mirror of
https://github.com/ganelson/inform.git
synced 2024-07-16 22:14:23 +03:00
138 lines
20 KiB
HTML
138 lines
20 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<head>
|
|
<title>Temporary Variables</title>
|
|
<link href="../docs-assets/Breadcrumbs.css" rel="stylesheet" rev="stylesheet" type="text/css">
|
|
<meta name="viewport" content="width=device-width initial-scale=1">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<meta http-equiv="Content-Language" content="en-gb">
|
|
|
|
<link href="../docs-assets/Contents.css" rel="stylesheet" rev="stylesheet" type="text/css">
|
|
<link href="../docs-assets/Progress.css" rel="stylesheet" rev="stylesheet" type="text/css">
|
|
<link href="../docs-assets/Navigation.css" rel="stylesheet" rev="stylesheet" type="text/css">
|
|
<link href="../docs-assets/Fonts.css" rel="stylesheet" rev="stylesheet" type="text/css">
|
|
<link href="../docs-assets/Base.css" rel="stylesheet" rev="stylesheet" type="text/css">
|
|
<script>
|
|
function togglePopup(material_id) {
|
|
var popup = document.getElementById(material_id);
|
|
popup.classList.toggle("show");
|
|
}
|
|
</script>
|
|
|
|
<link href="../docs-assets/Popups.css" rel="stylesheet" rev="stylesheet" type="text/css">
|
|
<link href="../docs-assets/Colours.css" rel="stylesheet" rev="stylesheet" type="text/css">
|
|
|
|
</head>
|
|
<body class="commentary-font">
|
|
<nav role="navigation">
|
|
<h1><a href="../index.html">
|
|
<img src="../docs-assets/Inform.png" height=72">
|
|
</a></h1>
|
|
<ul><li><a href="../index.html">home</a></li>
|
|
</ul><h2>Compiler</h2><ul>
|
|
<li><a href="../structure.html">structure</a></li>
|
|
<li><a href="../inbuildn.html">inbuild</a></li>
|
|
<li><a href="../inform7n.html">inform7</a></li>
|
|
<li><a href="../intern.html">inter</a></li>
|
|
<li><a href="../services.html">services</a></li>
|
|
<li><a href="../secrets.html">secrets</a></li>
|
|
</ul><h2>Other Tools</h2><ul>
|
|
<li><a href="../inblorbn.html">inblorb</a></li>
|
|
<li><a href="../indocn.html">indoc</a></li>
|
|
<li><a href="../inform6.html">inform6</a></li>
|
|
<li><a href="../inpolicyn.html">inpolicy</a></li>
|
|
<li><a href="../inrtpsn.html">inrtps</a></li>
|
|
</ul><h2>Resources</h2><ul>
|
|
<li><a href="../extensions.html">extensions</a></li>
|
|
<li><a href="../kits.html">kits</a></li>
|
|
</ul><h2>Repository</h2><ul>
|
|
<li><a href="https://github.com/ganelson/inform"><img src="../docs-assets/github.png" height=18> github</a></li>
|
|
</ul><h2>Related Projects</h2><ul>
|
|
<li><a href="../../../inweb/docs/index.html">inweb</a></li>
|
|
<li><a href="../../../intest/docs/index.html">intest</a></li>
|
|
|
|
</ul>
|
|
</nav>
|
|
<main role="main">
|
|
<!--Weave of 'Temporary Variables' generated by Inweb-->
|
|
<div class="breadcrumbs">
|
|
<ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="../inform7n.html">Inform7</a></li><li><a href="index.html">imperative</a></li><li><a href="index.html#3">Chapter 3: Functions</a></li><li><b>Temporary Variables</b></li></ul></div>
|
|
<p class="purpose">When the runtime code needs to borrow a global variable for a while.</p>
|
|
|
|
<p class="commentary firstcommentary"><a id="SP1" class="paragraph-anchor"></a><b>§1. </b>The "temporary global" is made available to runtime code for short periods
|
|
of time, and can hold any value (i.e., are not constrained to have any fixed
|
|
kind over the lifetime of the run). To obtain it, call one of these functions,
|
|
where <span class="extract"><span class="extract-syntax">K</span></span> is the kind it will have for the next little while:
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="function-syntax">TemporaryVariables::from_iname</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">TemporaryVariables::from_iname</span></span>:<br/>Matching Action Patterns - <a href="2-map.html#SP3_5_1_1_1_10">§3.5.1.1.1.10</a>, <a href="2-map.html#SP3_5_1_1_1_14">§3.5.1.1.1.14</a>, <a href="2-map.html#SP3_5_1_1_1_18">§3.5.1.1.1.18</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inter_name</span><span class="plain-syntax"> *</span><span class="identifier-syntax">temp_iname</span><span class="plain-syntax">, </span><span class="identifier-syntax">kind</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">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">temp</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NonlocalVariables::temporary_global_variable</span><span class="plain-syntax">();</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">RTVariables::store_in_this_iname</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="identifier-syntax">temp_iname</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">NonlocalVariables::set_kind</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="identifier-syntax">K</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">temp</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax">}</span>
|
|
|
|
<span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="function-syntax">TemporaryVariables::from_existing_variable</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">TemporaryVariables::from_existing_variable</span></span>:<br/>Matching Action Patterns - <a href="2-map.html#SP3_5_1_1_1_23">§3.5.1.1.1.23</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">existing</span><span class="plain-syntax">, </span><span class="identifier-syntax">kind</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">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">temp</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NonlocalVariables::temporary_global_variable</span><span class="plain-syntax">();</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">RTVariables::set_NVE_from_existing</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="identifier-syntax">existing</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">NonlocalVariables::set_kind</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="identifier-syntax">K</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">temp</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax">}</span>
|
|
|
|
<span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="function-syntax">TemporaryVariables::from_nve</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">TemporaryVariables::from_nve</span></span>:<br/>Matching Going Action Patterns - <a href="2-mgap.html#SP2_3">§2.3</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">nonlocal_variable_emission</span><span class="plain-syntax"> </span><span class="identifier-syntax">nve</span><span class="plain-syntax">, </span><span class="identifier-syntax">kind</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">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">temp</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NonlocalVariables::temporary_global_variable</span><span class="plain-syntax">();</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">RTVariables::set_NVE</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="identifier-syntax">nve</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">NonlocalVariables::set_kind</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="identifier-syntax">K</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">temp</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre>
