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From: lrs@esl.UUCP (Lynn Slater)
Newsgroups: comp.emacs
Subject: Re: scope rules for "let"
Message-ID: <568@esl.UUCP>
Date: 24 Feb 88 21:05:21 GMT
References: <3292@arthur.cs.purdue.edu>
Lines: 31
In-reply-to: narten@cs.purdue.EDU's message of 23 Feb 88 17:01:43 GMT

Posting-Front-End: GNU Emacs 18.44.12 of Mon Nov 16 1987 on esl (berkeley-unix)


>I have buffer that is readonly for keystrokes, but is made writable by
>functions operating on the buffer. I want the default to be readonly,
>with explicit action required to make the buffer write only.

I have solved this in much the manner you suggest. Check that there is
not some other problem. For Example code follows:

(defun highlight-region (p1 p2)
  "Highlight the current region."
  (interactive "r")
  (let ((s (buffer-substring p1 p2))
	(inverse-video t)
	;; Do not change the modified flag
	(modified-flag  (buffer-modified-p))
	;; shadow the true local value of read-only
	(buffer-read-only nil)
	;; Prevent the generation of autosave files
	;; Don't you just love dynamic variable binding?
	(buffer-auto-save-file-name nil)
	;; we do not have to worry about backup files because
	;; they are not generated unless the buffer is saved.
	)
    (delete-region p1 p2)
    ;; force a redisplay, so that the screen image of the line "changes" later
    (if (fboundp 'update-display)
	(update-display)
      (sit-for 0))
    (insert s)
    (if (fboundp 'update-display)
	(update-display)
      (sit-for 0))
    (set-buffer-modified-p modified-flag)))