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[Emacs-diffs] emacs-25 5c59970 2/3: * lisp/character-fold.el: Add suppor
From: |
Artur Malabarba |
Subject: |
[Emacs-diffs] emacs-25 5c59970 2/3: * lisp/character-fold.el: Add support for multi-char matches |
Date: |
Sat, 28 Nov 2015 16:22:15 +0000 |
branch: emacs-25
commit 5c5997002b0b0aded744d5828158243fd546b3ec
Author: Artur Malabarba <address@hidden>
Commit: Artur Malabarba <address@hidden>
* lisp/character-fold.el: Add support for multi-char matches
(character-fold-table): Now has an extra-slot. This is a second
char-table that holds multi-character matches. See docstring for
details.
(character-fold-to-regexp): Can build branching regexps when a
character's entry the extra slot of `character-fold-table' matches the
characters that succeed it.
---
lisp/character-fold.el | 173 +++++++++++++++++++++-----------
test/automated/character-fold-tests.el | 45 +++++++--
2 files changed, 149 insertions(+), 69 deletions(-)
diff --git a/lisp/character-fold.el b/lisp/character-fold.el
index 749d113..0086345 100644
--- a/lisp/character-fold.el
+++ b/lisp/character-fold.el
@@ -22,11 +22,15 @@
;;; Code:
+(eval-and-compile (put 'character-fold-table 'char-table-extra-slots 1))
(defconst character-fold-table
(eval-when-compile
(let ((equiv (make-char-table 'character-fold-table))
+ (equiv-multi (make-char-table 'character-fold-table))
(table (unicode-property-table-internal 'decomposition)))
+ (set-char-table-extra-slot equiv 0 equiv-multi)
+
;; Ensure the table is populated.
(let ((func (char-table-extra-slot table 1)))
(map-char-table (lambda (char v)
@@ -36,63 +40,61 @@
;; Compile a list of all complex characters that each simple
;; character should match.
+ ;; In summary this loop does 3 things:
+ ;; - A complex character might be allowed to match its decomp.
+ ;; - The decomp is allowed to match the complex character.
+ ;; - A single char of the decomp might be allowed to match the
+ ;; character.
+ ;; Some examples in the comments below.
(map-char-table
(lambda (char decomp)
(when (consp decomp)
- (if (symbolp (car decomp))
- ;; Discard a possible formatting tag.
- (setq decomp (cdr decomp))
- ;; If there's no formatting tag, ensure that char matches
- ;; its decomp exactly. This is because we want 'ä' to
- ;; match 'ä', but we don't want '¹' to match '1'.
- (aset equiv char
- (cons (apply #'string decomp)
- (aref equiv char))))
- ;; Finally, figure out whether char has a simpler
- ;; equivalent (char-aux). If so, ensure that char-aux
- ;; matches char and maybe its decomp too.
-
;; Skip trivial cases like ?a decomposing to (?a).
- (unless (or (and (eq char (car decomp))
- (not (cdr decomp))))
- (let ((dec-aux decomp)
- (fold-decomp t)
- char-aux found)
- (while (and dec-aux (not found))
- (setq char-aux (pop dec-aux))
- ;; Is char-aux a number or letter, per unicode standard?
- (setq found (memq (get-char-code-property char-aux
'general-category)
- '(Lu Ll Lt Lm Lo Nd Nl No))))
- (if found
- ;; Check if the decomp has more than one letter,
- ;; because then we don't want the first letter to
- ;; match the decomposition. This is because we
- ;; want 'f' to match 'ff' but not 'ff'.
- (dolist (char-aux dec-aux)
- (when (and fold-decomp
- (memq (get-char-code-property char-aux
'general-category)
- '(Lu Ll Lt Lm Lo Nd Nl No)))
- (setq fold-decomp nil)))
- ;; If there's no number or letter on the
- ;; decomp, take the first character in it.
- (setq found (car-safe decomp)))
- ;; Finally, we only fold multi-char decomp if at
- ;; least one of the chars is non-spacing (combining).
- (when fold-decomp
- (setq fold-decomp nil)
- (dolist (char-aux decomp)
- (when (and (not fold-decomp)
- (> (get-char-code-property char-aux
'canonical-combining-class) 0))
- (setq fold-decomp t))))
- ;; Add char to the list of characters that char-aux can
- ;; represent. Also possibly add its decomp, so we can
- ;; match multi-char representations like (format "a%c" 769)
- (when (and found (not (eq char char-aux)))
- (let ((chars (cons (char-to-string char) (aref equiv
char-aux))))
- (aset equiv char-aux
- (if fold-decomp
- (cons (apply #'string decomp) chars)
- chars))))))))
+ (unless (and (not (cdr decomp))
+ (eq char (car decomp)))
+ (if (symbolp (car decomp))
+ ;; Discard a possible formatting tag.
