Allow easy entry of single chars in `read-char-by-name'

* lisp/international/mule-cmds.el (read-char-by-name): Add optional
'allow-single' argument, meaning to accept single chars as themselves.

diff --git a/lisp/international/mule-cmds.el b/lisp/international/mule-cmds.el
index 12896cc4b0ede6590b8b024185e40088889dde4d..4137642528902b61c71b0e172dd88887e264bcaa 100644 (file)
--- a/lisp/international/mule-cmds.el
+++ b/lisp/international/mule-cmds.el
@@ -3195,7 +3195,7 @@ Defines the sorting order either by character names or their codepoints."
   :group 'mule
   :version "28.1")
 
-(defun read-char-by-name (prompt)
+(defun read-char-by-name (prompt &optional allow-single)
   "Read a character by its Unicode name or hex number string.
 Display PROMPT and read a string that represents a character by its
 Unicode property `name' or `old-name'.
@@ -3216,7 +3216,10 @@ Accept a name like \"CIRCULATION FUNCTION\", a hexadecimal
 number like \"2A10\", or a number in hash notation (e.g.,
 \"#x2a10\" for hex, \"10r10768\" for decimal, or \"#o25020\" for
 octal).  Treat otherwise-ambiguous strings like \"BED\" (U+1F6CF)
-as names, not numbers."
+as names, not numbers.
+
+Optional arg ALLOW-SINGLE non-nil means to additionally allow
+single characters to be treated as standing for themselves."
   (let* ((enable-recursive-minibuffers t)
         (completion-ignore-case t)
         (completion-tab-width 4)
@@ -3239,6 +3242,9 @@ as names, not numbers."
         (char
           (cond
            ((char-from-name input t))
+           ((and allow-single
+                 (string-match-p "\\`.\\'" input)
+                 (ignore-errors (string-to-char input))))
            ((string-match-p "\\`[[:xdigit:]]+\\'" input)
             (ignore-errors (string-to-number input 16)))
            ((string-match-p "\\`#\\([bBoOxX]\\|[0-9]+[rR]\\)[0-9a-zA-Z]+\\'"