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<!--Weave of 'The Model World' generated by Inweb-->
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<div class="breadcrumbs">
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<ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="../compiler.html">Inform7</a></li><li><a href="index.html">knowledge</a></li><li><a href="index.html#5">Chapter 5: Modelling</a></li><li><b>The Model World</b></li></ul></div>
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<p class="purpose">Once the assertions have all been read and reduced to inferences, we try to complete our model world.</p>
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<ul class="toc"><li><a href="5-tmw.html#SP1">§1. Introduction</a></li><li><a href="5-tmw.html#SP2">§2. Stage I</a></li><li><a href="5-tmw.html#SP3">§3. Stages II and III</a></li><li><a href="5-tmw.html#SP4">§4. Stage IV</a></li><li><a href="5-tmw.html#SP5">§5. Stage V</a></li></ul><hr class="tocbar">
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<p class="commentary firstcommentary"><a id="SP1" class="paragraph-anchor"></a><b>§1. Introduction. </b>World-building has five stages, written with Roman numerals I to V in this
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source code. The logic in this section is all quite simple, but plugins are
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allowed to intervene at each of the five stages, bringing domain-specific
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wisdom to the process.
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</p>
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<pre class="definitions code-font"><span class="definition-keyword">define</span> <span class="constant-syntax">WORLD_STAGE_I</span><span class="plain-syntax"> </span><span class="constant-syntax">1</span><span class="plain-syntax"> </span><span class="comment-syntax"> Deduce kinds for object instances</span>
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<span class="definition-keyword">define</span> <span class="constant-syntax">WORLD_STAGE_II</span><span class="plain-syntax"> </span><span class="constant-syntax">2</span><span class="plain-syntax"> </span><span class="comment-syntax"> First chance to add further properties or relationships</span>
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<span class="definition-keyword">define</span> <span class="constant-syntax">WORLD_STAGE_III</span><span class="plain-syntax"> </span><span class="constant-syntax">3</span><span class="plain-syntax"> </span><span class="comment-syntax"> Second chance to add further properties or relationships</span>
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<span class="definition-keyword">define</span> <span class="constant-syntax">WORLD_STAGE_IV</span><span class="plain-syntax"> </span><span class="constant-syntax">4</span><span class="plain-syntax"> </span><span class="comment-syntax"> Perform mutual consistency checks</span>
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<span class="definition-keyword">define</span> <span class="constant-syntax">WORLD_STAGE_V</span><span class="plain-syntax"> </span><span class="constant-syntax">5</span><span class="plain-syntax"> </span><span class="comment-syntax"> Post-game: only implementation details can be added</span>
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</pre>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">current_model_world_stage</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="comment-syntax"> not yet building the world model</span>
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">World::ask_plugins_at_stage</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">World::ask_plugins_at_stage</span></span>:<br/><a href="5-tmw.html#SP2">§2</a>, <a href="5-tmw.html#SP3">§3</a>, <a href="5-tmw.html#SP4">§4</a>, <a href="5-tmw.html#SP5">§5</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">S</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">S</span><span class="plain-syntax"> != </span><span class="identifier-syntax">current_model_world_stage</span><span class="plain-syntax"> + </span><span class="constant-syntax">1</span><span class="plain-syntax">) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"Stage mistimed"</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">current_model_world_stage</span><span class="plain-syntax"> = </span><span class="identifier-syntax">S</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">PluginCalls::complete_model</span><span class="plain-syntax">(</span><span class="identifier-syntax">S</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">}</span>
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">World::current_building_stage</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">World::current_building_stage</span></span>:<br/>Inference Subjects - <a href="4-is.html#SP9">§9</a><br/>Inferences - <a href="5-inf.html#SP2">§2</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">void</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">current_model_world_stage</span><span class="plain-syntax">;</span>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP2" class="paragraph-anchor"></a><b>§2. Stage I. </b>Deducing the kind of any object whose kind is not known. The core compiler
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has already done the best it can, but then it lacks domain-specific
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understanding. So the only business done is by plugins, which understand
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certain kinds and relationships better.
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</p>
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<p class="commentary">Some instances change their kinds in Stage I, and this can result in further
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creations by assembly sentences like "A handle is part of every door". Because
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of that, Stage I takes place at the end of traverse 2 of the source text and,
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uniquely, gets the opportunity to add fresh sentences to the source — thus
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extending the traverse. But by the end of Stage I, all kinds are fixed, and
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no further instances can be created.
