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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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<title>The Player</title>
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<main role="main">
<!--Weave of 'The Player' generated by Inweb-->
<div class="breadcrumbs">
<ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="../compiler.html">Inform7</a></li><li><a href="index.html">if</a></li><li><a href="index.html#3">Chapter 3: Space and Time</a></li><li><b>The Player</b></li></ul></div>
<p class="purpose">A plugin to give a special role to a person who is the protagonist.</p>
<ul class="toc"><li><a href="3-tp.html#SP1">&#167;1. Introduction</a></li><li><a href="3-tp.html#SP2">&#167;2. Variables of interest</a></li><li><a href="3-tp.html#SP4_1">&#167;4.1. Instances of interest</a></li><li><a href="3-tp.html#SP7">&#167;7. Linguistic variations</a></li><li><a href="3-tp.html#SP10">&#167;10. Model completion</a></li></ul><hr class="tocbar">
<p class="commentary firstcommentary"><a id="SP1" class="paragraph-anchor"></a><b>&#167;1. Introduction. </b>The player is, in some ways, just another instance of the "person" kind, so
how hard can this be?
</p>
<p class="commentary">One issue is that, uniquely of all instances in the world model, the player is not
explicitly created and located by the source text; it is simply implicit that
there is a player. Except, of course, that an author can sometimes write about
"the player" being a person who is indeed explicitly created; and can write
about "the player" as if this were a constant, when in fact it is a variable
because of the possibility of changing avatar in play. All in all, "the player"
has highly unusual semantics, even though an Inform user is barely aware of that.
</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">Player::start</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">Player::start</span></span>:<br/>IF Module - <a href="1-im.html#SP5">&#167;5</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="identifier-syntax">PluginManager::plug</span><span class="plain-syntax">(</span><span class="identifier-syntax">PRODUCTION_LINE_PLUG</span><span class="plain-syntax">, </span><a href="3-tp.html#SP1" class="function-link"><span class="function-syntax">Player::production_line</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PluginManager::plug</span><span class="plain-syntax">(</span><span class="identifier-syntax">NEW_VARIABLE_NOTIFY_PLUG</span><span class="plain-syntax">, </span><a href="3-tp.html#SP4" class="function-link"><span class="function-syntax">Player::new_variable_notify</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PluginManager::plug</span><span class="plain-syntax">(</span><span class="identifier-syntax">VARIABLE_VALUE_NOTIFY_PLUG</span><span class="plain-syntax">, </span><a href="3-tp.html#SP5" class="function-link"><span class="function-syntax">Player::variable_set_warning</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PluginManager::plug</span><span class="plain-syntax">(</span><span class="identifier-syntax">NEW_INSTANCE_NOTIFY_PLUG</span><span class="plain-syntax">, </span><a href="3-tp.html#SP4_3" class="function-link"><span class="function-syntax">Player::new_instance_notify</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PluginManager::plug</span><span class="plain-syntax">(</span><span class="identifier-syntax">IRREGULAR_GENITIVE_IN_ASSEMBLY_PLUG</span><span class="plain-syntax">, </span><a href="3-tp.html#SP7" class="function-link"><span class="function-syntax">Player::irregular_genitive</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PluginManager::plug</span><span class="plain-syntax">(</span><span class="identifier-syntax">COMPLETE_MODEL_PLUG</span><span class="plain-syntax">, </span><a href="3-tp.html#SP10" class="function-link"><span class="function-syntax">Player::complete_model</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PluginManager::plug</span><span class="plain-syntax">(</span><span class="identifier-syntax">REFINE_IMPLICIT_NOUN_PLUG</span><span class="plain-syntax">, </span><a href="3-tp.html#SP9" class="function-link"><span class="function-syntax">Player::refine_implicit_noun</span></a><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">PluginManager::plug</span><span class="plain-syntax">(</span><span class="identifier-syntax">DETECT_BODYSNATCHING_PLUG</span><span class="plain-syntax">, </span><a href="3-tp.html#SP6" class="function-link"><span class="function-syntax">Player::detect_bodysnatching</span></a><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">Player::production_line</span><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">stage</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">debugging</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">stopwatch_timer</span><span class="plain-syntax"> *</span><span class="identifier-syntax">sequence_timer</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">stage</span><span class="plain-syntax"> == </span><span class="identifier-syntax">TABLES_CSEQ</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">BENCH</span><span class="plain-syntax">(</span><span class="identifier-syntax">RTPlayer::InitialSituation</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="SP2" class="paragraph-anchor"></a><b>&#167;2. Variables of interest. </b>"Time of day" is a perfectly normal variable, and we only note down its
identity in order to find out if the author is setting an initial time of day.
