96 lines
3.8 KiB
HTML
96 lines
3.8 KiB
HTML
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<!DOCTYPE html>
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<html>
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<!-- Created by GNU Texinfo 7.1, https://www.gnu.org/software/texinfo/ -->
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<!-- This manual documents Guile version 3.0.10.
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Copyright (C) 1996-1997, 2000-2005, 2009-2023 Free Software Foundation,
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Inc.
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Copyright (C) 2021 Maxime Devos
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Copyright (C) 2024 Tomas Volf
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Permission is granted to copy, distribute and/or modify this document
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under the terms of the GNU Free Documentation License, Version 1.3 or
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any later version published by the Free Software Foundation; with no
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Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
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copy of the license is included in the section entitled "GNU Free
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Documentation License." -->
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<title>Introspection (Guile Reference Manual)</title>
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<meta name="description" content="Introspection (Guile Reference Manual)">
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<meta name="keywords" content="Introspection (Guile Reference Manual)">
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<meta name="viewport" content="width=device-width,initial-scale=1">
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<link href="index.html" rel="start" title="Top">
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<link href="Concept-Index.html" rel="index" title="Concept Index">
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<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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<link href="GOOPS.html" rel="up" title="GOOPS">
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<link href="GOOPS-Error-Handling.html" rel="next" title="GOOPS Error Handling">
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<link href="Inheritance.html" rel="prev" title="Inheritance">
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<link rel="stylesheet" type="text/css" href="https://www.gnu.org/software/gnulib/manual.css">
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</head>
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<body lang="en">
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<div class="section-level-extent" id="Introspection">
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<div class="nav-panel">
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<p>
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Next: <a href="GOOPS-Error-Handling.html" accesskey="n" rel="next">Error Handling</a>, Previous: <a href="Inheritance.html" accesskey="p" rel="prev">Inheritance</a>, Up: <a href="GOOPS.html" accesskey="u" rel="up">GOOPS</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
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</div>
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<hr>
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<h3 class="section" id="Introspection-1"><span>8.8 Introspection<a class="copiable-link" href="#Introspection-1"> ¶</a></span></h3>
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<p><em class="dfn">Introspection</em>, or <em class="dfn">reflection</em>, means being able to obtain
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information dynamically about GOOPS objects. It is perhaps best
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illustrated by considering an object oriented language that does not
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provide any introspection, namely C++.
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</p>
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<p>Nothing in C++ allows a running program to obtain answers to the following
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types of question:
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</p>
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<ul class="itemize mark-bullet">
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<li>What are the data members of this object or class?
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</li><li>What classes does this class inherit from?
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</li><li>Is this method call virtual or non-virtual?
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</li><li>If I invoke <code class="code">Employee::adjustHoliday()</code>, what class contains the
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<code class="code">adjustHoliday()</code> method that will be applied?
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</li></ul>
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<p>In C++, answers to such questions can only be determined by looking at
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the source code, if you have access to it. GOOPS, on the other hand,
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includes procedures that allow answers to these questions — or their
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GOOPS equivalents — to be obtained dynamically, at run time.
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</p>
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<ul class="mini-toc">
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<li><a href="Classes.html" accesskey="1">Classes</a></li>
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<li><a href="Instances.html" accesskey="2">Instances</a></li>
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<li><a href="Slots.html" accesskey="3">Slots</a></li>
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<li><a href="Generic-Functions.html" accesskey="4">Generic Functions</a></li>
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<li><a href="Accessing-Slots.html" accesskey="5">Accessing Slots</a></li>
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</ul>
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</div>
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</body>
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</html>
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