[Emacs-diffs] Changes to emacs/lisp/emacs-lisp/syntax.el

[Stefan Monnier]

Index: emacs/lisp/emacs-lisp/syntax.el
diff -c emacs/lisp/emacs-lisp/syntax.el:1.8 emacs/lisp/emacs-lisp/syntax.el:1.9
*** emacs/lisp/emacs-lisp/syntax.el:1.8 Wed Jul 16 11:17:02 2003
--- emacs/lisp/emacs-lisp/syntax.el     Wed Jul 16 11:40:25 2003
***************
*** 39,45 ****
  ;; - new functions `syntax-state', ... to replace uses of parse-partial-state
  ;;   with something higher-level (similar to syntax-ppss-context).
  ;; - interaction with mmm-mode.
- ;; - what to do when the buffer is narrowed ?
  
  ;;; Code:
  
--- 39,44 ----
***************
*** 118,258 ****
        (pt-min (point-min)))
      (if (and old-pos (> old-pos pos)) (setq old-pos nil))
      ;; Use the OLD-POS if usable and close.  Don't update the `last' cache.
!     (if (and old-pos (< (- pos old-pos)
!                       ;; The time to find PPSS using syntax-begin-function
!                       ;; is assumed to be about 2 * distance.
!                       (* 2 (/ (cdr (aref syntax-ppss-stats 5))
!                               (1+ (car (aref syntax-ppss-stats 5)))))))
!       (progn
!         (incf (car (aref syntax-ppss-stats 0)))
!         (incf (cdr (aref syntax-ppss-stats 0)) (- pos old-pos))
!         (parse-partial-sexp old-pos pos nil nil old-ppss))
! 
!       (cond
!        ;; Use OLD-PPSS if possible and close enough.
!        ((and (not old-pos) old-ppss
!            ;; BEWARE! We rely on the undocumented 9th field.
!            ;; The 9th field currently contains the list of positions
!            ;; of open-parens of the enclosing parens.  I.e.  those positions
!            ;; are outside of any string/comment and the first of those is
!            ;; outside of any paren (i.e. corresponds to a nil ppss).
!            ;; If this list is empty but we are in a string or comment,
!            ;; then the 8th field contains a similar "toplevel" position.
!            ;; If `pt-min' is too far from `pos', we could try to use
!            ;; other positions in (nth 9 old-ppss), but that doesn't seem
!            ;; to happen in practice and it would complicate this code
!            ;; (and the after-change-function code even more).  But maybe it
!            ;; would be useful in "degenerate" cases such as when the whole
!            ;; file is wrapped in a set of parenthesis.
!            (setq pt-min (or (car (nth 9 old-ppss))
!                             (nth 8 old-ppss)
!                             (nth 2 old-ppss)))
!            (<= pt-min pos) (< (- pos pt-min) syntax-ppss-max-span))
!       (incf (car (aref syntax-ppss-stats 1)))
!       (incf (cdr (aref syntax-ppss-stats 1)) (- pos pt-min))
!       (setq ppss (parse-partial-sexp pt-min pos)))
!        ;; The OLD-* data can't be used.  Consult the cache.
!        (t
!       (let ((cache-pred nil)
!             (cache syntax-ppss-cache)
!             (pt-min (point-min))
!             ;; I differentiate between PT-MIN and PT-BEST because I feel
!             ;; like it might be important to ensure that the cache is only
!             ;; filled with 100% sure data (whereas syntax-begin-function
!             ;; might return incorrect data).  Maybe that's just stupid.
!             (pt-best (point-min))
!             (ppss-best nil))
!         ;; look for a usable cache entry.
!         (while (and cache (< pos (caar cache)))
!           (setq cache-pred cache)
!           (setq cache (cdr cache)))
!         (if cache (setq pt-min (caar cache) ppss (cdar cache)))
! 
!         ;; Setup the after-change function if necessary.
!         (unless (or syntax-ppss-cache syntax-ppss-last)
!           (add-hook 'after-change-functions 'syntax-ppss-flush-cache nil t))
! 
!         ;; Use the best of OLD-POS and CACHE.
!         (if (or (not old-pos) (< old-pos pt-min))
!             (setq pt-best pt-min ppss-best ppss)
!           (incf (car (aref syntax-ppss-stats 4)))
!           (incf (cdr (aref syntax-ppss-stats 4)) (- pos old-pos))
!           (setq pt-best old-pos ppss-best old-ppss))
! 
!         ;; Use the `syntax-begin-function' if available.
!         ;; We could try using that function earlier, but:
!         ;; - The result might not be 100% reliable, so it's better to use
!         ;;   the cache if available.
!         ;; - The function might be slow.
!         ;; - If this function almost always finds a safe nearby spot,
!         ;;   the cache won't be populated, so consulting it is cheap.
!         (unless (or syntax-begin-function
!                     (not (boundp 'font-lock-beginning-of-syntax-function))
!                     (not font-lock-beginning-of-syntax-function))
!           (set (make-local-variable 'syntax-begin-function)
!                font-lock-beginning-of-syntax-function))
!         (when (and syntax-begin-function
!                    (progn (goto-char pos)
!                           (funcall syntax-begin-function)
!                           ;; Make sure it's better.
!                           (> (point) pt-best))
!                    ;; Simple sanity check.
!                    (not (memq (get-text-property (point) 'face)
!                               '(font-lock-string-face font-lock-comment-face
!                                 font-lock-doc-face))))
!           (incf (car (aref syntax-ppss-stats 5)))
!           (incf (cdr (aref syntax-ppss-stats 5)) (- pos (point)))
!           (setq pt-best (point) ppss-best nil))
  