"Player", though, behaves quite unusually: see above.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">player_VAR</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">time_of_day_VAR</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
</pre>
<p class="commentary firstcommentary"><a id="SP3" class="paragraph-anchor"></a><b>&#167;3. </b>As usual, no need to translate these; they are created in English.
</p>
<pre class="Preform-displayed-code all-displayed-code code-font">
<span class="Preform-function-syntax">&lt;notable-player-variables&gt;</span><span class="Preform-plain-syntax"> </span><span class="Preform-reserved-syntax">::=</span>
<span class="Preform-plain-syntax"> </span><span class="Preform-constant-syntax">player</span><span class="Preform-plain-syntax"> </span><span class="Preform-reserved-syntax">|</span>
<span class="Preform-plain-syntax"> </span><span class="Preform-constant-syntax">time</span><span class="Preform-plain-syntax"> </span><span class="Preform-constant-syntax">of</span><span class="Preform-plain-syntax"> </span><span class="Preform-constant-syntax">day</span>
</pre>
<ul class="endnotetexts"><li>This is <a href="../words-module/4-ap.html" class="internal">Preform grammar</a>, not regular C code.</li></ul>
<p class="commentary firstcommentary"><a id="SP4" class="paragraph-anchor"></a><b>&#167;4. </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">Player::new_variable_notify</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">Player::new_variable_notify</span></span>:<br/><a href="3-tp.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nlv</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="function-syntax">&lt;notable-player-variables&gt;(nlv-&gt;</span><span class="element-syntax">name</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="function-syntax">&lt;&lt;r&gt;&gt;</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax">:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">player_VAR</span><span class="plain-syntax"> = </span><span class="identifier-syntax">nlv</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">RTPlayer::player_schema</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_VAR</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_yourself</span><span class="plain-syntax">) </span><span class="named-paragraph-container code-font"><a href="3-tp.html#SP4_4" class="named-paragraph-link"><span class="named-paragraph">Alias the player variable to the yourself object</span><span class="named-paragraph-number">4.4</span></a></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="constant-syntax">1</span><span class="plain-syntax">:</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">time_of_day_VAR</span><span class="plain-syntax"> = </span><span class="identifier-syntax">nlv</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">RTVariables::make_initialisable</span><span class="plain-syntax">(</span><span class="identifier-syntax">time_of_day_VAR</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>
<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_1" class="paragraph-anchor"></a><b>&#167;4.1. Instances of interest. </b>Altogether we keep track of four instances, though the first pair often coincide,
and so do the second pair.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="identifier-syntax">instance</span><span class="plain-syntax"> *</span><span class="identifier-syntax">start_room</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">; </span><span class="comment-syntax"> room in which play begins: e.g., Barber's Shop</span>
<span class="identifier-syntax">instance</span><span class="plain-syntax"> *</span><span class="identifier-syntax">start_object</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">; </span><span class="comment-syntax"> object in which play begins: e.g., a barber's chair</span>
<span class="identifier-syntax">instance</span><span class="plain-syntax"> *</span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">; </span><span class="comment-syntax"> the player character object used in this run</span>
<span class="identifier-syntax">instance</span><span class="plain-syntax"> *</span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">; </span><span class="comment-syntax"> the default player character object, </span><span class="extract"><span class="extract-syntax">selfobj</span></span><span class="comment-syntax"> in I6</span>
</pre>
<p class="commentary firstcommentary"><a id="SP4_2" class="paragraph-anchor"></a><b>&#167;4.2. </b>The "yourself" instance is special in being tied, or "aliased", to the
"player" variable, so Inform needs to recognise it. (No need to translate; it
is created in English.)
