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emacs / src / character.c

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/* Basic character support.
   Copyright (C) 1995, 1997, 1998, 2001 Electrotechnical Laboratory, JAPAN.
     Licensed to the Free Software Foundation.
   Copyright (C) 2001 Free Software Foundation, Inc.
   Copyright (C) 2003
     National Institute of Advanced Industrial Science and Technology (AIST)
     Registration Number H13PRO009

This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* At first, see the document in `character.h' to understand the code
   in this file.  */

#ifdef emacs
#include <config.h>
#endif

#include <stdio.h>

#ifdef emacs

#include <sys/types.h>
#include "lisp.h"
#include "character.h"
#include "buffer.h"
#include "charset.h"
#include "composite.h"
#include "disptab.h"

#else  /* not emacs */

#include "mulelib.h"

#endif /* emacs */

Lisp_Object Qcharacterp;

/* Vector of translation table ever defined.
   ID of a translation table is used to index this vector.  */
Lisp_Object Vtranslation_table_vector;

/* A char-table for characters which may invoke auto-filling.  */
Lisp_Object Vauto_fill_chars;

Lisp_Object Qauto_fill_chars;

Lisp_Object Vchar_unify_table;

/* A char-table.  An element is non-nil iff the corresponding
   character has a printable glyph.  */
Lisp_Object Vprintable_chars;

/* A char-table.  An elemnent is a column-width of the corresponding
   character.  */
Lisp_Object Vchar_width_table;

/* A char-table.  An element is a symbol indicating the direction
   property of corresponding character.  */
Lisp_Object Vchar_direction_table;

/* Variable used locally in the macro FETCH_MULTIBYTE_CHAR.  */
unsigned char *_fetch_multibyte_char_p;

/* Char table of scripts.  */
Lisp_Object Vchar_script_table;

static Lisp_Object Qchar_script_table;

/* Mapping table from unibyte chars to multibyte chars.  */
int unibyte_to_multibyte_table[256];



int
char_string (c, p)
     int c;
     unsigned char *p;
{
  int bytes;

  if (c & CHAR_MODIFIER_MASK)
    {
      /* As an non-ASCII character can't have modifier bits, we just
	 ignore the bits.  */
      if (ASCII_CHAR_P ((c & ~CHAR_MODIFIER_MASK)))
	{
	  /* For Meta, Shift, and Control modifiers, we need special care.  */
	  if (c & CHAR_META)
	    {
	      /* Move the meta bit to the right place for a string.  */
	      c = (c & ~CHAR_META) | 0x80;
	    }
	  if (c & CHAR_SHIFT)
	    {
	      /* Shift modifier is valid only with [A-Za-z].  */
	      if ((c & 0377) >= 'A' && (c & 0377) <= 'Z')
		c &= ~CHAR_SHIFT;
	      else if ((c & 0377) >= 'a' && (c & 0377) <= 'z')
		c = (c & ~CHAR_SHIFT) - ('a' - 'A');
	    }
	  if (c & CHAR_CTL)
	    {
	      /* Simulate the code in lread.c.  */
	      /* Allow `\C- ' and `\C-?'.  */
	      if (c == (CHAR_CTL | ' '))
		c = 0;
	      else if (c == (CHAR_CTL | '?'))
		c = 127;
	      /* ASCII control chars are made from letters (both cases),
		 as well as the non-letters within 0100...0137.  */
	      else if ((c & 0137) >= 0101 && (c & 0137) <= 0132)
		c &= (037 | (~0177 & ~CHAR_CTL));
	      else if ((c & 0177) >= 0100 && (c & 0177) <= 0137)
		c &= (037 | (~0177 & ~CHAR_CTL));
	    }
	}

      /* If C still has any modifier bits, just ignore it.  */
      c &= ~CHAR_MODIFIER_MASK;
    }

