class="plain-syntax">: </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"style underline"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">3</span><span class="plain-syntax">: </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"style reverse"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">default:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"style roman"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">ENABLEPRINTING_BIP:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef TARGET_GLULX;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@setiosys 2 0; ! Set to use Glk\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@push 201; ! = GG_MAINWIN_ROCK;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@push 3; ! = wintype_TextBuffer\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@push 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@push 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@push 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@glk 35 5 sp; ! glk_window_open, pushing a window ID\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"@glk 47 1 0; ! glk_set_window to that window ID\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6">&#167;6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP6_10" class="paragraph-anchor"></a><b>&#167;6.10. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">The VM object tree</span><span class="named-paragraph-number">6.10</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">MOVE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"move "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" to "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_2C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">REMOVE_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"remove "</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">CHILD_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"child("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">CHILDREN_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"children("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">PARENT_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"parent("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">SIBLING_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"sibling("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">METACLASS_BIP:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"metaclass("</span><span class="plain-syntax">); </span><span class="constant-syntax">VNODE_1C</span><span class="plain-syntax">; </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">")"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP6">&#167;6</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP7" class="paragraph-anchor"></a><b>&#167;7. Support code for property accesses. </b>In the following, <span class="extract"><span class="extract-syntax">prop_node</span></span> is a <span class="extract"><span class="extract-syntax">VAL_IST</span></span> identifying the property being
accessed: we return the "inner name" as text, if we can find one. This will only
happen if the node evaluates to a named symbol which is the name of a property.
See <a href="2-vo.html" class="internal">Vanilla Objects</a> for more on inner names.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="function-syntax">I6TargetCode::inner_name</span><button class="popup" onclick="togglePopup('usagePopup10')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup10">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::inner_name</span></span>:<br/><a href="4-i6c2.html#SP6_2_1_2">&#167;6.2.1.2</a>, <a href="4-i6c2.html#SP6_3">&#167;6.3</a>, <a href="4-i6c2.html#SP6_4">&#167;6.4</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prop_node</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">prop_node</span><span class="plain-syntax">, </span><span class="identifier-syntax">VAL_IST</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_pair</span><span class="plain-syntax"> </span><span class="identifier-syntax">val</span><span class="plain-syntax"> = </span><span class="identifier-syntax">ValInstruction::value</span><span class="plain-syntax">(</span><span class="identifier-syntax">prop_node</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::is_symbolic</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">))</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterValuePairs::to_symbol_at</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">, </span><span class="identifier-syntax">prop_node</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">InterSymbol::get_flag</span><span class="plain-syntax">(</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">, </span><span class="identifier-syntax">ATTRIBUTE_MARK_ISYMF</span><span class="plain-syntax">))) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><a href="2-vo.html#SP3" class="function-link"><span class="function-syntax">VanillaObjects::inner_property_name</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">definition</span><span class="plain-syntax">, </span><span class="identifier-syntax">PROPERTY_IST</span><span class="plain-syntax">))) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><a href="2-vo.html#SP3" class="function-link"><span class="function-syntax">VanillaObjects::inner_property_name</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP8" class="paragraph-anchor"></a><b>&#167;8. </b><span class="extract"><span class="extract-syntax">I6TargetCode::pval_case</span></span> applies to a <span class="extract"><span class="extract-syntax">!propertyvalue</span></span> invocation node. That
has three children: the kind, the object/owner, and the property itself. We
look at the node and try to see if it's one of the two easy cases which enable
more efficient code to be compiled (see above): in fact, it almost always is.
</p>
<ul class="items"><li>&#9679; We return <span class="extract"><span class="extract-syntax">I6G_CAN_PROVE_IS_OBJ_ATTRIBUTE</span></span> if the kind is definitely <span class="extract"><span class="extract-syntax">OBJECT_TY</span></span>
and the property is stored in a VM-attribute;
</li><li>&#9679; Or <span class="extract"><span class="extract-syntax">I6G_CAN_PROVE_IS_OBJ_PROPERTY</span></span> if the kind is definitely <span class="extract"><span class="extract-syntax">OBJECT_TY</span></span>
and the property is stored in a VM-property;
</li><li>&#9679; Or <span class="extract"><span class="extract-syntax">I6G_CANNOT_PROVE</span></span> if we don't know.
