;;; paren.el --- highlight matching paren
-;; Copyright (C) 1993, 1996, 2001-2015 Free Software Foundation, Inc.
+;; Copyright (C) 1993, 1996, 2001-2016 Free Software Foundation, Inc.
;; Author: rms@gnu.org
;; Maintainer: emacs-devel@gnu.org
`expression' (meaning show the entire expression enclosed by the paren) and
`mixed' (meaning show the matching paren if it is visible, and the expression
otherwise)."
- :type '(choice (const parenthesis) (const expression) (const mixed))
- :group 'paren-showing)
+ :type '(choice (const parenthesis) (const expression) (const mixed)))
(defcustom show-paren-delay 0.125
"Time in seconds to delay before showing a matching paren.
(set sym val)
(show-paren-mode -1)
(set sym val)
- (show-paren-mode 1)))
- :group 'paren-showing)
+ (show-paren-mode 1))))
(defcustom show-paren-priority 1000
"Priority of paren highlighting overlays."
- :type 'integer
- :group 'paren-showing
+ :type 'integer
:version "21.1")
(defcustom show-paren-ring-bell-on-mismatch nil
"If non-nil, beep if mismatched paren is detected."
:type 'boolean
- :group 'paren-showing
:version "20.3")
-(define-obsolete-face-alias 'show-paren-match-face 'show-paren-match "22.1")
+(defcustom show-paren-when-point-inside-paren nil
+ "If non-nil, show parens when point is just inside one.
+This will only be done when point isn't also just outside a paren."
+ :type 'boolean
+ :version "25.1")
-(define-obsolete-face-alias 'show-paren-mismatch-face
- 'show-paren-mismatch "22.1")
+(defcustom show-paren-when-point-in-periphery nil
+ "If non-nil, show parens when point is in the line's periphery.
+The periphery is at the beginning or end of a line or in any
+whitespace there."
+ :type 'boolean
+ :version "25.1")
-(defvar show-paren-highlight-openparen t
- "Non-nil turns on openparen highlighting when matching forward.")
+(defcustom show-paren-highlight-openparen t
+ "Non-nil turns on openparen highlighting when matching forward.
+When nil, and point stands just before an open paren, the paren
+is not highlighted, the cursor being regarded as adequate to mark
+its position."
+ :type 'boolean)
(defvar show-paren--idle-timer nil)
(defvar show-paren--overlay
(delete-overlay show-paren--overlay)
(delete-overlay show-paren--overlay-1)))
+(defun show-paren--unescaped-p (pos)
+ "Determine whether the paren after POS is unescaped."
+ (save-excursion
+ (goto-char pos)
+ (= (logand (skip-syntax-backward "/\\") 1) 0)))
+
+(defun show-paren--categorize-paren (pos)
+ "Determine whether the character after POS has paren syntax,
+and if so, return a cons (DIR . OUTSIDE), where DIR is 1 for an
+open paren, -1 for a close paren, and OUTSIDE is the buffer
+position of the outside of the paren. If the character isn't a
+paren, or it is an escaped paren, return nil."
+ (cond
+ ((and (eq (syntax-class (syntax-after pos)) 4)
+ (show-paren--unescaped-p pos))
+ (cons 1 pos))
+ ((and (eq (syntax-class (syntax-after pos)) 5)
+ (show-paren--unescaped-p pos))
+ (cons -1 (1+ pos)))))
+
+(defun show-paren--locate-near-paren ()
+ "Locate an unescaped paren \"near\" point to show.
+If one is found, return the cons (DIR . OUTSIDE), where DIR is 1
+for an open paren, -1 for a close paren, and OUTSIDE is the buffer
+position of the outside of the paren. Otherwise return nil."
+ (let* ((ind-pos (save-excursion (back-to-indentation) (point)))
+ (eol-pos
+ (save-excursion
+ (end-of-line) (skip-chars-backward " \t" ind-pos) (point)))
+ (before (show-paren--categorize-paren (1- (point))))
+ (after (show-paren--categorize-paren (point))))
+ (cond
+ ;; Point is immediately outside a paren.
+ ((eq (car before) -1) before)
+ ((eq (car after) 1) after)
+ ;; Point is immediately inside a paren.
+ ((and show-paren-when-point-inside-paren before))
+ ((and show-paren-when-point-inside-paren after))
+ ;; Point is in the whitespace before the code.
+ ((and show-paren-when-point-in-periphery
+ (<= (point) ind-pos))
+ (or (show-paren--categorize-paren ind-pos)
+ (show-paren--categorize-paren (1- eol-pos))))
+ ;; Point is in the whitespace after the code.
+ ((and show-paren-when-point-in-periphery
+ (>= (point) eol-pos))
+ (show-paren--categorize-paren (1- eol-pos))))))
+
(defvar show-paren-data-function #'show-paren--default
- "Function to find the opener/closer at point and its match.
+ "Function to find the opener/closer \"near\" point and its match.
The function is called with no argument and should return either nil
-if there's no opener/closer at point, or a list of the form
+if there's no opener/closer near point, or a list of the form
\(HERE-BEG HERE-END THERE-BEG THERE-END MISMATCH)
-Where HERE-BEG..HERE-END is expected to be around point.")
+Where HERE-BEG..HERE-END is expected to be near point.")
