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<title>4/ap</title>
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<!--Weave of '4/los' generated by 7-->
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<ul class="crumbs"><li><a href="../webs.html">★</a></li><li><a href="index.html">if</a></li><li><a href="index.html#4">Chapter 4: Actions</a></li><li><b>Looping Over Scope</b></li></ul><p class="purpose">To compile routines capable of being passed as arguments to the I6 library routine for looping over parser scope at run-time, and so to provide an implementation for conditions such as "in the presence of Mrs Dalloway".</p>
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<ul class="toc"><li><a href="#SP1">§1. Definitions</a></li></ul><hr class="tocbar">
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<p class="inwebparagraph"><a id="SP1"></a><b>§1. Definitions. </b></p>
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<pre class="display">
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<span class="reserved">typedef</span><span class="plain"> </span><span class="reserved">struct</span><span class="plain"> </span><span class="reserved">loop_over_scope</span><span class="plain"> {</span>
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<span class="reserved">struct</span><span class="plain"> </span><span class="identifier">parse_node</span><span class="plain"> *</span><span class="identifier">what_to_find</span><span class="plain">;</span>
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<span class="reserved">struct</span><span class="plain"> </span><span class="identifier">inter_name</span><span class="plain"> *</span><span class="identifier">los_iname</span><span class="plain">;</span>
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<span class="identifier">MEMORY_MANAGEMENT</span>
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<span class="plain">} </span><span class="reserved">loop_over_scope</span><span class="plain">;</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="endnote">The structure loop_over_scope is accessed in 4/ap and here.</p>
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<p class="inwebparagraph"><a id="SP2"></a><b>§2. </b></p>
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<pre class="display">
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<span class="reserved">loop_over_scope</span><span class="plain"> *</span><span class="functiontext">PL::Actions::ScopeLoops::new</span><span class="plain">(</span><span class="identifier">parse_node</span><span class="plain"> *</span><span class="identifier">what</span><span class="plain">) {</span>
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<span class="reserved">loop_over_scope</span><span class="plain"> *</span><span class="identifier">los</span><span class="plain"> = </span><span class="identifier">CREATE</span><span class="plain">(</span><span class="reserved">loop_over_scope</span><span class="plain">);</span>
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<span class="identifier">los</span><span class="plain">-</span><span class="element">>what_to_find</span><span class="plain"> = </span><span class="identifier">ParseTree::duplicate</span><span class="plain">(</span><span class="identifier">what</span><span class="plain">);</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">Specifications::is_description</span><span class="plain">(</span><span class="identifier">what</span><span class="plain">)) {</span>
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<span class="identifier">los</span><span class="plain">-</span><span class="element">>what_to_find</span><span class="plain">-></span><span class="identifier">down</span><span class="plain"> = </span><span class="identifier">ParseTree::duplicate</span><span class="plain">(</span><span class="identifier">los</span><span class="plain">-</span><span class="element">>what_to_find</span><span class="plain">-></span><span class="identifier">down</span><span class="plain">);</span>
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<span class="identifier">Descriptions::clear_calling</span><span class="plain">(</span><span class="identifier">los</span><span class="plain">-</span><span class="element">>what_to_find</span><span class="plain">);</span>
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<span class="plain">}</span>
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<span class="identifier">inter_name</span><span class="plain"> *</span><span class="identifier">m_iname</span><span class="plain"> = </span><span class="identifier">InterNames::new</span><span class="plain">(</span><span class="identifier">LOOP_OVER_SCOPE_ROUTINE_INAMEF</span><span class="plain">);</span>
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<span class="identifier">compilation_module</span><span class="plain"> *</span><span class="identifier">C</span><span class="plain"> = </span><span class="identifier">Modules::find</span><span class="plain">(</span><span class="identifier">current_sentence</span><span class="plain">);</span>
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<span class="identifier">package_request</span><span class="plain"> *</span><span class="identifier">PR</span><span class="plain"> = </span><span class="identifier">Packaging::request_resource</span><span class="plain">(</span><span class="identifier">C</span><span class="plain">, </span><span class="identifier">GRAMMAR_SUBPACKAGE</span><span class="plain">);</span>
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<span class="identifier">los</span><span class="plain">-</span><span class="element">>los_iname</span><span class="plain"> = </span><span class="identifier">Packaging::function</span><span class="plain">(</span>