</li></ul>
<pre class="definitions code-font"><span class="definition-keyword">define</span> <span class="constant-syntax">I6G_CAN_PROVE_IS_OBJ_ATTRIBUTE</span><span class="plain-syntax"> </span><span class="constant-syntax">1</span>
<span class="definition-keyword">define</span> <span class="constant-syntax">I6G_CAN_PROVE_IS_OBJ_PROPERTY</span><span class="plain-syntax"> </span><span class="constant-syntax">2</span>
<span class="definition-keyword">define</span> <span class="constant-syntax">I6G_CANNOT_PROVE</span><span class="plain-syntax"> </span><span class="constant-syntax">3</span>
</pre>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::pval_case</span><button class="popup" onclick="togglePopup('usagePopup11')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup11">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::pval_case</span></span>:<br/><a href="4-i6c2.html#SP6_2_1">&#167;6.2.1</a>, <a href="4-i6c2.html#SP6_2_1_2">&#167;6.2.1.2</a>, <a href="4-i6c2.html#SP6_3">&#167;6.3</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">P</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">while</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">, </span><span class="identifier-syntax">REFERENCE_IST</span><span class="plain-syntax">)) </span><span class="identifier-syntax">P</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prop_node</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterTree::third_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><a href="4-i6c2.html#SP8" class="function-link"><span class="function-syntax">I6TargetCode::pval_case_inner</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">InterTree::first_child</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">), </span><span class="identifier-syntax">prop_node</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::pval_case_inner</span><button class="popup" onclick="togglePopup('usagePopup12')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup12">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::pval_case_inner</span></span>:<br/><a href="4-i6c2.html#SP6_4">&#167;6.4</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">kind_node</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prop_node</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">kind_symbol</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">kind_node</span><span class="plain-syntax">, </span><span class="identifier-syntax">VAL_IST</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_pair</span><span class="plain-syntax"> </span><span class="identifier-syntax">val</span><span class="plain-syntax"> = </span><span class="identifier-syntax">ValInstruction::value</span><span class="plain-syntax">(</span><span class="identifier-syntax">kind_node</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::is_symbolic</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">))</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">kind_symbol</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterValuePairs::to_symbol_at</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">, </span><span class="identifier-syntax">kind_node</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::eq</span><span class="plain-syntax">(</span><span class="identifier-syntax">InterSymbol::trans</span><span class="plain-syntax">(</span><span class="identifier-syntax">kind_symbol</span><span class="plain-syntax">), </span><span class="identifier-syntax">I</span><span class="string-syntax">"OBJECT_TY"</span><span class="plain-syntax">) == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">I6G_CANNOT_PROVE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">prop_node</span><span class="plain-syntax">, </span><span class="identifier-syntax">VAL_IST</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_pair</span><span class="plain-syntax"> </span><span class="identifier-syntax">val</span><span class="plain-syntax"> = </span><span class="identifier-syntax">ValInstruction::value</span><span class="plain-syntax">(</span><span class="identifier-syntax">prop_node</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">InterValuePairs::is_symbolic</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">))</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterValuePairs::to_symbol_at</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">, </span><span class="identifier-syntax">prop_node</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">InterSymbol::get_flag</span><span class="plain-syntax">(</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">, </span><span class="identifier-syntax">ATTRIBUTE_MARK_ISYMF</span><span class="plain-syntax">))) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">I6G_CAN_PROVE_IS_OBJ_ATTRIBUTE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">Inode::is</span><span class="plain-syntax">(</span><span class="identifier-syntax">prop_symbol</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">definition</span><span class="plain-syntax">, </span><span class="identifier-syntax">PROPERTY_IST</span><span class="plain-syntax">))) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">I6G_CAN_PROVE_IS_OBJ_PROPERTY</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">I6G_CANNOT_PROVE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP9" class="paragraph-anchor"></a><b>&#167;9. The final functions. </b>The generator above compiled calls to a handful of functions with names in the
form <span class="extract"><span class="extract-syntax">_final_*</span></span>; so these functions must clearly be supplied. It might seem that
they ought to be included in, say, BasicInformKit and not here. But:
</p>
<ul class="items"><li>(1) They are needed only for Inform 6 usage, whereas BasicInformKit contains
material used whatever the final code-generator;
</li><li>(2) They are written in genuine Inform 6 code, not kit code, which looks like
I6 and is very similar to it but is not quite the same. In kit code, <span class="extract"><span class="extract-syntax">O.P</span></span> means
"the value of the property P for the object O", but where <span class="extract"><span class="extract-syntax">P</span></span> is the metadata
array for the property. In genuine Inform 6, <span class="extract"><span class="extract-syntax">O.P</span></span> expects <span class="extract"><span class="extract-syntax">P</span></span> to be the actual
VM-property. The following functions need the latter interpretation in order to work.