          (cond
!          ;; Quick case when we found a nearby pos.
!          ((< (- pos pt-best) syntax-ppss-max-span)
!           (incf (car (aref syntax-ppss-stats 2)))
!           (incf (cdr (aref syntax-ppss-stats 2)) (- pos pt-best))
!           (setq ppss (parse-partial-sexp pt-best pos nil nil ppss-best)))
!          ;; Slow case: compute the state from some known position and
!          ;; populate the cache so we won't need to do it again soon.
           (t
!           (incf (car (aref syntax-ppss-stats 3)))
!           (incf (cdr (aref syntax-ppss-stats 3)) (- pos pt-min))
! 
!           ;; If `pt-min' is too far, add a few intermediate entries.
!           (while (> (- pos pt-min) (* 2 syntax-ppss-max-span))
!             (setq ppss (parse-partial-sexp
!                         pt-min (setq pt-min (/ (+ pt-min pos) 2))
!                         nil nil ppss))
!             (let ((pair (cons pt-min ppss)))
!               (if cache-pred
!                   (push pair (cdr cache-pred))
!                 (push pair syntax-ppss-cache))))
! 
!           ;; Compute the actual return value.
!           (setq ppss (parse-partial-sexp pt-min pos nil nil ppss))
! 
!           ;; Debugging check.
!           ;; (let ((real-ppss (parse-partial-sexp (point-min) pos)))
!           ;;   (setcar (last ppss 4) 0)
!           ;;   (setcar (last real-ppss 4) 0)
!           ;;   (setcar (last ppss 8) nil)
!           ;;   (setcar (last real-ppss 8) nil)
!           ;;   (unless (equal ppss real-ppss)
!           ;;     (message "!!Syntax: %s != %s" ppss real-ppss)
!           ;;     (setq ppss real-ppss)))
! 
!           ;; Store it in the cache.
!           (let ((pair (cons pos ppss)))
!             (if cache-pred
!                 (if (> (- (caar cache-pred) pos) syntax-ppss-max-span)
!                     (push pair (cdr cache-pred))
!                   (setcar cache-pred pair))
!               (if (or (null syntax-ppss-cache)
!                       (> (- (caar syntax-ppss-cache) pos)
!                          syntax-ppss-max-span))
!                   (push pair syntax-ppss-cache)
!                 (setcar syntax-ppss-cache pair)))))))))
! 
!       (setq syntax-ppss-last (cons pos ppss))
!       ppss)))
  
