1540 lines
176 KiB
HTML
1540 lines
176 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<head>
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<title>4/cl</title>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<meta http-equiv="Content-Language" content="en-gb">
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<link href="inweb.css" rel="stylesheet" rev="stylesheet" type="text/css">
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</head>
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<body>
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<!--Weave of '4/is' generated by 7-->
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<ul class="crumbs"><li><a href="../webs.html">★</a></li><li><a href="index.html">inweb 7</a></li><li><a href="index.html#4">Chapter 4: Languages</a></li><li><b>InC Support</b></li></ul><p class="purpose">To support a modest extension of C called InC.</p>
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<ul class="toc"><li><a href="#SP1">§1. Creation</a></li><li><a href="#SP3">§3. Parsing methods</a></li><li><a href="#SP3_1">§3.1. Parsing Preform grammar</a></li><li><a href="#SP3_1_1_1">§3.1.1.1. Parsing the body of Preform grammar</a></li><li><a href="#SP3_2">§3.2. Parsing I-literals</a></li><li><a href="#SP4">§4. Tangling methods</a></li><li><a href="#SP14">§14. Weaving</a></li><li><a href="#SP15">§15. Weaving methods</a></li><li><a href="#SP18">§18. Analysis methods</a></li></ul><hr class="tocbar">
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<p class="inwebparagraph"><a id="SP1"></a><b>§1. Creation. </b>As can be seen, InC is a basically C-like language, but in addition to having
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all of those methods, it has a whole lot more of its own.
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</p>
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<pre class="display">
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<span class="reserved">programming_language</span><span class="plain"> *</span><span class="functiontext">InCSupport::create</span><span class="plain">(</span><span class="reserved">void</span><span class="plain">) {</span>
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<span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">pl</span><span class="plain"> = </span><span class="functiontext">Languages::new_language</span><span class="plain">(</span><span class="identifier">I</span><span class="string">"InC"</span><span class="plain">, </span><span class="identifier">I</span><span class="string">".c"</span><span class="plain">);</span>
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<span class="identifier">pl</span><span class="plain">-</span><span class="element">>supports_namespaces</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
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<span class="functiontext">CLike::make_c_like</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">FURTHER_PARSING_PAR_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::further_parsing</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">SUPPRESS_EXPANSION_TAN_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::suppress_expansion</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">TANGLE_COMMAND_TAN_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::special_tangle_command</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">ADDITIONAL_PREDECLARATIONS_TAN_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::additional_predeclarations</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">WILL_TANGLE_EXTRA_LINE_TAN_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::will_insert_in_tangle</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">TANGLE_EXTRA_LINE_TAN_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::insert_in_tangle</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">TANGLE_CODE_UNUSUALLY_TAN_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::tangle_code</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">GNABEHS_TAN_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::gnabehs</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">ADDITIONAL_TANGLING_TAN_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::additional_tangling</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">SKIP_IN_WEAVING_WEA_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::skip_in_weaving</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">WEAVE_CODE_LINE_WEA_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::weave_code_line</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">NOTIFY_NEW_TAG_WEA_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::new_tag_declared</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">EARLY_PREWEAVE_ANALYSIS_ANA_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::analyse_code</span><span class="plain">);</span>
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<span class="identifier">METHOD_ADD</span><span class="plain">(</span><span class="identifier">pl</span><span class="plain">, </span><span class="constant">SHARE_ELEMENT_ANA_MTID</span><span class="plain">, </span><span class="functiontext">InCSupport::share_element</span><span class="plain">);</span>
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<span class="reserved">return</span><span class="plain"> </span><span class="identifier">pl</span><span class="plain">;</span>
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<span class="plain">}</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="endnote">The function InCSupport::create is used in 4/pl (<a href="4-pl.html#SP3">§3</a>).</p>
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<p class="inwebparagraph"><a id="SP2"></a><b>§2. </b>We will apply this special tag wherever Preform grammar is defined:
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</p>
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<pre class="display">
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<span class="reserved">theme_tag</span><span class="plain"> *</span><span class="identifier">Preform_theme</span><span class="plain"> = </span><span class="identifier">NULL</span><span class="plain">;</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="inwebparagraph"><a id="SP3"></a><b>§3. Parsing methods. </b>We only provide one parsing method, but it's a big one:
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</p>
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<pre class="display">
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<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">alphabetical_list_of_nonterminals</span><span class="plain"> = </span><span class="identifier">NULL</span><span class="plain">;</span>
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<span class="reserved">void</span><span class="plain"> </span><span class="functiontext">InCSupport::further_parsing</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">web</span><span class="plain"> *</span><span class="identifier">W</span><span class="plain">) {</span>
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<span class="reserved">chapter</span><span class="plain"> *</span><span class="identifier">C</span><span class="plain">;</span>
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<span class="reserved">section</span><span class="plain"> *</span><span class="identifier">S</span><span class="plain">;</span>
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<span class="identifier">LOOP_WITHIN_TANGLE</span><span class="plain">(</span><span class="identifier">C</span><span class="plain">, </span><span class="identifier">S</span><span class="plain">, </span><span class="functiontext">Tangler::primary_target</span><span class="plain">(</span><span class="identifier">W</span><span class="plain">)) {</span>
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<<span class="cwebmacro">Detect and deal with Preform grammar</span> <span class="cwebmacronumber">3.1</span>><span class="plain">;</span>
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<<span class="cwebmacro">Detect and deal with I-literals</span> <span class="cwebmacronumber">3.2</span>>
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<span class="plain">}</span>
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<span class="plain">}</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="endnote">The function InCSupport::further_parsing is used in <a href="#SP1">§1</a>.</p>
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<p class="inwebparagraph"><a id="SP3_1"></a><b>§3.1. Parsing Preform grammar. </b>This is where we look for declarations of nonterminals. Very little about
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the following code will make sense unless you've first read the Preform
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section of the <code class="display"><span class="extract">words</span></code> module, which is what we're supporting, and seen
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some examples of Preform being used in the Inform source code.
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</p>
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<p class="inwebparagraph">In parsing, we categorise the opening lines <code class="display"><span class="extract">PREFORM_LCAT</span></code>. Subsequent lines
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of grammar are <code class="display"><span class="extract">PREFORM_GRAMMAR_LCAT</span></code>; but the lines of InC code inside an
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<code class="display"><span class="extract">internal</span></code> definition remain just plain <code class="display"><span class="extract">CODE_BODY_LCAT</span></code> lines.
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</p>
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<pre class="definitions">
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<span class="definitionkeyword">define</span> <span class="constant">NOT_A_NONTERMINAL</span><span class="plain"> -4</span>
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<span class="definitionkeyword">define</span> <span class="constant">A_FLEXIBLE_NONTERMINAL</span><span class="plain"> -3</span>
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<span class="definitionkeyword">define</span> <span class="constant">A_VORACIOUS_NONTERMINAL</span><span class="plain"> -2</span>
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<span class="definitionkeyword">define</span> <span class="constant">A_GRAMMAR_NONTERMINAL</span><span class="plain"> -1</span>
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</pre>
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<p class="macrodefinition"><code class="display">
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<<span class="cwebmacrodefn">Detect and deal with Preform grammar</span> <span class="cwebmacronumber">3.1</span>> =
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</code></p>
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<pre class="displaydefn">
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">form</span><span class="plain"> = </span><span class="constant">NOT_A_NONTERMINAL</span><span class="plain">; </span> <span class="comment">one of the four values above, or a non-negative word count</span>
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<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">);</span>
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<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">header</span><span class="plain">);</span>
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<<span class="cwebmacro">Parse a Preform nonterminal header line</span> <span class="cwebmacronumber">3.1.1</span>><span class="plain">;</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">form</span><span class="plain"> != </span><span class="constant">NOT_A_NONTERMINAL</span><span class="plain">) </span><<span class="cwebmacro">Record a Preform nonterminal here</span> <span class="cwebmacronumber">3.1.3</span>><span class="plain">;</span>
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<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">);</span>
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<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">header</span><span class="plain">);</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="endnote">This code is used in <a href="#SP3">§3</a>.</p>
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<p class="inwebparagraph"><a id="SP3_1_1"></a><b>§3.1.1. </b>The keyword <code class="display"><span class="extract">internal</span></code> can be followed by an indication of the number
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of words the nonterminal will match: usually a decimal non-negative number,
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but optionally a question mark <code class="display"><span class="extract">?</span></code> to indicate voracity.
