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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<!--Weave of 'The Optimiser' generated by Inweb-->
<div class="breadcrumbs">
<ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="../compiler.html">Shared Modules</a></li><li><a href="index.html">words</a></li><li><a href="index.html#4">Chapter 4: Parsing</a></li><li><b>The Optimiser</b></li></ul></div>
<p class="purpose">To precalculate data which enables rapid parsing of source text against a Preform grammar.</p>
<ul class="toc"><li><a href="4-to.html#SP1">&#167;1. Optimisation calculations</a></li></ul><hr class="tocbar">
<p class="commentary firstcommentary"><a id="SP1"></a><b>&#167;1. Optimisation calculations. </b>After each round of fresh Preform grammar, we need to recalculate the various
maximum and minimum lengths, struts, and so on, because those all depend on
knowing the length of text a token will match, and new grammar may have
changed that.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">first_round_of_nt_optimisation_made</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::optimise_counts</span><button class="popup" onclick="togglePopup('usagePopup1')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup1">Usage of <span class="code-font"><span class="function-syntax">Optimiser::optimise_counts</span></span>:<br/>Loading Preform - <a href="4-lp.html#SP22">&#167;22</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">void</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_OVER</span><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::clear_rreq</span></a><span class="plain-syntax">(&amp;(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">marked_internal</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">optimised_in_this_pass</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">optimised_in_this_pass</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">min_nt_words</span><span class="plain-syntax"> = </span><span class="constant-syntax">1</span><span class="plain-syntax">; </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">max_nt_words</span><span class="plain-syntax"> = </span><span class="constant-syntax">INFINITE_WORD_COUNT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">first_round_of_nt_optimisation_made</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">first_round_of_nt_optimisation_made</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> #</span><span class="identifier-syntax">ifdef</span><span class="plain-syntax"> </span><span class="identifier-syntax">LINGUISTICS_MODULE</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LinguisticsModule::preform_optimiser</span><span class="plain-syntax">();</span>
<span class="plain-syntax"> #</span><span class="identifier-syntax">endif</span>
<span class="plain-syntax"> #</span><span class="identifier-syntax">ifdef</span><span class="plain-syntax"> </span><span class="identifier-syntax">PREFORM_OPTIMISER</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PREFORM_OPTIMISER</span><span class="plain-syntax">();</span>
<span class="plain-syntax"> #</span><span class="identifier-syntax">endif</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_OVER</span><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax">) </span><a href="4-to.html#SP1" class="function-link"><span class="function-syntax">Optimiser::optimise_nt</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_OVER</span><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax">) </span><a href="4-to.html#SP2" class="function-link"><span class="function-syntax">Optimiser::optimise_nt_reqs</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::optimise_nt</span><button class="popup" onclick="togglePopup('usagePopup2')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup2">Usage of <span class="code-font"><span class="function-syntax">Optimiser::optimise_nt</span></span>:<br/><a href="4-to.html#SP1_6">&#167;1.6</a>, <a href="4-to.html#SP18">&#167;18</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">optimised_in_this_pass</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">optimised_in_this_pass</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-to.html#SP1_1" class="named-paragraph-link"><span class="named-paragraph">Compute the minimum and maximum match lengths</span><span class="named-paragraph-number">1.1</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">production_list</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pl</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production_list</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production_list</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">production</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pr</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">last</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">; </span><span class="comment-syntax"> this will point to the last ptoken in the production</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-to.html#SP1_2" class="named-paragraph-link"><span class="named-paragraph">Compute front-end ptoken positions</span><span class="named-paragraph-number">1.2</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-to.html#SP1_3" class="named-paragraph-link"><span class="named-paragraph">Compute back-end ptoken positions</span><span class="named-paragraph-number">1.3</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-to.html#SP1_4" class="named-paragraph-link"><span class="named-paragraph">Compute struts within the production</span><span class="named-paragraph-number">1.4</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-to.html#SP1_5" class="named-paragraph-link"><span class="named-paragraph">Work out which ptokens are fast</span><span class="named-paragraph-number">1.5</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="4-to.html#SP1_6" class="named-paragraph-link"><span class="named-paragraph">Mark the vocabulary's incidence list with this nonterminal</span><span class="named-paragraph-number">1.6</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP1_1"></a><b>&#167;1.1. </b>The minimum matched text length for a nonterminal is the smallest of the
minima for its possible productions; for a production, it's the sum of the
minimum match lengths of its tokens.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Compute the minimum and maximum match lengths</span><span class="named-paragraph-number">1.1</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">min</span><span class="plain-syntax"> = -1, </span><span class="identifier-syntax">max</span><span class="plain-syntax"> = -1;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">production_list</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pl</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production_list</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production_list</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">production</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pr</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">min_p</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">, </span><span class="identifier-syntax">max_p</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_ptoken</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">min_t</span><span class="plain-syntax">, </span><span class="identifier-syntax">max_t</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP18" class="function-link"><span class="function-syntax">Optimiser::ptoken_extrema</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">, &amp;</span><span class="identifier-syntax">min_t</span><span class="plain-syntax">, &amp;</span><span class="identifier-syntax">max_t</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">min_p</span><span class="plain-syntax"> += </span><span class="identifier-syntax">min_t</span><span