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

[Miles Bader]

Index: emacs/lisp/emacs-lisp/regi.el
diff -c /dev/null emacs/lisp/emacs-lisp/regi.el:1.2.2.1
*** /dev/null   Tue Oct 14 19:32:26 2003
--- emacs/lisp/emacs-lisp/regi.el       Tue Oct 14 19:32:21 2003
***************
*** 0 ****
--- 1,259 ----
+ ;;; regi.el --- REGular expression Interpreting engine
+ 
+ ;; Copyright (C) 1993 Free Software Foundation, Inc.
+ 
+ ;; Author: 1993 Barry A. Warsaw, Century Computing, Inc. <address@hidden>
+ ;; Maintainer:    address@hidden
+ ;; Created:       24-Feb-1993
+ ;; Version:       1.8
+ ;; Last Modified: 1993/06/01 21:33:00
+ ;; Keywords:      extensions, matching
+ 
+ ;; This file is part of GNU Emacs.
+ 
+ ;; GNU Emacs is free software; you can redistribute it and/or modify
+ ;; it under the terms of the GNU General Public License as published by
+ ;; the Free Software Foundation; either version 2, or (at your option)
+ ;; any later version.
+ 
+ ;; GNU Emacs is distributed in the hope that it will be useful,
+ ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+ ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ ;; GNU General Public License for more details.
+ 
+ ;; You should have received a copy of the GNU General Public License
+ ;; along with GNU Emacs; see the file COPYING.  If not, write to the
+ ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ ;; Boston, MA 02111-1307, USA.
+ 
+ ;;; Commentary:
+ 
+ ;;; Code:
+ 
+ 
+ (defun regi-pos (&optional position col-p)
+   "Return the character position at various buffer positions.
+ Optional POSITION can be one of the following symbols:
+ 
+ `bol'  == beginning of line
+ `boi'  == beginning of indentation
+ `eol'  == end of line [default]
+ `bonl' == beginning of next line
+ `bopl' == beginning of previous line
+ 
+ Optional COL-P non-nil returns `current-column' instead of character 
position."
+   (save-excursion
+     (cond
+      ((eq position 'bol)  (beginning-of-line))
+      ((eq position 'boi)  (back-to-indentation))
+      ((eq position 'bonl) (forward-line 1))
+      ((eq position 'bopl) (forward-line -1))
+      (t (end-of-line)))
+     (if col-p (current-column) (point))))
+ 
+ (defun regi-mapcar (predlist func &optional negate-p case-fold-search-p)
+   "Build a regi frame where each element of PREDLIST appears exactly once.
+ The frame contains elements where each member of PREDLIST is
+ associated with FUNC, and optionally NEGATE-P and CASE-FOLD-SEARCH-P."
+   (let (frame tail)
+     (if (or negate-p case-fold-search-p)
+       (setq tail (list negate-p)))
+     (if case-fold-search-p
+       (setq tail (append tail (list case-fold-search-p))))
+     (while predlist
+       (let ((element (list (car predlist) func)))
+       (if tail
+           (setq element (append element tail)))
+       (setq frame (append frame (list element))
+             predlist (cdr predlist))
+       ))
+     frame))
+ 
+ 
+ (defun regi-interpret (frame &optional start end)
+   "Interpret the regi frame FRAME.
+ If optional START and END are supplied, they indicate the region of
+ interest, and the buffer is narrowed to the beginning of the line
+ containing START, and beginning of the line after the line containing
+ END.  Otherwise, point and mark are not set and processing continues
+ until your FUNC returns the `abort' symbol (see below).  Beware!  Not
+ supplying a START or END could put you in an infinite loop.
+ 
+ A regi frame is a list of entries of the form:
+ 
+      (PRED FUNC [NEGATE-P [CASE-FOLD-SEARCH]])
+ 
+ PRED is a predicate against which each line in the region is tested,
+ and if a match occurs, FUNC is `eval'd.  Point is then moved to the
+ beginning of the next line, the frame is reset and checking continues.
+ If a match doesn't occur, the next entry is checked against the
+ current line until all entries in the frame are checked.  At this
+ point, if no match occurred, the frame is reset and point is moved to
+ the next line.  Checking continues until every line in the region is
+ checked.  Optional NEGATE-P inverts the result of PRED before FUNC is
+ called and `case-fold-search' is bound to the optional value of
+ CASE-FOLD-SEARCH for the PRED check.
+ 
+ PRED can be a string, variable, function or one of the following
+ symbols: t, nil, `begin', `end', and `every'.  If PRED is a string, or
+ a variable or list that evaluates to a string, it is interpreted as a
+ regular expression and is matched against the current line (from the
+ beginning) using `looking-at'.  If PRED does not evaluate to a string,
+ it is interpreted as a binary value (nil or non-nil).
+ 
+ PRED can also be one of the following symbols:
+ 
+ t       -- always produces a true outcome
+ `begin' -- always executes before anything else
+ `end'   -- always executes after everything else
+ `every' -- execute after frame is matched on a line
+ 
+ Note that NEGATE-P and CASE-FOLD-SEARCH are meaningless if PRED is one
+ of these special symbols.  Only the first occurrence of each symbol in
+ a frame entry is used, the rest are ignored.