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</p>
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<p class="macrodefinition"><code class="display">
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<<span class="cwebmacrodefn">Parse a Preform nonterminal header line</span> <span class="cwebmacronumber">3.1.1</span>> =
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</code></p>
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<pre class="displaydefn">
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<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"(<%p+>) ::=%c*"</span><span class="plain">)) {</span>
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<span class="identifier">form</span><span class="plain"> = </span><span class="constant">A_GRAMMAR_NONTERMINAL</span><span class="plain">;</span>
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<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
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<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">header</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
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<<span class="cwebmacro">Parse the subsequent lines as Preform grammar</span> <span class="cwebmacronumber">3.1.1.1</span>><span class="plain">;</span>
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<span class="plain">} </span><span class="reserved">else</span><span class="plain"> </span><span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"((<%p+>) internal %?) {%c*"</span><span class="plain">)) {</span>
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<span class="identifier">form</span><span class="plain"> = </span><span class="constant">A_VORACIOUS_NONTERMINAL</span><span class="plain">;</span>
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<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[1]);</span>
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<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">header</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
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<span class="plain">} </span><span class="reserved">else</span><span class="plain"> </span><span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"((<%p+>) internal) {%c*"</span><span class="plain">)) {</span>
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<span class="identifier">form</span><span class="plain"> = </span><span class="constant">A_FLEXIBLE_NONTERMINAL</span><span class="plain">;</span>
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<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[1]);</span>
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<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">header</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
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<span class="plain">} </span><span class="reserved">else</span><span class="plain"> </span><span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"((<%p+>) internal (%d+)) {%c*"</span><span class="plain">)) {</span>
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<span class="identifier">form</span><span class="plain"> = </span><span class="functiontext">Str::atoi</span><span class="plain">(</span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[2], 0);</span>
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<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[1]);</span>
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<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">header</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
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<span class="plain">}</span>
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<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="endnote">This code is used in <a href="#SP3_1">§3.1</a>.</p>
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<p class="inwebparagraph"><a id="SP3_1_2"></a><b>§3.1.2. </b>Each Preform nonterminal defined in the tangle will cause one of these
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structures to be created:
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</p>
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<pre class="display">
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<span class="reserved">typedef</span><span class="plain"> </span><span class="reserved">struct</span><span class="plain"> </span><span class="reserved">preform_nonterminal</span><span class="plain"> {</span>
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<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">nt_name</span><span class="plain">; </span> <span class="comment">e.g., <code class="display"><span class="extract"><action-clause></span></code></span>
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<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">unangled_name</span><span class="plain">; </span> <span class="comment">e.g., <code class="display"><span class="extract">action-clause</span></code></span>
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<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">as_C_identifier</span><span class="plain">; </span> <span class="comment">e.g., <code class="display"><span class="extract">action_clause_NTM</span></code></span>
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">as_function</span><span class="plain">; </span> <span class="comment">defined internally, that is, parsed by a C function</span>
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">voracious</span><span class="plain">; </span> <span class="comment">a voracious nonterminal: see "The English Syntax of Inform"</span>
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">min_word_count</span><span class="plain">; </span> <span class="comment">for internals only</span>
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">max_word_count</span><span class="plain">;</span>
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">takes_pointer_result</span><span class="plain">; </span> <span class="comment">right-hand formula defines <code class="display"><span class="extract">*XP</span></code>, not <code class="display"><span class="extract">*X</span></code></span>
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<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">where_defined</span><span class="plain">;</span>
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<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">next_pnt_alphabetically</span><span class="plain">;</span>
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<span class="constant">MEMORY_MANAGEMENT</span>
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<span class="plain">} </span><span class="reserved">preform_nonterminal</span><span class="plain">;</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="endnote">The structure preform_nonterminal is accessed in 5/tf and here.</p>
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<p class="inwebparagraph"><a id="SP3_1_3"></a><b>§3.1.3. </b>We will
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</p>
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<p class="macrodefinition"><code class="display">
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<<span class="cwebmacrodefn">Record a Preform nonterminal here</span> <span class="cwebmacronumber">3.1.3</span>> =
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</code></p>
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<pre class="displaydefn">
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<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">pnt</span><span class="plain"> = </span><span class="identifier">CREATE</span><span class="plain">(</span><span class="reserved">preform_nonterminal</span><span class="plain">);</span>
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<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>where_defined</span><span class="plain"> = </span><span class="identifier">L</span><span class="plain">;</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>nt_name</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">);</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>unangled_name</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">);</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">);</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>next_pnt_alphabetically</span><span class="plain"> = </span><span class="identifier">NULL</span><span class="plain">;</span>
|
|
<<span class="cwebmacro">Apply unangling cream to name</span> <span class="cwebmacronumber">3.1.3.1</span>><span class="plain">;</span>
|
|
<<span class="cwebmacro">Compose a C identifier for the nonterminal</span> <span class="cwebmacronumber">3.1.3.2</span>><span class="plain">;</span>
|
|
<<span class="cwebmacro">Work out the parsing characteristics of the nonterminal</span> <span class="cwebmacronumber">3.1.3.3</span>><span class="plain">;</span>
|
|
|
|
<<span class="cwebmacro">Insertion-sort this this nonterminal into the alphabetical list</span> <span class="cwebmacronumber">3.1.3.4</span>><span class="plain">;</span>
|
|
<<span class="cwebmacro">Register the nonterminal with the line and paragraph from which it comes</span> <span class="cwebmacronumber">3.1.3.5</span>><span class="plain">;</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1">§3.1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_3_1"></a><b>§3.1.3.1. </b><code class="display">
|
|
<<span class="cwebmacrodefn">Apply unangling cream to name</span> <span class="cwebmacronumber">3.1.3.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">pntname</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"%<(%c*)%>"</span><span class="plain">)) </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>unangled_name</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
|
|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1_3">§3.1.3</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_3_2"></a><b>§3.1.3.2. </b>When the program we are tangling is eventually running, each nonterminal
|
|
will be represented by a pointer to a unique data structure for it. Inweb
|
|
automatically compiles code to create these pointers; and here's how it
|
|
works out their names.
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Compose a C identifier for the nonterminal</span> <span class="cwebmacronumber">3.1.3.2</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="functiontext">Str::delete_first_character</span><span class="plain">(</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">);</span>
|
|
<span class="identifier">LOOP_THROUGH_TEXT</span><span class="plain">(</span><span class="identifier">pos</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::get</span><span class="plain">(</span><span class="identifier">pos</span><span class="plain">) == </span><span class="character">'-'</span><span class="plain">) </span><span class="functiontext">Str::put</span><span class="plain">(</span><span class="identifier">pos</span><span class="plain">, </span><span class="character">'_'</span><span class="plain">);</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::get</span><span class="plain">(</span><span class="identifier">pos</span><span class="plain">) == </span><span class="character">'>'</span><span class="plain">) { </span><span class="functiontext">Str::put</span><span class="plain">(</span><span class="identifier">pos</span><span class="plain">, 0); </span><span class="reserved">break</span><span class="plain">; }</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">WRITE_TO</span><span class="plain">(</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">, </span><span class="string">"_NTM"</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1_3">§3.1.3</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_3_3"></a><b>§3.1.3.3. </b>"Artamène ou le Grand Cyrus", by Georges or possibly his sister Madeleine
|
|
de Scudéry, published around 1650, runs to 1,954,300 words. If you can write
|
|
an Inform source text 500 times longer than that, then you may need to raise
|
|
the following definition:
|
|
</p>
|
|
|
|
|
|
<pre class="definitions">
|
|
<span class="definitionkeyword">define</span> <span class="constant">INFINITE_WORD_COUNT</span><span class="plain"> 1000000000</span>
|
|
</pre>
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Work out the parsing characteristics of the nonterminal</span> <span class="cwebmacronumber">3.1.3.3</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>voracious</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">; </span><span class="reserved">if</span><span class="plain"> (</span><span class="identifier">form</span><span class="plain"> == </span><span class="constant">A_VORACIOUS_NONTERMINAL</span><span class="plain">) </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>voracious</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_function</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">; </span><span class="reserved">if</span><span class="plain"> (</span><span class="identifier">form</span><span class="plain"> == </span><span class="constant">A_GRAMMAR_NONTERMINAL</span><span class="plain">) </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_function</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>takes_pointer_result</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>nt_name</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"<k-%c+"</span><span class="plain">)) </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>takes_pointer_result</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>nt_name</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"<s-%c+"</span><span class="plain">)) </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>takes_pointer_result</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
|
|
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">min</span><span class="plain"> = 1, </span><span class="identifier">max</span><span class="plain"> = </span><span class="identifier">form</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">form</span><span class="plain"> < 0) </span><span class="identifier">max</span><span class="plain"> = </span><span class="constant">INFINITE_WORD_COUNT</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">max</span><span class="plain"> == 0) </span><span class="identifier">min</span><span class="plain"> = 0;</span>
|
|
<span class="reserved">else</span><span class="plain"> </span><span class="reserved">if</span><span class="plain"> (</span><span class="identifier">max</span><span class="plain"> != </span><span class="constant">INFINITE_WORD_COUNT</span><span class="plain">) </span><span class="identifier">min</span><span class="plain"> = </span><span class="identifier">max</span><span class="plain">;</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>min_word_count</span><span class="plain"> = </span><span class="identifier">min</span><span class="plain">;</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>max_word_count</span><span class="plain"> = </span><span class="identifier">max</span><span class="plain">;</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1_3">§3.1.3</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_3_4"></a><b>§3.1.3.4. </b><code class="display">
|
|
<<span class="cwebmacrodefn">Insertion-sort this this nonterminal into the alphabetical list</span> <span class="cwebmacronumber">3.1.3.4</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">alphabetical_list_of_nonterminals</span><span class="plain"> == </span><span class="identifier">NULL</span><span class="plain">) </span><span class="identifier">alphabetical_list_of_nonterminals</span><span class="plain"> = </span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="reserved">else</span><span class="plain"> {</span>
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">placed</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">last</span><span class="plain"> = </span><span class="identifier">NULL</span><span class="plain">;</span>
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">seq</span><span class="plain"> = </span><span class="identifier">alphabetical_list_of_nonterminals</span><span class="plain">; </span><span class="identifier">seq</span><span class="plain">;</span>
|
|
<span class="identifier">seq</span><span class="plain"> = </span><span class="identifier">seq</span><span class="plain">-</span><span class="element">>next_pnt_alphabetically</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::cmp</span><span class="plain">(</span><span class="identifier">pntname</span><span class="plain">, </span><span class="identifier">seq</span><span class="plain">-</span><span class="element">>nt_name</span><span class="plain">) < 0) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">seq</span><span class="plain"> == </span><span class="identifier">alphabetical_list_of_nonterminals</span><span class="plain">) {</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>next_pnt_alphabetically</span><span class="plain"> = </span><span class="identifier">alphabetical_list_of_nonterminals</span><span class="plain">;</span>
|
|
<span class="identifier">alphabetical_list_of_nonterminals</span><span class="plain"> = </span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="plain">} </span><span class="reserved">else</span><span class="plain"> {</span>
|
|
<span class="identifier">last</span><span class="plain">-</span><span class="element">>next_pnt_alphabetically</span><span class="plain"> = </span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>next_pnt_alphabetically</span><span class="plain"> = </span><span class="identifier">seq</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">placed</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">break</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">last</span><span class="plain"> = </span><span class="identifier">seq</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">placed</span><span class="plain"> == </span><span class="constant">FALSE</span><span class="plain">) </span><span class="identifier">last</span><span class="plain">-</span><span class="element">>next_pnt_alphabetically</span><span class="plain"> = </span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1_3">§3.1.3</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_3_5"></a><b>§3.1.3.5. </b><code class="display">
|
|
<<span class="cwebmacrodefn">Register the nonterminal with the line and paragraph from which it comes</span> <span class="cwebmacronumber">3.1.3.5</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="identifier">L</span><span class="plain">-</span><span class="element">>preform_nonterminal_defined</span><span class="plain"> = </span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">Preform_theme</span><span class="plain">) </span><span class="functiontext">Tags::add_to_paragraph</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>owning_paragraph</span><span class="plain">, </span><span class="identifier">Preform_theme</span><span class="plain">, </span><span class="identifier">NULL</span><span class="plain">);</span>
|
|
<span class="identifier">L</span><span class="plain">-</span><span class="element">>category</span><span class="plain"> = </span><span class="constant">PREFORM_LCAT</span><span class="plain">;</span>
|
|
<span class="identifier">L</span><span class="plain">-</span><span class="element">>text_operand</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">header</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1_3">§3.1.3</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_1_1"></a><b>§3.1.1.1. Parsing the body of Preform grammar. </b>After a line like <code class="display"><span class="extract"><action-clause> ::=</span></code>, Preform grammar follows on subsequent
|
|
lines until we hit the end of the paragraph, or a white-space line, whichever
|
|
comes first. Each line of grammar is categorised <code class="display"><span class="extract">PREFORM_GRAMMAR_LCAT</span></code>.
|
|
If we have a line with an arrow, like so:
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">porcupine tree ==> 2</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">then the text on the left goes into <code class="display"><span class="extract">text_operand</span></code> and the right into
|
|
<code class="display"><span class="extract">text_operand2</span></code>, with the arrow itself (and white space around it) cut out.