class="plain-syntax">; </span><span class="identifier-syntax">max_p</span><span class="plain-syntax"> += </span><span class="identifier-syntax">max_t</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">min_p</span><span class="plain-syntax"> &gt; </span><span class="constant-syntax">INFINITE_WORD_COUNT</span><span class="plain-syntax">) </span><span class="identifier-syntax">min_p</span><span class="plain-syntax"> = </span><span class="constant-syntax">INFINITE_WORD_COUNT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">max_p</span><span class="plain-syntax"> &gt; </span><span class="constant-syntax">INFINITE_WORD_COUNT</span><span class="plain-syntax">) </span><span class="identifier-syntax">max_p</span><span class="plain-syntax"> = </span><span class="constant-syntax">INFINITE_WORD_COUNT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">min_pr_words</span><span class="plain-syntax"> = </span><span class="identifier-syntax">min_p</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">max_pr_words</span><span class="plain-syntax"> = </span><span class="identifier-syntax">max_p</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">min</span><span class="plain-syntax"> == -1) &amp;&amp; (</span><span class="identifier-syntax">max</span><span class="plain-syntax"> == -1)) { </span><span class="identifier-syntax">min</span><span class="plain-syntax"> = </span><span class="identifier-syntax">min_p</span><span class="plain-syntax">; </span><span class="identifier-syntax">max</span><span class="plain-syntax"> = </span><span class="identifier-syntax">max_p</span><span class="plain-syntax">; }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">min_p</span><span class="plain-syntax"> &lt; </span><span class="identifier-syntax">min</span><span class="plain-syntax">) </span><span class="identifier-syntax">min</span><span class="plain-syntax"> = </span><span class="identifier-syntax">min_p</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">max_p</span><span class="plain-syntax"> &gt; </span><span class="identifier-syntax">max</span><span class="plain-syntax">) </span><span class="identifier-syntax">max</span><span class="plain-syntax"> = </span><span class="identifier-syntax">max_p</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">min</span><span class="plain-syntax"> &gt;= </span><span class="constant-syntax">1</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">min_nt_words</span><span class="plain-syntax"> = </span><span class="identifier-syntax">min</span><span class="plain-syntax">; </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">max_nt_words</span><span class="plain-syntax"> = </span><span class="identifier-syntax">max</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-to.html#SP1">&#167;1</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP1_2"></a><b>&#167;1.2. </b>A token is "elastic" if it can match text of differing lengths, and
"inelastic" otherwise. For example, in English, &lt;indefinite-article&gt; is
elastic (it always matches a single word). If the first ptoken is inelastic,
we know it must match words 1 to \(L_1\) of whatever text is to be matched,
and we give it position 1; if the second is also inelastic, that will match
\(L_1+1\) to \(L_2\), and it gets position \(L_1+1\); and so on. As soon as we
hit an elastic token &mdash; a wildcard like <span class="extract"><span class="extract-syntax">...</span></span>, for example &mdash; this
predictability stops, and we can only assign position 0, which means that
we don't know.
</p>
<p class="commentary">Note that we only assign a nonzero position if we know where the ptoken both
starts and finishes; it's not enough just to know where it starts.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Compute front-end ptoken positions</span><span class="named-paragraph-number">1.2</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">posn</span><span class="plain-syntax"> = </span><span class="constant-syntax">1</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_ptoken</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">last</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">L</span><span class="plain-syntax"> = </span><a href="4-to.html#SP17" class="function-link"><span class="function-syntax">Optimiser::ptoken_width</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">posn</span><span class="plain-syntax"> != </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">L</span><span class="plain-syntax"> != </span><span class="constant-syntax">PTOKEN_ELASTIC</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_position</span><span class="plain-syntax"> = </span><span class="identifier-syntax">posn</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">posn</span><span class="plain-syntax"> += </span><span class="identifier-syntax">L</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_position</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="comment-syntax"> thus clearing any expired positions from earlier</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">posn</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-to.html#SP1">&#167;1</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP1_3"></a><b>&#167;1.3. </b>And similarly from the back end, if there are inelastic ptokens at the end
of the production (and which are separated from the front end by at least one
elastic one).
</p>
<p class="commentary">The following has quadratic running time in the number of tokens in the
production, but this is never larger than about 10.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Compute back-end ptoken positions</span><span class="named-paragraph-number">1.3</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">posn</span><span class="plain-syntax"> = -1;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">last</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax">; ) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_position</span><span class="plain-syntax"> != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">break</span><span class="plain-syntax">; </span><span class="comment-syntax"> don't use a back-end position if there's a front one</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">L</span><span class="plain-syntax"> = </span><a href="4-to.html#SP17" class="function-link"><span class="function-syntax">Optimiser::ptoken_width</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">posn</span><span class="plain-syntax"> != </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">L</span><span class="plain-syntax"> != </span><span class="constant-syntax">PTOKEN_ELASTIC</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_position</span><span class="plain-syntax"> = </span><span class="identifier-syntax">posn</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">posn</span><span class="plain-syntax"> -= </span><span class="identifier-syntax">L</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prevt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">prevt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_ptoken</span><span class="plain-syntax">; </span><span class="identifier-syntax">prevt</span><span class="plain-syntax">; </span><span class="identifier-syntax">prevt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">prevt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">prevt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax"> == </span><span class="identifier-syntax">pt</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">prevt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-to.html#SP1">&#167;1</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP1_4"></a><b>&#167;1.4. </b>By definition, a strut is a maximal sequence of one or more inelastic ptokens
each of which has no known position. (Clearly if one of them has a known
position then all of them have, but we're in no hurry so we don't exploit that.)
