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<html>
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<head>
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<title>Metadata</title>
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<h1><a href="../index.html">
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<img src="../docs-assets/Inform.png" height=72">
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</a></h1>
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<ul><li><a href="../index.html">home</a></li>
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<li><a href="../../../inweb/index.html">inweb</a></li>
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<li><a href="../../../intest/index.html">intest</a></li>
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</ul>
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</nav>
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<main role="main">
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<!--Weave of 'Metadata' generated by Inweb-->
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<div class="breadcrumbs">
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<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">bytecode</a></li><li><a href="index.html#3">Chapter 3: Their Instructions</a></li><li><b>Metadata</b></li></ul></div>
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<p class="purpose">Looking up metadata in special constants.</p>
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<p class="commentary firstcommentary"><a id="SP1" class="paragraph-anchor"></a><b>§1. </b>This section is in some ways a postscript to <a href="4-tcc2.html" class="internal">The Constant Construct</a>. If
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constants are created which have names matching...
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Metadata::valid_key</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">Metadata::valid_key</span></span>:<br/>Symbols - <a href="2-sym.html#SP2">§2</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::get_at</span><span class="plain-syntax">(</span><span class="identifier-syntax">key</span><span class="plain-syntax">, </span><span class="constant-syntax">0</span><span class="plain-syntax">) == </span><span class="character-syntax">'^'</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP2" class="paragraph-anchor"></a><b>§2. </b>...then their symbols are given the <span class="extract"><span class="extract-syntax">METADATA_KEY_ISYMF</span></span> flag: see
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<a href="2-sym.html#SP2" class="internal">InterSymbol::new_for_symbols_table</a>. These symbols never code-generate: see
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<a href="../final-module/2-vc.html" class="internal">Vanilla Constants (in final)</a>. It follows that metadata cannot be part of the
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program at runtime. Nor can metadata be wired to anything else, either way
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round — see <a href="2-tw2.html#SP5" class="internal">Wiring::wire_to</a>.
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</p>
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<p class="commentary">So the only purpose metadata can serve is to annotate the program, to assist
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tools such as the <a href="../pipeline-module/index.html" class="internal">pipeline</a> module. Metadata helps with linking, optimisation,
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and similar tasks.
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</p>
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<p class="commentary">Since metadata exists solely so that other parts of the Inform tool chain can
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read its values, we clearly need an API for doing that, and this is the point
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of the present section.
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</p>
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<p class="commentary firstcommentary"><a id="SP3" class="paragraph-anchor"></a><b>§3. </b>Some metadata keys are expected, and others are optional. The following
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determines whether a given package <span class="extract"><span class="extract-syntax">pack</span></span> contains a value for metadata <span class="extract"><span class="extract-syntax">key</span></span>:
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="function-syntax">Metadata::value_node</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">Metadata::value_node</span></span>:<br/><a href="3-mtd.html#SP4">§4</a>, <a href="3-mtd.html#SP5">§5</a>, <a href="3-mtd.html#SP6">§6</a>, <a href="3-mtd.html#SP7">§7</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">md</span><span class="plain-syntax"> = </span><a href="2-st.html#SP7" class="function-link"><span class="function-syntax">InterSymbolsTable::symbol_from_name</span></a><span class="plain-syntax">(</span><a href="2-pck.html#SP10" class="function-link"><span class="function-syntax">InterPackage::scope</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">), </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">md</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">md</span><span class="plain-syntax">-></span><span class="element-syntax">definition</span><span class="plain-syntax">;</span>
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<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>
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<span class="plain-syntax">}</span>
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Metadata::exists</span><span class="plain-syntax">(</span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="3-mtd.html#SP3" class="function-link"><span class="function-syntax">Metadata::value_node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP4" class="paragraph-anchor"></a><b>§4. </b>So for each kind of data we allow, we provide a required and an optional
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version, which differ only in that the required version halts with an error
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if the key is missing.
