Document clamp function

appendices/migration86/new-functions.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="utf-8"?>
+<sect1 xml:id="migration86.new-functions">
+ <title>New Functions</title>
+
+ <sect2 xml:id="migration86.new-functions.core">
+  <title>Core</title>
+
+  <simplelist>
+   <!-- RFC: https://wiki.php.net/rfc/clamp_v2 -->
+   <member><function>clamp</function></member>
+  </simplelist>
+ </sect2>
+
+</sect1>
+ <!-- Keep this comment at the end of the file
+ Local variables:
+ mode: sgml
+ sgml-omittag:t
+ sgml-shorttag:t
+ sgml-minimize-attributes:nil
+ sgml-always-quote-attributes:t
+ sgml-indent-step:1
+ sgml-indent-data:t
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+ sgml-default-dtd-file:"~/.phpdoc/manual.ced"
+ sgml-exposed-tags:nil
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+ sgml-local-ecat-files:nil
+ End:
+ vim600: syn=xml fen fdm=syntax fdl=2 si
+ vim: et tw=78 syn=sgml
+ vi: ts=1 sw=1
+ -->

reference/array/versions.xml

@@ -66,6 +66,7 @@
  <function name='array_walk_recursive' from='PHP 5, PHP 7, PHP 8'/>
  <function name='arsort' from='PHP 4, PHP 5, PHP 7, PHP 8'/>
  <function name='asort' from='PHP 4, PHP 5, PHP 7, PHP 8'/>
+ <function name='clamp' from='PHP 8 &gt;= 8.6.0'/>
  <function name='compact' from='PHP 4, PHP 5, PHP 7, PHP 8'/>
  <function name='count' from='PHP 4, PHP 5, PHP 7, PHP 8'/>
  <function name='current' from='PHP 4, PHP 5, PHP 7, PHP 8'/>

reference/math/functions/clamp.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<!-- $Revision$ -->
+<refentry xml:id="function.clamp" xmlns="http://docbook.org/ns/docbook">
+ <refnamediv>
+  <refname>clamp</refname>
+  <refpurpose>Return the given value if in range, else return the nearest bound</refpurpose>
+ </refnamediv>
+ <refsect1 role="description">
+  &reftitle.description;
+   <methodsynopsis>
+    <type>mixed</type><methodname>clamp</methodname>
+    <methodparam><type>mixed</type><parameter>value</parameter></methodparam>
+    <methodparam><type>mixed</type><parameter>min</parameter></methodparam>
+    <methodparam><type>mixed</type><parameter>max</parameter></methodparam>
+   </methodsynopsis>
+  <para>
+   Return the given value if in range of <parameter>min</parameter> and <parameter>max</parameter>.
+   Else if it's lower than <parameter>min</parameter>, return <parameter>min</parameter>.
+   Else return <parameter>max</parameter>.
+  </para>
+  <note>
+   <para>
+    Values of different types will be compared using the <link linkend="language.operators.comparison">
+    standard comparison rules</link>. For instance, a non-numeric <type>string</type> will be
+    compared to an <type>int</type> as though it were <literal>0</literal>, but multiple non-numeric
+    <type>string</type> values will be compared alphanumerically. The actual value returned will be of the
+    original type with no conversion applied.
+   </para>
+  </note>
+  <caution>
+   <simpara>
+    Be careful when passing arguments of different types because
+    <function>clamp</function> can produce unpredictable results.
+   </simpara>
+  </caution>
+ </refsect1>
+ <refsect1 role="parameters">
+  &reftitle.parameters;
+  <para>
+   <variablelist>
+    <varlistentry>
+     <term><parameter>value</parameter></term>
+     <listitem>
+      <para>
+       Any <link linkend="language.operators.comparison">comparable</link>
+       value to be clamped between <parameter>min</parameter> and <parameter>max</parameter>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term><parameter>min</parameter></term>
+     <listitem>
+      <para>
+       A <link linkend="language.operators.comparison">comparable</link> minimum to limit
+       the <parameter>value</parameter> to.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term><parameter>max</parameter></term>
+     <listitem>
+      <para>
+       A <link linkend="language.operators.comparison">comparable</link> maximum to limit
+       the <parameter>value</parameter> to.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </para>
+ </refsect1>
+ <refsect1 role="returnvalues">
+  &reftitle.returnvalues;
+  <para>
+   <function>clamp</function> returns the parameter <parameter>value</parameter> if
+   considered "between" <parameter>min</parameter> and <parameter>max</parameter> according to standard
+   comparisons.
+  </para>
+  <para>
+   If <parameter>value</parameter> is <constant>NAN</constant>, then the returned value will also be
+   <constant>NAN</constant>.
+  </para>
+ </refsect1>
+
+ <refsect1 role="errors">
+  &reftitle.errors;
+  <para>
+   If <parameter>min</parameter> is greater than <parameter>max</parameter>,
+   <function>clamp</function> throws a <classname>ValueError</classname>.
+  </para>
+  <para>
+   If <parameter>min</parameter> or <parameter>max</parameter> is <constant>NAN</constant>,
+   <function>clamp</function> throws a <classname>ValueError</classname>.
+  </para>
+ </refsect1>
+
+ <refsect1 role="examples">
+  &reftitle.examples;
+  <para>
+   <example>
+    <title>Example uses of <function>clamp</function></title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+echo clamp(-5, min: 0, max: 100), PHP_EOL;  // 0
+echo clamp(55, min: 0, max: 100), PHP_EOL;  // 55
+echo clamp(103, min: 0, max: 100), PHP_EOL;  // 100
+
+echo clamp("J", min: "A", max: "F"), PHP_EOL;  // "F"
+
+clamp(
+    new \DateTimeImmutable('2025-08-01'),
+    min: new \DateTimeImmutable('2025-08-15'),
+    max: new \DateTimeImmutable('2025-09-15'),
+)->format('Y-m-d'), PHP_EOL; // 2025-08-15
+?>
+]]>
+    </programlisting>
+   </example>
+  </para>
+
+ </refsect1>
+ <refsect1 role="seealso">
+  &reftitle.seealso;
+  <para>
+   <simplelist>
+    <member><function>min</function></member>
+    <member><function>max</function></member>
+   </simplelist>
+  </para>
+ </refsect1>
+</refentry>
+<!-- Keep this comment at the end of the file
+Local variables:
+mode: sgml
+sgml-omittag:t
+sgml-shorttag:t
+sgml-minimize-attributes:nil
+sgml-always-quote-attributes:t
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+sgml-default-dtd-file:"~/.phpdoc/manual.ced"
+sgml-exposed-tags:nil
+sgml-local-catalogs:nil
+sgml-local-ecat-files:nil
+End:
+vim600: syn=xml fen fdm=syntax fdl=2 si
+vim: et tw=78 syn=sgml
+vi: ts=1 sw=1
+-->