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Compute struts within the production</span><span class="named-paragraph-number">1.4</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_struts</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_ptoken</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_position</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><a href="4-to.html#SP17" class="function-link"><span class="function-syntax">Optimiser::ptoken_width</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">) != </span><span class="constant-syntax">PTOKEN_ELASTIC</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_struts</span><span class="plain-syntax"> &gt;= </span><span class="constant-syntax">MAX_STRUTS_PER_PRODUCTION</span><span class="plain-syntax">) </span><span class="reserved-syntax">continue</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">struts</span><span class="plain-syntax">[</span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_struts</span><span class="plain-syntax">] = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">strut_lengths</span><span class="plain-syntax">[</span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_struts</span><span class="plain-syntax">] = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">while</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_position</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><a href="4-to.html#SP17" class="function-link"><span class="function-syntax">Optimiser::ptoken_width</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">) != </span><span class="constant-syntax">PTOKEN_ELASTIC</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">strut_number</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_struts</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">strut_lengths</span><span class="plain-syntax">[</span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_struts</span><span class="plain-syntax">] += </span><a href="4-to.html#SP17" class="function-link"><span class="function-syntax">Optimiser::ptoken_width</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) </span><span class="reserved-syntax">break</span><span class="plain-syntax">; </span><span class="comment-syntax"> should be impossible</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_struts</span><span class="plain-syntax">++;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-to.html#SP1">&#167;1</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP1_5"></a><b>&#167;1.5. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Work out which ptokens are fast</span><span class="named-paragraph-number">1.5</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_ptoken</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_category</span><span class="plain-syntax"> == </span><span class="constant-syntax">FIXED_WORD_PTC</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_position</span><span class="plain-syntax"> != </span><span class="constant-syntax">0</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> &amp;&amp; (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">range_starts</span><span class="plain-syntax"> &lt; </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">range_ends</span><span class="plain-syntax"> &lt; </span><span class="constant-syntax">0</span><span class="plain-syntax">))</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_is_fast</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-to.html#SP1">&#167;1</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP1_6"></a><b>&#167;1.6. </b>Weak requirement: one word in range must match one of these bits
Strong ": all bits in this range must be matched by one word
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Mark the vocabulary's incidence list with this nonterminal</span><span class="named-paragraph-number">1.6</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">first_production</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::clear_rreq</span></a><span class="plain-syntax">(&amp;(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> #</span><span class="identifier-syntax">ifdef</span><span class="plain-syntax"> </span><span class="identifier-syntax">PREFORM_CIRCULARITY_BREAKER</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PREFORM_CIRCULARITY_BREAKER</span><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> #</span><span class="identifier-syntax">endif</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> </span><span class="identifier-syntax">nnt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::clear_rreq</span></a><span class="plain-syntax">(&amp;</span><span class="identifier-syntax">nnt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production_list</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production_list</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">production</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pr</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_ptoken</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_category</span><span class="plain-syntax"> == </span><span class="constant-syntax">FIXED_WORD_PTC</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">negated_ptoken</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">alt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">alt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">; </span><span class="identifier-syntax">alt</span><span class="plain-syntax">; </span><span class="identifier-syntax">alt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">alt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">alternative_ptoken</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP3" class="function-link"><span class="function-syntax">Optimiser::set_nt_incidence</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">alt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ve_pt</span><span class="plain-syntax">, </span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production_list</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production_list</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">production</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pr</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> </span><span class="identifier-syntax">prt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::clear_rreq</span></a><span class="plain-syntax">(&amp;</span><span class="identifier-syntax">prt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">all</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">, </span><span class="identifier-syntax">first</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_ptoken</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax">; </span><span class="identifier-syntax">pt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_ptoken</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::clear_rreq</span></a><span class="plain-syntax">(&amp;(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">token_req</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_category</span><span class="plain-syntax"> == </span><span class="constant-syntax">FIXED_WORD_PTC</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">negated_ptoken</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">alt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">alt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">; </span><span class="identifier-syntax">alt</span><span class="plain-syntax">; </span><span class="identifier-syntax">alt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">alt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">alternative_ptoken</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP3" class="function-link"><span class="function-syntax">Optimiser::set_nt_incidence</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">alt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ve_pt</span><span class="plain-syntax">, </span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::atomic_rreq</span></a><span class="plain-syntax">(&amp;(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">token_req</span><span class="plain-syntax">), </span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="identifier-syntax">all</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">self_referential</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">, </span><span class="identifier-syntax">empty</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_category</span><span class="plain-syntax"> == </span><span class="constant-syntax">NONTERMINAL_PTC</span><span class="plain-syntax">) &amp;&amp;</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">min_nt_words</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_pt</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">max_nt_words</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">))</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">empty</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">; </span><span class="comment-syntax"> even if negated, notice</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_category</span><span class="plain-syntax"> == </span><span class="constant-syntax">NONTERMINAL_PTC</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">negated_ptoken</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="comment-syntax"> if (pt-&gt;nt_pt == nt) self_referential = TRUE;</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP1" class="function-link"><span