[Emacs-diffs] trunk r118135: Trigger showing when point is in the "periphery" of a line or just

[Alan Mackenzie]

------------------------------------------------------------
revno: 118135
revision-id: address@hidden
parent: address@hidden
committer: Alan Mackenzie <address@hidden>
branch nick: trunk
timestamp: Thu 2014-10-16 20:29:44 +0000
message:
  Trigger showing when point is in the "periphery" of a line or just
  inside a paren.
  paren.el (show-paren-style, show-paren-delay)
  (show-paren-priority, show-paren-ring-bell-on-mismatch): Remove
  superfluous :group specifications.
  (show-paren-when-point-inside-paren)
  (show-paren-when-point-in-periphery): New customizable variables.
  (show-paren-highlight-openparen): Make into a defcustom.
  (show-paren--unescaped-p, show-paren--categorize-paren)
  (show-paren--locate-near-paren): New defuns.
  (show-paren--default): Refaactor and trigger on more paren
  positions.
  (show-paren-function): Small consequential changes.
modified:
  lisp/ChangeLog                 changelog-20091113204419-o5vbwnq5f7feedwu-1432
  lisp/paren.el                  paren.el-20091113204419-o5vbwnq5f7feedwu-601

=== modified file 'lisp/ChangeLog'
--- a/lisp/ChangeLog    2014-10-16 19:56:43 +0000
+++ b/lisp/ChangeLog    2014-10-16 20:29:44 +0000
@@ -1,3 +1,19 @@
+2014-10-16  Alan Mackenzie  <address@hidden>
+
+       Trigger showing when point is in the "periphery" of a line or just
+       inside a paren.
+       * paren.el (show-paren-style, show-paren-delay)
+       (show-paren-priority, show-paren-ring-bell-on-mismatch): Remove
+       superfluous :group specifications.
+       (show-paren-when-point-inside-paren)
+       (show-paren-when-point-in-periphery): New customizable variables.
+       (show-paren-highlight-openparen): Make into a defcustom.
+       (show-paren--unescaped-p, show-paren--categorize-paren)
+       (show-paren--locate-near-paren): New defuns.
+       (show-paren--default): Refaactor and trigger on more paren
+       positions.
+       (show-paren-function): Small consequential changes.
+
 2014-10-16  Tom Tromey  <address@hidden>
 
        * files.el (auto-mode-alist): Use javascript-mode for .jsm

=== modified file 'lisp/paren.el'
--- a/lisp/paren.el     2014-02-10 01:34:22 +0000
+++ b/lisp/paren.el     2014-10-16 20:29:44 +0000
@@ -43,8 +43,7 @@
 `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.
@@ -57,28 +56,39 @@
             (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")
 
+(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")
+
+(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")
+
 (define-obsolete-face-alias 'show-paren-match-face 'show-paren-match "22.1")
 
 (define-obsolete-face-alias 'show-paren-mismatch-face
   'show-paren-mismatch "22.1")
 
-(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."
+  :type 'boolean)
 
 (defvar show-paren--idle-timer nil)
 (defvar show-paren--overlay
@@ -112,76 +122,113 @@
     (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.
@@ -215,7 +262,8 @@
         ;; 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
@@ -234,7 +282,7 @@
                                           (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