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| author | Tino Calancha <tino.calancha@gmail.com> | 2017-07-17 21:30:50 +0900 |
|---|---|---|
| committer | Tino Calancha <tino.calancha@gmail.com> | 2017-07-17 21:30:50 +0900 |
| commit | 76e1f7d00fbff7bf8183ba85db2f67a11aa2d5ce (patch) | |
| tree | ac3d9fbe5fa46dbad70b527355e2f1ba997f36f8 /doc/lispref/lists.texi | |
| parent | 4968aa685b85840d79258ff6b61ba2bcfb99e2bc (diff) | |
| download | emacs-76e1f7d00fbff7bf8183ba85db2f67a11aa2d5ce.tar.gz emacs-76e1f7d00fbff7bf8183ba85db2f67a11aa2d5ce.tar.bz2 emacs-76e1f7d00fbff7bf8183ba85db2f67a11aa2d5ce.zip | |
alist-get: Add optional arg TESTFN
If TESTFN is non-nil, then it is the predicate to lookup
the alist. Otherwise, use 'eq' (Bug#27584).
* lisp/subr.el (alist-get): Add optional arg FULL.
* lisp/emacs-lisp/map.el (map-elt, map-put): Add optional arg TESTFN.
* lisp/emacs-lisp/gv.el (alist-get): Update expander.
* doc/lispref/lists.texi (Association Lists): Update manual.
* etc/NEWS: Announce the changes.
* test/lisp/emacs-lisp/map-tests.el (test-map-put-testfn-alist)
(test-map-elt-testfn): New tests.
Diffstat (limited to 'doc/lispref/lists.texi')
| -rw-r--r-- | doc/lispref/lists.texi | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/doc/lispref/lists.texi b/doc/lispref/lists.texi index 966d8f18b17..0c993806824 100644 --- a/doc/lispref/lists.texi +++ b/doc/lispref/lists.texi @@ -1589,16 +1589,20 @@ keys may not be symbols: @end smallexample @end defun -@defun alist-get key alist &optional default remove -This function is like @code{assq}, but instead of returning the entire -association for @var{key} in @var{alist}, -@w{@code{(@var{key} . @var{value})}}, it returns just the @var{value}. -If @var{key} is not found in @var{alist}, it returns @var{default}. - -This is a generalized variable (@pxref{Generalized Variables}) that -can be used to change a value with @code{setf}. When using it to set -a value, optional argument @var{remove} non-@code{nil} means to remove -@var{key} from @var{alist} if the new value is @code{eql} to @var{default}. +@defun alist-get key alist &optional default remove testfn +This function is similar to @code{assq}. It finds the first +association @w{@code{(@var{key} . @var{value})}} by comparing +@var{key} with @var{alist} elements, and, if found, returns the +@var{value} of that association. If no association is found, the +function returns @var{default}. Comparison of @var{key} against +@var{alist} elements uses the function specified by @var{testfn}, +defaulting to @code{eq}. + +This is a generalized variable (@pxref{Generalized Variables}) +that can be used to change a value with @code{setf}. When +using it to set a value, optional argument @var{remove} non-@code{nil} +means to remove @var{key}'s association from @var{alist} if the new +value is @code{eql} to @var{default}. @end defun @defun rassq value alist |