class="function-syntax">Optimiser::optimise_nt</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_pt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">token_req</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">self_referential</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">empty</span><span class="plain-syntax"> == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">first</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">prt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">token_req</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP6" class="function-link"><span class="function-syntax">Optimiser::concatenate_rreq</span></a><span class="plain-syntax">(&amp;</span><span class="identifier-syntax">prt</span><span class="plain-syntax">, &amp;(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">token_req</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">first</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">first_production</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nnt</span><span class="plain-syntax"> = </span><span class="identifier-syntax">prt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP12" class="function-link"><span class="function-syntax">Optimiser::disjoin_rreq</span></a><span class="plain-syntax">(&amp;</span><span class="identifier-syntax">nnt</span><span class="plain-syntax">, &amp;</span><span class="identifier-syntax">prt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">first_production</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">production_req</span><span class="plain-syntax"> = </span><span class="identifier-syntax">prt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax"> = </span><span class="identifier-syntax">nnt</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> #</span><span class="identifier-syntax">ifdef</span><span class="plain-syntax"> </span><span class="identifier-syntax">PREFORM_CIRCULARITY_BREAKER</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PREFORM_CIRCULARITY_BREAKER</span><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> #</span><span class="identifier-syntax">endif</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="4-to.html#SP1">&#167;1</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP2"></a><b>&#167;2. </b></p>
<p class="commentary">The constant <span class="extract"><span class="extract-syntax">AL_BITMAP</span></span> used in this code has a pleasingly Arabic sound to it
&mdash; a second-magnitude star, an idiotically tall hotel &mdash; but is in fact a
combination of the meaning codes found in an adjective list.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::optimise_nt_reqs</span><button class="popup" onclick="togglePopup('usagePopup3')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup3">Usage of <span class="code-font"><span class="function-syntax">Optimiser::optimise_nt_reqs</span></span>:<br/><a href="4-to.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">production_list</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pl</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production_list</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax">; </span><span class="identifier-syntax">pl</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production_list</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">production</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pr</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prev_req</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pl</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">first_production</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax">; </span><span class="identifier-syntax">pr</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">next_production</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP2" class="function-link"><span class="function-syntax">Optimiser::optimise_req</span></a><span class="plain-syntax">(&amp;(</span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">production_req</span><span class="plain-syntax">), </span><span class="identifier-syntax">prev_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">prev_req</span><span class="plain-syntax"> = &amp;(</span><span class="identifier-syntax">pr</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">production_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP2" class="function-link"><span class="function-syntax">Optimiser::optimise_req</span></a><span class="plain-syntax">(&amp;(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">), </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::optimise_req</span><span class="plain-syntax">(</span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">req</span><span class="plain-syntax">, </span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prev</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">) == </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">) </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">) == </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">) </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">) == </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">) </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">) == </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">) </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">) == </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">) </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">) == </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">) </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">) == </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">) </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">) == </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">) </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">) == </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">) </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_requirements</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">))</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_requirements</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ditto_flag</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">prev</span><span class="plain-syntax">) &amp;&amp;</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> == </span><span class="identifier-syntax">prev</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> == </span><span class="identifier-syntax">prev</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">) &amp;&amp;</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax"> == </span><span class="identifier-syntax">prev</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> == </span><span class="identifier-syntax">prev</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">) &amp;&amp;</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax"> == </span><span class="identifier-syntax">prev</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> == </span><span class="identifier-syntax">prev</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">))</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ditto_flag</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP3"></a><b>&#167;3. </b></p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::mark_nt_as_requiring_itself</span><span class="plain-syntax">(</span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::mark_nt_as_requiring_itself_first</span><span class="plain-syntax">(</span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">FS_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::mark_nt_as_requiring_itself_conj</span><span class="plain-syntax">(</span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">CS_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">FS_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::mark_nt_as_requiring_itself_augmented</span><span class="plain-syntax">(</span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">x</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) + </span><span class="identifier-syntax">x</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nonterminal_req</span><span class="plain-syntax">.</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) + </span><span class="identifier-syntax">x</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::set_nt_incidence</span><button class="popup" onclick="togglePopup('usagePopup4')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup4">Usage of <span class="code-font"><span class="function-syntax">Optimiser::set_nt_incidence</span></span>:<br/><a href="4-to.html#SP1_6">&#167;1.6</a>, <a href="4-to.html#SP4">&#167;4</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">vocabulary_entry</span><span class="plain-syntax"> *</span><span class="identifier-syntax">ve</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">R</span><span class="plain-syntax"> = </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">ve</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">R</span><span class="plain-syntax"> |= (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::set_ntb</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">ve</span><span class="plain-syntax">, </span><span class="identifier-syntax">R</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::test_nt_incidence</span><span class="plain-syntax">(</span><span class="reserved-syntax">vocabulary_entry</span><span class="plain-syntax"> *</span><span class="identifier-syntax">ve</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">R</span><span class="plain-syntax"> = </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">ve</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">R</span><span class="plain-syntax"> &amp; (</span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">))) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP4"></a><b>&#167;4. </b></p>