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Parse the subsequent lines as Preform grammar</span> <span class="cwebmacronumber">3.1.1.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">AL</span><span class="plain">;</span>
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="identifier">AL</span><span class="plain"> = </span><span class="identifier">L</span><span class="plain">; (</span><span class="identifier">AL</span><span class="plain">) && (</span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>category</span><span class="plain"> == </span><span class="constant">CODE_BODY_LCAT</span><span class="plain">); </span><span class="identifier">AL</span><span class="plain"> = </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>next_line</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::string_is_white_space</span><span class="plain">(</span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>text</span><span class="plain">)) </span><span class="reserved">break</span><span class="plain">;</span>
|
|
<span class="identifier">AL</span><span class="plain">-</span><span class="element">>category</span><span class="plain"> = </span><span class="constant">PREFORM_GRAMMAR_LCAT</span><span class="plain">;</span>
|
|
|
|
<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"(%c+) ==> (%c*)"</span><span class="plain">)) {</span>
|
|
<span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
|
|
<span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand2</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[1]);</span>
|
|
<span class="plain">} </span><span class="reserved">else</span><span class="plain"> {</span>
|
|
<span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand</span><span class="plain"> = </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>text</span><span class="plain">;</span>
|
|
<span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand2</span><span class="plain"> = </span><span class="functiontext">Str::new</span><span class="plain">();</span>
|
|
<span class="plain">}</span>
|
|
<<span class="cwebmacro">Remove any C comment from the left side of the arrow</span> <span class="cwebmacronumber">3.1.1.1.1</span>><span class="plain">;</span>
|
|
<<span class="cwebmacro">Detect any nonterminal variables being set on the right side of the arrow</span> <span class="cwebmacronumber">3.1.1.1.2</span>><span class="plain">;</span>
|
|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1_1">§3.1.1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_1_1_1"></a><b>§3.1.1.1.1. </b>In case we have a comment at the end of the grammar, like this:
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">porcupine tree /* what happens now? */</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">we want to remove it. The regular expression here isn't terribly legible, but
|
|
trust me, it's correct.
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Remove any C comment from the left side of the arrow</span> <span class="cwebmacronumber">3.1.1.1.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"(%c*)%/%*%c*%*%/ *"</span><span class="plain">))</span>
|
|
<span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
|
|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1_1_1">§3.1.1.1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_1_1_2"></a><b>§3.1.1.1.2. </b>Note that nonterminal variables are, by default, integers. If their names
|
|
are divided internally with a colon, however, as <code class="display"><span class="extract"><<structure:name>></span></code>, then
|
|
they have the type <code class="display"><span class="extract">structure *</span></code>.
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Detect any nonterminal variables being set on the right side of the arrow</span> <span class="cwebmacronumber">3.1.1.1.2</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">to_scan</span><span class="plain">); </span><span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">to_scan</span><span class="plain">, </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand2</span><span class="plain">);</span>
|
|
<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
|
|
<span class="reserved">while</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">to_scan</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"%c*?<<(%P+?)>> =(%c*)"</span><span class="plain">)) {</span>
|
|
<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">var_given</span><span class="plain">); </span><span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">var_given</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
|
|
<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">type_given</span><span class="plain">); </span><span class="identifier">WRITE_TO</span><span class="plain">(</span><span class="identifier">type_given</span><span class="plain">, </span><span class="string">"int"</span><span class="plain">);</span>
|
|
<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">to_scan</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[1]);</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">var_given</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"(%p+):%p+"</span><span class="plain">)) {</span>
|
|
<span class="functiontext">Str::clear</span><span class="plain">(</span><span class="identifier">type_given</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE_TO</span><span class="plain">(</span><span class="identifier">type_given</span><span class="plain">, </span><span class="string">"%S *"</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
|
|
<span class="plain">}</span>
|
|
<span class="reserved">nonterminal_variable</span><span class="plain"> *</span><span class="identifier">ntv</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">ntv</span><span class="plain">, </span><span class="reserved">nonterminal_variable</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq</span><span class="plain">(</span><span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_name</span><span class="plain">, </span><span class="identifier">var_given</span><span class="plain">))</span>
|
|
<span class="reserved">break</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">ntv</span><span class="plain"> == </span><span class="identifier">NULL</span><span class="plain">) </span><<span class="cwebmacro">This one's new, so create a new nonterminal variable</span> <span class="cwebmacronumber">3.1.1.1.2.2</span>><span class="character">;</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">var_given</span><span class="plain">);</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">type_given</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">to_scan</span><span class="plain">);</span>
|
|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1_1_1">§3.1.1.1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_1_1_2_1"></a><b>§3.1.1.1.2.1. </b>Nonterminal variables are actually just global C variables, and their C
|
|
identifiers need to avoid hyphens and colons. For example, <code class="display"><span class="extract"><<kind:ref>></span></code>
|
|
has identifier <code class="display"><span class="extract">"kind_ref_NTMV"</span></code>. Each one is recorded in a structure thus:
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">typedef</span><span class="plain"> </span><span class="reserved">struct</span><span class="plain"> </span><span class="reserved">nonterminal_variable</span><span class="plain"> {</span>
|
|
<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">ntv_name</span><span class="plain">; </span> <span class="comment">e.g., <code class="display"><span class="extract">"num"</span></code></span>
|
|
<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">ntv_type</span><span class="plain">; </span> <span class="comment">e.g., <code class="display"><span class="extract">"int"</span></code></span>
|
|
<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">ntv_identifier</span><span class="plain">; </span> <span class="comment">e.g., <code class="display"><span class="extract">"num_NTMV"</span></code></span>
|
|
<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">first_mention</span><span class="plain">; </span> <span class="comment">first usage</span>
|
|
<span class="constant">MEMORY_MANAGEMENT</span>
|
|
<span class="plain">} </span><span class="reserved">nonterminal_variable</span><span class="plain">;</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The structure nonterminal_variable is private to this section.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_1_1_1_2_2"></a><b>§3.1.1.1.2.2. </b><code class="display">
|
|
<<span class="cwebmacrodefn">This one's new, so create a new nonterminal variable</span> <span class="cwebmacronumber">3.1.1.1.2.2</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="identifier">ntv</span><span class="plain"> = </span><span class="identifier">CREATE</span><span class="plain">(</span><span class="reserved">nonterminal_variable</span><span class="plain">);</span>
|
|
<span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_name</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">var_given</span><span class="plain">);</span>
|
|
<span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_type</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">type_given</span><span class="plain">);</span>
|
|
<span class="identifier">LOOP_THROUGH_TEXT</span><span class="plain">(</span><span class="identifier">P</span><span class="plain">, </span><span class="identifier">var_given</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> ((</span><span class="functiontext">Str::get</span><span class="plain">(</span><span class="identifier">P</span><span class="plain">) == </span><span class="character">'-'</span><span class="plain">) || (</span><span class="functiontext">Str::get</span><span class="plain">(</span><span class="identifier">P</span><span class="plain">) == </span><span class="character">':'</span><span class="plain">))</span>
|
|
<span class="functiontext">Str::put</span><span class="plain">(</span><span class="identifier">P</span><span class="plain">, </span><span class="character">'_'</span><span class="plain">);</span>
|
|
<span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_identifier</span><span class="plain"> = </span><span class="functiontext">Str::new</span><span class="plain">();</span>
|
|
<span class="identifier">WRITE_TO</span><span class="plain">(</span><span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_identifier</span><span class="plain">, </span><span class="string">"%S_NTMV"</span><span class="plain">, </span><span class="identifier">var_given</span><span class="plain">);</span>
|
|
<span class="identifier">ntv</span><span class="plain">-</span><span class="element">>first_mention</span><span class="plain"> = </span><span class="identifier">AL</span><span class="plain">;</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_1_1_1_2">§3.1.1.1.2</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_2"></a><b>§3.2. Parsing I-literals. </b>A simpler but useful further addition to C is that we recognise a new form
|
|
of string literal: <code class="display"><span class="extract">I"quartz"</span></code> makes a constant text stream with the content
|
|
"quartz".
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Detect and deal with I-literals</span> <span class="cwebmacronumber">3.2</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="reserved">int</span><span class="plain"> </span><span class="identifier">i</span><span class="plain"> = 0, </span><span class="identifier">quoted</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">; </span><span class="identifier">i</span><span class="plain"> < </span><span class="functiontext">Str::len</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">); </span><span class="identifier">i</span><span class="plain">++) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">) == </span><span class="character">'"'</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> ((</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">-1) != </span><span class="character">'\</span><span class="plain">\</span><span class="character">'</span><span class="plain">) &&</span>
|
|
<span class="plain">((</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">-1) != </span><span class="character">'\</span><span class="plain">'</span><span class="character">'</span><span class="plain">) || (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+1) != </span><span class="character">'\</span><span class="plain">'</span><span class="character">'</span><span class="plain">)))</span>
|
|
<span class="identifier">quoted</span><span class="plain"> = </span><span class="identifier">quoted</span><span class="plain">?</span><span class="constant">FALSE</span><span class="plain">:</span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> ((</span><span class="identifier">fundamental_mode</span><span class="plain"> != </span><span class="constant">WEAVE_MODE</span><span class="plain">) && (</span><span class="identifier">quoted</span><span class="plain"> == </span><span class="constant">FALSE</span><span class="plain">) &&</span>
|
|
<span class="plain">(</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">) == </span><span class="character">'I'</span><span class="plain">) && (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+1) == </span><span class="character">'"'</span><span class="plain">))</span>
|
|
<<span class="cwebmacro">This looks like an I-literal</span> <span class="cwebmacronumber">3.2.1</span>><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3">§3</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_2_1"></a><b>§3.2.1. </b><code class="display">
|
|
<<span class="cwebmacrodefn">This looks like an I-literal</span> <span class="cwebmacronumber">3.2.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">lit</span><span class="plain">);</span>
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">i_was</span><span class="plain"> = </span><span class="identifier">i</span><span class="plain">;</span>
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">ended</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="identifier">i</span><span class="plain"> += 2;</span>
|
|
<span class="reserved">while</span><span class="plain"> (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">)) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">) == </span><span class="character">'"'</span><span class="plain">) { </span><span class="identifier">ended</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">; </span><span class="reserved">break</span><span class="plain">; }</span>
|
|
<span class="identifier">PUT_TO</span><span class="plain">(</span><span class="identifier">lit</span><span class="plain">, </span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">++));</span>
|
|
<span class="plain">}</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">ended</span><span class="plain">) </span><<span class="cwebmacro">This is definitely an I-literal</span> <span class="cwebmacronumber">3.2.1.2</span>><span class="plain">;</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">lit</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_2">§3.2</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_2_1_1"></a><b>§3.2.1.1. </b>Each I-literal results in an instance of the following being created. The
|
|
I-literal <code class="display"><span class="extract">I"quartz"</span></code> would have content <code class="display"><span class="extract">quartz</span></code> and identifier something
|
|
like <code class="display"><span class="extract">TL_IS_123</span></code>.
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">typedef</span><span class="plain"> </span><span class="reserved">struct</span><span class="plain"> </span><span class="reserved">text_literal</span><span class="plain"> {</span>
|
|
<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">tl_identifier</span><span class="plain">;</span>
|
|
<span class="reserved">struct</span><span class="plain"> </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">tl_content</span><span class="plain">;</span>
|
|
<span class="constant">MEMORY_MANAGEMENT</span>
|
|
<span class="plain">} </span><span class="reserved">text_literal</span><span class="plain">;</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The structure text_literal is private to this section.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP3_2_1_2"></a><b>§3.2.1.2. </b>So suppose we've got a line of web such as
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">text_stream *T = I"quartz";</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">We create the necessary I-literal, and splice the line so that it now reads
|
|
<code class="display"><span class="extract">text_stream *T = TL_IS_123;</span></code>. (That's why we don't call any of this on a
|
|
weave run; we're actually amending the code of the web.)