</p>
<pre class="Preform-displayed-code all-displayed-code code-font">
<span class="Preform-function-syntax">&lt;notable-player-instances&gt;</span><span class="Preform-plain-syntax"> </span><span class="Preform-reserved-syntax">::=</span>
<span class="Preform-plain-syntax"> </span><span class="Preform-constant-syntax">yourself</span>
</pre>
<ul class="endnotetexts"><li>This is <a href="../words-module/4-ap.html" class="internal">Preform grammar</a>, not regular C code.</li></ul>
<p class="commentary firstcommentary"><a id="SP4_3" class="paragraph-anchor"></a><b>&#167;4.3. </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">Player::new_instance_notify</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">Player::new_instance_notify</span></span>:<br/><a href="3-tp.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">instance</span><span class="plain-syntax"> *</span><span class="identifier-syntax">inst</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">wording</span><span class="plain-syntax"> </span><span class="identifier-syntax">IW</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Instances::get_name</span><span class="plain-syntax">(</span><span class="identifier-syntax">inst</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="function-syntax">&lt;notable-player-instances&gt;</span><span class="plain-syntax">(</span><span class="identifier-syntax">IW</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax"> = </span><span class="identifier-syntax">inst</span><span class="plain-syntax">; </span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax"> = </span><span class="identifier-syntax">I_yourself</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">player_VAR</span><span class="plain-syntax">) </span><span class="named-paragraph-container code-font"><a href="3-tp.html#SP4_4" class="named-paragraph-link"><span class="named-paragraph">Alias the player variable to the yourself object</span><span class="named-paragraph-number">4.4</span></a></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>
<span class="identifier-syntax">instance</span><span class="plain-syntax"> *</span><span class="function-syntax">Player::get_start_room</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">Player::get_start_room</span></span>:<br/>Spatial Model - <a href="3-sm.html#SP40">&#167;40</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">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">start_room</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP4_4" class="paragraph-anchor"></a><b>&#167;4.4. </b>As can be seen, as soon as both "yourself" (object) and "player" (variable)
have been created, they are aliased together. This is a form of tacit pointer
dereferencing, though authors probably don't think of it that way. A normal
object variable is like a pointer to an object, rather than an object itself,
and so the following doesn't make sense:
</p>
<blockquote>
<p>The top prize is an object that varies. The top prize is in the desk drawer.</p>
</blockquote>
<p class="commentary">Clearly something goes in the desk drawer, but it's quite ambiguous what: the
problem is that "top prize" describes some object, but it's not clear which.
(Inform generally disallows this even if the source text explicitly gives a
value for top prize.) But "player" is unusual because Inform authors are
encouraged always to describe the player object that way, and often don't
realise that it's a variable at all &mdash; and most of the time it never changes
its value, of course, but simply remains equal to "yourself" throughout play.
So we want to allow this sort of thing:
</p>
<blockquote>
<p>The player is in the Cage.</p>
</blockquote>
<p class="commentary">even though it has exactly the same problem as the top prize. We get around
this by treating "player", in assertions, as if it were its own initial
value ("yourself") &mdash; in effect, we silently dereference it. This is
aliasing.