  MAYBE_UNIFY_CHAR (c);

  if (c <= MAX_3_BYTE_CHAR)
    {
      bytes = CHAR_STRING (c, p);
    }
  else if (c <= MAX_4_BYTE_CHAR)
    {
      p[0] = (0xF0 | (c >> 18));
      p[1] = (0x80 | ((c >> 12) & 0x3F));
      p[2] = (0x80 | ((c >> 6) & 0x3F));
      p[3] = (0x80 | (c & 0x3F));
      bytes = 4;
    }
  else if (c <= MAX_5_BYTE_CHAR)
    {
      p[0] = 0xF8;
      p[1] = (0x80 | ((c >> 18) & 0x0F));
      p[2] = (0x80 | ((c >> 12) & 0x3F));
      p[3] = (0x80 | ((c >> 6) & 0x3F));
      p[4] = (0x80 | (c & 0x3F));
      bytes = 5;
    }
  else
    {
      c = CHAR_TO_BYTE8 (c);
      bytes = BYTE8_STRING (c, p);
    }

  return bytes;
}


int
string_char (p, advanced, len)
     const unsigned char *p;
     const unsigned char **advanced;
     int *len;
{
  int c;
  const unsigned char *saved_p = p;

  if (*p < 0x80 || ! (*p & 0x20) || ! (*p & 0x10))
    {
      c = STRING_CHAR_ADVANCE (p);
    }
  else if (! (*p & 0x08))
    {
      c = ((((p)[0] & 0xF) << 18)
	   | (((p)[1] & 0x3F) << 12)
	   | (((p)[2] & 0x3F) << 6)
	   | ((p)[3] & 0x3F));
      p += 4;
    }
  else
    {
      c = ((((p)[1] & 0x3F) << 18)
	   | (((p)[2] & 0x3F) << 12)
	   | (((p)[3] & 0x3F) << 6)
	   | ((p)[4] & 0x3F));
      p += 5;
    }

  MAYBE_UNIFY_CHAR (c);

  if (len)
    *len = p - saved_p;
  if (advanced)
    *advanced = p;
  return c;
}


/* Translate character C by translation table TABLE.  If C is
   negative, translate a character specified by CHARSET and CODE.  If
   no translation is found in TABLE, return the untranslated
   character.  If TABLE is a list, elements are char tables.  In this
   case, translace C by all tables.  */

int
translate_char (table, c)
     Lisp_Object table;
     int c;
{
  if (CHAR_TABLE_P (table))
    {
      Lisp_Object ch;

      ch = CHAR_TABLE_REF (table, c);
      if (CHARACTERP (ch))
	c = XINT (ch);
    }
  else
    {
      for (; CONSP (table); table = XCDR (table))
	c = translate_char (XCAR (table), c);
    }
  return c;
}

/* Convert the multibyte character C to unibyte 8-bit character based
   on the current value of charset_unibyte.  If dimension of
   charset_unibyte is more than one, return (C & 0xFF).

   The argument REV_TBL is now ignored.  It will be removed in the
   future.  */

int
multibyte_char_to_unibyte (c, rev_tbl)
     int c;
     Lisp_Object rev_tbl;
{
  struct charset *charset;
  unsigned c1;

  if (CHAR_BYTE8_P (c))
    return CHAR_TO_BYTE8 (c);
  charset = CHARSET_FROM_ID (charset_unibyte);
  c1 = ENCODE_CHAR (charset, c);
  return ((c1 != CHARSET_INVALID_CODE (charset)) ? c1 : c & 0xFF);
}


DEFUN ("characterp", Fcharacterp, Scharacterp, 1, 2, 0,
       doc: /* Return non-nil if OBJECT is a character.  */)
     (object, ignore)
     Lisp_Object object, ignore;
{
  return (CHARACTERP (object) ? Qt : Qnil);
}

DEFUN ("max-char", Fmax_char, Smax_char, 0, 0, 0,
       doc: /* Return the character of the maximum code.  */)
     ()
{
  return make_number (MAX_CHAR);
}