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">This is definitely an I-literal</span> <span class="cwebmacronumber">3.2.1.2</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">text_literal</span><span class="plain"> *</span><span class="identifier">tl</span><span class="plain"> = </span><span class="identifier">CREATE</span><span class="plain">(</span><span class="reserved">text_literal</span><span class="plain">);</span>
|
|
<span class="identifier">tl</span><span class="plain">-</span><span class="element">>tl_identifier</span><span class="plain"> = </span><span class="functiontext">Str::new</span><span class="plain">();</span>
|
|
<span class="identifier">WRITE_TO</span><span class="plain">(</span><span class="identifier">tl</span><span class="plain">-</span><span class="element">>tl_identifier</span><span class="plain">, </span><span class="string">"TL_IS_%d"</span><span class="plain">, </span><span class="identifier">tl</span><span class="plain">-</span><span class="element">>allocation_id</span><span class="plain">);</span>
|
|
<span class="identifier">tl</span><span class="plain">-</span><span class="element">>tl_content</span><span class="plain"> = </span><span class="functiontext">Str::duplicate</span><span class="plain">(</span><span class="identifier">lit</span><span class="plain">);</span>
|
|
<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">before</span><span class="plain">);</span>
|
|
<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">after</span><span class="plain">);</span>
|
|
<span class="functiontext">Str::copy</span><span class="plain">(</span><span class="identifier">before</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">);</span>
|
|
<span class="functiontext">Str::truncate</span><span class="plain">(</span><span class="identifier">before</span><span class="plain">, </span><span class="identifier">i_was</span><span class="plain">);</span>
|
|
<span class="functiontext">Str::copy_tail</span><span class="plain">(</span><span class="identifier">after</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+1);</span>
|
|
<span class="functiontext">Str::clear</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE_TO</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="string">"%S%S"</span><span class="plain">, </span><span class="identifier">before</span><span class="plain">, </span><span class="identifier">tl</span><span class="plain">-</span><span class="element">>tl_identifier</span><span class="plain">);</span>
|
|
<span class="identifier">i</span><span class="plain"> = </span><span class="functiontext">Str::len</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE_TO</span><span class="plain">(</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="string">"%S"</span><span class="plain">, </span><span class="identifier">after</span><span class="plain">);</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">before</span><span class="plain">);</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">after</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP3_2_1">§3.2.1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP4"></a><b>§4. Tangling methods. </b>Suppress the expansion of macros occurring on a line introduced by a <code class="display"><span class="extract">//</span></code>
|
|
comment. (This avoids problems when tangling code that's been commented out.)
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="functiontext">InCSupport::suppress_expansion</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">material</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> ((</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">material</span><span class="plain">, 0) == </span><span class="character">'/'</span><span class="plain">) && (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">material</span><span class="plain">, 1) == </span><span class="character">'/'</span><span class="plain">))</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::suppress_expansion is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP5"></a><b>§5. </b>InC does three things which C doesn't: it allows the namespaced function
|
|
names like <code class="display"><span class="extract">Section::function()</span></code>; it allows Foundation-class-style string
|
|
literals marked with an I, <code class="display"><span class="extract">I"like this"</span></code>, which we will call I-literals;
|
|
and it allows Preform natural language grammar to be mixed in with code.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">The following routine is a hook needed for two of these. It recognises
|
|
two special tangling commands:
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<ul class="items"><li>(a) <code class="display"><span class="extract">[[nonterminals]]</span></code> tangles to code which initialises the Preform
|
|
grammar. (The grammar defines the meaning of nonterminals such as
|
|
<code class="display"><span class="extract"><sentence></span></code>. They're not terminal in the sense that they are defined
|
|
as combinations of other things.) In practice, this needs to appear once
|
|
in any program using Preform. For the Inform project, that's done in the
|
|
<code class="display"><span class="extract">words</span></code> module of the Inform 7 compiler.
|
|
</li></ul>
|
|
<ul class="items"><li>(b) <code class="display"><span class="extract">[[textliterals]]</span></code> tangles to code which initialises the I-literals.
|
|
</li></ul>
|
|
|
|
<pre class="display">
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="functiontext">InCSupport::special_tangle_command</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">me</span><span class="plain">, </span><span class="constant">OUTPUT_STREAM</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">data</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">data</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"nonterminals"</span><span class="plain">)) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"register_tangled_nonterminals();\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">data</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"textliterals"</span><span class="plain">)) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"register_tangled_text_literals();\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::special_tangle_command is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP6"></a><b>§6. </b>Time to predeclare things. InC is going to create a special function, right
|
|
at the end of the code, which "registers" the nonterminals, creating their
|
|
run-time data structures; we must predeclare this function. It will set values
|
|
for the pointers <code class="display"><span class="extract">action_clause_NTM</span></code>, and so on; these are global variables,
|
|
which we initially declare as <code class="display"><span class="extract">NULL</span></code>.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">We also declare the nonterminal variables like <code class="display"><span class="extract">kind_ref_NTMV</span></code>, initialising
|
|
all integers to zero and all pointers to <code class="display"><span class="extract">NULL</span></code>.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">We do something similar, but simpler, to declare text stream constants.
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">void</span><span class="plain"> </span><span class="functiontext">InCSupport::additional_predeclarations</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">OUT</span><span class="plain">, </span><span class="reserved">web</span><span class="plain"> *</span><span class="identifier">W</span><span class="plain">) {</span>
|
|
<span class="reserved">chapter</span><span class="plain"> *</span><span class="identifier">C</span><span class="plain">;</span>
|
|
<span class="reserved">section</span><span class="plain"> *</span><span class="identifier">S</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_WITHIN_TANGLE</span><span class="plain">(</span><span class="identifier">C</span><span class="plain">, </span><span class="identifier">S</span><span class="plain">, </span><span class="functiontext">Tangler::primary_target</span><span class="plain">(</span><span class="identifier">W</span><span class="plain">))</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>preform_nonterminal_defined</span><span class="plain">) {</span>
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">pnt</span><span class="plain"> = </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>preform_nonterminal_defined</span><span class="plain">;</span>
|
|
<span class="functiontext">Languages::insert_line_marker</span><span class="plain">(</span><span class="identifier">OUT</span><span class="plain">, </span><span class="identifier">W</span><span class="plain">-</span><span class="element">>main_language</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"nonterminal *%S = NULL;\</span><span class="plain">n</span><span class="string">"</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
|
|
<span class="reserved">nonterminal_variable</span><span class="plain"> *</span><span class="identifier">ntv</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">ntv</span><span class="plain">, </span><span class="reserved">nonterminal_variable</span><span class="plain">)</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"%S %S = %s;\</span><span class="plain">n</span><span class="string">"</span><span class="plain">,</span>
|
|
<span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_type</span><span class="plain">, </span><span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_identifier</span><span class="plain">,</span>
|
|
<span class="plain">(</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_type</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"int"</span><span class="plain">))?</span><span class="string">"0"</span><span class="plain">:</span><span class="string">"NULL"</span><span class="plain">);</span>
|
|
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"void register_tangled_nonterminals(void);\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
|
|
<span class="reserved">text_literal</span><span class="plain"> *</span><span class="identifier">tl</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">tl</span><span class="plain">, </span><span class="reserved">text_literal</span><span class="plain">)</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"text_stream *%S = NULL;\</span><span class="plain">n</span><span class="string">"</span><span class="plain">, </span><span class="identifier">tl</span><span class="plain">-</span><span class="element">>tl_identifier</span><span class="plain">);</span>
|
|
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"void register_tangled_text_literals(void);\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::additional_predeclarations is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP7"></a><b>§7. </b>And here are the promised routines, which appear at the very end of the code.
|
|
They make use of macros and data structures defined in the Inform 7 web.
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">void</span><span class="plain"> </span><span class="functiontext">InCSupport::gnabehs</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">OUT</span><span class="plain">, </span><span class="reserved">web</span><span class="plain"> *</span><span class="identifier">W</span><span class="plain">) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"void register_tangled_nonterminals(void) {\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="reserved">chapter</span><span class="plain"> *</span><span class="identifier">C</span><span class="plain">;</span>
|
|
<span class="reserved">section</span><span class="plain"> *</span><span class="identifier">S</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_WITHIN_TANGLE</span><span class="plain">(</span><span class="identifier">C</span><span class="plain">, </span><span class="identifier">S</span><span class="plain">, </span><span class="functiontext">Tangler::primary_target</span><span class="plain">(</span><span class="identifier">W</span><span class="plain">))</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>preform_nonterminal_defined</span><span class="plain">) {</span>
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">pnt</span><span class="plain"> = </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>preform_nonterminal_defined</span><span class="plain">;</span>
|
|
<span class="functiontext">Languages::insert_line_marker</span><span class="plain">(</span><span class="identifier">OUT</span><span class="plain">, </span><span class="identifier">W</span><span class="plain">-</span><span class="element">>main_language</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">);</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_function</span><span class="plain">) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">t</span><span class="string">INTERNAL_NONTERMINAL(L\</span><span class="plain">"</span><span class="string">%S\</span><span class="plain">"</span><span class="string">, %S, %d, %d);\</span><span class="plain">n</span><span class="string">"</span><span class="plain">,</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>nt_name</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">,</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>min_word_count</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>max_word_count</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">t</span><span class="string">%S->voracious = %d;\</span><span class="plain">n</span><span class="string">"</span><span class="plain">,</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>voracious</span><span class="plain">);</span>
|
|
<span class="plain">} </span><span class="reserved">else</span><span class="plain"> {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">t</span><span class="string">REGISTER_NONTERMINAL(L\</span><span class="plain">"</span><span class="string">%S\</span><span class="plain">"</span><span class="string">, %S);\</span><span class="plain">n</span><span class="string">"</span><span class="plain">,</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>nt_name</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"}\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"void register_tangled_text_literals(void) {\</span><span class="plain">n</span><span class="string">"</span><span class="plain">); </span><span class="constant">INDENT</span><span class="plain">;</span>
|
|
<span class="reserved">text_literal</span><span class="plain"> *</span><span class="identifier">tl</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">tl</span><span class="plain">, </span><span class="reserved">text_literal</span><span class="plain">)</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"%S = Str::literal(L\</span><span class="plain">"</span><span class="string">%S\</span><span class="plain">"</span><span class="string">);\</span><span class="plain">n</span><span class="string">"</span><span class="plain">, </span><span class="identifier">tl</span><span class="plain">-</span><span class="element">>tl_identifier</span><span class="plain">, </span><span class="identifier">tl</span><span class="plain">-</span><span class="element">>tl_content</span><span class="plain">);</span>
|
|
<span class="constant">OUTDENT</span><span class="plain">; </span><span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"}\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::gnabehs is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP8"></a><b>§8. </b>That's it for big structural additions to the tangled C code. Now we turn
|
|
to how to tangle the lines we've given special categories to.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">We need to tangle <code class="display"><span class="extract">PREFORM_LCAT</span></code> lines (those holding nonterminal declarations)
|
|
in a special way...
