82 lines
3.4 KiB
HTML
82 lines
3.4 KiB
HTML
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Copyright (C) 2024 Tomas Volf
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<title>Alist Key Equality (Guile Reference Manual)</title>
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<div class="subsubsection-level-extent" id="Alist-Key-Equality">
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Next: <a href="Adding-or-Setting-Alist-Entries.html" accesskey="n" rel="next">Adding or Setting Alist Entries</a>, Up: <a href="Association-Lists.html" accesskey="u" rel="up">Association Lists</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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<h4 class="subsubsection" id="Alist-Key-Equality-1"><span>6.6.20.1 Alist Key Equality<a class="copiable-link" href="#Alist-Key-Equality-1"> ¶</a></span></h4>
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<p>All of Guile’s dedicated association list procedures, apart from
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<code class="code">acons</code>, come in three flavors, depending on the level of equality
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that is required to decide whether an existing key in the association
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list is the same as the key that the procedure call uses to identify the
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required entry.
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</p>
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<ul class="itemize mark-bullet">
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<li>Procedures with <em class="dfn">assq</em> in their name use <code class="code">eq?</code> to determine key
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equality.
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</li><li>Procedures with <em class="dfn">assv</em> in their name use <code class="code">eqv?</code> to determine
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key equality.
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</li><li>Procedures with <em class="dfn">assoc</em> in their name use <code class="code">equal?</code> to
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determine key equality.
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</li></ul>
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<p><code class="code">acons</code> is an exception because it is used to build association
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lists which do not require their entries’ keys to be unique.
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