Subject: bug#32599: 25.2; Feature request: input PUA characters by name

From: [email-masked] (Janusz S. Bień)
Date: Wed, 30 Dec 2020 18:49:26 +0100

Let me to approach the problem from another angle.

Input of Unicode characters by name is done by "insert-char" defined in
editfns.c. The code is quite short:

--8<---------------cut here---------------start------------->8---
DEFUN ("insert-char", Finsert_char, Sinsert_char, 1, 3,
       "(list (read-char-by-name \"Insert character (Unicode name or hex): \")\
              (prefix-numeric-value current-prefix-arg)\
              t))",
       doc: /* Insert COUNT copies of CHARACTER.
Interactively, prompt for CHARACTER.  You can specify CHARACTER in one
of these ways:

 - As its Unicode character name, e.g. \"LATIN SMALL LETTER A\".
   Completion is available; if you type a substring of the name
   preceded by an asterisk `*', Emacs shows all names which include
   that substring, not necessarily at the beginning of the name.

[...]

The optional third argument INHERIT, if non-nil, says to inherit text
properties from adjoining text, if those properties are sticky.  If
called interactively, INHERIT is t.  */)
  (Lisp_Object character, Lisp_Object count, Lisp_Object inherit)
{
  int i, stringlen;
  register ptrdiff_t n;
  int c, len;
  unsigned char str[MAX_MULTIBYTE_LENGTH];
  char string[4000];

  CHECK_CHARACTER (character);
  if (NILP (count))
    XSETFASTINT (count, 1);
  else
    CHECK_FIXNUM (count);
  c = XFIXNAT (character);

  if (!NILP (BVAR (current_buffer, enable_multibyte_characters)))
    len = CHAR_STRING (c, str);
  else
    str[0] = c, len = 1;
  if (XFIXNUM (count) <= 0)
    return Qnil;
  if (BUF_BYTES_MAX / len < XFIXNUM (count))
    buffer_overflow ();
  n = XFIXNUM (count) * len;
  stringlen = min (n, sizeof string - sizeof string % len);
  for (i = 0; i < stringlen; i++)
    string[i] = str[i % len];
  while (n > stringlen)
    {
      maybe_quit ();
      if (!NILP (inherit))
	insert_and_inherit (string, stringlen);
      else
	insert (string, stringlen);
      n -= stringlen;
    }
  if (!NILP (inherit))
    insert_and_inherit (string, n);
  else
    insert (string, n);
  return Qnil;
}
--8<---------------cut here---------------end--------------->8---

Which part of the code is responsible for prompting, name input and
consulting the character names list?

Best regards

Janusz

-- 
             ,   
Janusz S. Bien
emeryt (emeritus)
https://sites.google.com/view/jsbien