Re: Patch: Follow convention for reading with the minibuffer.

[Juri Linkov <juri@jurta.org>]

> Putting the colon at the end is definitely better.  Can someone fix
> C-x b to work that way?

I guess the current format of the default buffer prompt was easier
to implement.  Finding an appropriate place in the given prompt to
insert the default value is not a trivial task to do in C.  As users
can provide an arbitrary prompt (e.g. the example in the Emacs Lisp
manual suggest using the question mark: "Buffer name? ", where the
right place for the default value is just before the question mark:
"Buffer name (default foo)? "), a heuristics should be used to parse
the prompt and to find a place to insert the default value.

Ideally, there should exist a special prompt-formatting function with
two arguments: `prompt' and `default'.  For example, the default
function and format value would look like:

(defvar prompt-default-format " (default %s): ")

(defun format-prompt-default (prompt default)
  ;; If there is no default yet in the prompt
  (if (not (string-match (replace-regexp-in-string
			  "%s" ".*" prompt-default-format nil t)
			 prompt))
      (setq prompt (replace-regexp-in-string
		    " *\\W? *$"
		    (format prompt-default-format default)
		    prompt)))
  prompt)

>     PS: Actually I even prefer
>
> 	Enter the answer [42]:
>
>       because minibuffer width is limited.
>
> Now that the minibuffer prompt can be continued, saving space there is
> less important than it would have been before.  And the word "default"
> will serve to explain to new users.

With the special formatting function and the format variable this
would be easy to customize:

(setq prompt-default-format " [%s]: ")
(read-buffer "Buffer name: " "foo" t)

will display the prompt:

Buffer name [foo]:

-- 
Juri Linkov
http://www.jurta.org/emacs/