+ (setq decomp (cdr decomp))
+ ;; If there's no formatting tag, ensure that char matches
+ ;; its decomp exactly. This is because we want 'ä' to
+ ;; match 'ä', but we don't want '¹' to match '1'.
+ (aset equiv char
+ (cons (apply #'string decomp)
+ (aref equiv char))))
+
+ ;; Allow the entire decomp to match char. If decomp has
+ ;; multiple characters, this is done by adding an entry
+ ;; to the alist of the first character in decomp. This
+ ;; allows 'ff' to match 'ff', 'ä' to match 'ä', and '1' to
+ ;; match '¹'.
+ (let ((make-decomp-match-char
+ (lambda (decomp char)
+ (if (cdr decomp)
+ (aset equiv-multi (car decomp)
+ (cons (cons (apply #'string (cdr decomp))
+ (regexp-quote (string char)))
+ (aref equiv-multi (car decomp))))
+ (aset equiv (car decomp)
+ (cons (char-to-string char)
+ (aref equiv (car decomp))))))))
+ (funcall make-decomp-match-char decomp char)
+ ;; Do it again, without the non-spacing characters.
+ ;; This allows 'a' to match 'ä'.
+ (let ((simpler-decomp nil)
+ (found-one nil))
+ (dolist (c decomp)
+ (if (> (get-char-code-property c
'canonical-combining-class) 0)
+ (setq found-one t)
+ (push c simpler-decomp)))
+ (when (and simpler-decomp found-one)
+ (funcall make-decomp-match-char simpler-decomp char)
+ ;; Finally, if the decomp only had one spacing
+ ;; character, we allow this character to match the
+ ;; decomp. This is to let 'a' match 'ä'.
+ (unless (cdr simpler-decomp)
+ (aset equiv (car simpler-decomp)
+ (cons (apply #'string decomp)
+ (aref equiv (car simpler-decomp)))))))))))
table)
;; Add some manual entries.
@@ -112,7 +114,27 @@
(aset equiv char re))))
equiv)
equiv))
- "Used for folding characters of the same group during search.")
+ "Used for folding characters of the same group during search.
+This is a char-table with the `character-fold-table' subtype.
+
+Let us refer to the character in question by char-x.
+Each entry is either nil (meaning char-x only matches literally)
+or a regexp. This regexp should match anything that char-x can
+match by itself \(including char-x). For instance, the default
+regexp for the ?+ character is \"[+⁺₊﬩﹢+]\".
+
+This table also has one extra slot which is also a char-table.
+Each entry in the extra slot is an alist used for multi-character
+matching (which may be nil). The elements of the alist should
+have the form (SUFFIX . OTHER-REGEXP). If the characters after
+char-x are equal to SUFFIX, then this combination of char-x +
+SUFFIX is allowed to match OTHER-REGEXP. This is in addition to
+char-x being allowed to match REGEXP.
+For instance, the default alist for ?f includes:
+ \((\"fl\" . \"ffl\") (\"fi\" . \"ffi\")
+ (\"i\" . \"fi\") (\"f\" . \"ff\"))
+
+Exceptionally for the space character (32), ALIST is ignored.")
(defun character-fold--make-space-string (n)
"Return a string that matches N spaces."
@@ -122,13 +144,17 @@
(make-list n (or (aref character-fold-table ?\s) " ")))))
;;;###autoload
-(defun character-fold-to-regexp (string &optional _lax)
+(defun character-fold-to-regexp (string &optional _lax from)
"Return a regexp matching anything that character-folds into STRING.
Any character in STRING that has an entry in
`character-fold-table' is replaced with that entry (which is a
-regexp) and other characters are `regexp-quote'd."
+regexp) and other characters are `regexp-quote'd.
+
+FROM is for internal use. It specifies an index in the STRING
+from which to start."
(let ((spaces 0)
- (i 0)
+ (multi-char-table (char-table-extra-slot character-fold-table 0))
+ (i (or from 0))
(end (length string))
(out nil))
;; When the user types a space, we want to match the table entry
@@ -145,9 +171,36 @@ regexp) and other characters are `regexp-quote'd."
(c (when (> spaces 0)
(push (character-fold--make-space-string spaces) out)
(setq spaces 0))
- (push (or (aref character-fold-table c)
- (regexp-quote (string c)))
- out)))
+ (let ((regexp (or (aref character-fold-table c)
+ (regexp-quote (string c))))
+ ;; Long string. The regexp would probably be too long.