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<span class="identifier">InterNames::one_off</span><span class="plain">(</span><span class="identifier">I</span><span class="string">"loop_over_scope_fn"</span><span class="plain">, </span><span class="identifier">PR</span><span class="plain">),</span>
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<span class="identifier">PR</span><span class="plain">,</span>
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<span class="identifier">m_iname</span><span class="plain">);</span>
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<span class="reserved">return</span><span class="plain"> </span><span class="identifier">los</span><span class="plain">;</span>
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<span class="plain">}</span>
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<span class="reserved">loop_over_scope</span><span class="plain"> *</span><span class="identifier">latest_los</span><span class="plain"> = </span><span class="identifier">NULL</span><span class="plain">;</span>
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<span class="reserved">int</span><span class="plain"> </span><span class="functiontext">PL::Actions::ScopeLoops::compilation_coroutine</span><span class="plain">(</span><span class="reserved">void</span><span class="plain">) {</span>
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<span class="reserved">int</span><span class="plain"> </span><span class="identifier">N</span><span class="plain"> = 0;</span>
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<span class="reserved">while</span><span class="plain"> (</span><span class="identifier">TRUE</span><span class="plain">) {</span>
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<span class="reserved">loop_over_scope</span><span class="plain"> *</span><span class="identifier">los</span><span class="plain">;</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">latest_los</span><span class="plain"> == </span><span class="identifier">NULL</span><span class="plain">)</span>
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<span class="identifier">los</span><span class="plain"> = </span><span class="identifier">FIRST_OBJECT</span><span class="plain">(</span><span class="reserved">loop_over_scope</span><span class="plain">);</span>
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<span class="reserved">else</span><span class="plain"> </span><span class="identifier">los</span><span class="plain"> = </span><span class="identifier">NEXT_OBJECT</span><span class="plain">(</span><span class="identifier">latest_los</span><span class="plain">, </span><span class="reserved">loop_over_scope</span><span class="plain">);</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">los</span><span class="plain"> == </span><span class="identifier">NULL</span><span class="plain">) </span><span class="reserved">break</span><span class="plain">;</span>
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<span class="identifier">latest_los</span><span class="plain"> = </span><span class="identifier">los</span><span class="plain">;</span>
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<<span class="cwebmacro">Compile an individual loop-over-scope</span> <span class="cwebmacronumber">2.1</span>><span class="plain">;</span>
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<span class="identifier">N</span><span class="plain">++;</span>
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<span class="plain">}</span>
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<span class="reserved">return</span><span class="plain"> </span><span class="identifier">N</span><span class="plain">;</span>
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<span class="plain">}</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="endnote">The function PL::Actions::ScopeLoops::new is used in 4/ap (<a href="4-ap.html#SP34_1_1_1">§34.1.1.1</a>).</p>
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<p class="endnote">The function PL::Actions::ScopeLoops::compilation_coroutine appears nowhere else.</p>
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<p class="inwebparagraph"><a id="SP2_1"></a><b>§2.1. </b><code class="display">
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<<span class="cwebmacrodefn">Compile an individual loop-over-scope</span> <span class="cwebmacronumber">2.1</span>> =
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</code></p>
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<pre class="displaydefn">
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<span class="identifier">packaging_state</span><span class="plain"> </span><span class="identifier">save</span><span class="plain"> = </span><span class="identifier">Routines::begin</span><span class="plain">(</span><span class="identifier">los</span><span class="plain">-</span><span class="element">>los_iname</span><span class="plain">);</span>
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<span class="identifier">ph_stack_frame</span><span class="plain"> *</span><span class="identifier">phsf</span><span class="plain"> = </span><span class="identifier">Frames::current_stack_frame</span><span class="plain">();</span>
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<span class="identifier">local_variable</span><span class="plain"> *</span><span class="identifier">it_lv</span><span class="plain"> = </span><span class="identifier">LocalVariables::add_pronoun</span><span class="plain">(</span><span class="identifier">phsf</span><span class="plain">, </span><span class="identifier">EMPTY_WORDING</span><span class="plain">, </span><span class="identifier">K_object</span><span class="plain">);</span>