<pre class="definitions code-font"><span class="definition-keyword">define</span> <span class="constant-syntax">RESERVED_NT_BITS</span><span class="plain-syntax"> </span><span class="constant-syntax">6</span>
</pre>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::nt_bitmap_bit</span><button class="popup" onclick="togglePopup('usagePopup5')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup5">Usage of <span class="code-font"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></span>:<br/><a href="4-to.html#SP3">&#167;3</a>, <a href="4-to.html#SP16">&#167;16</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_req_bit</span><span class="plain-syntax"> == -1) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">b</span><span class="plain-syntax"> = </span><span class="constant-syntax">RESERVED_NT_BITS</span><span class="plain-syntax"> + ((</span><span class="identifier-syntax">no_req_bits</span><span class="plain-syntax">++)%(32-</span><span class="constant-syntax">RESERVED_NT_BITS</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_req_bit</span><span class="plain-syntax"> = (1 &lt;&lt; </span><span class="identifier-syntax">b</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_req_bit</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::assign_bitmap_bit</span><span class="plain-syntax">(</span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">b</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">nt</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"null NT"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">nt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_req_bit</span><span class="plain-syntax"> = (1 &lt;&lt; </span><span class="identifier-syntax">b</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::test_word</span><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">wn</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">b</span><span class="plain-syntax"> = </span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">wn</span><span class="plain-syntax">))) &amp; </span><span class="identifier-syntax">b</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::mark_word</span><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">wn</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP3" class="function-link"><span class="function-syntax">Optimiser::set_nt_incidence</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">wn</span><span class="plain-syntax">), </span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::mark_vocabulary</span><span class="plain-syntax">(</span><span class="reserved-syntax">vocabulary_entry</span><span class="plain-syntax"> *</span><span class="identifier-syntax">ve</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP3" class="function-link"><span class="function-syntax">Optimiser::set_nt_incidence</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">ve</span><span class="plain-syntax">, </span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::test_vocabulary</span><span class="plain-syntax">(</span><span class="reserved-syntax">vocabulary_entry</span><span class="plain-syntax"> *</span><span class="identifier-syntax">ve</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">b</span><span class="plain-syntax"> = </span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">ve</span><span class="plain-syntax">)) &amp; </span><span class="identifier-syntax">b</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::get_range_disjunction</span><span class="plain-syntax">(</span><span class="reserved-syntax">wording</span><span class="plain-syntax"> </span><span class="identifier-syntax">W</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">R</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_THROUGH_WORDING</span><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">, </span><span class="identifier-syntax">W</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">R</span><span class="plain-syntax"> |= </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">R</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::get_range_conjunction</span><span class="plain-syntax">(</span><span class="reserved-syntax">wording</span><span class="plain-syntax"> </span><span class="identifier-syntax">W</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">R</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_THROUGH_WORDING</span><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">, </span><span class="identifier-syntax">W</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">i</span><span class="plain-syntax"> == </span><a href="3-wrd.html#SP8" class="function-link"><span class="function-syntax">Wordings::first_wn</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">W</span><span class="plain-syntax">)) </span><span class="identifier-syntax">R</span><span class="plain-syntax"> = </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="identifier-syntax">R</span><span class="plain-syntax"> &amp;= </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">R</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP5"></a><b>&#167;5. </b></p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::nt_bitmap_violates</span><button class="popup" onclick="togglePopup('usagePopup6')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup6">Usage of <span class="code-font"><span class="function-syntax">Optimiser::nt_bitmap_violates</span></span>:<br/>Preform - <a href="4-prf.html#SP1_2">&#167;1.2</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">wording</span><span class="plain-syntax"> </span><span class="identifier-syntax">W</span><span class="plain-syntax">, </span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">req</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">no_requirements</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="3-wrd.html#SP8" class="function-link"><span class="function-syntax">Wordings::length</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">W</span><span class="plain-syntax">) == </span><span class="constant-syntax">1</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">bm</span><span class="plain-syntax"> = </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><a href="3-wrd.html#SP8" class="function-link"><span class="function-syntax">Wordings::first_wn</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">W</span><span class="plain-syntax">)));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">C_set</span><span class="plain-syntax"> = ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">) | (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">D_set</span><span class="plain-syntax"> = ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">) | (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">F_set</span><span class="plain-syntax"> = ((</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">) | (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">C_set</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">D_set</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">disj</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_THROUGH_WORDING</span><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">, </span><span class="identifier-syntax">W</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">bm</span><span class="plain-syntax"> = </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">disj</span><span class="plain-syntax"> |= </span><span class="identifier-syntax">bm</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">i</span><span class="plain-syntax"> == </span><a href="3-wrd.html#SP8" class="function-link"><span class="function-syntax">Wordings::first_wn</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">W</span><span class="plain-syntax">)) &amp;&amp; (</span><span class="identifier-syntax">F_set</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">disj</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">disj</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">C_set</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_THROUGH_WORDING</span><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">, </span><span class="identifier-syntax">W</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">bm</span><span class="plain-syntax"> = </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">i</span><span class="plain-syntax"> == </span><a href="3-wrd.html#SP8" class="function-link"><span class="function-syntax">Wordings::first_wn</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">W</span><span class="plain-syntax">)) &amp;&amp; (</span><span class="identifier-syntax">F_set</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">D_set</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">disj</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_THROUGH_WORDING</span><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">, </span><span class="identifier-syntax">W</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">bm</span><span class="plain-syntax"> = </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">i</span><span class="plain-syntax">));</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">disj</span><span class="plain-syntax"> |= </span><span class="identifier-syntax">bm</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">i</span><span class="plain-syntax"> == </span><a href="3-wrd.html#SP8" class="function-link"><span class="function-syntax">Wordings::first_wn</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">W</span><span class="plain-syntax">)) &amp;&amp; (</span><span class="identifier-syntax">F_set</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">disj</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">disj</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">F_set</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">bm</span><span class="plain-syntax"> = </span><a href="2-vcb.html#SP12" class="function-link"><span class="function-syntax">Vocabulary::get_ntb</span></a><span class="plain-syntax">(</span><a href="3-lxr.html#SP20" class="function-link"><span class="function-syntax">Lexer::word</span></a><span class="plain-syntax">(</span><a href="3-wrd.html#SP8" class="function-link"><span class="function-syntax">Wordings::first_wn</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">W</span><span class="plain-syntax">)));</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) != (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((((</span><span class="identifier-syntax">bm</span><span class="plain-syntax">) &amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP6"></a><b>&#167;6. </b>The first operation on RRs is concatenation. Suppose we are required to