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="constant-syntax">inter_ti</span><span class="plain-syntax"> </span><span class="function-syntax">Metadata::read_numeric</span><span class="plain-syntax">(</span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">D</span><span class="plain-syntax"> = </span><a href="3-mtd.html#SP3" class="function-link"><span class="function-syntax">Metadata::value_node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">D</span><span class="plain-syntax">) </span><span class="named-paragraph-container code-font"><a href="3-mtd.html#SP4_1" class="named-paragraph-link"><span class="named-paragraph">Extract the numeric value</span><span class="named-paragraph-number">4.1</span></a></span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><a href="3-mtd.html#SP8" class="function-link"><span class="function-syntax">Metadata::err</span></a><span class="plain-syntax">(</span><span class="string-syntax">"not defined"</span><span class="plain-syntax">, </span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">); </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
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<span class="plain-syntax">}</span>
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<span class="constant-syntax">inter_ti</span><span class="plain-syntax"> </span><span class="function-syntax">Metadata::read_optional_numeric</span><span class="plain-syntax">(</span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">D</span><span class="plain-syntax"> = </span><a href="3-mtd.html#SP3" class="function-link"><span class="function-syntax">Metadata::value_node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">D</span><span class="plain-syntax">) </span><span class="named-paragraph-container code-font"><a href="3-mtd.html#SP4_1" class="named-paragraph-link"><span class="named-paragraph">Extract the numeric value</span><span class="named-paragraph-number">4.1</span></a></span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP4_1" class="paragraph-anchor"></a><b>§4.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Extract the numeric value</span><span class="named-paragraph-number">4.1</span></span><span class="comment-syntax"> =</span>
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="4-tcc2.html#SP8" class="function-link"><span class="function-syntax">ConstantInstruction::list_format</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">D</span><span class="plain-syntax">) == </span><span class="constant-syntax">CONST_LIST_FORMAT_NONE</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inter_pair</span><span class="plain-syntax"> </span><span class="identifier-syntax">val</span><span class="plain-syntax"> = </span><a href="4-tcc2.html#SP8" class="function-link"><span class="function-syntax">ConstantInstruction::constant</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">D</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="3-ivp.html#SP5" class="function-link"><span class="function-syntax">InterValuePairs::is_number</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">) == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">)</span>
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<span class="plain-syntax"> </span><a href="3-mtd.html#SP8" class="function-link"><span class="function-syntax">Metadata::err</span></a><span class="plain-syntax">(</span><span class="string-syntax">"not numeric"</span><span class="plain-syntax">, </span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><a href="3-ivp.html#SP4" class="function-link"><span class="function-syntax">InterValuePairs::to_number</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> }</span>
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</pre>
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<ul class="endnotetexts"><li>This code is used in <a href="3-mtd.html#SP4">§4</a> (twice).</li></ul>
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<p class="commentary firstcommentary"><a id="SP5" class="paragraph-anchor"></a><b>§5. </b>A metadata key cannot be wired to a symbol; but it can have its value set
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to a symbol, so:
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="function-syntax">Metadata::required_symbol</span><span class="plain-syntax">(</span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">D</span><span class="plain-syntax"> = </span><a href="3-mtd.html#SP3" class="function-link"><span class="function-syntax">Metadata::value_node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">D</span><span class="plain-syntax">) </span><span class="named-paragraph-container code-font"><a href="3-mtd.html#SP5_1" class="named-paragraph-link"><span class="named-paragraph">Extract the symbolic value</span><span class="named-paragraph-number">5.1</span></a></span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><a href="3-mtd.html#SP8" class="function-link"><span class="function-syntax">Metadata::err</span></a><span class="plain-syntax">(</span><span class="string-syntax">"required symbolic metadata not supplied"</span><span class="plain-syntax">, </span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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<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>
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<span class="plain-syntax">}</span>
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<span class="reserved-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="function-syntax">Metadata::optional_symbol</span><span class="plain-syntax">(</span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">D</span><span class="plain-syntax"> = </span><a href="3-mtd.html#SP3" class="function-link"><span class="function-syntax">Metadata::value_node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">D</span><span class="plain-syntax">) </span><span class="named-paragraph-container code-font"><a href="3-mtd.html#SP5_1" class="named-paragraph-link"><span class="named-paragraph">Extract the symbolic value</span><span class="named-paragraph-number">5.1</span></a></span><span class="plain-syntax">;</span>
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<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>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP5_1" class="paragraph-anchor"></a><b>§5.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Extract the symbolic value</span><span class="named-paragraph-number">5.1</span></span><span class="comment-syntax"> =</span>
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">D</span><span class="plain-syntax">) && (</span><a href="4-tcc2.html#SP8" class="function-link"><span class="function-syntax">ConstantInstruction::list_format</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">D</span><span class="plain-syntax">) == </span><span class="constant-syntax">CONST_LIST_FORMAT_NONE</span><span class="plain-syntax">)) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inter_pair</span><span class="plain-syntax"> </span><span class="identifier-syntax">val</span><span class="plain-syntax"> = </span><a href="4-tcc2.html#SP8" class="function-link"><span class="function-syntax">ConstantInstruction::constant</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">D</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="3-ivp.html#SP14" class="function-link"><span class="function-syntax">InterValuePairs::is_symbolic</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">) == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">)</span>
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<span class="plain-syntax"> </span><a href="3-mtd.html#SP8" class="function-link"><span class="function-syntax">Metadata::err</span></a><span class="plain-syntax">(</span><span class="string-syntax">"not symbolic"</span><span class="plain-syntax">, </span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><a href="3-ivp.html#SP13" class="function-link"><span class="function-syntax">InterValuePairs::to_symbol_in</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">, </span><span class="identifier-syntax">pack</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> }</span>
