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(assoc-default): Rewrite not to use dolist.

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Richard M. Stallman 1998-08-08 23:07:06 +00:00
parent fdbd749a3f
commit 8a288450ca
1 changed files with 16 additions and 10 deletions
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26
lisp/subr.el
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@ -94,17 +94,23 @@ If N is bigger than the length of X, return X."
(setq x (cdr x)))
x))
(defun assoc-default (el alist test default)
"Find object EL in a pseudo-alist ALIST.
ALIST is a list of conses or objects. Each element (or the element's
car, if it. is a cons) is compared with EL by calling TEST.
If TEST returns non-nil, the element matches;
then `assoc-default' returns the cdr of the element (if it is a cons),
(defun assoc-default (key alist &optional test default)
"Find object KEY in a pseudo-alist ALIST.
ALIST is a list of conses or objects. Each element (or the element's car,
if it is a cons) is compared with KEY by evaluating (TEST (car elt) KEY).
If that is non-nil, the element matches;
then `assoc-default' returns the element's cdr, if it is a cons,
or DEFAULT if the element is not a cons.
If no element matches, the value is nil."
(dolist (rr alist)
(when (funcall test el (if (consp rr) (car rr) rr))
(return (if (consp rr) (cdr rr) default)))))
If no element matches, the value is nil.
If TEST is omitted or nil, `equal' is used."
(let (found (tail alist) value)
(while (and tail (not found))
(let ((elt (car tail)))
(when (funcall (or test 'equal) (if (consp elt) (car elt) elt) key)
(setq found t value (if (consp elt) (cdr elt) default))))
(setq tail (cdr tail)))
value))
;;;; Keymap support.