continue on the support for local variables list semi-automatic

insertion. I put a new file in lib with basic tools for file variables
lists.

1 files changed, 226 insertions, 0 deletions

diff --git a/lib/local-vars-list.el b/lib/local-vars-list.el
new file mode 100644
index 00000000..7038ebf9
--- /dev/null
+++ b/lib/local-vars-list.el
@@ -0,0 +1,226 @@
+;;; local-vars.el --- local variables list utilities
+;; Copyright (C) 2006 Pierre Courtieu
+;; Authors: Pierre Courtieu
+;; Maintainer: Pierre Courtieu <Pierre.Courtieu@cnam.fr>
+
+;; This software is free software; you can redistribute it and/or
+;; modify it under the terms of the GNU General Public
+;; License version 2, as published by the Free Software Foundation.
+;; 
+;; This software 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 version 2 for more details
+;; (enclosed in the file GPL).
+;;
+;; See documentation in variable holes-short-doc.
+;;
+
+;;; Commentary:
+;; See documentation in variable holes-doc.
+
+;;; History:
+;; 
+
+;;; Help:
+
+(defconst local-vars-list-doc nil
+  "Quoting emacs info:
+
+A file can contain a \"local variables list\", which specifies the values to use for
+certain Emacs variables when that file is edited. See info node \"(xemacs)File
+Variables\". 
+
+local-vars-list provides two useful functions:
+
+\\[local-vars-list-get] that reads a local variable value at the end of the file.
+
+\\[local-vars-list-set] that writes a local variable value at the end of the file.")
+
+(defun local-vars-list-help (describe-variable 'local-vars-list-doc))
+
+;;TOTO: use the code in xemacs-sources/lisp/files.el
+;; in particular the function hack-local-variables-last-page
+
+(defun local-vars-list-insert-empty-zone ()
+  "Insert an empty local variables zone at the end of the buffer.
+Indents the zone according to mode after insertion."
+  (save-excursion
+    (goto-char (point-max))
+    (let ((pt (point)))
+      (cond 
+       ((not comment-start)
+	(insert 
+	 "
+*** Local Variables: ***
+*** End: ***
+" 
+	 ))
+
+       ((string-equal comment-end "")
+	(insert 
+	 (format
+	  "
+%s** Local Variables: ***
+%s** End: ***
+"
+	  comment-start comment-start)))
+
+       (t
+	(insert 
+	 (format
+	  "
+%s
+*** Local Variables: ***
+*** End: ***
+%s"
+	  comment-start comment-end))
+	))
+      (indent-region pt (point) nil)
+      (message "%s" "Local variables zone added at the end of the buffer."))))
+
+
+(defun local-vars-list-find ()
+  "Find the local variable definition paragraph. 
+Return a list containing the prefix and the suffix of its first line,
+or throw 'notfound if not found. Sets the point at the beginning of
+the second line of the paragraph."
+  (goto-char (point-max))
+  (catch 'notfound
+    (if (not (re-search-backward "Local Variables:" nil t)) (throw 'notfound nil))  
+    (let ((bol (save-excursion (beginning-of-line) (point)))
+	  (eol (save-excursion (end-of-line) (point)))
+	  (lpattern)
+	  (rpattern))
+      (setq lpattern (buffer-substring bol (point)))
+      (re-search-forward "Local Variables:" eol t)
+      (setq rpattern (buffer-substring (point) eol))
+      (forward-line 1) 
+      (beginning-of-line)
+      (cons lpattern (cons rpattern nil)))))
+
+(defun local-vars-list-goto-var (symb lpat rpat)
+  "Search a line defining local variable symb at current line and below. 
+If successful set point to the beginning of the *value* and return t.
+Otherwise set point to the beginning of the last line of the local
+variables list (the one containing \"End:\"), and return nil.
+
+lpat and rpat are the suffix and prefix of the local variable list. 
+
+Note: this function must be called when at the beginning of a local
+variable definition (or at the \"End:\" line)."
+  (let* ((symbname (symbol-name symb))