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">World::deduce_object_instance_kinds</span><span class="plain-syntax">(</span><span class="reserved-syntax">void</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><a href="5-tmw.html#SP1" class="function-link"><span class="function-syntax">World::ask_plugins_at_stage</span></a><span class="plain-syntax">(</span><span class="constant-syntax">WORLD_STAGE_I</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP3" class="paragraph-anchor"></a><b>§3. Stages II and III. </b>This is an opportunity for plugins to add further properties or relationships
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on the basis of contextual understanding. Two stages, and thus two opportunities,
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are provided here to avoid timing issues where one plugin has to act earlier
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than another.
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</p>
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<p class="commentary">If a plugin is going to change the compilation order of the objects (as the
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spatial-model plugin does), it must do so during Stage III, not Stage II.
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">World::stages_II_and_III</span><span class="plain-syntax">(</span><span class="reserved-syntax">void</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inference_subject</span><span class="plain-syntax"> *</span><span class="identifier-syntax">infs</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_OVER</span><span class="plain-syntax">(</span><span class="identifier-syntax">infs</span><span class="plain-syntax">, </span><span class="reserved-syntax">inference_subject</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><a href="4-is.html#SP23" class="function-link"><span class="function-syntax">InferenceSubjects::complete_model</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">infs</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><a href="5-ia.html#SP2" class="function-link"><span class="function-syntax">Properties::Appearance::reallocate</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">infs</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_OVER</span><span class="plain-syntax">(</span><span class="identifier-syntax">infs</span><span class="plain-syntax">, </span><span class="reserved-syntax">inference_subject</span><span class="plain-syntax">)</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">Assertions::Implications::consider_all</span><span class="plain-syntax">(</span><span class="identifier-syntax">infs</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><a href="5-tmw.html#SP1" class="function-link"><span class="function-syntax">World::ask_plugins_at_stage</span></a><span class="plain-syntax">(</span><span class="constant-syntax">WORLD_STAGE_II</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><a href="5-tmw.html#SP1" class="function-link"><span class="function-syntax">World::ask_plugins_at_stage</span></a><span class="plain-syntax">(</span><span class="constant-syntax">WORLD_STAGE_III</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP4" class="paragraph-anchor"></a><b>§4. Stage IV. </b>This is for consistency checks or to store away useful data, but where
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nothing in the model may be changed — no properties or relationships
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may be added.
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">World::stage_IV</span><span class="plain-syntax">(</span><span class="reserved-syntax">void</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">inference_subject</span><span class="plain-syntax"> *</span><span class="identifier-syntax">infs</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_OVER</span><span class="plain-syntax">(</span><span class="identifier-syntax">infs</span><span class="plain-syntax">, </span><span class="reserved-syntax">inference_subject</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><a href="4-is.html#SP24" class="function-link"><span class="function-syntax">InferenceSubjects::check_model</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">infs</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="5-tmw.html#SP4_1" class="named-paragraph-link"><span class="named-paragraph">Check that properties are permitted</span><span class="named-paragraph-number">4.1</span></a></span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="5-tmw.html#SP4_2" class="named-paragraph-link"><span class="named-paragraph">Check that properties are not contradictory</span><span class="named-paragraph-number">4.2</span></a></span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> </span><a href="5-tmw.html#SP1" class="function-link"><span class="function-syntax">World::ask_plugins_at_stage</span></a><span class="plain-syntax">(</span><span class="constant-syntax">WORLD_STAGE_IV</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP4_1" class="paragraph-anchor"></a><b>§4.1. </b>These two checks may seem a little odd. After all, we've been throwing out
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impossible inferences with problem messages all along, while reading the
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source text. Why not perform these checks then, too?
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</p>
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<p class="commentary">The answer is that both depend not only on the subject of the inferences
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made, but also on what that subject inherits from. Suppose we are told:
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</p>
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<blockquote>
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<p>The cup is in the Yellow Cupboard. The Cupboard is lighted.</p>
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</blockquote>
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<p class="commentary">When we make the "lighted" inference, we know for certain what subject
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it's about — the Yellow Cupboard — but not where this lives in the
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inference-subject hierarchy, because that depends on the kind of the
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Cupboard. Is it a room, or a container? We don't yet know (and won't until
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Stage I of model-completion), so we aren't in a position to judge whether
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or not it's permitted to have the property "lighted". This is why the
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check is postponed until after Stage I, and it seems natural to perform
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it here in Stage IV, so that we also catch any accidents due to bugs
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in plugins which add inconsistent properties.
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</p>
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<p class="commentary">A nameless property added in Stages II and III does not need permission.
