(Emacs) Text is read only?

问题:

So I was working in emacs and the suddenly, the slime-repl sbcl says text is read only. Well that's great because now I can't type anything into it. How do I fix?

回答1:

"Buffer is read-only" can be cured by C-x C-q but as Drew & phils said,
"Text is read-only" is very different -- it means some part of the buffer has a read-only property.
Try moving away from the read-only part, e.g., to the end of the buffer.

Emacs Lisp Manual > elisp.info > Text > Text Properties > Special Properties

 Since changing properties counts as modifying the buffer, it is not
 possible to remove a `read-only' property unless you know the
 special trick: bind `inhibit-read-only' to a non-`nil' value and
 then remove the property.  *Note Read Only Buffers::.

thus to erase the entire buffer regardless:

M-: (let ((inhibit-read-only t)) (erase-buffer)) RET

or to remove all properties:

(let ((inhibit-read-only t)) (set-text-properties (point-min) (point-max) ()))

回答2:

Possible cause of such a message may be this: you are trying to print something over the REPL prompt, for example CL-US|ER> (+ 1 2). This text in the SLIME buffer is read-only. Note the space after >, it is the part of the prompt.

回答3:

I can't offer any insight into why you ended up with undesirable read-only text properties, but I occasionally encounter similar situations and so find the following command useful.

Select the region in question (or C-xh for the entire buffer), and run M-x set-region-writeable to remove the read-only text properties.

(defun set-region-writeable (begin end)
  "Removes the read-only text property from the marked region."
  ;; See http://stackoverflow.com/questions/7410125
  (interactive "r")
  (let ((modified (buffer-modified-p))
        (inhibit-read-only t))
    (remove-text-properties begin end '(read-only t))
    (set-buffer-modified-p modified)))

回答4:

The keyboard shortcut C-x C-q is the default binding for read-only-mode, which can be enabled or disabled with that shortcut. Describing that keyboard shortcut sequence with C-h k C-x C-q yields the following buffer printout:

C-x C-q runs the command read-only-mode, which is an interactive
compiled Lisp function in `simple.el'.

It is bound to C-x C-q.

(read-only-mode &optional ARG)

Change whether the current buffer is read-only.
With prefix argument ARG, make the buffer read-only if ARG is
positive, otherwise make it writable.  If buffer is read-only
and `view-read-only' is non-nil, enter view mode.

Do not call this from a Lisp program unless you really intend to
do the same thing as the C-x C-q command, including
possibly enabling or disabling View mode.  Also, note that this
command works by setting the variable `buffer-read-only', which
does not affect read-only regions caused by text properties.  To
ignore read-only status in a Lisp program (whether due to text
properties or buffer state), bind `inhibit-read-only' temporarily
to a non-nil value.

So, another way to call that option would be to use: M-x read-only-mode RET

回答5:

You can change read-only mode by doing: M-x -> toggle-read-only -> RET (in other words press enter)

回答6:

I solved this by first opening two frames, one with a .lisp file opened and the other with the slime-repl.

From the frame with the .lisp file, I applied C-c C-j on a line of code (e.g (+ 1 2)).

This copied the line of code down to the slime-repl and evaluated it.

This also somehow solved the problem with the "text is read only" problem.

回答7:

Try typing C-c M-o RET (it will clear the console and add a new line), I had a problem similar to yours and for it fixed it.