;;; regexp-opt.el --- generate efficient regexps to match strings
-;; Copyright (C) 1994-2011 Free Software Foundation, Inc.
+;; Copyright (C) 1994-2014 Free Software Foundation, Inc.
;; Author: Simon Marshall <simon@gnu.org>
-;; Maintainer: FSF
+;; Maintainer: emacs-devel@gnu.org
;; Keywords: strings, regexps, extensions
;; This file is part of GNU Emacs.
\f
;;; Workhorse functions.
-(eval-when-compile
- (require 'cl))
-
(defun regexp-opt-group (strings &optional paren lax)
"Return a regexp to match a string in the sorted list STRINGS.
If PAREN non-nil, output regexp parentheses around returned regexp.
If LAX non-nil, don't output parentheses if it doesn't require them.
-Merges keywords to avoid backtracking in Emacs' regexp matcher."
+Merges keywords to avoid backtracking in Emacs's regexp matcher."
;; The basic idea is to find the shortest common prefix or suffix, remove it
;; and recurse. If there is no prefix, we divide the list into two so that
;; \(at least) one half will have at least a one-character common prefix.
(regexp-opt-group suffixes t t)
close-group))
- (let* ((sgnirts (mapcar (lambda (s)
- (concat (nreverse (string-to-list s))))
- strings))
+ (let* ((sgnirts (mapcar #'reverse strings))
(xiffus (try-completion "" sgnirts)))
(if (> (length xiffus) 0)
;; common suffix: take it and recurse on the prefixes.
'string-lessp)))
(concat open-group
(regexp-opt-group prefixes t t)
- (regexp-quote
- (concat (nreverse (string-to-list xiffus))))
+ (regexp-quote (nreverse xiffus))
close-group))
;; Otherwise, divide the list into those that start with a
(defun regexp-opt-charset (chars)
- "Return a regexp to match a character in CHARS."
+ "Return a regexp to match a character in CHARS.
+CHARS should be a list of characters."
;; The basic idea is to find character ranges. Also we take care in the
;; position of character set meta characters in the character set regexp.
;;
;;
;; Make a character map but extract character set meta characters.
(dolist (char chars)
- (case char
- (?\]
- (setq bracket "]"))
- (?^
- (setq caret "^"))
- (?-
- (setq dash "-"))
- (otherwise
- (aset charmap char t))))
+ (cond
+ ((eq char ?\])
+ (setq bracket "]"))
+ ((eq char ?^)
+ (setq caret "^"))
+ ((eq char ?-)
+ (setq dash "-"))
+ (t
+ (aset charmap char t))))
;;
;; Make a character set from the map using ranges where applicable.
(map-char-table
(setq charset (format "%s%c-%c" charset start end))
(while (>= end start)
(setq charset (format "%s%c" charset start))
- (incf start)))
+ (setq start (1+ start))))
(setq start (car c) end (cdr c)))
(if (= (1- c) end) (setq end c)
(if (> end (+ start 2))
(setq charset (format "%s%c-%c" charset start end))
(while (>= end start)
(setq charset (format "%s%c" charset start))
- (incf start)))
+ (setq start (1+ start))))
(setq start c end c)))))
charmap)
(when (>= end start)
(setq charset (format "%s%c-%c" charset start end))
(while (>= end start)
(setq charset (format "%s%c" charset start))
- (incf start))))
+ (setq start (1+ start)))))
;;
;; Make sure a caret is not first and a dash is first or last.
(if (and (string-equal charset "") (string-equal bracket ""))
- (concat "[" dash caret "]")
+ (if (string-equal dash "")
+ "\\^" ; [^] is not a valid regexp
+ (concat "[" dash caret "]"))
(concat "[" bracket charset caret dash "]"))))
(provide 'regexp-opt)