</li></ul>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">I6TargetCode::end_generation</span><button class="popup" onclick="togglePopup('usagePopup13')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup13">Usage of <span class="code-font"><span class="function-syntax">I6TargetCode::end_generation</span></span>:<br/>Generating Inform 6 - <a href="4-fi6.html#SP7">&#167;7</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generator</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gtr</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">segmentation_pos</span><span class="plain-syntax"> </span><span class="identifier-syntax">saved</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP12" class="function-link"><span class="function-syntax">CodeGen::select</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="constant-syntax">functions_I7CGS</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax"> = </span><a href="2-cg.html#SP14" class="function-link"><span class="function-syntax">CodeGen::current</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP9_1" class="named-paragraph-link"><span class="named-paragraph">Most general implementation of !propertyvalue</span><span class="named-paragraph-number">9.1</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP9_2" class="named-paragraph-link"><span class="named-paragraph">Most general implementation of !propertyexists</span><span class="named-paragraph-number">9.2</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP9_3" class="named-paragraph-link"><span class="named-paragraph">Most general implementation of !propertyarray</span><span class="named-paragraph-number">9.3</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP9_4" class="named-paragraph-link"><span class="named-paragraph">Most general implementation of !propertylength</span><span class="named-paragraph-number">9.4</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP9_5" class="named-paragraph-link"><span class="named-paragraph">Most general implementation of writing to a property</span><span class="named-paragraph-number">9.5</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-i6c2.html#SP9_6" class="named-paragraph-link"><span class="named-paragraph">Implementation of !messageX</span><span class="named-paragraph-number">9.6</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><a href="2-cg.html#SP12" class="function-link"><span class="function-syntax">CodeGen::deselect</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">saved</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP9_1" class="paragraph-anchor"></a><b>&#167;9.1. </b>See <a href="4-i6o.html" class="internal">Inform 6 Objects</a> for the runtime contents of the array of property
metadata <span class="extract"><span class="extract-syntax">p</span></span>. The following is more or less a safe general-purpose wrapper for
the Inform 6 operator <span class="extract"><span class="extract-syntax">.</span></span>, used as an rvalue, in cases where we cannot prove
it would be safe to use <span class="extract"><span class="extract-syntax">.</span></span> directly:
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Most general implementation of !propertyvalue</span><span class="named-paragraph-number">9.1</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef BASICINFORMKIT;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_propertyvalue K o p t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K == OBJECT_TY) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (metaclass(o) == Object) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) { if (o has p) rtrue; rfalse; }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (o provides p) return o.p;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" rfalse;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = value_property_holders--&gt;K;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return (t.(p--&gt;1))--&gt;(o+COL_HSIZE);\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP9">&#167;9</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP9_2" class="paragraph-anchor"></a><b>&#167;9.2. </b>Similarly, this is a safe wrapper for <span class="extract"><span class="extract-syntax">provides</span></span>:
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Most general implementation of !propertyexists</span><span class="named-paragraph-number">9.2</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef BASICINFORMKIT;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_propertyexists K o p holder;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"if (K == OBJECT_TY) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if ((o) &amp;&amp; (metaclass(o) == Object)) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if ((p--&gt;0 == 2) || (o provides p--&gt;1)) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" rtrue;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" rfalse;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" rfalse;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"} else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if ((o &gt;= 1) &amp;&amp; (o &lt;= value_ranges--&gt;K)) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" holder = value_property_holders--&gt;K;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if ((holder) &amp;&amp; (holder provides p--&gt;1)) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" rtrue;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" rfalse;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" rfalse;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"}\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"rfalse; ];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP9">&#167;9</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP9_3" class="paragraph-anchor"></a><b>&#167;9.3. </b>And this for <span class="extract"><span class="extract-syntax">.&amp;</span></span>. Note that we always return 0 if the owner is not an object.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Most general implementation of !propertyarray</span><span class="named-paragraph-number">9.3</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef BASICINFORMKIT;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_propertyarray K o p v t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K ~= OBJECT_TY) return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return o.&amp;p;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP9">&#167;9</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP9_4" class="paragraph-anchor"></a><b>&#167;9.4. </b>And this for <span class="extract"><span class="extract-syntax">.#</span></span>. Again, we always return 0 if the owner is not an object.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Most general implementation of !propertylength</span><span class="named-paragraph-number">9.4</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef BASICINFORMKIT;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_propertylength K o p v t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K ~= OBJECT_TY) return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return o.#p;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP9">&#167;9</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP9_5" class="paragraph-anchor"></a><b>&#167;9.5. </b>And this is a safe way to write to or otherwise alter <span class="extract"><span class="extract-syntax">O.P</span></span>, laboriously
written out as seven functions. (Speed is more important than conciseness here.)