+	 (found nil) (endreached nil)
+	 (eol))
+    (while (and (not found) (not endreached))
+      (setq eol (save-excursion (end-of-line) (point)))
+      (search-forward lpat eol)
+      (re-search-forward "\\([^ :]+\\):" eol)
+      (let ((varname (match-string 1)))
+	(message "varname = %s" varname)
+	(cond 
+	 ((string-equal varname "End") (setq endreached t) (beginning-of-line))
+	 ((string-equal varname symbname) (setq found t))
+	 (t (forward-line 1) (beginning-of-line))
+	 ))
+      (message "found %s" found)
+      (message "endreached %s" endreached)
+      )
+    (if found t nil)))
+
+
+; precond: really be on a var def line
+(defun local-vars-list-get-current (lpat rpat)
+  "Return the value written in the local variable list at current line.
+
+lpat and rpat are the suffix and prefix of the local variable list.
+
+Note: this function must be called when at the beginning of a local
+variable definition (or at the \"End:\" line)."
+  (let ((bol (save-excursion (beginning-of-line) (point)))
+	(eol (save-excursion (end-of-line) (point)))
+	(varname ""))
+    (catch 'notfound
+      (if (not (search-forward lpat eol t)) (throw 'notfound nil))
+      (if (not (re-search-forward "\\([^ :]+\\):" eol t)) (throw 'notfound nil))
+      (setq varname (match-string 1))
+      (let ((boexp (point)))
+	(if (not (search-forward rpat eol t)) (throw 'notfound nil))
+	(search-backward rpat bol)	; should always succeed
+	(read (buffer-substring boexp (point))))))) ; TODO: catch errors here?
+
+
+
+(defun local-vars-list-set-current (val lpat rpat)
+  "Write the value val in the local variable list at current line.
+
+lpat and rpat are the suffix and prefix of the local variable list.
+
+Note: this function must be called when at the beginning of a local
+variable definition (or at the \"End:\" line)."
+  (let ((bol (save-excursion (beginning-of-line) (point)))
+	(eol (save-excursion (end-of-line) (point)))
+	(varname ""))
+    (search-forward lpat eol)
+    (re-search-forward "\\([^ :]+\\):" eol)
+    (setq varname (match-string 1))
+    (let ((boexp (point)))
+      (search-forward rpat eol)
+      (search-backward rpat bol)
+      (kill-region boexp (point))
+      (insert (format " %S " val))
+      )
+    )  
+  )
+
+
+(defun local-vars-list-get (symb)
+  "Return the value written in the local variable list for variable symb.
+Raises an error if symb is not in the list."
+  (save-excursion
+    (let* 
+	((lrpat (local-vars-list-find))
+	 (dummy (if lrpat t (error "local variables zone not found. ")))
+	 (lpat (car lrpat))
+	 (rpat (car (cdr lrpat)))
+	 )
+      (beginning-of-line)
+      (if (local-vars-list-goto-var symb lpat rpat)
+	  t 
+	(error "variable %s not found" symb))
+      (beginning-of-line)
+      (local-vars-list-get-current lpat rpat))))
+
+(defun local-vars-list-set (symb val)
+  "Write the value val in the local variable list for variable symb.
+If the variable is already specified in the list, replace the value. If no local
+variable list is found, create one at the end of the buffer first."
+  (save-excursion
+    (let ((lrpat (local-vars-list-find)))
+      (if (not lrpat) 
+          (progn 
+            (local-vars-list-insert-empty-zone)
+            (setq lrpat (local-vars-list-find))))
+      (beginning-of-line)
+      (let ((lpat (car lrpat))
+            (rpat (car (cdr lrpat))))
+        (if (local-vars-list-goto-var symb lpat rpat)
+            (progn (beginning-of-line)
+                   (local-vars-list-set-current val lpat rpat))
+          (insert (format "%s%s: %S%s\n" lpat (symbol-name symb) val rpat))
+          (forward-line -1)
+          (indent-according-to-mode))))))
+
+
+(provide 'local-vars-list)
+
+
+
+;;; Local Variables: ***
+;;; fill-column: 85 ***
+;;; indent-tabs-mode: nil ***
+;;; End: ***
+
+
+