From: Mattias Engdegård <mattiase@acm.org>
Date: Tue, 9 Apr 2019 14:56:37 +0000 (+0200)
Subject: Clarify the TESTFN argument to `alist-get'
X-Git-Tag: emacs-26.2~12
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=00a2d57;p=emacs.git

Clarify the TESTFN argument to `alist-get'

* lisp/subr.el (alist-get):
Rephrase the initial text to clarify the meaning of the TESTFN argument.
It's an equality predicate, not a look-up function (Bug#35206).

(cherry picked from commit c81465580fe262f28ce47502c00f4afcbe3b8f8d)
---

diff --git a/lisp/subr.el b/lisp/subr.el
index 44199a50754..54bee8a809f 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -752,9 +752,9 @@ Elements of ALIST that are not conses are ignored."
   alist)
 
 (defun alist-get (key alist &optional default remove testfn)
-  "Return the value associated with KEY in ALIST.
+  "Find the first element of ALIST whose `car' equals KEY and return its `cdr'.
 If KEY is not found in ALIST, return DEFAULT.
-Use TESTFN to lookup in the alist if non-nil.  Otherwise, use `assq'.
+Equality with KEY is tested by TESTFN, defaulting to `eq'.
 
 This is a generalized variable suitable for use with `setf'.
 When using it to set a value, optional argument REMOVE non-nil