+ 
+ Your FUNC can return values which control regi processing.  If a list
+ is returned from your function, it can contain any combination of the
+ following elements:
+ 
+ the symbol `continue'
+      Tells regi to continue processing frame-entries after a match,
+      instead of resetting to the first entry and advancing to the next
+      line, as is the default behavior.  When returning this symbol,
+      you must take care not to enter an infinite loop.
+ 
+ the symbol `abort'
+      Tells regi to terminate processing this frame.  any end
+      frame-entry is still processed.
+ 
+ the list `(frame . NEWFRAME)'
+      Tells regi to use NEWFRAME as its current frame.  In other words,
+      your FUNC can modify the executing regi frame on the fly.
+ 
+ the list `(step . STEP)'
+      Tells regi to move STEP number of lines forward during normal
+      processing.  By default, regi moves forward 1 line.  STEP can be
+      negative, but be careful of infinite loops.
+ 
+ You should usually take care to explicitly return nil from your
+ function if no action is to take place.  Your FUNC will always be
+ `eval'ed.  The following variables will be temporarily bound to some
+ useful information:
+ 
+ `curline'
+      the current line in the buffer, as a string
+ 
+ `curframe'
+      the full, current frame being executed
+ 
+ `curentry'
+      the current frame entry being executed."
+ 
+   (save-excursion
+     (save-restriction
+       (let (begin-tag end-tag every-tag current-frame working-frame donep)
+ 
+       ;; set up the narrowed region
+       (and start
+            end
+            (let* ((tstart start)
+                   (start (min start end))
+                   (end   (max start end)))
+              (narrow-to-region
+               (progn (goto-char end) (regi-pos 'bonl))
+               (progn (goto-char start) (regi-pos 'bol)))))
+ 
+       ;; lets find the special tags and remove them from the working
+       ;; frame. note that only the last special tag is used.
+       (mapcar
+        (function
+         (lambda (entry)
+           (let ((pred (car entry))
+                 (func (car (cdr entry))))
+             (cond
+              ((eq pred 'begin) (setq begin-tag func))
+              ((eq pred 'end)   (setq end-tag func))
+              ((eq pred 'every) (setq every-tag func))
+              (t
+               (setq working-frame (append working-frame (list entry))))
+              ) ; end-cond
+             )))
+        frame) ; end-mapcar
+ 
+       ;; execute the begin entry
+       (eval begin-tag)
+ 
+       ;; now process the frame
+       (setq current-frame working-frame)
+       (while (not (or donep (eobp)))
+         (let* ((entry            (car current-frame))
+                (pred             (nth 0 entry))
+                (func             (nth 1 entry))
+                (negate-p         (nth 2 entry))
+                (case-fold-search (nth 3 entry))
+                match-p)
+           (catch 'regi-throw-top
+             (cond
+              ;; we are finished processing the frame for this line
+              ((not current-frame)
+               (setq current-frame working-frame) ;reset frame
+               (forward-line 1)
+               (throw 'regi-throw-top t))
+              ;; see if predicate evaluates to a string
+              ((stringp (setq match-p (eval pred)))
+               (setq match-p (looking-at match-p)))
+              ) ; end-cond
+ 
+             ;; now that we've done the initial matching, check for
+             ;; negation of match
+             (and negate-p
+                  (setq match-p (not match-p)))
+ 
+             ;; if the line matched, package up the argument list and
+             ;; funcall the FUNC
+             (if match-p
+                  (let* ((curline (buffer-substring
+                                   (regi-pos 'bol)
+                                   (regi-pos 'eol)))
+                         (curframe current-frame)
+                         (curentry entry)
+                         (result (eval func))
+                         (step (or (cdr (assq 'step result)) 1))
+                         )
+                    ;; changing frame on the fly?
+                    (if (assq 'frame result)
+                        (setq working-frame (cdr (assq 'frame result))))
+ 
+                    ;; continue processing current frame?
+                    (if (memq 'continue result)
+                        (setq current-frame (cdr current-frame))
+                      (forward-line step)
+                      (setq current-frame working-frame))
+ 
+                    ;; abort current frame?
+                    (if (memq 'abort result)
+                        (progn
+                          (setq donep t)
+                          (throw 'regi-throw-top t)))
+                    ) ; end-let
+ 
+               ;; else if no match occurred, then process the next
+               ;; frame-entry on the current line
+               (setq current-frame (cdr current-frame))
+ 
+               ) ; end-if match-p
+             ) ; end catch
+           ) ; end let
+ 
+         ;; after every cycle, evaluate every-tag
+         (eval every-tag)
+         ) ; end-while
+ 
+       ;; now process the end entry
+       (eval end-tag)))))
+ 
+ 
+ (provide 'regi)
+ 
+ ;;; arch-tag: 804b4e45-4109-4f76-9a88-21887b881747
+ ;;; regi.el ends here