Teach 'max-char' about the Unicode code range

* src/character.c (Fmax_char): Accept an optional argument
UNICODE, and, if non-nil, return the maximum codepoint defined by
Unicode.

* lisp/emacs-lisp/comp.el (comp-known-type-specifiers): Update the
signature of 'max-char'.

* etc/NEWS:
* doc/lispref/nonascii.texi (Character Codes): Update the
documentation of 'max-char'.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/character.c b/src/character.c
index 968daccafa7..dc21649b226 100644
--- a/src/character.c
+++ b/src/character.c
@@ -178,12 +178,14 @@ usage: (characterp OBJECT)  */
   return (CHARACTERP (object) ? Qt : Qnil);
 }
 
-DEFUN ("max-char", Fmax_char, Smax_char, 0, 0, 0,
-       doc: /* Return the character of the maximum code.  */
+DEFUN ("max-char", Fmax_char, Smax_char, 0, 1, 0,
+       doc: /* Return the maximum character code.
+If UNICODE is non-nil, return the maximum character code defined
+by the Unicode Standard.  */
        attributes: const)
-  (void)
+  (Lisp_Object unicode)
 {
-  return make_fixnum (MAX_CHAR);
+  return unicode ? make_fixnum (MAX_UNICODE_CHAR) : make_fixnum (MAX_CHAR);
 }
 
 DEFUN ("unibyte-char-to-multibyte", Funibyte_char_to_multibyte,