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="functiontext">InCSupport::will_insert_in_tangle</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">L</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>category</span><span class="plain"> == </span><span class="constant">PREFORM_LCAT</span><span class="plain">) </span><span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::will_insert_in_tangle is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP9"></a><b>§9. </b>...and this is how. As can be seen, each nonterminal turns into a C function.
|
|
In the case of an internal definition, like
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain"><k-kind-for-template> internal {</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">we tangle this opening line to
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">int k_kind_for_template_NTM(wording W, int *X, void **XP) {</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">that is, to a function which returns <code class="display"><span class="extract">TRUE</span></code> if it makes a match on the text
|
|
excerpt in Inform's source text, <code class="display"><span class="extract">FALSE</span></code> otherwise; if it matches and produces
|
|
an integer and/or pointer result, these are copied into <code class="display"><span class="extract">*X</span></code> and <code class="display"><span class="extract">*XP</span></code>. The
|
|
remaining lines of the function are tangled unaltered, i.e., following the
|
|
same rules as for the body of any other C function.
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">void</span><span class="plain"> </span><span class="functiontext">InCSupport::insert_in_tangle</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">OUT</span><span class="plain">, </span><span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">L</span><span class="plain">) {</span>
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">pnt</span><span class="plain"> = </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>preform_nonterminal_defined</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_function</span><span class="plain">) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"int %SR(wording W, int *X, void **XP) {\</span><span class="plain">n</span><span class="string">"</span><span class="plain">,</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">);</span>
|
|
<span class="plain">} </span><span class="reserved">else</span><span class="plain"> {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"int %SC(int *X, void **XP, int *R, void **RP, wording *FW, wording W) {\</span><span class="plain">n</span><span class="string">"</span><span class="plain">,</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">);</span>
|
|
<<span class="cwebmacro">Compile the body of the compositor function</span> <span class="cwebmacronumber">9.1</span>><span class="plain">;</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"}\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::insert_in_tangle is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP9_1"></a><b>§9.1. </b>On the other hand, a grammar nonterminal tangles to a "compositor function".
|
|
Thus the opening line
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain"><action-clause> ::=</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">tangles to a function header:
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">int action_clause_NTMC(int *X, void **XP, int *R, void **RP, wording *FW, wording W) {</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">Subsequent lines of the nonterminal are categorised <code class="display"><span class="extract">PREFORM_GRAMMAR_LCAT</span></code>
|
|
and thus won't tangle to code at all, by the usual rules; so we tangle from
|
|
them directly here.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">Composition is what happens after a successful match of the text in the
|
|
word range <code class="display"><span class="extract">W</span></code>. The idea is that, especially if the pattern was
|
|
complicated, we will need to "compose" the results of parsing individual
|
|
pieces of it into a result for the whole. These partial results can be found
|
|
in the arrays <code class="display"><span class="extract">R[n]</span></code> and <code class="display"><span class="extract">RP[n]</span></code> passed as parameters; recall that every
|
|
nonterminal has in principle both an integer and a pointer result, though
|
|
often one or both is undefined.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">A simple example would be
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain"><cardinal-number> + <cardinal-number> ==> R[1] + R[2]</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">where the composition function would be called on a match of, say, "5 + 7",
|
|
and would find the values 5 and 7 in <code class="display"><span class="extract">R[1]</span></code> and <code class="display"><span class="extract">R[2]</span></code> respectively. It would
|
|
then add these together, store 12 in <code class="display"><span class="extract">*X</span></code>, and return <code class="display"><span class="extract">TRUE</span></code> to show that all
|
|
was well.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">A more typical example, drawn from the actual Inform 7 web, is:
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain"><k-kind-of-kind> <k-formal-kind-variable> ==> Kinds::variable_construction(R[2], RP[1])</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">which says that the composite result — the right-hand formula — is formed by
|
|
calling a particular routine on the integer result of subexpression 2
|
|
(<code class="display"><span class="extract"><k-formal-kind-variable></span></code>) and the pointer result of subexpression 1
|
|
(<code class="display"><span class="extract"><k-kind-of-kind></span></code>). The answer, the composite result, that is, must be
|
|
placed in <code class="display"><span class="extract">*X</span></code> and <code class="display"><span class="extract">*XP</span></code>. (Composition functions are also allowed to
|
|
invalidate the result, by returning <code class="display"><span class="extract">FALSE</span></code>, and have other tricks up their
|
|
sleeves, but none of that is handled by Inweb: see the Inform 7 web for more
|
|
on this.)
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Compile the body of the compositor function</span> <span class="cwebmacronumber">9.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">needs_collation</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">AL</span><span class="plain"> = </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>next_line</span><span class="plain">;</span>
|
|
<span class="plain">((</span><span class="identifier">AL</span><span class="plain">) && (</span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>category</span><span class="plain"> == </span><span class="constant">PREFORM_GRAMMAR_LCAT</span><span class="plain">));</span>
|
|
<span class="identifier">AL</span><span class="plain"> = </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>next_line</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::len</span><span class="plain">(</span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand2</span><span class="plain">) > 0)</span>
|
|
<span class="identifier">needs_collation</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">needs_collation</span><span class="plain">) </span><<span class="cwebmacro">At least one of the grammar lines provided an arrow and formula</span> <span class="cwebmacronumber">9.1.2</span>>
|
|
<span class="reserved">else</span><span class="plain"> </span><<span class="cwebmacro">None of the grammar lines provided an arrow and formula</span> <span class="cwebmacronumber">9.1.1</span>><span class="plain">;</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">t</span><span class="string">return TRUE;\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP9">§9</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP9_1_1"></a><b>§9.1.1. </b>In the absence of any <code class="display"><span class="extract">==></span></code> formulae, we simply set <code class="display"><span class="extract">*X</span></code> to the default
|
|
result supplied; this is the production number within the grammar (0 for the
|
|
first line, 1 for the second, and so on) by default, with an undefined pointer.
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">None of the grammar lines provided an arrow and formula</span> <span class="cwebmacronumber">9.1.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">t</span><span class="string">*X = R[0];\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP9_1">§9.1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP9_1_2"></a><b>§9.1.2. </b><code class="display">
|
|
<<span class="cwebmacrodefn">At least one of the grammar lines provided an arrow and formula</span> <span class="cwebmacronumber">9.1.2</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">t</span><span class="string">switch(R[0]) {\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">c</span><span class="plain"> = 0;</span>
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">AL</span><span class="plain"> = </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>next_line</span><span class="plain">;</span>
|
|
<span class="plain">((</span><span class="identifier">AL</span><span class="plain">) && (</span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>category</span><span class="plain"> == </span><span class="constant">PREFORM_GRAMMAR_LCAT</span><span class="plain">));</span>
|
|
<span class="identifier">AL</span><span class="plain"> = </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>next_line</span><span class="plain">, </span><span class="identifier">c</span><span class="plain">++) {</span>
|
|
<span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">formula</span><span class="plain"> = </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand2</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::len</span><span class="plain">(</span><span class="identifier">formula</span><span class="plain">) > 0) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">t</span><span class="string">\</span><span class="plain">t</span><span class="string">case %d: "</span><span class="plain">, </span><span class="identifier">c</span><span class="plain">);</span>
|
|
<<span class="cwebmacro">Tangle the formula on the right-hand side of the arrow</span> <span class="cwebmacronumber">9.1.2.1</span>><span class="plain">;</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">";\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"#pragma clang diagnostic push\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"#pragma clang diagnostic ignored \</span><span class="plain">"</span><span class="string">-Wunreachable-code\</span><span class="plain">"</span><span class="string">\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"break;\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"#pragma clang diagnostic pop\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">t</span><span class="string">\</span><span class="plain">t</span><span class="string">default: *X = R[0]; break;\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">t</span><span class="string">}\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP9_1">§9.1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP9_1_2_1"></a><b>§9.1.2.1. </b>We assume that the RHS of the arrow is an expression to be evaluated,
|
|
and that it produces an integer or a pointer according to what the
|
|
non-terminal expects as its main result. But we make one exception: if
|
|
the formula begins with a paragraph macro, then it can't be an expression,
|
|
and instead we read it as code in a void context. (This code will, we
|
|
assume, set <code class="display"><span class="extract">*X</span></code> and/or <code class="display"><span class="extract">*XP</span></code> in some ingenious way of its own.)
|
|
</p>
|
|
|
|
<p class="inwebparagraph">Within the body of the formula, we allow a pseudo-macro to work: <code class="display"><span class="extract">WR[n]</span></code>
|
|
expands to word range <code class="display"><span class="extract">n</span></code> in the match which we're compositing. This actually
|
|
expands like so:
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">action_clause_NTM->range_result[n]</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">which saves a good deal of typing. (A regular C preprocessor macro couldn't
|
|
easily do this, because it needs to include the identifier name of the
|
|
nonterminal being parsed.)
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Tangle the formula on the right-hand side of the arrow</span> <span class="cwebmacronumber">9.1.2.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
|
|
<span class="reserved">if</span><span class="plain"> (!</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">formula</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"@<%c*"</span><span class="plain">)) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>takes_pointer_result</span><span class="plain">) </span><span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"*XP = "</span><span class="plain">);</span>
|
|
<span class="reserved">else</span><span class="plain"> </span><span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"*X = "</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">expanded</span><span class="plain">);</span>
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="reserved">int</span><span class="plain"> </span><span class="identifier">i</span><span class="plain">=0; </span><span class="identifier">i</span><span class="plain"> < </span><span class="functiontext">Str::len</span><span class="plain">(</span><span class="identifier">formula</span><span class="plain">); </span><span class="identifier">i</span><span class="plain">++) {</span>
|
|
<span class="reserved">if</span><span class="plain"> ((</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">formula</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">) == </span><span class="character">'W'</span><span class="plain">) && (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">formula</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+1) == </span><span class="character">'R'</span><span class="plain">) &&</span>
|
|
<span class="plain">(</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">formula</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+2) == </span><span class="character">'['</span><span class="plain">) &&</span>
|
|
<span class="plain">(</span><span class="identifier">isdigit</span><span class="plain">(</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">formula</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+3))) && (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">formula</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+4) == </span><span class="character">']'</span><span class="plain">)) {</span>
|
|
<span class="identifier">WRITE_TO</span><span class="plain">(</span><span class="identifier">expanded</span><span class="plain">,</span>
|
|
<span class="string">"%S->range_result[%c]"</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">, </span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">formula</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+3));</span>
|
|
<span class="identifier">i</span><span class="plain"> += 4;</span>
|
|
<span class="plain">} </span><span class="reserved">else</span><span class="plain"> {</span>
|
|
<span class="identifier">PUT_TO</span><span class="plain">(</span><span class="identifier">expanded</span><span class="plain">, </span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">formula</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">));</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
<span class="functiontext">Tangler::tangle_code</span><span class="plain">(</span><span class="identifier">OUT</span><span class="plain">, </span><span class="identifier">expanded</span><span class="plain">, </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>owning_section</span><span class="plain">, </span><span class="identifier">AL</span><span class="plain">);</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">expanded</span><span class="plain">);</span>
|
|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP9_1_2">§9.1.2</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP10"></a><b>§10. </b>Going down from line level to the tangling of little excerpts of C code,
|
|
we also provide for some other special extensions to C.