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</p>
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<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Check that properties are permitted</span><span class="named-paragraph-number">4.1</span></span><span class="comment-syntax"> =</span>
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="plain-syntax"> </span><span class="reserved-syntax">inference</span><span class="plain-syntax"> *</span><span class="identifier-syntax">inf</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">KNOWLEDGE_LOOP</span><span class="plain-syntax">(</span><span class="identifier-syntax">inf</span><span class="plain-syntax">, </span><span class="identifier-syntax">infs</span><span class="plain-syntax">, </span><span class="identifier-syntax">property_inf</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">property</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prn</span><span class="plain-syntax"> = </span><a href="5-pi.html#SP7" class="function-link"><span class="function-syntax">PropertyInferences::get_property</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">inf</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Wordings::nonempty</span><span class="plain-syntax">(</span><span class="identifier-syntax">prn</span><span class="plain-syntax">-></span><span class="element-syntax">name</span><span class="plain-syntax">))</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="4-pp.html#SP2" class="function-link"><span class="function-syntax">PropertyPermissions::find</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">infs</span><span class="plain-syntax">, </span><span class="identifier-syntax">prn</span><span class="plain-syntax">, </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">) == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">)</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">StandardProblems::inference_problem</span><span class="plain-syntax">(</span><span class="identifier-syntax">_p_</span><span class="plain-syntax">(</span><span class="identifier-syntax">PM_PropertyNotPermitted</span><span class="plain-syntax">),</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">infs</span><span class="plain-syntax">, </span><span class="identifier-syntax">inf</span><span class="plain-syntax">, </span><span class="string-syntax">"is not allowed to exist"</span><span class="plain-syntax">,</span>
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<span class="plain-syntax"> </span><span class="string-syntax">"because you haven't said it is. What properties something can "</span>
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<span class="plain-syntax"> </span><span class="string-syntax">"have depends on what kind of thing it is: see the Index for "</span>
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<span class="plain-syntax"> </span><span class="string-syntax">"details."</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> }</span>
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</pre>
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<ul class="endnotetexts"><li>This code is used in <a href="5-tmw.html#SP4">§4</a>.</li></ul>
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<p class="commentary firstcommentary"><a id="SP4_2" class="paragraph-anchor"></a><b>§4.2. </b>The following contradiction checks do not apply to properties added
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in Stages II and III, since those are often Inter hacks added for run-time
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convenience, and don't have to follow the I7 rules.
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</p>
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<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Check that properties are not contradictory</span><span class="named-paragraph-number">4.2</span></span><span class="comment-syntax"> =</span>
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="plain-syntax"> </span><span class="reserved-syntax">inference</span><span class="plain-syntax"> *</span><span class="identifier-syntax">narrow</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">KNOWLEDGE_LOOP</span><span class="plain-syntax">(</span><span class="identifier-syntax">narrow</span><span class="plain-syntax">, </span><span class="identifier-syntax">infs</span><span class="plain-syntax">, </span><span class="identifier-syntax">property_inf</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="5-inf.html#SP3" class="function-link"><span class="function-syntax">Inferences::during_stage</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">narrow</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">property</span><span class="plain-syntax"> *</span><span class="identifier-syntax">prn</span><span class="plain-syntax"> = </span><a href="5-pi.html#SP7" class="function-link"><span class="function-syntax">PropertyInferences::get_property</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">narrow</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">sign</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><a href="5-inf.html#SP3" class="function-link"><span class="function-syntax">Inferences::get_certainty</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">narrow</span><span class="plain-syntax">) < </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="identifier-syntax">sign</span><span class="plain-syntax"> = -1;</span>
|
|
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="5-tmw.html#SP4_2_1" class="named-paragraph-link"><span class="named-paragraph">Look for clashes concerning this property from wider inferences</span><span class="named-paragraph-number">4.2.1</span></a></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-prp.html#SP13" class="function-link"><span class="function-syntax">Properties::is_either_or</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">prn</span><span class="plain-syntax">)) &&</span>
|
|
