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+ <h3 class="section">Inheritance and Keymaps</h3>   <p>A keymap can inherit the bindings of another keymap, which we call the <em>parent keymap</em>. Such a keymap looks like this: </p> <div class="example"> <pre class="example">(keymap <var>elements</var>… . <var>parent-keymap</var>)
+</pre>
+</div> <p>The effect is that this keymap inherits all the bindings of <var>parent-keymap</var>, whatever they may be at the time a key is looked up, but can add to them or override them with <var>elements</var>. </p> <p>If you change the bindings in <var>parent-keymap</var> using <code>define-key</code> or other key-binding functions, these changed bindings are visible in the inheriting keymap, unless shadowed by the bindings made by <var>elements</var>. The converse is not true: if you use <code>define-key</code> to change bindings in the inheriting keymap, these changes are recorded in <var>elements</var>, but have no effect on <var>parent-keymap</var>. </p> <p>The proper way to construct a keymap with a parent is to use <code>set-keymap-parent</code>; if you have code that directly constructs a keymap with a parent, please convert the program to use <code>set-keymap-parent</code> instead. </p> <dl> <dt id="keymap-parent">Function: <strong>keymap-parent</strong> <em>keymap</em>
+</dt> <dd><p>This returns the parent keymap of <var>keymap</var>. If <var>keymap</var> has no parent, <code>keymap-parent</code> returns <code>nil</code>. </p></dd>
+</dl> <dl> <dt id="set-keymap-parent">Function: <strong>set-keymap-parent</strong> <em>keymap parent</em>
+</dt> <dd>
+<p>This sets the parent keymap of <var>keymap</var> to <var>parent</var>, and returns <var>parent</var>. If <var>parent</var> is <code>nil</code>, this function gives <var>keymap</var> no parent at all. </p> <p>If <var>keymap</var> has submaps (bindings for prefix keys), they too receive new parent keymaps that reflect what <var>parent</var> specifies for those prefix keys. </p>
+</dd>
+</dl> <p>Here is an example showing how to make a keymap that inherits from <code>text-mode-map</code>: </p> <div class="example"> <pre class="example">(let ((map (make-sparse-keymap)))
+  (set-keymap-parent map text-mode-map)
+  map)
+</pre>
+</div> <p>A non-sparse keymap can have a parent too, but this is not very useful. A non-sparse keymap always specifies something as the binding for every numeric character code without modifier bits, even if it is <code>nil</code>, so these character’s bindings are never inherited from the parent keymap. </p>  <p>Sometimes you want to make a keymap that inherits from more than one map. You can use the function <code>make-composed-keymap</code> for this. </p> <dl> <dt id="make-composed-keymap">Function: <strong>make-composed-keymap</strong> <em>maps &amp;optional parent</em>
+</dt> <dd><p>This function returns a new keymap composed of the existing keymap(s) <var>maps</var>, and optionally inheriting from a parent keymap <var>parent</var>. <var>maps</var> can be a single keymap or a list of more than one. When looking up a key in the resulting new map, Emacs searches in each of the <var>maps</var> in turn, and then in <var>parent</var>, stopping at the first match. A <code>nil</code> binding in any one of <var>maps</var> overrides any binding in <var>parent</var>, but it does not override any non-<code>nil</code> binding in any other of the <var>maps</var>. </p></dd>
+</dl> <p>For example, here is how Emacs sets the parent of <code>help-mode-map</code>, such that it inherits from both <code>button-buffer-map</code> and <code>special-mode-map</code>: </p> <div class="example"> <pre class="example">(defvar help-mode-map
+  (let ((map (make-sparse-keymap)))
+    (set-keymap-parent map
+      (make-composed-keymap button-buffer-map special-mode-map))
+    ... map) ... )
+</pre>
+</div><div class="_attribution">
+  <p class="_attribution-p">
+    Copyright &copy; 1990-1996, 1998-2022 Free Software Foundation, Inc. <br>Licensed under the GNU GPL license.<br>
+    <a href="https://www.gnu.org/software/emacs/manual/html_node/elisp/Inheritance-and-Keymaps.html" class="_attribution-link">https://www.gnu.org/software/emacs/manual/html_node/elisp/Inheritance-and-Keymaps.html</a>
+  </p>
+</div>