(defun show-paren--default ()
- (let* ((oldpos (point))
- (dir (cond ((eq (syntax-class (syntax-after (1- (point)))) 5) -1)
- ((eq (syntax-class (syntax-after (point))) 4) 1)))
- (unescaped
- (when dir
- ;; Verify an even number of quoting characters precede the paren.
- ;; Follow the same logic as in `blink-matching-open'.
- (= (if (= dir -1) 1 0)
- (logand 1 (- (point)
- (save-excursion
- (if (= dir -1) (forward-char -1))
- (skip-syntax-backward "/\\")
- (point)))))))
- (here-beg (if (eq dir 1) (point) (1- (point))))
- (here-end (if (eq dir 1) (1+ (point)) (point)))
- pos mismatch)
+ (let* ((temp (show-paren--locate-near-paren))
+ (dir (car temp))
+ (outside (cdr temp))
+ pos mismatch here-beg here-end)
;;
;; Find the other end of the sexp.
- (when unescaped
- (save-excursion
- (save-restriction
- ;; Determine the range within which to look for a match.
- (when blink-matching-paren-distance
- (narrow-to-region
- (max (point-min) (- (point) blink-matching-paren-distance))
- (min (point-max) (+ (point) blink-matching-paren-distance))))
- ;; Scan across one sexp within that range.
- ;; Errors or nil mean there is a mismatch.
- (condition-case ()
- (setq pos (scan-sexps (point) dir))
- (error (setq pos t mismatch t)))
- ;; Move back the other way and verify we get back to the
- ;; starting point. If not, these two parens don't really match.
- ;; Maybe the one at point is escaped and doesn't really count,
- ;; or one is inside a comment.
- (when (integerp pos)
- (unless (condition-case ()
- (eq (point) (scan-sexps pos (- dir)))
- (error nil))
- (setq pos nil)))
- ;; If found a "matching" paren, see if it is the right
- ;; kind of paren to match the one we started at.
- (if (not (integerp pos))
- (if mismatch (list here-beg here-end nil nil t))
- (let ((beg (min pos oldpos)) (end (max pos oldpos)))
- (unless (eq (syntax-class (syntax-after beg)) 8)
- (setq mismatch
- (not (or (eq (char-before end)
- ;; This can give nil.
- (cdr (syntax-after beg)))
- (eq (char-after beg)
- ;; This can give nil.
- (cdr (syntax-after (1- end))))
- ;; The cdr might hold a new paren-class
- ;; info rather than a matching-char info,
- ;; in which case the two CDRs should match.
- (eq (cdr (syntax-after (1- end)))
- (cdr (syntax-after beg)))))))
- (list here-beg here-end
- (if (= dir 1) (1- pos) pos)
- (if (= dir 1) pos (1+ pos))
- mismatch))))))))
+ (when dir
+ (setq here-beg (if (eq dir 1) outside (1- outside))
+ here-end (if (eq dir 1) (1+ outside) outside))
+ (save-restriction
+ ;; Determine the range within which to look for a match.
+ (when blink-matching-paren-distance
+ (narrow-to-region
+ (max (point-min) (- (point) blink-matching-paren-distance))
+ (min (point-max) (+ (point) blink-matching-paren-distance))))
+ ;; Scan across one sexp within that range.
+ ;; Errors or nil mean there is a mismatch.
+ (condition-case ()
+ (setq pos (scan-sexps outside dir))
+ (error (setq pos t mismatch t)))
+ ;; Move back the other way and verify we get back to the
+ ;; starting point. If not, these two parens don't really match.
+ ;; Maybe the one at point is escaped and doesn't really count,
+ ;; or one is inside a comment.
+ (when (integerp pos)
+ (unless (condition-case ()
+ (eq outside (scan-sexps pos (- dir)))
+ (error nil))
+ (setq pos nil)))
+ ;; If found a "matching" paren, see if it is the right
+ ;; kind of paren to match the one we started at.
+ (if (not (integerp pos))
+ (if mismatch (list here-beg here-end nil nil t))
+ (let ((beg (min pos outside)) (end (max pos outside)))
+ (unless (eq (syntax-class (syntax-after beg)) 8)
+ (setq mismatch
+ (not (or (eq (char-before end)
+ ;; This can give nil.
+ (cdr (syntax-after beg)))
+ (eq (char-after beg)
+ ;; This can give nil.
+ (cdr (syntax-after (1- end))))
+ ;; The cdr might hold a new paren-class
+ ;; info rather than a matching-char info,
+ ;; in which case the two CDRs should match.
+ (eq (cdr (syntax-after (1- end)))
+ (cdr (syntax-after beg)))))))
+ (list here-beg here-end
+ (if (= dir 1) (1- pos) pos)
+ (if (= dir 1) pos (1+ pos))
+ mismatch)))))))
;; Find the place to show, if there is one,
;; and show it until input arrives.
;; Otherwise, turn off any such highlighting.
(if (or (not here-beg)
(and (not show-paren-highlight-openparen)
- (> here-end (point))
+ (> here-end (point))
+ (<= here-beg (point))
(integerp there-beg)))
(delete-overlay show-paren--overlay-1)
(move-overlay show-paren--overlay-1
(1- there-end) (1+ there-beg))))
(not (pos-visible-in-window-p closest)))))
(move-overlay show-paren--overlay
- (point)
+ (if (< there-beg here-beg) here-end here-beg)
(if (< there-beg here-beg) there-beg there-end)
(current-buffer))
(move-overlay show-paren--overlay