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">void</span><span class="plain"> </span><span class="functiontext">InCSupport::tangle_code</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">OUT</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">original</span><span class="plain">) {</span>
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">fcall_pos</span><span class="plain"> = -1;</span>
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="reserved">int</span><span class="plain"> </span><span class="identifier">i</span><span class="plain"> = 0; </span><span class="identifier">i</span><span class="plain"> < </span><span class="functiontext">Str::len</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">); </span><span class="identifier">i</span><span class="plain">++) {</span>
|
|
<<span class="cwebmacro">Double-colons are namespace dividers in function names</span> <span class="cwebmacronumber">10.1</span>><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">) == </span><span class="character">'<'</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+1) == </span><span class="character">'<'</span><span class="plain">) {</span>
|
|
<<span class="cwebmacro">Double-angles sometimes delimit Preform variable names</span> <span class="cwebmacronumber">10.2</span>><span class="plain">;</span>
|
|
<span class="plain">} </span><span class="reserved">else</span><span class="plain"> {</span>
|
|
<<span class="cwebmacro">Single-angles sometimes delimit Preform nonterminal names</span> <span class="cwebmacronumber">10.3</span>><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">i</span><span class="plain"> == </span><span class="identifier">fcall_pos</span><span class="plain">) {</span>
|
|
<span class="identifier">fcall_pos</span><span class="plain"> = -1;</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">", NULL, NULL"</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">PUT</span><span class="plain">(</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">));</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::tangle_code is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP10_1"></a><b>§10.1. </b>For example, a function name like:
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">Text::Parsing::get_next</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">must be rewritten as
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">Text__Parsing__get_next</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">since colons aren't valid in C identifiers. The following is prone to all
|
|
kinds of misreadings, of course; it picks up any use of <code class="display"><span class="extract">::</span></code> between an
|
|
alphanumberic character and a letter. In particular, code like
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">printf("Trying Text::Parsing::get_next now.\n");</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">will be rewritten as
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">printf("Trying Text__Parsing__get_next now.\n");</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">This is probably unwanted, but it doesn't matter, because these Inform-only
|
|
extension features of Inweb aren't intended for general use: only for
|
|
Inform, where no misreadings occur.
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Double-colons are namespace dividers in function names</span> <span class="cwebmacronumber">10.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">if</span><span class="plain"> ((</span><span class="identifier">i</span><span class="plain"> > 0) && (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">) == </span><span class="character">':'</span><span class="plain">) && (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+1) == </span><span class="character">':'</span><span class="plain">) &&</span>
|
|
<span class="plain">(</span><span class="identifier">isalpha</span><span class="plain">(</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+2))) && (</span><span class="identifier">isalnum</span><span class="plain">(</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">-1)))) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"__"</span><span class="plain">); </span><span class="identifier">i</span><span class="plain">++;</span>
|
|
<span class="reserved">continue</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP10">§10</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP10_2"></a><b>§10.2. </b>Angle brackets around a valid Preform variable name expand into its
|
|
C identifier; for example, <code class="display"><span class="extract"><<R>></span></code> becomes <code class="display"><span class="extract">most_recent_result</span></code>.
|
|
We take no action if it's not a valid name, so <code class="display"><span class="extract"><<fish>></span></code> becomes
|
|
just <code class="display"><span class="extract"><<fish>></span></code>.
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Double-angles sometimes delimit Preform variable names</span> <span class="cwebmacronumber">10.2</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
|
|
<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">check_this</span><span class="plain">);</span>
|
|
<span class="functiontext">Str::substr</span><span class="plain">(</span><span class="identifier">check_this</span><span class="plain">, </span><span class="functiontext">Str::at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">), </span><span class="functiontext">Str::end</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">));</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">check_this</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"<<(%P+)>>%c*"</span><span class="plain">)) {</span>
|
|
<span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">putative</span><span class="plain"> = </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0];</span>
|
|
<span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">pv_identifier</span><span class="plain"> = </span><span class="functiontext">InCSupport::nonterminal_variable_identifier</span><span class="plain">(</span><span class="identifier">putative</span><span class="plain">);</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">pv_identifier</span><span class="plain">) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"%S"</span><span class="plain">, </span><span class="identifier">pv_identifier</span><span class="plain">);</span>
|
|
<span class="identifier">i</span><span class="plain"> += </span><span class="functiontext">Str::len</span><span class="plain">(</span><span class="identifier">putative</span><span class="plain">) + 3;</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">check_this</span><span class="plain">);</span>
|
|
<span class="reserved">continue</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">check_this</span><span class="plain">);</span>
|
|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP10">§10</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP10_3"></a><b>§10.3. </b>Similarly for nonterminals; <code class="display"><span class="extract"><k-kind></span></code> might become <code class="display"><span class="extract">k_kind_NTM</span></code>.
|
|
Here, though, there's a complication:
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">if (<k-kind>(W)) { ...</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">must expand to:
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain">if (Text__Languages__parse_nt_against_word_range(k_kind_NTM, W, NULL, NULL)) { ...</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">This is all syntactic sugar to make it easier to see parsing in action.
|
|
Anyway, it means we have to set <code class="display"><span class="extract">fcall_pos</span></code> to remember to add in the
|
|
two <code class="display"><span class="extract">NULL</span></code> arguments when we hit the <code class="display"><span class="extract">)</span></code> a little later. We're doing all
|
|
of this fairly laxly, but as before: it only needs to work for Inform,
|
|
and Inform doesn't cause any trouble.
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Single-angles sometimes delimit Preform nonterminal names</span> <span class="cwebmacronumber">10.3</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
|
|
<span class="identifier">TEMPORARY_TEXT</span><span class="plain">(</span><span class="identifier">check_this</span><span class="plain">);</span>
|
|
<span class="functiontext">Str::substr</span><span class="plain">(</span><span class="identifier">check_this</span><span class="plain">, </span><span class="functiontext">Str::at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">), </span><span class="functiontext">Str::end</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">));</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">check_this</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"(<%p+>)%c*"</span><span class="plain">)) {</span>
|
|
<span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">putative</span><span class="plain"> = </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0];</span>
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">pnt</span><span class="plain"> = </span><span class="functiontext">InCSupport::nonterminal_by_name</span><span class="plain">(</span><span class="identifier">putative</span><span class="plain">);</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">pnt</span><span class="plain">) {</span>
|
|
<span class="identifier">i</span><span class="plain"> += </span><span class="functiontext">Str::len</span><span class="plain">(</span><span class="identifier">putative</span><span class="plain">) - 1;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">i</span><span class="plain">+1) == </span><span class="character">'('</span><span class="plain">) {</span>
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">arity</span><span class="plain"> = 1;</span>
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="reserved">int</span><span class="plain"> </span><span class="identifier">j</span><span class="plain"> = </span><span class="identifier">i</span><span class="plain">+2, </span><span class="identifier">bl</span><span class="plain"> = 1; ((</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">j</span><span class="plain">)) && (</span><span class="identifier">bl</span><span class="plain"> > 0)); </span><span class="identifier">j</span><span class="plain">++) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">j</span><span class="plain">) == </span><span class="character">'('</span><span class="plain">) </span><span class="identifier">bl</span><span class="plain">++;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">j</span><span class="plain">) == </span><span class="character">')'</span><span class="plain">) { </span><span class="identifier">bl</span><span class="plain">--; </span><span class="reserved">if</span><span class="plain"> (</span><span class="identifier">bl</span><span class="plain"> == 0) </span><span class="identifier">fcall_pos</span><span class="plain"> = </span><span class="identifier">j</span><span class="plain">; }</span>
|
|
<span class="reserved">if</span><span class="plain"> ((</span><span class="functiontext">Str::get_at</span><span class="plain">(</span><span class="identifier">original</span><span class="plain">, </span><span class="identifier">j</span><span class="plain">) == </span><span class="character">','</span><span class="plain">) && (</span><span class="identifier">bl</span><span class="plain"> == 1)) </span><span class="identifier">arity</span><span class="plain">++;</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"Preform__parse_nt_against_word_range("</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"%S"</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_C_identifier</span><span class="plain">);</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">fcall_pos</span><span class="plain"> >= 0) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">", "</span><span class="plain">); </span><span class="identifier">i</span><span class="plain">++;</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">check_this</span><span class="plain">);</span>
|
|
<span class="reserved">continue</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">DISCARD_TEXT</span><span class="plain">(</span><span class="identifier">check_this</span><span class="plain">);</span>
|
|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP10">§10</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP11"></a><b>§11. </b>We needed two little routines to find nonterminals and their variables by
|
|
name. They're not very efficient, but experience shows that even on a web
|
|
the size of Inform 7, there's no significant gain from speeding them up
|
|
(with, say, a hash table).
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="functiontext">InCSupport::nonterminal_by_name</span><span class="plain">(</span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">name</span><span class="plain">) {</span>
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">pnt</span><span class="plain">, </span><span class="reserved">preform_nonterminal</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq</span><span class="plain">(</span><span class="identifier">name</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>nt_name</span><span class="plain">))</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="identifier">NULL</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::nonterminal_by_name is used in <a href="#SP10_3">§10.3</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP12"></a><b>§12. </b>The special variables <code class="display"><span class="extract"><<R>></span></code> and <code class="display"><span class="extract"><<RP>></span></code> hold the results,
|
|
integer and pointer, for the most recent successful match. They're defined
|
|
in the Inform 7 web (see the code for parsing text against Preform grammars),
|
|
not by Inweb.