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Alias the player variable to the yourself object</span><span class="named-paragraph-number">4.4</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">inference_subject</span><span class="plain-syntax"> *</span><span class="identifier-syntax">subj</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">InferenceSubjects::alias_to_nonlocal_variable</span><span class="plain-syntax">(</span><span class="identifier-syntax">subj</span><span class="plain-syntax">, </span><span class="identifier-syntax">player_VAR</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">NonlocalVariables::set_alias</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_VAR</span><span class="plain-syntax">, </span><span class="identifier-syntax">subj</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="3-tp.html#SP4">&#167;4</a>, <a href="3-tp.html#SP4_3">&#167;4.3</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP5" class="paragraph-anchor"></a><b>&#167;5. </b>We also, though, want to look out for this sort of thing:
</p>
<blockquote>
<p>The player is Lord Collingwood.</p>
</blockquote>
<p class="commentary">because an assertion like this causes <span class="extract"><span class="extract-syntax">player_character_object</span></span> to diverge from
<span class="extract"><span class="extract-syntax">I_yourself</span></span>; here of course it becomes the Lord Collingwood object.
</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">Player::variable_set_warning</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">Player::variable_set_warning</span></span>:<br/><a href="3-tp.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">nonlocal_variable</span><span class="plain-syntax"> *</span><span class="identifier-syntax">nlv</span><span class="plain-syntax">, </span><span class="identifier-syntax">parse_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">val</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">nlv</span><span class="plain-syntax"> == </span><span class="identifier-syntax">player_VAR</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">instance</span><span class="plain-syntax"> *</span><span class="identifier-syntax">npc</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Rvalues::to_object_instance</span><span class="plain-syntax">(</span><span class="identifier-syntax">val</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">npc</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax"> = </span><span class="identifier-syntax">npc</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">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">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" class="paragraph-anchor"></a><b>&#167;6. </b>But it gets worse: as well as aliasing, there is bodysnatching. Our problem
is that once the author has written "The player is Lord Collingwood.", it's
clear that the "yourself" object shouldn't appear anywhere. But there are
two problems with that: one, the I6 template code needs it to exist, even if
it isn't in the model world; and two, we've just aliased "player" to it.
</p>
<p class="commentary">Bodysnatching allows one object (the "snatcher") to take over the life of
another (the "victim"), so that inferences made about the victim are diverted
to the snatcher. Thus if the source text reads:
</p>
<blockquote>
<p>The player is Lord Collingwood. The player carries a spyglass.</p>
</blockquote>
<p class="commentary">the second sentence goes through two transformations: first, because of
aliasing, Inform decides to draw an inference about "yourself", rather
than complaining that "player" is indefinite; and second, because of
bodysnatching, the Collingwood object (snatcher) takes over the inference
from the yourself object (victim). So Collingwood gets the spyglass, as
the source text clearly intended.
</p>
<p class="commentary">Bodysnatching is used only when <span class="extract"><span class="extract-syntax">player_character_object</span></span> differs from <span class="extract"><span class="extract-syntax">I_yourself</span></span>,
that is, when the source text explicitly sets a value for "player".