|
|
<p class="commentary firstcommentary"><a id="SP2" class="paragraph-anchor"></a><b>§2. </b>A set of up to 8 globals are also available to store "formal parameters",
|
|
again for short periods of time:
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">formal_par_vars_made</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">formal_par_VAR</span><span class="plain-syntax">[8];</span>
|
|
<span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="function-syntax">TemporaryVariables::formal_parameter</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">TemporaryVariables::formal_parameter</span></span>:<br/>Functions - <a href="3-fnc.html#SP6_1_2">§6.1.2</a>, <a href="3-fnc.html#SP6_1_4">§6.1.4</a><br/>Compile Invocations - <a href="5-ci.html#SP1_3_1_2_1_1_1">§1.3.1.2.1.1.1</a>, <a href="5-ci.html#SP1_3_1_2_1_2">§1.3.1.2.1.2</a>, <a href="5-ci.html#SP1_3_1_2_1_3">§1.3.1.2.1.3</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">i</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">i</span><span class="plain-syntax"> >= </span><span class="constant-syntax">8</span><span class="plain-syntax">) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"too many formal parameter variables"</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">formal_par_vars_made</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">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">j</span><span class="plain-syntax">=0; </span><span class="identifier-syntax">j</span><span class="plain-syntax"><8; </span><span class="identifier-syntax">j</span><span class="plain-syntax">++) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">formal_par_VAR</span><span class="plain-syntax">[</span><span class="identifier-syntax">j</span><span class="plain-syntax">] = </span><span class="identifier-syntax">NonlocalVariables::new</span><span class="plain-syntax">(</span><span class="identifier-syntax">EMPTY_WORDING</span><span class="plain-syntax">, </span><span class="identifier-syntax">K_object</span><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">RTVariables::set_hierarchy_location</span><span class="plain-syntax">(</span><span class="identifier-syntax">formal_par_VAR</span><span class="plain-syntax">[</span><span class="identifier-syntax">j</span><span class="plain-syntax">],</span>
|
|
<span class="plain-syntax"> </span><a href="3-tv.html#SP2" class="function-link"><span class="function-syntax">TemporaryVariables::hl_of_formal_parameter</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">j</span><span class="plain-syntax">));</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">formal_par_vars_made</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">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nlv</span><span class="plain-syntax"> = </span><span class="identifier-syntax">formal_par_VAR</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</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">nlv</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax">}</span>
|
|
|
|
<span class="identifier-syntax">inter_name</span><span class="plain-syntax"> *</span><span class="function-syntax">TemporaryVariables::iname_of_formal_parameter</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">TemporaryVariables::iname_of_formal_parameter</span></span>:<br/>Compile Invocations - <a href="5-ci.html#SP1_3_1_2_1_2">§1.3.1.2.1.2</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">n</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">Hierarchy::find</span><span class="plain-syntax">(</span><a href="3-tv.html#SP2" class="function-link"><span class="function-syntax">TemporaryVariables::hl_of_formal_parameter</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">n</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">TemporaryVariables::hl_of_formal_parameter</span><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">n</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">n</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">0</span><span class="plain-syntax">: </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">formal_par0_HL</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="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">formal_par1_HL</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="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">formal_par2_HL</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="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">formal_par3_HL</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">4</span><span class="plain-syntax">: </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">formal_par4_HL</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">5</span><span class="plain-syntax">: </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">formal_par5_HL</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">6</span><span class="plain-syntax">: </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">formal_par6_HL</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">7</span><span class="plain-syntax">: </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">formal_par7_HL</span><span class="plain-syntax">;</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">"bad formal par number"</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> -1;</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre>
|
|
<nav role="progress"><div class="progresscontainer">
|
|
<ul class="progressbar"><li class="progressprev"><a href="3-lv.html">❮</a></li><li class="progresschapter"><a href="P-wtmd.html">P</a></li><li class="progresschapter"><a href="1-im.html">1</a></li><li class="progresschapter"><a href="2-cv.html">2</a></li><li class="progresscurrentchapter">3</li><li class="progresssection"><a href="3-sf.html">sf</a></li><li class="progresssection"><a href="3-lvs.html">lvs</a></li><li class="progresssection"><a href="3-lv.html">lv</a></li><li class="progresscurrent">tv</li><li class="progresssection"><a href="3-lp.html">lp</a></li><li class="progresssection"><a href="3-cb.html">cb</a></li><li class="progresssection"><a href="3-fnc.html">fnc</a></li><li class="progresssection"><a href="3-jl.html">jl</a></li><li class="progresssection"><a href="3-pr.html">pr</a></li><li class="progresssection"><a href="3-cls.html">cls</a></li><li class="progresssection"><a href="3-cid.html">cid</a></li><li class="progresschapter"><a href="4-cs.html">4</a></li><li class="progresschapter"><a href="5-cbal.html">5</a></li><li class="progressnext"><a href="3-lp.html">❯</a></li></ul></div>
|
|
</nav><!--End of weave-->
|
|
|
|
</main>
|
|
</body>
|
|
</html>
|
|
|