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Most general implementation of writing to a property</span><span class="named-paragraph-number">9.5</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef BASICINFORMKIT;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_store_property K o p v t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K == OBJECT_TY) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (metaclass(o) == Object) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (v) give o p; else give o ~p;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else if (o provides p) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" o.p = v;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ((value_property_holders--&gt;K).(p--&gt;1))--&gt;(o+COL_HSIZE) = v;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_preinc_property K o p t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K == OBJECT_TY) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (metaclass(o) == Object) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (o has p) { give o ~p; rfalse; } give o p; rtrue;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else if (o provides p) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return ++(o.p);\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return ++(((value_property_holders--&gt;K).(p--&gt;1))--&gt;(o+COL_HSIZE));\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_predec_property K o p t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K == OBJECT_TY) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (metaclass(o) == Object) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (o has p) { give o ~p; rfalse; } give o p; rtrue;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else if (o provides p) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return --(o.p);\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return --(((value_property_holders--&gt;K).(p--&gt;1))--&gt;(o+COL_HSIZE));\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_postinc_property K o p t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K == OBJECT_TY) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (metaclass(o) == Object) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (o has p) { give o ~p; rtrue; } give o p; rfalse;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else if (o provides p) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return (o.p)++;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return (((value_property_holders--&gt;K).(p--&gt;1))--&gt;(o+COL_HSIZE))++;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_postdec_property K o p t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K == OBJECT_TY) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (metaclass(o) == Object) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (o has p) { give o ~p; rtrue; } give o p; rfalse;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else if (o provides p) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return (o.p)--;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return (((value_property_holders--&gt;K).(p--&gt;1))--&gt;(o+COL_HSIZE))--;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_setbit_property K o p v t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K == OBJECT_TY) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (metaclass(o) == Object) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (v &amp; 1) give o p;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else if (o provides p) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" o.p = o.p | v;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ((value_property_holders--&gt;K).(p--&gt;1))--&gt;(o+COL_HSIZE) =\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ((value_property_holders--&gt;K).(p--&gt;1))--&gt;(o+COL_HSIZE) | v;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_clearbit_property K o p v t;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (K == OBJECT_TY) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (metaclass(o) == Object) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" t = p--&gt;0; p = p--&gt;1;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (t == 2) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (v &amp; 1) give o ~p;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else if (o provides p) {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" o.p = o.p &amp; ~v;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" } else {\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ((value_property_holders--&gt;K).(p--&gt;1))--&gt;(o+COL_HSIZE) =\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" ((value_property_holders--&gt;K).(p--&gt;1))--&gt;(o+COL_HSIZE) &amp; ~v;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" }\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP9">&#167;9</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP9_6" class="paragraph-anchor"></a><b>&#167;9.6. </b>It's not entirely clear what the result of trying to send a message to an
either/or property ought to be: nobody should ever do that. We're going to say
that it's 0 here.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Implementation of !messageX</span><span class="named-paragraph-number">9.6</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#ifdef BASICINFORMKIT;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_message0 o p q x a rv;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (p--&gt;0 == 2) return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" q = p--&gt;1; return o.q();\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_message1 o p v1 q x a rv;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (p--&gt;0 == 2) return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" q = p--&gt;1; return o.q(v1);\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_message2 o p v1 v2 q x a rv;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (p--&gt;0 == 2) return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" q = p--&gt;1; return o.q(v1, v2);\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"[ _final_message3 o p v1 v2 v3 q x a rv;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" if (p--&gt;0 == 2) return 0;\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">" q = p--&gt;1; return o.q(v1, v2, v3);\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"];\n"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"#endif;\n"</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-i6c2.html#SP9">&#167;9</a>.</li></ul>
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