mirrors/emacs
1
Fork 0
mirror of git://git.sv.gnu.org/emacs.git synced 2026-01-03 18:41:25 -08:00
Code Issues Projects Releases Wiki Activity

* lisp/emacs-lisp/pcase.el (pcase-split-memq): Overenthusiastic optimisation.

Browse source 
(pcase-u1): Handle the case of a lambda pred.
This commit is contained in:
Stefan Monnier 2010-09-01 12:03:08 +02:00
parent da43765da1
commit 4de81ee0d2
3 changed files with 27 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

34
lisp/emacs-lisp/pcase.el
View file

@ -290,9 +290,13 @@ MATCH is the pattern that needs to be matched, of the form:
(defun pcase-split-memq (elems pat)
;; Based on pcase-split-eq.
(cond
;; The same match will give the same result.
;; The same match will give the same result, but we don't know how
;; to check it.
;; (???
;; (cons :pcase-succeed nil))
;; A match for one of the elements may succeed or fail.
((and (eq (car-safe pat) '\`) (member (cadr pat) elems))
(cons :pcase-succeed nil))
nil)
;; A different match will fail if this one succeeds.
((and (eq (car-safe pat) '\`)
;; (or (integerp (cadr pat)) (symbolp (cadr pat))
@ -383,18 +387,20 @@ and otherwise defers to REST which is a list of branches of the form
`(,(cadr upat) ,sym)
(let* ((exp (cadr upat))
;; `vs' is an upper bound on the vars we need.
(vs (pcase-fgrep (mapcar #'car vars) exp)))
(if vs
;; Let's not replace `vars' in `exp' since it's
;; too difficult to do it right, instead just
;; let-bind `vars' around `exp'.
`(let ,(mapcar (lambda (var)
(list var (cdr (assq var vars))))
vs)
;; FIXME: `vars' can capture `sym'. E.g.
;; (pcase x ((and `(,x . ,y) (pred (fun x)))))
(,@exp ,sym))
`(,@exp ,sym))))
(vs (pcase-fgrep (mapcar #'car vars) exp))
(call (if (functionp exp)
`(,exp ,sym) `(,@exp ,sym))))
(if (null vs)
call
;; Let's not replace `vars' in `exp' since it's
;; too difficult to do it right, instead just
;; let-bind `vars' around `exp'.
`(let ,(mapcar (lambda (var)
(list var (cdr (assq var vars))))
vs)
;; FIXME: `vars' can capture `sym'. E.g.
;; (pcase x ((and `(,x . ,y) (pred (fun x)))))
,call))))
(pcase-u1 matches code vars then-rest)
(pcase-u else-rest))))
((symbolp upat)