ZelphirKaltstahl
/
the-seasoned-schemer-notes


			
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<div id="content" class="content">
<h1 class="title">Commandments</h1>
<div id="table-of-contents" role="doc-toc">
<h2>Table of Contents</h2>
<div id="text-table-of-contents" role="doc-toc">
<ul>
<li><a href="#commandment-11">1. 11 - The Eleventh Commandment - Accumulation of results or maintaining state</a></li>
<li><a href="#commandment-12">2. 12 - The Twelfth Commandment - Avoiding of unchanging iteration arguments</a></li>
<li><a href="#commandment-13">3. 13 - The Thirteenth Commandment - Usage of <code class="src src-scheme">(letrec ...)</code> or named <code class="src src-scheme">let</code> or inner <code class="src src-scheme">(define ...)</code></a></li>
<li><a href="#commandment-14">4. 14 - The Fourteenth Commandment - Usage of <code class="src src-scheme">(call-with-current-continuation ...)</code></a></li>
<li><a href="#commandment-15">5. 15 - The Fifteenth Commandment - Usage of <code class="src src-scheme">(let ...)</code></a></li>
</ul>
</div>
</div>


<div id="outline-container-commandment-11" class="outline-2">
<h2 id="commandment-11"><span class="section-number-2">1.</span> 11 - The Eleventh Commandment - Accumulation of results or maintaining state</h2>
<div class="outline-text-2" id="text-commandment-11">
<blockquote>
<p>
Use additional arguments when a function needs to know what other arguments to the function have been like so far.
</p>
</blockquote>
</div>
</div>

<div id="outline-container-commandment-12" class="outline-2">
<h2 id="commandment-12"><span class="section-number-2">2.</span> 12 - The Twelfth Commandment - Avoiding of unchanging iteration arguments</h2>
<div class="outline-text-2" id="text-commandment-12">
<blockquote>
<p>
Use <code>(letrec ...)</code> to remove arguments that do not change for recursive application.
</p>
</blockquote>

<p>
However, in some Scheme dialects one can also use <code>define</code> in all or most contexts (definition contexts), so that one does not need to use <code>letrec</code>.
</p>
</div>
</div>

<div id="outline-container-commandment-13" class="outline-2">
<h2 id="commandment-13"><span class="section-number-2">3.</span> 13 - The Thirteenth Commandment - Usage of <code class="src src-scheme">(letrec ...)</code> or named <code class="src src-scheme">let</code> or inner <code class="src src-scheme">(define ...)</code></h2>
<div class="outline-text-2" id="text-commandment-13">
<blockquote>
<p>
Use <code class="src src-scheme">(letrec ...)</code> to hide and to protect functions.
</p>
</blockquote>
</div>
</div>

<div id="outline-container-commandment-14" class="outline-2">
<h2 id="commandment-14"><span class="section-number-2">4.</span> 14 - The Fourteenth Commandment - Usage of <code class="src src-scheme">(call-with-current-continuation ...)</code></h2>
<div class="outline-text-2" id="text-commandment-14">
<blockquote>
<p>
Use <code class="src src-scheme">(letcc ...)</code> to return values abruptly and promptly.
</p>
</blockquote>

<p>
However, in Scheme dialects, it is called <code class="src src-scheme">(call-with-current-continuation ...)</code> instead. One could write a macro transforming it into <code class="src src-scheme">(letrec ...)</code> though.
</p>
</div>
</div>

<div id="outline-container-commandment-15" class="outline-2">
<h2 id="commandment-15"><span class="section-number-2">5.</span> 15 - The Fifteenth Commandment - Usage of <code class="src src-scheme">(let ...)</code></h2>
<div class="outline-text-2" id="text-commandment-15">
<p>
Use <code class="src src-scheme">(let ...)</code> to name the values of repeated expressions in a function definition if they may be evaluated twice for one and the same use of the function.
</p>
</div>
</div>
</div>
<div id="postamble" class="status">
<p class="date">Date: 2023-03-04 Sa 00:00</p>
<p class="author">Author: Zelphir Kaltstahl</p>
<p class="date">Created: 2023-03-05 So 13:36</p>
<p class="validation"><a href="https://validator.w3.org/check?uri=referer">Validate</a></p>
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