match some words against X, then some more against Y.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::concatenate_rreq</span><button class="popup" onclick="togglePopup('usagePopup7')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup7">Usage of <span class="code-font"><span class="function-syntax">Optimiser::concatenate_rreq</span></span>:<br/><a href="4-to.html#SP1_6">&#167;1.6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">req</span><span class="plain-syntax">, </span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">with</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP7" class="function-link"><span class="function-syntax">Optimiser::concatenate_ds</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP9" class="function-link"><span class="function-syntax">Optimiser::concatenate_dw</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP8" class="function-link"><span class="function-syntax">Optimiser::concatenate_cs</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP10" class="function-link"><span class="function-syntax">Optimiser::concatenate_cw</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP11" class="function-link"><span class="function-syntax">Optimiser::concatenate_fs</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP11" class="function-link"><span class="function-syntax">Optimiser::concatenate_fw</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP7"></a><b>&#167;7. </b>The strong requirements are well-defined. Suppose all of the bits of <span class="extract"><span class="extract-syntax">m1</span></span>
are found in X, and all of the bits of <span class="extract"><span class="extract-syntax">m2</span></span> are found in Y. Then clearly
all of the bits in the union of these two sets are found in XY, and that's
the strongest requirement we can make. So:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::concatenate_ds</span><button class="popup" onclick="togglePopup('usagePopup8')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup8">Usage of <span class="code-font"><span class="function-syntax">Optimiser::concatenate_ds</span></span>:<br/><a href="4-to.html#SP6">&#167;6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax"> | </span><span class="identifier-syntax">m2</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP8"></a><b>&#167;8. </b>Similarly, suppose all of the bits of <span class="extract"><span class="extract-syntax">m1</span></span> are found in every word of X,
and all of those of <span class="extract"><span class="extract-syntax">m2</span></span> are in every word of Y. The most which can be said
about every word of XY is to take the intersection, so:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::concatenate_cs</span><button class="popup" onclick="togglePopup('usagePopup9')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup9">Usage of <span class="code-font"><span class="function-syntax">Optimiser::concatenate_cs</span></span>:<br/><a href="4-to.html#SP6">&#167;6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">m2</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP9"></a><b>&#167;9. </b>Now suppose that at least one bit of <span class="extract"><span class="extract-syntax">m1</span></span> can be found in X, and one bit
of <span class="extract"><span class="extract-syntax">m2</span></span> can be found in Y. This gives us two pieces of information about
XY, and we can freely choose which to go for: we may as well pick <span class="extract"><span class="extract-syntax">m1</span></span> and
say that one bit of <span class="extract"><span class="extract-syntax">m1</span></span> can be found in XY. In principle we ought to choose
the rarest for best effect, but that's too much work.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::concatenate_dw</span><button class="popup" onclick="togglePopup('usagePopup10')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup10">Usage of <span class="code-font"><span class="function-syntax">Optimiser::concatenate_dw</span></span>:<br/><a href="4-to.html#SP6">&#167;6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">m1</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">; </span><span class="comment-syntax"> the case where we have no information about X</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">m2</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">; </span><span class="comment-syntax"> and about Y</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">; </span><span class="comment-syntax"> the general case discussed above</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP10"></a><b>&#167;10. </b>Now suppose that each word of X matches at least one bit of <span class="extract"><span class="extract-syntax">m1</span></span>, and
similarly for Y and <span class="extract"><span class="extract-syntax">m2</span></span>. Then each word of XY matches at least one bit of
the union, so:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::concatenate_cw</span><button class="popup" onclick="togglePopup('usagePopup11')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup11">Usage of <span class="code-font"><span class="function-syntax">Optimiser::concatenate_cw</span></span>:<br/><a href="4-to.html#SP6">&#167;6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">m1</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="comment-syntax"> the case where we have no information about X</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">m2</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="comment-syntax"> and about Y</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax"> | </span><span class="identifier-syntax">m2</span><span class="plain-syntax">; </span><span class="comment-syntax"> the general case discussed above</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP11"></a><b>&#167;11. </b>The first word of XY is the first word of X, so:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::concatenate_fs</span><button class="popup" onclick="togglePopup('usagePopup12')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup12">Usage of <span class="code-font"><span class="function-syntax">Optimiser::concatenate_fs</span></span>:<br/><a href="4-to.html#SP6">&#167;6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::concatenate_fw</span><button class="popup" onclick="togglePopup('usagePopup13')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup13">Usage of <span class="code-font"><span class="function-syntax">Optimiser::concatenate_fw</span></span>:<br/><a href="4-to.html#SP6">&#167;6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP12"></a><b>&#167;12. </b>The second operation is disjunction: we'll write X/Y, meaning that the text
has to match either X or Y. This is easier, since it amounts to a disguised
form of de Morgan's laws.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::disjoin_rreq</span><button class="popup" onclick="togglePopup('usagePopup14')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup14">Usage of <span class="code-font"><span class="function-syntax">Optimiser::disjoin_rreq</span></span>:<br/><a href="4-to.html#SP1_6">&#167;1.6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">req</span><span class="plain-syntax">, </span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">with</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP13" class="function-link"><span class="function-syntax">Optimiser::disjoin_ds</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP15" class="function-link"><span class="function-syntax">Optimiser::disjoin_dw</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP14" class="function-link"><span class="function-syntax">Optimiser::disjoin_cs</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::disjoin_cw</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::disjoin_fs</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> = </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::disjoin_fw</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">, </span><span class="identifier-syntax">with</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP13"></a><b>&#167;13. </b>Suppose all of the bits of <span class="extract"><span class="extract-syntax">m1</span></span> are found in X, and all of the bits of <span class="extract"><span class="extract-syntax">m2</span></span>
are found in Y. Then the best we can say is that all of the bits in the
intersection of these two sets are found in X/Y. (If they have no bits in
common, we can't say anything.)