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">text_stream</span><span class="plain"> *</span><span class="functiontext">InCSupport::nonterminal_variable_identifier</span><span class="plain">(</span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">name</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">name</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"r"</span><span class="plain">)) </span><span class="reserved">return</span><span class="plain"> </span><span class="identifier">I</span><span class="string">"most_recent_result"</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">name</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"rp"</span><span class="plain">)) </span><span class="reserved">return</span><span class="plain"> </span><span class="identifier">I</span><span class="string">"most_recent_result_p"</span><span class="plain">;</span>
|
|
<span class="reserved">nonterminal_variable</span><span class="plain"> *</span><span class="identifier">ntv</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">ntv</span><span class="plain">, </span><span class="reserved">nonterminal_variable</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq</span><span class="plain">(</span><span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_name</span><span class="plain">, </span><span class="identifier">name</span><span class="plain">))</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="identifier">ntv</span><span class="plain">-</span><span class="element">>ntv_identifier</span><span class="plain">;</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="identifier">NULL</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::nonterminal_variable_identifier is used in <a href="#SP10_2">§10.2</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP13"></a><b>§13. </b>We saw above that the grammar lines following a non-internal declaration
|
|
were divided into actual grammar, then an arrow, then a formula. The formulae
|
|
were tangled into "composition functions", but the grammar itself was
|
|
simply thrown away. It doesn't appear anywhere in the C code tangled by
|
|
Inweb.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">So what does happen to it? The answer is that it's transcribed into an
|
|
auxiliary file called <code class="display"><span class="extract">Syntax.preform</span></code>, which Inform, once it is compiled,
|
|
will read in at run-time. This is how that happens:
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">void</span><span class="plain"> </span><span class="functiontext">InCSupport::additional_tangling</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">web</span><span class="plain"> *</span><span class="identifier">W</span><span class="plain">, </span><span class="reserved">tangle_target</span><span class="plain"> *</span><span class="identifier">target</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">NUMBER_CREATED</span><span class="plain">(</span><span class="reserved">preform_nonterminal</span><span class="plain">) > 0) {</span>
|
|
<span class="reserved">pathname</span><span class="plain"> *</span><span class="identifier">P</span><span class="plain"> = </span><span class="functiontext">Reader::tangled_folder</span><span class="plain">(</span><span class="identifier">W</span><span class="plain">);</span>
|
|
<span class="reserved">filename</span><span class="plain"> *</span><span class="identifier">Syntax</span><span class="plain"> = </span><span class="functiontext">Filenames::in_folder</span><span class="plain">(</span><span class="identifier">P</span><span class="plain">, </span><span class="identifier">I</span><span class="string">"Syntax.preform"</span><span class="plain">);</span>
|
|
|
|
<span class="reserved">text_stream</span><span class="plain"> </span><span class="identifier">TO_struct</span><span class="plain">;</span>
|
|
<span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">OUT</span><span class="plain"> = &</span><span class="identifier">TO_struct</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">STREAM_OPEN_TO_FILE</span><span class="plain">(</span><span class="identifier">OUT</span><span class="plain">, </span><span class="identifier">Syntax</span><span class="plain">, </span><span class="constant">ISO_ENC</span><span class="plain">) == </span><span class="constant">FALSE</span><span class="plain">)</span>
|
|
<span class="functiontext">Errors::fatal_with_file</span><span class="plain">(</span><span class="string">"unable to write Preform file"</span><span class="plain">, </span><span class="identifier">Syntax</span><span class="plain">);</span>
|
|
|
|
<span class="identifier">WRITE_TO</span><span class="plain">(</span><span class="constant">STDOUT</span><span class="plain">, </span><span class="string">"Writing Preform syntax to: %/f\</span><span class="plain">n</span><span class="string">"</span><span class="plain">, </span><span class="identifier">Syntax</span><span class="plain">);</span>
|
|
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"[Preform syntax generated by inweb: do not edit.]\</span><span class="plain">n</span><span class="string">\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Bibliographic::data_exists</span><span class="plain">(</span><span class="identifier">W</span><span class="plain">, </span><span class="identifier">I</span><span class="string">"Preform Language"</span><span class="plain">))</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"language %S\</span><span class="plain">n</span><span class="string">"</span><span class="plain">, </span><span class="functiontext">Bibliographic::get_datum</span><span class="plain">(</span><span class="identifier">W</span><span class="plain">, </span><span class="identifier">I</span><span class="string">"Preform Language"</span><span class="plain">));</span>
|
|
|
|
<<span class="cwebmacro">Actually write out the Preform syntax</span> <span class="cwebmacronumber">13.1</span>><span class="plain">;</span>
|
|
<span class="identifier">STREAM_CLOSE</span><span class="plain">(</span><span class="identifier">OUT</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::additional_tangling is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP13_1"></a><b>§13.1. </b>See the "English Syntax of Inform" document for a heavily annotated
|
|
form of the result of the following. Note a useful convention: if the
|
|
right-hand side of the arrow in a grammar line uses a paragraph macro which
|
|
mentions a problem message, then we transcribe a Preform comment to that
|
|
effect. (This really is a comment: Inform ignores it, but it makes the
|
|
file more comprehensible to human eyes.) For example,
|
|
</p>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="plain"><article> kind ==> @<Issue C8PropertyOfKind problem@></span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph">(The code in this paragraph macro will indeed issue this problem message, we
|
|
assume.)
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="cwebmacrodefn">Actually write out the Preform syntax</span> <span class="cwebmacronumber">13.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">chapter</span><span class="plain"> *</span><span class="identifier">C</span><span class="plain">;</span>
|
|
<span class="reserved">section</span><span class="plain"> *</span><span class="identifier">S</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_WITHIN_TANGLE</span><span class="plain">(</span><span class="identifier">C</span><span class="plain">, </span><span class="identifier">S</span><span class="plain">, </span><span class="identifier">target</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">L</span><span class="plain">-</span><span class="element">>category</span><span class="plain"> == </span><span class="constant">PREFORM_LCAT</span><span class="plain">) {</span>
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">pnt</span><span class="plain"> = </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>preform_nonterminal_defined</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_function</span><span class="plain">)</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">n</span><span class="string">%S internal\</span><span class="plain">n</span><span class="string">"</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>nt_name</span><span class="plain">);</span>
|
|
<span class="reserved">else</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">n</span><span class="string">%S ::=\</span><span class="plain">n</span><span class="string">"</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text_operand</span><span class="plain">);</span>
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">AL</span><span class="plain"> = </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>next_line</span><span class="plain">;</span>
|
|
<span class="plain">((</span><span class="identifier">AL</span><span class="plain">) && (</span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>category</span><span class="plain"> == </span><span class="constant">PREFORM_GRAMMAR_LCAT</span><span class="plain">));</span>
|
|
<span class="identifier">AL</span><span class="plain"> = </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>next_line</span><span class="plain">) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"%S"</span><span class="plain">, </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand</span><span class="plain">);</span>
|
|
<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">AL</span><span class="plain">-</span><span class="element">>text_operand2</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"%c+Issue (%c+) problem%c+"</span><span class="plain">))</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"[issues %S]"</span><span class="plain">, </span><span class="identifier">mr</span><span class="element">.exp</span><span class="plain">[0]);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP13">§13</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP14"></a><b>§14. Weaving. </b>The following isn't a method, but is called by the weaver directly. It adds
|
|
additional endnotes to the woven form of a paragraph which includes Preform
|
|
nonterminal definitions:
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">void</span><span class="plain"> </span><span class="functiontext">InCSupport::weave_grammar_index</span><span class="plain">(</span><span class="constant">OUTPUT_STREAM</span><span class="plain">) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">\</span><span class="string">raggedright\</span><span class="plain">\</span><span class="string">tolerance=10000"</span><span class="plain">);</span>
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="reserved">for</span><span class="plain"> (</span><span class="identifier">pnt</span><span class="plain"> = </span><span class="identifier">alphabetical_list_of_nonterminals</span><span class="plain">; </span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="identifier">pnt</span><span class="plain"> = </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>next_pnt_alphabetically</span><span class="plain">) {</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">\</span><span class="string">line{\</span><span class="plain">\</span><span class="string">nonterminal{%S}%s"</span>
|
|
<span class="string">"\</span><span class="plain">\</span><span class="string">leaders\</span><span class="plain">\</span><span class="string">hbox to 1em{\</span><span class="plain">\</span><span class="string">hss.\</span><span class="plain">\</span><span class="string">hss}\</span><span class="plain">\</span><span class="string">hfill {\</span><span class="plain">\</span><span class="string">xreffont %S}}\</span><span class="plain">n</span><span class="string">"</span><span class="plain">,</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>unangled_name</span><span class="plain">,</span>
|
|
<span class="plain">(</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>as_function</span><span class="plain">)?</span><span class="string">" (internal)"</span><span class="plain">:</span><span class="string">""</span><span class="plain">,</span>
|
|
<span class="identifier">pnt</span><span class="plain">-</span><span class="element">>where_defined</span><span class="plain">-</span><span class="element">>owning_section</span><span class="plain">-</span><span class="element">>range</span><span class="plain">);</span>
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">said_something</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<<span class="cwebmacro">List where the nonterminal appears in other Preform declarations</span> <span class="cwebmacronumber">14.2</span>><span class="plain">;</span>
|
|
<<span class="cwebmacro">List where the nonterminal is called from Inform code</span> <span class="cwebmacronumber">14.1</span>><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">said_something</span><span class="plain"> == </span><span class="constant">FALSE</span><span class="plain">)</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">\</span><span class="string">par\</span><span class="plain">\</span><span class="string">hangindent=3em{\</span><span class="plain">\</span><span class="string">it unused}\</span><span class="plain">n</span><span class="string">\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">\</span><span class="string">penalty-1000\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">\</span><span class="string">smallbreak\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">\</span><span class="string">hrule\</span><span class="plain">\</span><span class="string">smallbreak\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::weave_grammar_index is used in 3/tw (<a href="3-tw.html#SP1_3_3_1_2">§1.3.3.1.2</a>).</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP14_1"></a><b>§14.1. </b><code class="display">
|
|
<<span class="cwebmacrodefn">List where the nonterminal is called from Inform code</span> <span class="cwebmacronumber">14.1</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">section</span><span class="plain"> *</span><span class="identifier">S</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">S</span><span class="plain">, </span><span class="reserved">section</span><span class="plain">) </span><span class="identifier">S</span><span class="plain">-</span><span class="element">>scratch_flag</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="reserved">hash_table_entry</span><span class="plain"> *</span><span class="identifier">hte</span><span class="plain"> = </span><span class="functiontext">Analyser::find_hash_entry</span><span class="plain">(</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>where_defined</span><span class="plain">-</span><span class="element">>owning_section</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>unangled_name</span><span class="plain">, </span><span class="constant">FALSE</span><span class="plain">);</span>
|
|
<span class="reserved">hash_table_entry_usage</span><span class="plain"> *</span><span class="identifier">hteu</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER_LINKED_LIST</span><span class="plain">(</span><span class="identifier">hteu</span><span class="plain">, </span><span class="reserved">hash_table_entry_usage</span><span class="plain">, </span><span class="identifier">hte</span><span class="plain">-</span><span class="element">>usages</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">hteu</span><span class="plain">-</span><span class="element">>form_of_usage</span><span class="plain"> & </span><span class="constant">PREFORM_IN_CODE_USAGE</span><span class="plain">)</span>
|
|
<span class="identifier">hteu</span><span class="plain">-</span><span class="element">>usage_recorded_at</span><span class="plain">-</span><span class="element">>under_section</span><span class="plain">-</span><span class="element">>scratch_flag</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">use_count</span><span class="plain"> = 0;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">S</span><span class="plain">, </span><span class="reserved">section</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">S</span><span class="plain">-</span><span class="element">>scratch_flag</span><span class="plain">)</span>
|
|
<span class="identifier">use_count</span><span class="plain">++;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">use_count</span><span class="plain"> > 0) {</span>
|
|
<span class="identifier">said_something</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">\</span><span class="string">par\</span><span class="plain">\</span><span class="string">hangindent=3em{\</span><span class="plain">\</span><span class="string">it called from} "</span><span class="plain">);</span>