  ;; Debugging functions
  
--- 117,267 ----
        (pt-min (point-min)))
      (if (and old-pos (> old-pos pos)) (setq old-pos nil))
      ;; Use the OLD-POS if usable and close.  Don't update the `last' cache.
!     (condition-case nil
!       (if (and old-pos (< (- pos old-pos)
!                           ;; The time to use syntax-begin-function and
!                           ;; find PPSS is assumed to be about 2 * distance.
!                           (* 2 (/ (cdr (aref syntax-ppss-stats 5))
!                                   (1+ (car (aref syntax-ppss-stats 5)))))))
!           (progn
!             (incf (car (aref syntax-ppss-stats 0)))
!             (incf (cdr (aref syntax-ppss-stats 0)) (- pos old-pos))
!             (parse-partial-sexp old-pos pos nil nil old-ppss))
  
          (cond
!          ;; Use OLD-PPSS if possible and close enough.
!          ((and (not old-pos) old-ppss
!                ;; BEWARE! We rely on the undocumented 9th field.  The 9th
!                ;; field currently contains the list of positions of
!                ;; open-parens of the enclosing parens.  I.e. those
!                ;; positions are outside of any string/comment
!                ;; and the first of those is outside of any paren
!                ;; (i.e. corresponds to a nil ppss).  If this list is empty
!                ;; but we are in a string or comment, then the 8th field
!                ;; contains a similar "toplevel" position.  If `pt-min' is
!                ;; too far from `pos', we could try to use other positions
!                ;; in (nth 9 old-ppss), but that doesn't seem to happen in
!                ;; practice and it would complicate this code (and the
!                ;; after-change-function code even more).  But maybe it
!                ;; would be useful in "degenerate" cases such as when the
!                ;; whole file is wrapped in a set of parenthesis.
!                (setq pt-min (or (car (nth 9 old-ppss))
!                                 (nth 8 old-ppss)
!                                 (nth 2 old-ppss)))
!                (<= pt-min pos) (< (- pos pt-min) syntax-ppss-max-span))
!           (incf (car (aref syntax-ppss-stats 1)))
!           (incf (cdr (aref syntax-ppss-stats 1)) (- pos pt-min))
!           (setq ppss (parse-partial-sexp pt-min pos)))
!          ;; The OLD-* data can't be used.  Consult the cache.
           (t
!           (let ((cache-pred nil)
!                 (cache syntax-ppss-cache)
!                 (pt-min (point-min))
!                 ;; I differentiate between PT-MIN and PT-BEST because
!                 ;; I feel like it might be important to ensure that the
!                 ;; cache is only filled with 100% sure data (whereas
!                 ;; syntax-begin-function might return incorrect data).
!                 ;; Maybe that's just stupid.
!                 (pt-best (point-min))
!                 (ppss-best nil))
!             ;; look for a usable cache entry.
!             (while (and cache (< pos (caar cache)))
!               (setq cache-pred cache)
!               (setq cache (cdr cache)))
!             (if cache (setq pt-min (caar cache) ppss (cdar cache)))
! 
!             ;; Setup the after-change function if necessary.
!             (unless (or syntax-ppss-cache syntax-ppss-last)
!               (add-hook 'after-change-functions
!                         'syntax-ppss-flush-cache nil t))
! 
!             ;; Use the best of OLD-POS and CACHE.
!             (if (or (not old-pos) (< old-pos pt-min))
!                 (setq pt-best pt-min ppss-best ppss)
!               (incf (car (aref syntax-ppss-stats 4)))
!               (incf (cdr (aref syntax-ppss-stats 4)) (- pos old-pos))
!               (setq pt-best old-pos ppss-best old-ppss))
! 
!             ;; Use the `syntax-begin-function' if available.
!             ;; We could try using that function earlier, but:
!             ;; - The result might not be 100% reliable, so it's better to use
!             ;;   the cache if available.