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<span class="identifier">inter_symbol</span><span class="plain"> *</span><span class="identifier">it_s</span><span class="plain"> = </span><span class="identifier">LocalVariables::declare_this</span><span class="plain">(</span><span class="identifier">it_lv</span><span class="plain">, </span><span class="identifier">FALSE</span><span class="plain">, 8);</span>
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<span class="identifier">Emit::inv_primitive</span><span class="plain">(</span><span class="identifier">if_interp</span><span class="plain">);</span>
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<span class="identifier">Emit::down</span><span class="plain">();</span>
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<span class="identifier">LocalVariables::begin_condition_emit</span><span class="plain">();</span>
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<span class="identifier">value_holster</span><span class="plain"> </span><span class="identifier">VH</span><span class="plain"> = </span><span class="identifier">Holsters::new</span><span class="plain">(</span><span class="identifier">INTER_VAL_VHMODE</span><span class="plain">);</span>
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<span class="reserved">if</span><span class="plain"> (</span><span class="identifier">los</span><span class="plain">-</span><span class="element">>what_to_find</span><span class="plain">) {</span>
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<span class="identifier">parse_node</span><span class="plain"> *</span><span class="identifier">lv_sp</span><span class="plain"> = </span><span class="identifier">Lvalues::new_LOCAL_VARIABLE</span><span class="plain">(</span><span class="identifier">EMPTY_WORDING</span><span class="plain">, </span><span class="identifier">it_lv</span><span class="plain">);</span>
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<span class="functiontext">PL::Actions::Patterns::compile_pattern_match_clause_inner</span><span class="plain">(</span><span class="identifier">FALSE</span><span class="plain">, &</span><span class="identifier">VH</span><span class="plain">,</span>
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<span class="identifier">lv_sp</span><span class="plain">, </span><span class="identifier">FALSE</span><span class="plain">, </span><span class="identifier">los</span><span class="plain">-</span><span class="element">>what_to_find</span><span class="plain">, </span><span class="identifier">K_object</span><span class="plain">, </span><span class="identifier">FALSE</span><span class="plain">);</span>
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<span class="plain">} </span><span class="reserved">else</span>
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<span class="identifier">Emit::val</span><span class="plain">(</span><span class="identifier">K_truth_state</span><span class="plain">, </span><span class="identifier">LITERAL_IVAL</span><span class="plain">, 0);</span>
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<span class="identifier">LocalVariables::end_condition_emit</span><span class="plain">();</span>
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<span class="identifier">Emit::code</span><span class="plain">();</span>
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<span class="identifier">Emit::down</span><span class="plain">();</span>
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<span class="identifier">Emit::inv_primitive</span><span class="plain">(</span><span class="identifier">store_interp</span><span class="plain">);</span>
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<span class="identifier">Emit::down</span><span class="plain">();</span>
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<span class="identifier">Emit::ref_iname</span><span class="plain">(</span><span class="identifier">K_value</span><span class="plain">, </span><span class="identifier">InterNames::extern</span><span class="plain">(</span><span class="identifier">LOSRV_EXNAMEF</span><span class="plain">));</span>
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<span class="identifier">Emit::val_symbol</span><span class="plain">(</span><span class="identifier">K_value</span><span class="plain">, </span><span class="identifier">it_s</span><span class="plain">);</span>
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<span class="identifier">Emit::up</span><span class="plain">();</span>
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<span class="identifier">Emit::up</span><span class="plain">();</span>
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<span class="identifier">Emit::up</span><span class="plain">();</span>
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<span class="identifier">Routines::end</span><span class="plain">(</span><span class="identifier">save</span><span class="plain">);</span>
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</pre>
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<p class="inwebparagraph"></p>
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<p class="endnote">This code is used in <a href="#SP2">§2</a>.</p>
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<hr class="tocbar">
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<ul class="toc"><li><a href="4-ap.html">Back to 'Action Patterns'</a></li><li><a href="4-nap.html">Continue with 'Named Action Patterns'</a></li></ul><hr class="tocbar">
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<!--End of weave-->
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