/usr/lib/swi-prolog/doc/Manual/loadfilehook.html

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<h2 id="sec:loadfilehook"><a id="sec:B.9"><span class="sec-nr">B.9</span> <span class="sec-title">Hooks 
for loading files</span></a></h2>

<a id="sec:loadfilehook"></a>

<p>All loading of source files is achieved by <a id="idx:loadfiles2:1896"></a><a class="pred" href="consulting.html#load_files/2">load_files/2</a>. 
The hook
<a id="idx:prologloadfile2:1897"></a><a class="pred" href="loadfilehook.html#prolog_load_file/2">prolog_load_file/2</a> 
can be used to load Prolog code from non-files or even load entirely 
different information, such as foreign files.

<dl class="latex">
<dt class="pubdef"><a id="prolog_load_file/2"><strong>prolog_load_file</strong>(<var>+Spec, 
+Options</var>)</a></dt>
<dd class="defbody">
Load a single object. If this call succeeds, <a id="idx:loadfiles2:1898"></a><a class="pred" href="consulting.html#load_files/2">load_files/2</a> 
assumes the action has been taken care of. This hook is only called if <var>Options</var> 
does not contain the <code>stream(Input)</code> option. The hook must be 
defined in the module <code>user</code>.

<p>This can be used to load from unusual places. For example, library
<code>library(http/http_load)</code> loads Prolog directly from an HTTP 
server. It can also be used to load source in unusual forms, such as 
loading compressed files without decompressing them first. There is 
currently no example of that.</dd>
<dt class="pubdef"><a id="prolog:comment_hook/3"><strong>prolog:comment_hook</strong>(<var>+Comments, 
+Pos, +Term</var>)</a></dt>
<dd class="defbody">
This hook allows for processing comments encountered by the compiler. If 
this hook is defined, the compiler calls <a id="idx:readterm2:1899"></a><a class="pred" href="termrw.html#read_term/2">read_term/2</a> 
with the option
<code>comments(Comments)</code>. If the list of comments returned by
<a id="idx:readterm2:1900"></a><a class="pred" href="termrw.html#read_term/2">read_term/2</a> 
is not empty it calls this comment hook with the following arguments.

<p>
<ul class="latex">
<li><var>Comments</var> is the non-empty list of comments. Each comment 
is a pair <var>Position</var>-<var>String</var>, where
<var>String</var> is a string object (see <a class="sec" href="strings.html">section 
4.24</a>) that contains the comment <em>including</em> delimiters. 
Consecutive line comments are returned as a single comment.
<li><var>Pos</var> is a stream-position term that describes the starting 
position of <var>Term</var>
<li><var>Term</var> is the term read.
</ul>

<p>This hook is exploited by the documentation system. See
<a id="idx:streampositiondata3:1901"></a><a class="pred" href="IO.html#stream_position_data/3">stream_position_data/3</a>. 
See also <a id="idx:readterm3:1902"></a><a class="pred" href="termrw.html#read_term/3">read_term/3</a>.
</dd>
</dl>

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swi-prolog-nox 6.6.4-2ubuntu1 / usr / lib / swi-prolog / doc / Manual / loadfilehook.html
