Subject: Re: bug#60312: 30.0.50; Feature Request: Customize yes-or-n-p prompt from elisp:

From: Robert Pluim <[email-masked]>
Date: Tue, 03 Jan 2023 15:52:47 +0100

>>>>> On Sun, 25 Dec 2022 20:19:28 +0300, Jean Louis <[email-masked]> said:

    Jean> * T.V Raman" via "Bug reports for GNU Emacs, the Swiss army knife of text editors <[email-masked]> [2022-12-25 18:24]:
    >> AUTO_STRING (yes_or_no, "(yes or no) ");
    >> 
    >> I'd like to be able to customize this in some cases to something more
    >> terse  --- hearing "yes or no " each time gets wordy.

    Jean> It can help to people who use different languages as well.

    Jean> This implies that also characters y and n shall be customizable.

That might be going a bit far.

TV, how does the below work for you? I thought `yes-or-no-p-prompt'
would have been overkill, so I painted this particular bikeshed as
`yes-or-no-prompt'.

Robert
-- 

diff --git i/doc/emacs/mini.texi w/doc/emacs/mini.texi
index 90e50a41d53..e4ec4cd3785 100644
--- i/doc/emacs/mini.texi
+++ w/doc/emacs/mini.texi
@@ -953,12 +953,14 @@ Yes or No Prompts
 @end smallexample
 
 @cindex yes or no prompt
+@vindex yes-or-no-prompt
   The second type of yes-or-no query is typically employed if giving
 the wrong answer would have serious consequences; it thus features a
-longer prompt ending with @samp{(yes or no)}.  For example, if you
-invoke @kbd{C-x k} (@code{kill-buffer}) on a file-visiting buffer with
-unsaved changes, Emacs activates the minibuffer with a prompt like
-this:
+longer prompt ending with @samp{(yes or no)} (or the value of
+@code{yes-or-no-prompt} if you've customized that).  For example, if
+you invoke @kbd{C-x k} (@code{kill-buffer}) on a file-visiting buffer
+with unsaved changes, Emacs activates the minibuffer with a prompt
+like this:
 
 @smallexample
 Buffer foo.el modified; kill anyway? (yes or no)
diff --git i/doc/lispref/minibuf.texi w/doc/lispref/minibuf.texi
index 332a453619c..546e46813ec 100644
--- i/doc/lispref/minibuf.texi
+++ w/doc/lispref/minibuf.texi
@@ -2233,10 +2233,12 @@ Yes-or-No Queries
 @code{nil} if the user types @samp{no}.  The user must type @key{RET} to
 finalize the response.  Upper and lower case are equivalent.
 
-@code{yes-or-no-p} starts by displaying @var{prompt} in the minibuffer,
-followed by @w{@samp{(yes or no) }}.  The user must type one of the
-expected responses; otherwise, the function responds @samp{Please answer
-yes or no.}, waits about two seconds and repeats the request.
+@vindex yes-or-no-prompt
+@code{yes-or-no-p} starts by displaying @var{prompt} in the
+minibuffer, followed by the value of @code{yes-or-no-prompt} (default
+@w{@samp{(yes or no) }}).  The user must type one of the expected
+responses; otherwise, the function responds @samp{Please answer yes or
+no.}, waits about two seconds and repeats the request.
 
 @code{yes-or-no-p} requires more work from the user than
 @code{y-or-n-p} and is appropriate for more crucial decisions.
diff --git i/lisp/cus-start.el w/lisp/cus-start.el
index d7fb56c9854..197c41c5ebb 100644
--- i/lisp/cus-start.el
+++ w/lisp/cus-start.el
@@ -310,6 +310,7 @@ minibuffer-prompt-properties--setter
                       (const :tag "Off" :value nil)
                       (const :tag "On" :value t)
                       (const :tag "Auto-raise" :value auto-raise)) "26.1")
+             (yes-or-no-prompt menu string "30.1")
 	     ;; fontset.c
 	     ;; FIXME nil is the initial value, fontset.el setqs it.
 	     (vertical-centering-font-regexp display
diff --git i/src/fns.c w/src/fns.c
index eeb65cadf3f..1a7b6b11c44 100644
--- i/src/fns.c
+++ w/src/fns.c
@@ -3173,14 +3173,16 @@ DEFUN ("yes-or-no-p", Fyes_or_no_p, Syes_or_no_p, 1, 1, 0,
 Return t if answer is yes, and nil if the answer is no.
 
 PROMPT is the string to display to ask the question; `yes-or-no-p'
-adds \"(yes or no) \" to it.  It does not need to end in space, but if
-it does up to one space will be removed.
+appends `yes-or-no-prompt' (default \"(yes or no) \") to it.  It does
+not need to end in space, but if it does up to one space will be
+removed.
 
 The user must confirm the answer with RET, and can edit it until it
 has been confirmed.
 
 If the `use-short-answers' variable is non-nil, instead of asking for
-\"yes\" or \"no\", this function will ask for \"y\" or \"n\".
+\"yes\" or \"no\", this function will ask for \"y\" or \"n\" (and
+ignore the value of `yes-or-no-prompt').
 
 If dialog boxes are supported, a dialog box will be used
 if `last-nonmenu-event' is nil, and `use-dialog-box' is non-nil.  */)
@@ -3205,8 +3207,7 @@ DEFUN ("yes-or-no-p", Fyes_or_no_p, Syes_or_no_p, 1, 1, 0,
   if (use_short_answers)
     return call1 (intern ("y-or-n-p"), prompt);
 
-  AUTO_STRING (yes_or_no, "(yes or no) ");
-  prompt = CALLN (Fconcat, prompt, yes_or_no);
+  prompt = CALLN (Fconcat, prompt, Vyes_or_no_prompt);
 
   specpdl_ref count = SPECPDL_INDEX ();
   specbind (Qenable_recursive_minibuffers, Qt);
@@ -6257,9 +6258,15 @@ syms_of_fns (void)
 We recommend against setting this variable non-nil, because `yes-or-no-p'
 is intended to be used when users are expected not to respond too
 quickly, but to take their time and perhaps think about the answer.
-The same variable also affects the function `read-answer'.  */);
+The same variable also affects the function `read-answer'.  See also
+`yes-or-no-prompt'.  */);
   use_short_answers = false;
 
+  DEFVAR_LISP ("yes-or-no-prompt", Vyes_or_no_prompt,
+    doc: /* String to append when `yes-or-no-p' asks a question.
+For best results this should end in a space.  */);
+  Vyes_or_no_prompt = make_unibyte_string ("(yes or no) ", strlen ("(yes or no) "));
+
   defsubr (&Sidentity);
   defsubr (&Srandom);
   defsubr (&Slength);