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</pre>
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<ul class="endnotetexts"><li>This code is used in <a href="3-mtd.html#SP5">§5</a> (twice).</li></ul>
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<p class="commentary firstcommentary"><a id="SP6" class="paragraph-anchor"></a><b>§6. </b>Text:
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="function-syntax">Metadata::required_textual</span><span class="plain-syntax">(</span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">D</span><span class="plain-syntax"> = </span><a href="3-mtd.html#SP3" class="function-link"><span class="function-syntax">Metadata::value_node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">D</span><span class="plain-syntax">) </span><span class="named-paragraph-container code-font"><a href="3-mtd.html#SP6_1" class="named-paragraph-link"><span class="named-paragraph">Extract the textual value</span><span class="named-paragraph-number">6.1</span></a></span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><a href="3-mtd.html#SP8" class="function-link"><span class="function-syntax">Metadata::err</span></a><span class="plain-syntax">(</span><span class="string-syntax">"required textual metadata not supplied"</span><span class="plain-syntax">, </span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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|
<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>
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|
<span class="plain-syntax">}</span>
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|
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|
<span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="function-syntax">Metadata::optional_textual</span><span class="plain-syntax">(</span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
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|
<span class="plain-syntax"> </span><span class="reserved-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">D</span><span class="plain-syntax"> = </span><a href="3-mtd.html#SP3" class="function-link"><span class="function-syntax">Metadata::value_node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">D</span><span class="plain-syntax">) </span><span class="named-paragraph-container code-font"><a href="3-mtd.html#SP6_1" class="named-paragraph-link"><span class="named-paragraph">Extract the textual value</span><span class="named-paragraph-number">6.1</span></a></span><span class="plain-syntax">;</span>
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|
<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>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP6_1" class="paragraph-anchor"></a><b>§6.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Extract the textual value</span><span class="named-paragraph-number">6.1</span></span><span class="comment-syntax"> =</span>
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|
</p>
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|
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<pre class="displayed-code all-displayed-code code-font">
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|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="4-tcc2.html#SP8" class="function-link"><span class="function-syntax">ConstantInstruction::list_format</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">D</span><span class="plain-syntax">) == </span><span class="constant-syntax">CONST_LIST_FORMAT_NONE</span><span class="plain-syntax">) {</span>
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|
<span class="plain-syntax"> </span><span class="reserved-syntax">inter_pair</span><span class="plain-syntax"> </span><span class="identifier-syntax">val</span><span class="plain-syntax"> = </span><a href="4-tcc2.html#SP8" class="function-link"><span class="function-syntax">ConstantInstruction::constant</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">D</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="3-ivp.html#SP7" class="function-link"><span class="function-syntax">InterValuePairs::is_text</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">val</span><span class="plain-syntax">) == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">)</span>
|
|
<span class="plain-syntax"> </span><a href="3-mtd.html#SP8" class="function-link"><span class="function-syntax">Metadata::err</span></a><span class="plain-syntax">(</span><span class="string-syntax">"not textual"</span><span class="plain-syntax">, </span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><a href="3-ivp.html#SP6" class="function-link"><span class="function-syntax">InterValuePairs::to_text</span></a><span class="plain-syntax">(</span><a href="2-pck.html#SP4" class="function-link"><span class="function-syntax">InterPackage::tree</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">), </span><span class="identifier-syntax">val</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> }</span>
|
|
</pre>
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|
<ul class="endnotetexts"><li>This code is used in <a href="3-mtd.html#SP6">§6</a> (twice).</li></ul>
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|
<p class="commentary firstcommentary"><a id="SP7" class="paragraph-anchor"></a><b>§7. </b>Lists (which are optional only, and return only as the node from which values
|
|
must then be extracted):
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="reserved-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="function-syntax">Metadata::optional_list</span><span class="plain-syntax">(</span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">D</span><span class="plain-syntax"> = </span><a href="3-mtd.html#SP3" class="function-link"><span class="function-syntax">Metadata::value_node</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">D</span><span class="plain-syntax">) && (</span><a href="4-tcc2.html#SP8" class="function-link"><span class="function-syntax">ConstantInstruction::list_format</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">D</span><span class="plain-syntax">) == </span><span class="constant-syntax">CONST_LIST_FORMAT_WORDS</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">D</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>
|
|
</pre>
|
|
<p class="commentary firstcommentary"><a id="SP8" class="paragraph-anchor"></a><b>§8. </b>Metadata errors are fatal:
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|
</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">Metadata::err</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">Metadata::err</span></span>:<br/><a href="3-mtd.html#SP4">§4</a>, <a href="3-mtd.html#SP4_1">§4.1</a>, <a href="3-mtd.html#SP5">§5</a>, <a href="3-mtd.html#SP5_1">§5.1</a>, <a href="3-mtd.html#SP6">§6</a>, <a href="3-mtd.html#SP6_1">§6.1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">char</span><span class="plain-syntax"> *</span><span class="identifier-syntax">err</span><span class="plain-syntax">, </span><span class="reserved-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">key</span><span class="plain-syntax">) {</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">"Error on metadata '%S' in package '"</span><span class="plain-syntax">, </span><span class="identifier-syntax">key</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><a href="2-pck.html#SP19" class="function-link"><span class="function-syntax">InterPackage::write_URL</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">STDERR</span><span class="plain-syntax">, </span><span class="identifier-syntax">pack</span><span class="plain-syntax">);</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">"': %s\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">err</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="identifier-syntax">err</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre>
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|
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