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::disjoin_ds</span><button class="popup" onclick="togglePopup('usagePopup15')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup15">Usage of <span class="code-font"><span class="function-syntax">Optimiser::disjoin_ds</span></span>:<br/><a href="4-to.html#SP12">&#167;12</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">m2</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP14"></a><b>&#167;14. </b>Similarly, suppose all of the bits of <span class="extract"><span class="extract-syntax">m1</span></span> are found in every word of X,
and all of those of <span class="extract"><span class="extract-syntax">m2</span></span> are in every word of Y. The most which can be said
about every word of XY is to take the intersection, so:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::disjoin_cs</span><button class="popup" onclick="togglePopup('usagePopup16')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup16">Usage of <span class="code-font"><span class="function-syntax">Optimiser::disjoin_cs</span></span>:<br/><a href="4-to.html#SP12">&#167;12</a>, <a href="4-to.html#SP16">&#167;16</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax"> &amp; </span><span class="identifier-syntax">m2</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP15"></a><b>&#167;15. </b>Now suppose that at least one bit of <span class="extract"><span class="extract-syntax">m1</span></span> can be found in X, and one bit
of <span class="extract"><span class="extract-syntax">m2</span></span> can be found in Y. All we can say is that one of these various bits
must be found in X/Y, so:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::disjoin_dw</span><button class="popup" onclick="togglePopup('usagePopup17')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup17">Usage of <span class="code-font"><span class="function-syntax">Optimiser::disjoin_dw</span></span>:<br/><a href="4-to.html#SP12">&#167;12</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">m1</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="comment-syntax"> the case where we have no information about X</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">m2</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="comment-syntax"> and about Y</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax"> | </span><span class="identifier-syntax">m2</span><span class="plain-syntax">; </span><span class="comment-syntax"> the general case discussed above</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP16"></a><b>&#167;16. </b>And exactly the same is true for conjunctions:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::disjoin_cw</span><button class="popup" onclick="togglePopup('usagePopup18')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup18">Usage of <span class="code-font"><span class="function-syntax">Optimiser::disjoin_cw</span></span>:<br/><a href="4-to.html#SP12">&#167;12</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">m1</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="comment-syntax"> the case where we have no information about X</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">m2</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="comment-syntax"> and about Y</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax"> | </span><span class="identifier-syntax">m2</span><span class="plain-syntax">; </span><span class="comment-syntax"> the general case discussed above</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::disjoin_fw</span><button class="popup" onclick="togglePopup('usagePopup19')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup19">Usage of <span class="code-font"><span class="function-syntax">Optimiser::disjoin_fw</span></span>:<br/><a href="4-to.html#SP12">&#167;12</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><a href="4-to.html#SP16" class="function-link"><span class="function-syntax">Optimiser::disjoin_cw</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="identifier-syntax">m2</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::disjoin_fs</span><button class="popup" onclick="togglePopup('usagePopup20')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup20">Usage of <span class="code-font"><span class="function-syntax">Optimiser::disjoin_fs</span></span>:<br/><a href="4-to.html#SP12">&#167;12</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">m2</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><a href="4-to.html#SP14" class="function-link"><span class="function-syntax">Optimiser::disjoin_cs</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">m1</span><span class="plain-syntax">, </span><span class="identifier-syntax">m2</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::clear_rreq</span><button class="popup" onclick="togglePopup('usagePopup21')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup21">Usage of <span class="code-font"><span class="function-syntax">Optimiser::clear_rreq</span></span>:<br/><a href="4-to.html#SP1">&#167;1</a>, <a href="4-to.html#SP1_6">&#167;1.6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">req</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::atomic_rreq</span><button class="popup" onclick="togglePopup('usagePopup22')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup22">Usage of <span class="code-font"><span class="function-syntax">Optimiser::atomic_rreq</span></span>:<br/><a href="4-to.html#SP1_6">&#167;1.6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">req</span><span class="plain-syntax">, </span><span class="reserved-syntax">nonterminal</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">b</span><span class="plain-syntax"> = </span><a href="4-to.html#SP4" class="function-link"><span class="function-syntax">Optimiser::nt_bitmap_bit</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">nt</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax"> = </span><span class="identifier-syntax">b</span><span class="plain-syntax">; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax"> = </span><span class="identifier-syntax">b</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax"> = </span><span class="identifier-syntax">b</span><span class="plain-syntax">; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax"> = </span><span class="identifier-syntax">b</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::log_range_requirement</span><button class="popup" onclick="togglePopup('usagePopup23')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup23">Usage of <span class="code-font"><span class="function-syntax">Optimiser::log_range_requirement</span></span>:<br/>Loading Preform - <a href="4-lp.html#SP13">&#167;13</a><br/>Preform - <a href="4-prf.html#SP1_2">&#167;1.2</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">range_requirement</span><span