</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">Player::detect_bodysnatching</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">Player::detect_bodysnatching</span></span>:<br/><a href="3-tp.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inference_subject</span><span class="plain-syntax"> *</span><span class="identifier-syntax">body</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">snatcher</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inference_subject</span><span class="plain-syntax"> **</span><span class="identifier-syntax">counterpart</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">player_character_object</span><span class="plain-syntax"> == </span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax">) ||</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</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="identifier-syntax">kind</span><span class="plain-syntax"> *</span><span class="identifier-syntax">KP</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Instances::to_kind</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">kind</span><span class="plain-syntax"> *</span><span class="identifier-syntax">KY</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Instances::to_kind</span><span class="plain-syntax">(</span><span class="identifier-syntax">I_yourself</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">Kinds::conforms_to</span><span class="plain-syntax">(</span><span class="identifier-syntax">KP</span><span class="plain-syntax">, </span><span class="identifier-syntax">KY</span><span class="plain-syntax">)) &amp;&amp; (</span><span class="identifier-syntax">Kinds::ne</span><span class="plain-syntax">(</span><span class="identifier-syntax">KP</span><span class="plain-syntax">, </span><span class="identifier-syntax">KY</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">body</span><span class="plain-syntax"> == </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">snatcher</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">counterpart</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">I_yourself</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">TRUE</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">body</span><span class="plain-syntax"> == </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">snatcher</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">counterpart</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_character_object</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">TRUE</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="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">body</span><span class="plain-syntax"> == </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">snatcher</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">counterpart</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">I_yourself</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">TRUE</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">body</span><span class="plain-syntax"> == </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">snatcher</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">counterpart</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_character_object</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">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">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="SP7" class="paragraph-anchor"></a><b>&#167;7. Linguistic variations. </b>Thankfully everything else is straightforward. The following is used to
ensure that assemblies such as "A nose is part of every person" produces
"your nose" rather than "yourself's nose":
</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">Player::irregular_genitive</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">Player::irregular_genitive</span></span>:<br/><a href="3-tp.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inference_subject</span><span class="plain-syntax"> *</span><span class="identifier-syntax">owner</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">genitive</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">propriety</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">owner</span><span class="plain-syntax"> == </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE_TO</span><span class="plain-syntax">(</span><span class="identifier-syntax">genitive</span><span class="plain-syntax">, </span><span class="string-syntax">"your "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">propriety</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">TRUE</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">player_character_object</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax">) &amp;&amp;</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax"> != </span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax">) &amp;&amp;</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">owner</span><span class="plain-syntax"> == </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax">))) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE_TO</span><span class="plain-syntax">(</span><span class="identifier-syntax">genitive</span><span class="plain-syntax">, </span><span class="string-syntax">"your "</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> *</span><span class="identifier-syntax">propriety</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">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="SP8" class="paragraph-anchor"></a><b>&#167;8. </b>The adjectives "worn" and "carried" &mdash; as in, "The nautical chart is
carried." &mdash; implicitly refer to the player as the unstated term in the
relationship; that makes them our business here. "Initially carried" is
now deprecated, but is provided as synonymous with "carried" because it
was once an either/or property in the clumsier early stages of Inform 7,
and people still sometimes type it.
</p>
<pre class="Preform-displayed-code all-displayed-code code-font">
<span class="Preform-function-syntax">&lt;implicit-player-relationship&gt;</span><span class="Preform-plain-syntax"> </span><span class="Preform-reserved-syntax">::=</span>
<span class="Preform-plain-syntax"> </span><span class="Preform-constant-syntax">worn</span><span class="Preform-plain-syntax"> </span><span class="Preform-reserved-syntax">|</span>
<span class="Preform-plain-syntax"> </span><span class="Preform-constant-syntax">carried</span><span class="Preform-plain-syntax"> </span><span class="Preform-reserved-syntax">|</span>
<span class="Preform-plain-syntax"> </span><span class="Preform-constant-syntax">initially</span><span class="Preform-plain-syntax"> </span><span class="Preform-constant-syntax">carried</span>
</pre>
<ul class="endnotetexts"><li>This is <a href="../words-module/4-ap.html" class="internal">Preform grammar</a>, not regular C code.</li></ul>
<p class="commentary firstcommentary"><a id="SP9" class="paragraph-anchor"></a><b>&#167;9. </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">Player::refine_implicit_noun</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">Player::refine_implicit_noun</span></span>:<br/><a href="3-tp.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">parse_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">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="function-syntax">&lt;implicit-player-relationship&gt;</span><span class="plain-syntax">(</span><span class="identifier-syntax">Node::get_text</span><span class="plain-syntax">(</span><span class="identifier-syntax">p</span><span class="plain-syntax">))) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">Refiner::give_subject_to_noun</span><span class="plain-syntax">(</span><span class="identifier-syntax">p</span><span class="plain-syntax">, </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_character_object</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">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="SP10" class="paragraph-anchor"></a><b>&#167;10. Model completion. </b>At stage III, we add a property to make things work out nicely in the event
of a change of player.