!             ;; - The function might be slow.
!             ;; - If this function almost always finds a safe nearby spot,
!             ;;   the cache won't be populated, so consulting it is cheap.
!             (when (and (not syntax-begin-function)
!                        (boundp 'font-lock-beginning-of-syntax-function)
!                        font-lock-beginning-of-syntax-function)
!               (set (make-local-variable 'syntax-begin-function)
!                    font-lock-beginning-of-syntax-function))
!             (when (and syntax-begin-function
!                        (progn (goto-char pos)
!                               (funcall syntax-begin-function)
!                               ;; Make sure it's better.
!                               (> (point) pt-best))
!                        ;; Simple sanity check.
!                        (not (memq (get-text-property (point) 'face)
!                                   '(font-lock-string-face font-lock-doc-face
!                                     font-lock-comment-face))))
!               (incf (car (aref syntax-ppss-stats 5)))
!               (incf (cdr (aref syntax-ppss-stats 5)) (- pos (point)))
!               (setq pt-best (point) ppss-best nil))
! 
!             (cond
!              ;; Quick case when we found a nearby pos.
!              ((< (- pos pt-best) syntax-ppss-max-span)
!               (incf (car (aref syntax-ppss-stats 2)))
!               (incf (cdr (aref syntax-ppss-stats 2)) (- pos pt-best))
!               (setq ppss (parse-partial-sexp pt-best pos nil nil ppss-best)))
!              ;; Slow case: compute the state from some known position and
!              ;; populate the cache so we won't need to do it again soon.
!              (t
!               (incf (car (aref syntax-ppss-stats 3)))
!               (incf (cdr (aref syntax-ppss-stats 3)) (- pos pt-min))
! 
!               ;; If `pt-min' is too far, add a few intermediate entries.
!               (while (> (- pos pt-min) (* 2 syntax-ppss-max-span))
!                 (setq ppss (parse-partial-sexp
!                             pt-min (setq pt-min (/ (+ pt-min pos) 2))
!                             nil nil ppss))
!                 (let ((pair (cons pt-min ppss)))
!                   (if cache-pred
!                       (push pair (cdr cache-pred))
!                     (push pair syntax-ppss-cache))))
! 
!               ;; Compute the actual return value.
!               (setq ppss (parse-partial-sexp pt-min pos nil nil ppss))
! 
!               ;; Debugging check.
!               ;; (let ((real-ppss (parse-partial-sexp (point-min) pos)))
!               ;;   (setcar (last ppss 4) 0)
!               ;;   (setcar (last real-ppss 4) 0)
!               ;;   (setcar (last ppss 8) nil)
!               ;;   (setcar (last real-ppss 8) nil)
!               ;;   (unless (equal ppss real-ppss)
!               ;;     (message "!!Syntax: %s != %s" ppss real-ppss)
!               ;;     (setq ppss real-ppss)))
! 
!               ;; Store it in the cache.
!               (let ((pair (cons pos ppss)))
!                 (if cache-pred
!                     (if (> (- (caar cache-pred) pos) syntax-ppss-max-span)
!                         (push pair (cdr cache-pred))
!                       (setcar cache-pred pair))
!                   (if (or (null syntax-ppss-cache)
!                           (> (- (caar syntax-ppss-cache) pos)
!                              syntax-ppss-max-span))
!                       (push pair syntax-ppss-cache)
!                     (setcar syntax-ppss-cache pair)))))))))
! 
!         (setq syntax-ppss-last (cons pos ppss))
!         ppss)
!       (args-out-of-range
!        ;; If the buffer is more narrowed than when we built the cache,
!        ;; we may end up calling parse-partial-sexp with a position before
!        ;; point-min.  In that case, just parse from point-min assuming
!        ;; a nil state.
!        (parse-partial-sexp (point-min) pos)))))
  
  ;; Debugging functions