<span class="plain-syntax"> (</span><a href="3-ep.html#SP6" class="function-link"><span class="function-syntax">EitherOrProperties::get_negation</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">prn</span><span class="plain-syntax">))) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">prn</span><span class="plain-syntax"> = </span><a href="3-ep.html#SP6" class="function-link"><span class="function-syntax">EitherOrProperties::get_negation</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">prn</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">sign</span><span class="plain-syntax"> = -</span><span class="identifier-syntax">sign</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="5-tmw.html#SP4_2_1" class="named-paragraph-link"><span class="named-paragraph">Look for clashes concerning this property from wider inferences</span><span class="named-paragraph-number">4.2.1</span></a></span><span class="plain-syntax">;</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="5-tmw.html#SP4">§4</a>.</li></ul>
|
|
<p class="commentary firstcommentary"><a id="SP4_2_1" class="paragraph-anchor"></a><b>§4.2.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Look for clashes concerning this property from wider inferences</span><span class="named-paragraph-number">4.2.1</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">inference_subject</span><span class="plain-syntax"> *</span><span class="identifier-syntax">boss</span><span class="plain-syntax"> = </span><a href="4-is.html#SP11" class="function-link"><span class="function-syntax">InferenceSubjects::narrowest_broader_subject</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">infs</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">boss</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">inference</span><span class="plain-syntax"> *</span><span class="identifier-syntax">wide</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">KNOWLEDGE_LOOP</span><span class="plain-syntax">(</span><span class="identifier-syntax">wide</span><span class="plain-syntax">, </span><span class="identifier-syntax">boss</span><span class="plain-syntax">, </span><span class="identifier-syntax">property_inf</span><span class="plain-syntax">)</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="5-inf.html#SP3" class="function-link"><span class="function-syntax">Inferences::during_stage</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">wide</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">prn</span><span class="plain-syntax"> == </span><a href="5-pi.html#SP7" class="function-link"><span class="function-syntax">PropertyInferences::get_property</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">wide</span><span class="plain-syntax">))</span>
|
|
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="5-tmw.html#SP4_2_1_1" class="named-paragraph-link"><span class="named-paragraph">Check that these differently scoped inferences do not clash</span><span class="named-paragraph-number">4.2.1.1</span></a></span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">boss</span><span class="plain-syntax"> = </span><a href="4-is.html#SP11" class="function-link"><span class="function-syntax">InferenceSubjects::narrowest_broader_subject</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">boss</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> }</span>
|
|
</pre>
|
|
<ul class="endnotetexts"><li>This code is used in <a href="5-tmw.html#SP4_2">§4.2</a> (twice).</li></ul>
|
|
<p class="commentary firstcommentary"><a id="SP4_2_1_1" class="paragraph-anchor"></a><b>§4.2.1.1. </b>It's never a problem when a vague fact about something general is contradicted
|
|
by a fact about something specific; the problem comes with something like this:
|
|
</p>
|
|
|
|
<blockquote>
|
|
<p>A door is always open. The Marble Portal is a closed door.</p>
|
|
</blockquote>
|
|
|
|
<p class="commentary">Here the "wide" property inference, for the "door" kind, is <span class="extract"><span class="extract-syntax">CERTAIN_CE</span></span>
|
|
rather than <span class="extract"><span class="extract-syntax">LIKELY_CE</span></span>, and so we can't allow the "narrow" inference,
|
|
about the Portal, to stand.
|
|
</p>
|
|
|
|
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Check that these differently scoped inferences do not clash</span><span class="named-paragraph-number">4.2.1.1</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">abcw</span><span class="plain-syntax"> = </span><a href="5-inf.html#SP3" class="function-link"><span class="function-syntax">Inferences::get_certainty</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">wide</span><span class="plain-syntax">); </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">abcw</span><span class="plain-syntax"> < </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="identifier-syntax">abcw</span><span class="plain-syntax"> = -</span><span class="identifier-syntax">abcw</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">abcw</span><span class="plain-syntax"> == </span><span class="identifier-syntax">CERTAIN_CE</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">clash</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">wide_sign</span><span class="plain-syntax"> = </span><span class="constant-syntax">1</span><span class="plain-syntax">; </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="5-inf.html#SP3" class="function-link"><span class="function-syntax">Inferences::get_certainty</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">wide</span><span class="plain-syntax">) < </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="identifier-syntax">wide_sign</span><span class="plain-syntax"> = -1;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="3-prp.html#SP13" class="function-link"><span class="function-syntax">Properties::is_either_or</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">prn</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">parse_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">narrow_val</span><span class="plain-syntax"> = </span><a href="5-pi.html#SP7" class="function-link"><span class="function-syntax">PropertyInferences::get_value</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">narrow</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">parse_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">wide_val</span><span class="plain-syntax"> = </span><a href="5-pi.html#SP7" class="function-link"><span