+ (alist (unless (> end 60)
+ (aref multi-char-table c))))
+ (push (let ((alist-out '("\\)")))
+ (pcase-dolist (`(,suffix . ,out-regexp) alist)
+ (let ((len-suf (length suffix)))
+ (when (eq (compare-strings suffix 0 nil
+ string (1+ i) (+ i 1
len-suf)
+ nil)
+ t)
+ ;; FIXME: If N suffixes match, we "branch"
+ ;; out into N+1 executions for the rest of
+ ;; the string. This involves redundant
+ ;; work and makes a huge regexp.
+ (push (concat "\\|" out-regexp
+ (character-fold-to-regexp
+ string nil (+ i 1 len-suf)))
+ alist-out))))
+ ;; If no suffixes matched, just go on.
+ (if (not (cdr alist-out))
+ regexp
+ ;; Otherwise, add a branch for the
+ ;; no-suffix case, and stop the loop here.
+ (prog1 (apply #'concat "\\(?:" regexp
+ (character-fold-to-regexp string nil (1+
i))
+ alist-out)
+ (setq i end))))
+ out))))
(setq i (1+ i)))
(when (> spaces 0)
(push (character-fold--make-space-string spaces) out))
diff --git a/test/automated/character-fold-tests.el
b/test/automated/character-fold-tests.el
index 40f0aec..aa2ee96 100644
--- a/test/automated/character-fold-tests.el
+++ b/test/automated/character-fold-tests.el
@@ -43,7 +43,7 @@
(character-fold--test-search-with-contents w w))))
(ert-deftest character-fold--test-lax-whitespace ()
- (dotimes (n 100)
+ (dotimes (n 50)
(let ((w1 (character-fold--random-word n))
(w2 (character-fold--random-word n))
(search-spaces-regexp "\\s-+"))
@@ -52,17 +52,44 @@
(concat w1 " " w2))
(character-fold--test-search-with-contents
(concat w1 "\s\n\s\t\f\t\n\r\t" w2)
- (concat w1 (make-string 90 ?\s) w2)))))
+ (concat w1 (make-string 10 ?\s) w2)))))
+
+(defun character-fold--test-match-exactly (string &rest strings-to-match)
+ (let ((re (concat "\\`" (character-fold-to-regexp string) "\\'")))
+ (dolist (it strings-to-match)
+ (should (string-match re it)))))
+
+(ert-deftest character-fold--test-some-defaults ()
+ (dolist (it '(("ffl" . "ffl") ("ffi" . "ffi")
+ ("fi" . "fi") ("ff" . "ff")
+ ("ä" . "ä")))
+ (character-fold--test-search-with-contents (cdr it) (car it))
+ (let ((multi (char-table-extra-slot character-fold-table 0))
+ (character-fold-table (make-char-table 'character-fold-table)))
+ (set-char-table-extra-slot character-fold-table 0 multi)
+ (character-fold--test-match-exactly (car it) (cdr it)))))
(ert-deftest character-fold--test-fold-to-regexp ()
- (let ((character-fold-table (make-char-table 'character-fold-table)))
- (aset character-fold-table ?a "abc")
- (aset character-fold-table ?1 "123")
+ (let ((character-fold-table (make-char-table 'character-fold-table))
+ (multi (make-char-table 'character-fold-table)))
+ (set-char-table-extra-slot character-fold-table 0 multi)
+ (aset character-fold-table ?a "xx")
+ (aset character-fold-table ?1 "44")
(aset character-fold-table ?\s "-!-")
- (should (equal (character-fold-to-regexp "a1a1")
- "abc123abc123"))
- (should (equal (character-fold-to-regexp "a1 a 1")
- "abc123\\(?: \\|-!--!-\\)abc\\(?: \\|-!-\\)123"))))
+ (character-fold--test-match-exactly "a1a1" "xx44xx44")
+ (character-fold--test-match-exactly "a1 a 1" "xx44-!--!-xx-!-44")
+ (aset multi ?a '(("1" . "99")
+ ("2" . "88")
+ ("12" . "77")))
+ (character-fold--test-match-exactly "a" "xx")
+ (character-fold--test-match-exactly "a1" "xx44" "99")
+ (character-fold--test-match-exactly "a12" "77" "xx442" "992")
+ (character-fold--test-match-exactly "a2" "88")
+ (aset multi ?1 '(("2" . "yy")))
+ (character-fold--test-match-exactly "a1" "xx44" "99")
+ (character-fold--test-match-exactly "a12" "77" "xx442" "992")
+ (character-fold--test-match-exactly "a12" "xxyy")))
+
(provide 'character-fold-tests)
;;; character-fold-tests.el ends here