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="identifier">c</span><span class="plain"> = 0;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">S</span><span class="plain">, </span><span class="reserved">section</span><span class="plain">)</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">S</span><span class="plain">-</span><span class="element">>scratch_flag</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">c</span><span class="plain">++ > 0) </span><span class="identifier">WRITE</span><span class="plain">(</span><span class="string">", "</span><span class="plain">);</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"{\</span><span class="plain">\</span><span class="string">xreffont %S}"</span><span class="plain">, </span><span class="identifier">S</span><span class="plain">-</span><span class="element">>range</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">n</span><span class="string">\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">This code is used in <a href="#SP14">§14</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP14_2"></a><b>§14.2. </b><code class="display">
|
|
<<span class="cwebmacrodefn">List where the nonterminal appears in other Preform declarations</span> <span class="cwebmacronumber">14.2</span>> =
|
|
</code></p>
|
|
|
|
|
|
<pre class="displaydefn">
|
|
<span class="reserved">section</span><span class="plain"> *</span><span class="identifier">S</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">S</span><span class="plain">, </span><span class="reserved">section</span><span class="plain">) </span><span class="identifier">S</span><span class="plain">-</span><span class="element">>scratch_flag</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="reserved">hash_table_entry</span><span class="plain"> *</span><span class="identifier">hte</span><span class="plain"> = </span><span class="functiontext">Analyser::find_hash_entry</span><span class="plain">(</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>where_defined</span><span class="plain">-</span><span class="element">>owning_section</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>unangled_name</span><span class="plain">, </span><span class="constant">FALSE</span><span class="plain">);</span>
|
|
<span class="reserved">hash_table_entry_usage</span><span class="plain"> *</span><span class="identifier">hteu</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER_LINKED_LIST</span><span class="plain">(</span><span class="identifier">hteu</span><span class="plain">, </span><span class="reserved">hash_table_entry_usage</span><span class="plain">, </span><span class="identifier">hte</span><span class="plain">-</span><span class="element">>usages</span><span class="plain">)</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">hteu</span><span class="plain">-</span><span class="element">>form_of_usage</span><span class="plain"> & </span><span class="constant">PREFORM_IN_GRAMMAR_USAGE</span><span class="plain">)</span>
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<span class="identifier">hteu</span><span class="plain">-</span><span class="element">>usage_recorded_at</span><span class="plain">-</span><span class="element">>under_section</span><span class="plain">-</span><span class="element">>scratch_flag</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">use_count</span><span class="plain"> = 0;</span>
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<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">S</span><span class="plain">, </span><span class="reserved">section</span><span class="plain">)</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">S</span><span class="plain">-</span><span class="element">>scratch_flag</span><span class="plain">)</span>
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<span class="identifier">use_count</span><span class="plain">++;</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">use_count</span><span class="plain"> > 0) {</span>
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<span class="identifier">said_something</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
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<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">\</span><span class="string">par\</span><span class="plain">\</span><span class="string">hangindent=3em{\</span><span class="plain">\</span><span class="string">it used by other nonterminals in} "</span><span class="plain">);</span>
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">c</span><span class="plain"> = 0;</span>
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<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">S</span><span class="plain">, </span><span class="reserved">section</span><span class="plain">)</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">S</span><span class="plain">-</span><span class="element">>scratch_flag</span><span class="plain">) {</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">c</span><span class="plain">++ > 0) </span><span class="identifier">WRITE</span><span class="plain">(</span><span class="string">", "</span><span class="plain">);</span>
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<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"{\</span><span class="plain">\</span><span class="string">xreffont %S}"</span><span class="plain">, </span><span class="identifier">S</span><span class="plain">-</span><span class="element">>range</span><span class="plain">);</span>
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<span class="plain">}</span>
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<span class="identifier">WRITE</span><span class="plain">(</span><span class="string">"\</span><span class="plain">n</span><span class="string">\</span><span class="plain">n</span><span class="string">"</span><span class="plain">);</span>
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<span class="plain">}</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="endnote">This code is used in <a href="#SP14">§14</a>.</p>
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<p class="inwebparagraph"><a id="SP15"></a><b>§15. Weaving methods. </b>If we're weaving just a document of Preform grammar, then we skip any lines
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of C code which appear in <code class="display"><span class="extract">internal</span></code> nonterminal definitions:
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</p>
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<pre class="display">
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">skipping_internal</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">, </span><span class="identifier">preform_production_count</span><span class="plain"> = 0;</span>
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<span class="reserved">int</span><span class="plain"> </span><span class="functiontext">InCSupport::skip_in_weaving</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">weave_target</span><span class="plain"> *</span><span class="identifier">wv</span><span class="plain">, </span><span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">L</span><span class="plain">) {</span>
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<span class="reserved">if</span><span class="plain"> ((</span><span class="identifier">Preform_theme</span><span class="plain">) && (</span><span class="identifier">wv</span><span class="plain">-</span><span class="element">>theme_match</span><span class="plain"> == </span><span class="identifier">Preform_theme</span><span class="plain">)) {</span>
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<span class="reserved">match_results</span><span class="plain"> </span><span class="identifier">mr</span><span class="plain"> = </span><span class="functiontext">Regexp::create_mr</span><span class="plain">();</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"}%c*"</span><span class="plain">)) {</span>
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<span class="identifier">skipping_internal</span><span class="plain"> = </span><span class="constant">FALSE</span><span class="plain">; </span><span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">); </span><span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">; }</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">skipping_internal</span><span class="plain">) { </span><span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">); </span><span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">; }</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Regexp::match</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">-</span><span class="element">>text</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"<%c*?> internal%c*"</span><span class="plain">)) </span><span class="identifier">skipping_internal</span><span class="plain"> = </span><span class="constant">TRUE</span><span class="plain">;</span>
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|
<span class="functiontext">Regexp::dispose_of</span><span class="plain">(&</span><span class="identifier">mr</span><span class="plain">);</span>
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|
<span class="plain">}</span>
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<span class="reserved">return</span><span class="plain"> </span><span class="constant">FALSE</span><span class="plain">;</span>
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|
<span class="plain">}</span>
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|
</pre>
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|
<p class="inwebparagraph"></p>
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|
|
|
<p class="endnote">The function InCSupport::skip_in_weaving is used in <a href="#SP1">§1</a>.</p>
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|
<p class="inwebparagraph"><a id="SP16"></a><b>§16. </b>And here is the TeX code for displaying Preform grammar:
|
|
</p>
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|
|
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<pre class="display">
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|
<span class="reserved">int</span><span class="plain"> </span><span class="functiontext">InCSupport::weave_code_line</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">OUT</span><span class="plain">,</span>
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|
<span class="reserved">weave_target</span><span class="plain"> *</span><span class="identifier">wv</span><span class="plain">, </span><span class="reserved">web</span><span class="plain"> *</span><span class="identifier">W</span><span class="plain">, </span><span class="reserved">chapter</span><span class="plain"> *</span><span class="identifier">C</span><span class="plain">, </span><span class="reserved">section</span><span class="plain"> *</span><span class="identifier">S</span><span class="plain">, </span><span class="reserved">source_line</span><span class="plain"> *</span><span class="identifier">L</span><span class="plain">,</span>
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|
<span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">matter</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">concluding_comment</span><span class="plain">) {</span>
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|
<span class="reserved">if</span><span class="plain"> ((</span><span class="identifier">Preform_theme</span><span class="plain">) && (</span><span class="identifier">wv</span><span class="plain">-</span><span class="element">>theme_match</span><span class="plain"> == </span><span class="identifier">Preform_theme</span><span class="plain">))</span>
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|
<span class="reserved">return</span><span class="plain"> </span><span class="functiontext">Formats::preform_document</span><span class="plain">(</span><span class="identifier">OUT</span><span class="plain">, </span><span class="identifier">wv</span><span class="plain">, </span><span class="identifier">W</span><span class="plain">, </span><span class="identifier">C</span><span class="plain">, </span><span class="identifier">S</span><span class="plain">, </span><span class="identifier">L</span><span class="plain">,</span>
|
|
<span class="identifier">matter</span><span class="plain">, </span><span class="identifier">concluding_comment</span><span class="plain">);</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::weave_code_line is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP17"></a><b>§17. </b>In paragraphs where we spot Preform nonterminals being defined, we're
|
|
going to automatically apply the tag <code class="display"><span class="extract">^"Preform"</span></code>, but only if it already
|
|
exists. We watch for it here:
|
|
</p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">void</span><span class="plain"> </span><span class="functiontext">InCSupport::new_tag_declared</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">theme_tag</span><span class="plain"> *</span><span class="identifier">tag</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">tag</span><span class="plain">-</span><span class="element">>tag_name</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"Preform"</span><span class="plain">)) </span><span class="identifier">Preform_theme</span><span class="plain"> = </span><span class="identifier">tag</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::new_tag_declared is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="inwebparagraph"><a id="SP18"></a><b>§18. Analysis methods. </b></p>
|
|
|
|
|
|
<pre class="display">
|
|
<span class="reserved">void</span><span class="plain"> </span><span class="functiontext">InCSupport::analyse_code</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">web</span><span class="plain"> *</span><span class="identifier">W</span><span class="plain">) {</span>
|
|
<span class="reserved">preform_nonterminal</span><span class="plain"> *</span><span class="identifier">pnt</span><span class="plain">;</span>
|
|
<span class="identifier">LOOP_OVER</span><span class="plain">(</span><span class="identifier">pnt</span><span class="plain">, </span><span class="reserved">preform_nonterminal</span><span class="plain">)</span>
|
|
<span class="functiontext">Analyser::find_hash_entry</span><span class="plain">(</span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>where_defined</span><span class="plain">-</span><span class="element">>owning_section</span><span class="plain">, </span><span class="identifier">pnt</span><span class="plain">-</span><span class="element">>unangled_name</span><span class="plain">, </span><span class="constant">TRUE</span><span class="plain">);</span>
|
|
<span class="plain">}</span>
|
|
|
|
<span class="reserved">int</span><span class="plain"> </span><span class="functiontext">InCSupport::share_element</span><span class="plain">(</span><span class="reserved">programming_language</span><span class="plain"> *</span><span class="identifier">self</span><span class="plain">, </span><span class="reserved">text_stream</span><span class="plain"> *</span><span class="identifier">elname</span><span class="plain">) {</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">elname</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"word_ref1"</span><span class="plain">)) </span><span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">elname</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"word_ref2"</span><span class="plain">)) </span><span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">elname</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"next"</span><span class="plain">)) </span><span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">elname</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"down"</span><span class="plain">)) </span><span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">elname</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"allocation_id"</span><span class="plain">)) </span><span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">if</span><span class="plain"> (</span><span class="functiontext">Str::eq_wide_string</span><span class="plain">(</span><span class="identifier">elname</span><span class="plain">, </span><span class="identifier">L</span><span class="string">"method_set"</span><span class="plain">)) </span><span class="reserved">return</span><span class="plain"> </span><span class="constant">TRUE</span><span class="plain">;</span>
|
|
<span class="reserved">return</span><span class="plain"> </span><span class="constant">FALSE</span><span class="plain">;</span>
|
|
<span class="plain">}</span>
|
|
</pre>
|
|
|
|
<p class="inwebparagraph"></p>
|
|
|
|
<p class="endnote">The function InCSupport::analyse_code is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<p class="endnote">The function InCSupport::share_element is used in <a href="#SP1">§1</a>.</p>
|
|
|
|
<!--End of weave: 993 lines from a web of 20880-->
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</body>
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</html>
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