class="function-syntax">PropertyInferences::get_value</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">wide</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">Rvalues::compare_CONSTANT</span><span class="plain-syntax">(</span><span class="identifier-syntax">narrow_val</span><span class="plain-syntax">, </span><span class="identifier-syntax">wide_val</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">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"Clash of $P and $P\n $I\n $I\n"</span><span class="plain-syntax">,</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">narrow_val</span><span class="plain-syntax">, </span><span class="identifier-syntax">wide_val</span><span class="plain-syntax">, </span><span class="identifier-syntax">narrow</span><span class="plain-syntax">, </span><span class="identifier-syntax">wide</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">clash</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">sign</span><span class="plain-syntax"> != </span><span class="identifier-syntax">wide_sign</span><span class="plain-syntax">) </span><span class="identifier-syntax">clash</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">clash</span><span class="plain-syntax">)?</span><span class="identifier-syntax">FALSE: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">clash</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">abcn</span><span class="plain-syntax"> = </span><a href="5-inf.html#SP3" class="function-link"><span class="function-syntax">Inferences::get_certainty</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">narrow</span><span class="plain-syntax">); </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">abcn</span><span class="plain-syntax"> < </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="identifier-syntax">abcn</span><span class="plain-syntax"> = -</span><span class="identifier-syntax">abcn</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">abcn</span><span class="plain-syntax"> == </span><span class="identifier-syntax">CERTAIN_CE</span><span class="plain-syntax">)</span>
|
|
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="5-tmw.html#SP4_2_1_1_1" class="named-paragraph-link"><span class="named-paragraph">Issue a problem message for clash with wider inference</span><span class="named-paragraph-number">4.2.1.1.1</span></a></span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span>
|
|
<span class="plain-syntax"> </span><a href="5-inf.html#SP4" class="function-link"><span class="function-syntax">Inferences::render_impossible</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">narrow</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="5-tmw.html#SP4_2_1">§4.2.1</a>.</li></ul>
|
|
<p class="commentary firstcommentary"><a id="SP4_2_1_1_1" class="paragraph-anchor"></a><b>§4.2.1.1.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Issue a problem message for clash with wider inference</span><span class="named-paragraph-number">4.2.1.1.1</span></span><span class="comment-syntax"> =</span>
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"Checking infs $j compatible with infs $j for property $Y:\n $I\n $I\n"</span><span class="plain-syntax">,</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">infs</span><span class="plain-syntax">, </span><span class="identifier-syntax">boss</span><span class="plain-syntax">, </span><span class="identifier-syntax">prn</span><span class="plain-syntax">, </span><span class="identifier-syntax">narrow</span><span class="plain-syntax">, </span><span class="identifier-syntax">wide</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">StandardProblems::infs_contradiction_problem</span><span class="plain-syntax">(</span><span class="identifier-syntax">_p_</span><span class="plain-syntax">(</span><span class="identifier-syntax">PM_InstanceContradiction</span><span class="plain-syntax">),</span>
|
|
<span class="plain-syntax"> </span><a href="5-inf.html#SP3" class="function-link"><span class="function-syntax">Inferences::where_inferred</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">narrow</span><span class="plain-syntax">), </span><a href="5-inf.html#SP3" class="function-link"><span class="function-syntax">Inferences::where_inferred</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">wide</span><span class="plain-syntax">), </span><span class="identifier-syntax">infs</span><span class="plain-syntax">,</span>
|
|
<span class="plain-syntax"> </span><span class="string-syntax">"therefore has to have two contradictory states of the same property at once"</span><span class="plain-syntax">,</span>
|
|
<span class="plain-syntax"> </span><span class="string-syntax">"which is impossible. When a kind's definition says that something is 'always' "</span>
|
|
<span class="plain-syntax"> </span><span class="string-syntax">"true, there is no way to override that for particular things of the kind."</span><span class="plain-syntax">);</span>
|
|
</pre>
|
|
<ul class="endnotetexts"><li>This code is used in <a href="5-tmw.html#SP4_2_1_1">§4.2.1.1</a>.</li></ul>
|
|
<p class="commentary firstcommentary"><a id="SP5" class="paragraph-anchor"></a><b>§5. Stage V. </b>A final chance to add properties which may assist the run-time implementation
|
|
of whatever a plugin is concerned with, but which is not allowed to make
|
|
changes to the model as it would be understood by the author.
|
|
</p>
|
|
|
|
<p class="commentary">For example, the <a href="../runtime-module/2-ic.html" class="internal">Instance Counting (in runtime)</a> plugin adds low-level properties
|
|
to improve run-time performance, but they have no names and cannot be referred
|
|
to or accessed by code written in Inform 7; they exist at the level of Inter only.
|
|
</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">World::stage_V</span><span class="plain-syntax">(</span><span class="reserved-syntax">void</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><a href="5-tmw.html#SP1" class="function-link"><span class="function-syntax">World::ask_plugins_at_stage</span></a><span class="plain-syntax">(</span><span class="constant-syntax">WORLD_STAGE_V</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre>
|
|
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