class="plain-syntax"> *</span><span class="identifier-syntax">req</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">) { </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">" DW: %08x"</span><span class="plain-syntax">, </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DW_req</span><span class="plain-syntax">); }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">) { </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">" DS: %08x"</span><span class="plain-syntax">, </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">DS_req</span><span class="plain-syntax">); }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">) { </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">" CW: %08x"</span><span class="plain-syntax">, </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CW_req</span><span class="plain-syntax">); }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">) { </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">" CS: %08x"</span><span class="plain-syntax">, </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">CS_req</span><span class="plain-syntax">); }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">) { </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">" FW: %08x"</span><span class="plain-syntax">, </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FW_req</span><span class="plain-syntax">); }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">) { </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">" FS: %08x"</span><span class="plain-syntax">, </span><span class="identifier-syntax">req</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">FS_req</span><span class="plain-syntax">); }</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP17"></a><b>&#167;17. </b>Now to define elasticity:
</p>
<pre class="definitions code-font"><span class="definition-keyword">define</span> <span class="constant-syntax">PTOKEN_ELASTIC</span><span class="plain-syntax"> -1</span>
</pre>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::ptoken_width</span><button class="popup" onclick="togglePopup('usagePopup24')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup24">Usage of <span class="code-font"><span class="function-syntax">Optimiser::ptoken_width</span></span>:<br/><a href="4-to.html#SP1_2">&#167;1.2</a>, <a href="4-to.html#SP1_3">&#167;1.3</a>, <a href="4-to.html#SP1_4">&#167;1.4</a><br/>Preform - <a href="4-prf.html#SP1_2_1_2_3_3_3_1">&#167;1.2.1.2.3.3.3.1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pt</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">min</span><span class="plain-syntax">, </span><span class="identifier-syntax">max</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP18" class="function-link"><span class="function-syntax">Optimiser::ptoken_extrema</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">, &amp;</span><span class="identifier-syntax">min</span><span class="plain-syntax">, &amp;</span><span class="identifier-syntax">max</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">min</span><span class="plain-syntax"> != </span><span class="identifier-syntax">max</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">PTOKEN_ELASTIC</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">min</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP18"></a><b>&#167;18. </b>An interesting point here is that the negation of a ptoken can in principle
have any length, except that we specified <span class="extract"><span class="extract-syntax">^ example</span></span> to match only a single
word &mdash; any word other than "example". So the extrema for <span class="extract"><span class="extract-syntax">^ example</span></span> are
1 and 1, whereas for <span class="extract"><span class="extract-syntax">^ &lt;sample-nonterminal&gt;</span></span> they would have to be 0 and
infinity.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Optimiser::ptoken_extrema</span><button class="popup" onclick="togglePopup('usagePopup25')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup25">Usage of <span class="code-font"><span class="function-syntax">Optimiser::ptoken_extrema</span></span>:<br/><a href="4-to.html#SP1_1">&#167;1.1</a>, <a href="4-to.html#SP17">&#167;17</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">ptoken</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pt</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">min_t</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">max_t</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">min_t</span><span class="plain-syntax"> = </span><span class="constant-syntax">1</span><span class="plain-syntax">; *</span><span class="identifier-syntax">max_t</span><span class="plain-syntax"> = </span><span class="constant-syntax">1</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">negated_ptoken</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_category</span><span class="plain-syntax"> != </span><span class="constant-syntax">FIXED_WORD_PTC</span><span class="plain-syntax">) { *</span><span class="identifier-syntax">min_t</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; *</span><span class="identifier-syntax">max_t</span><span class="plain-syntax"> = </span><span class="constant-syntax">INFINITE_WORD_COUNT</span><span class="plain-syntax">; }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">ptoken_category</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">NONTERMINAL_PTC:</span>
<span class="plain-syntax"> </span><a href="4-to.html#SP1" class="function-link"><span class="function-syntax">Optimiser::optimise_nt</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_pt</span><span class="plain-syntax">); </span><span class="comment-syntax"> recurse as needed to find its extrema</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">min_t</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">min_nt_words</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">max_t</span><span class="plain-syntax"> = </span><span class="identifier-syntax">pt</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">nt_pt</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">max_nt_words</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">MULTIPLE_WILDCARD_PTC:</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">max_t</span><span class="plain-syntax"> = </span><span class="constant-syntax">INFINITE_WORD_COUNT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">POSSIBLY_EMPTY_WILDCARD_PTC:</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">min_t</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">max_t</span><span class="plain-syntax"> = </span><span class="constant-syntax">INFINITE_WORD_COUNT</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax">}</span>
</pre>
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