</p>
<p class="commentary">Otherwise we take no interest until stage IV, a point at which kinds of
objects and the spatial model for them are both completely worked out. We
won't change anything: all we will do is calculate the start object and the
start room by looking at where the player sits in the spatial model.
</p>
<p class="commentary">Very often, the source text doesn't specify where the player is, and then
we assume he is freestanding in the earliest defined room.
</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">Player::complete_model</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">Player::complete_model</span></span>:<br/><a href="3-tp.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">stage</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">stage</span><span class="plain-syntax"> == </span><span class="identifier-syntax">WORLD_STAGE_III</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax">)) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">property</span><span class="plain-syntax"> *</span><span class="identifier-syntax">P_ssn</span><span class="plain-syntax"> = </span><span class="identifier-syntax">ValueProperties::new_nameless</span><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="string-syntax">"saved_short_name"</span><span class="plain-syntax">, </span><span class="identifier-syntax">K_text</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">ValueProperties::assert</span><span class="plain-syntax">(</span><span class="identifier-syntax">P_ssn</span><span class="plain-syntax">, </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">I_yourself</span><span class="plain-syntax">),</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">Rvalues::from_unescaped_wording</span><span class="plain-syntax">(</span><span class="identifier-syntax">Feeds::feed_text</span><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="string-syntax">"yourself"</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="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">stage</span><span class="plain-syntax"> == </span><span class="identifier-syntax">WORLD_STAGE_IV</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="3-tp.html#SP10_1" class="named-paragraph-link"><span class="named-paragraph">Set the start room to the earliest room defined in the source text</span><span class="named-paragraph-number">10.1</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="3-tp.html#SP10_2" class="named-paragraph-link"><span class="named-paragraph">If the start room is still null, there's no room, so issue a problem</span><span class="named-paragraph-number">10.2</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="3-tp.html#SP10_3" class="named-paragraph-link"><span class="named-paragraph">Otherwise see if the player has explicitly been placed in the model world</span><span class="named-paragraph-number">10.3</span></a></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="SP10_1" class="paragraph-anchor"></a><b>&#167;10.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Set the start room to the earliest room defined in the source text</span><span class="named-paragraph-number">10.1</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">instance</span><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">LOOP_OVER_INSTANCES</span><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="plain-syntax">, </span><span class="identifier-syntax">K_object</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-sm.html#SP7" class="function-link"><span class="function-syntax">Spatial::object_is_a_room</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="plain-syntax">)) &amp;&amp; (</span><span class="identifier-syntax">start_room</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> &amp;&amp; (</span><span class="identifier-syntax">Projects::draws_from_source_file</span><span class="plain-syntax">(</span><span class="identifier-syntax">Task::project</span><span class="plain-syntax">(),</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">Instances::get_creating_file</span><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">start_room</span><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">LOOP_OVER_INSTANCES</span><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="plain-syntax">, </span><span class="identifier-syntax">K_object</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-sm.html#SP7" class="function-link"><span class="function-syntax">Spatial::object_is_a_room</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="plain-syntax">)) &amp;&amp; (</span><span class="identifier-syntax">start_room</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">))</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">start_room</span><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">start_object</span><span class="plain-syntax"> = </span><span class="identifier-syntax">start_room</span><span class="plain-syntax">;</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="3-tp.html#SP10">&#167;10</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP10_2" class="paragraph-anchor"></a><b>&#167;10.2. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">If the start room is still null, there's no room, so issue a problem</span><span class="named-paragraph-number">10.2</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">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">start_room</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) &amp;&amp; (</span><span class="identifier-syntax">Task::wraps_existing_storyfile</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">StandardProblems::unlocated_problem</span><span class="plain-syntax">(</span><span class="identifier-syntax">Task::syntax_tree</span><span class="plain-syntax">(), </span><span class="identifier-syntax">_p_</span><span class="plain-syntax">(</span><span class="identifier-syntax">PM_NoStartRoom</span><span class="plain-syntax">),</span>
<span class="plain-syntax"> </span><span class="string-syntax">"There doesn't seem to be any location in this story, so there's "</span>
<span class="plain-syntax"> </span><span class="string-syntax">"nowhere for the player to begin. This may be because I have "</span>
<span class="plain-syntax"> </span><span class="string-syntax">"misunderstood what was meant to be a room and what wasn't: I "</span>
<span class="plain-syntax"> </span><span class="string-syntax">"only know something is a room if you tell me explicitly ('The "</span>
<span class="plain-syntax"> </span><span class="string-syntax">"Observatory is a room') or if you imply it by giving map "</span>
<span class="plain-syntax"> </span><span class="string-syntax">"directions ('East of the Observatory is the Planetarium')."</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>
<ul class="endnotetexts"><li>This code is used in <a href="3-tp.html#SP10">&#167;10</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP10_3" class="paragraph-anchor"></a><b>&#167;10.3. </b>If the source text said nothing about the player's location, then the
player object will be a disconnected node in the containment tree: it will,
in fact, have no progenitor. In that event, the start room already calculated
will do. But otherwise:
</p>
<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Otherwise see if the player has explicitly been placed in the model world</span><span class="named-paragraph-number">10.3</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">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">start_object</span><span class="plain-syntax"> = </span><a href="3-sm.html#SP28" class="function-link"><span class="function-syntax">Spatial::progenitor</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">player_character_object</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">start_object</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">start_room</span><span class="plain-syntax"> = </span><span class="identifier-syntax">start_object</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">start_room</span><span class="plain-syntax">) &amp;&amp; (</span><a href="3-sm.html#SP28" class="function-link"><span class="function-syntax">Spatial::progenitor</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">start_room</span><span class="plain-syntax">)))</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">start_room</span><span class="plain-syntax"> = </span><a href="3-sm.html#SP28" class="function-link"><span class="function-syntax">Spatial::progenitor</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">start_room</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">start_room</span><span class="plain-syntax">) &amp;&amp; (</span><a href="3-sm.html#SP7" class="function-link"><span class="function-syntax">Spatial::object_is_a_room</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">start_room</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">StandardProblems::object_problem</span><span class="plain-syntax">(</span><span class="identifier-syntax">_p_</span><span class="plain-syntax">(</span><span class="identifier-syntax">PM_StartsOutsideRooms</span><span class="plain-syntax">),</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">start_object</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="string-syntax">"seems to be where the player is supposed to begin"</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="string-syntax">"but (so far as I know) it is not a room, nor is it ultimately "</span>
<span class="plain-syntax"> </span><span class="string-syntax">"contained inside a room."</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inference</span><span class="plain-syntax"> *</span><span class="identifier-syntax">inf</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">POSITIVE_KNOWLEDGE_LOOP</span><span class="plain-syntax">(</span><span class="identifier-syntax">inf</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">Instances::as_subject</span><span class="plain-syntax">(</span><span class="identifier-syntax">player_character_object</span><span class="plain-syntax">), </span><span class="identifier-syntax">part_of_inf</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">StandardProblems::object_problem</span><span class="plain-syntax">(</span><span class="identifier-syntax">_p_</span><span class="plain-syntax">(</span><span class="identifier-syntax">PM_PlayerIsPart</span><span class="plain-syntax">),</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">start_object</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="string-syntax">"seems to have the player attached as a component part"</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="string-syntax">"which is not allowed. The player can be in a room, or "</span>
<span class="plain-syntax"> </span><span class="string-syntax">"inside a container, or on a supporter, but can't be part "</span>
<span class="plain-syntax"> </span><span class="string-syntax">"of something."</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="3-tp.html#SP10">&#167;10</a>.</li></ul>
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