DEFUN ("unibyte-char-to-multibyte", Funibyte_char_to_multibyte,
       Sunibyte_char_to_multibyte, 1, 1, 0,
       doc: /* Convert the unibyte character CH to multibyte character.
The multibyte character is a result of decoding CH by
the current unibyte charset (see `unibyte-charset').  */)
     (ch)
     Lisp_Object ch;
{
  int c;
  struct charset *charset;

  CHECK_CHARACTER (ch);
  c = XFASTINT (ch);
  if (c >= 0400)
    error ("Invalid unibyte character: %d", c);
  charset = CHARSET_FROM_ID (charset_unibyte);
  c = DECODE_CHAR (charset, c);
  if (c < 0)
    c = BYTE8_TO_CHAR (XFASTINT (ch));
  return make_number (c);
}

DEFUN ("multibyte-char-to-unibyte", Fmultibyte_char_to_unibyte,
       Smultibyte_char_to_unibyte, 1, 1, 0,
       doc: /* Convert the multibyte character CH to unibyte character.\n\
The unibyte character is a result of encoding CH by
the current primary charset (value of `charset-primary').  */)
     (ch)
     Lisp_Object ch;
{
  int c;

  CHECK_CHARACTER (ch);
  c = XFASTINT (ch);
  c = CHAR_TO_BYTE8 (c);
  return make_number (c);
}

DEFUN ("char-bytes", Fchar_bytes, Schar_bytes, 1, 1, 0,
       doc: /* Return 1 regardless of the argument CHAR.
This is now an obsolete function.  We keep it just for backward compatibility.	 */)
     (ch)
     Lisp_Object ch;
{
  CHECK_CHARACTER (ch);
  return make_number (1);
}

DEFUN ("char-width", Fchar_width, Schar_width, 1, 1, 0,
       doc: /* Return width of CHAR when displayed in the current buffer.
The width is measured by how many columns it occupies on the screen.
Tab is taken to occupy `tab-width' columns.  */)
     (ch)
       Lisp_Object ch;
{
  Lisp_Object disp;
  int c, width;
  struct Lisp_Char_Table *dp = buffer_display_table ();

  CHECK_CHARACTER (ch);
  c = XINT (ch);

  /* Get the way the display table would display it.  */
  disp = dp ? DISP_CHAR_VECTOR (dp, c) : Qnil;

  if (VECTORP (disp))
    width = ASIZE (disp);
  else
    width = CHAR_WIDTH (c);

  return make_number (width);
}

/* Return width of string STR of length LEN when displayed in the
   current buffer.  The width is measured by how many columns it
   occupies on the screen.  If PRECISION > 0, return the width of
   longest substring that doesn't exceed PRECISION, and set number of
   characters and bytes of the substring in *NCHARS and *NBYTES
   respectively.  */

int
c_string_width (str, len, precision, nchars, nbytes)
     const unsigned char *str;
     int precision, *nchars, *nbytes;
{
  int i = 0, i_byte = 0;
  int width = 0;
  struct Lisp_Char_Table *dp = buffer_display_table ();

  while (i_byte < len)
    {
      int bytes, thiswidth;
      Lisp_Object val;
      int c = STRING_CHAR_AND_LENGTH (str + i_byte, len - i_byte, bytes);

      if (dp)
	{
	  val = DISP_CHAR_VECTOR (dp, c);
	  if (VECTORP (val))
	    thiswidth = XVECTOR (val)->size;
	  else
	    thiswidth = CHAR_WIDTH (c);
	}
      else
	{
	  thiswidth = CHAR_WIDTH (c);
	}

      if (precision > 0
	  && (width + thiswidth > precision))
	{
	  *nchars = i;
	  *nbytes = i_byte;
	  return width;
	}
      i++;
      i_byte += bytes;
      width += thiswidth;
  }

  if (precision > 0)
    {
      *nchars = i;
      *nbytes = i_byte;
    }

  return width;
}

/* Return width of string STR of length LEN when displayed in the
   current buffer.  The width is measured by how many columns it
   occupies on the screen.  */

int
strwidth (str, len)
     unsigned char *str;
     int len;
{
  return c_string_width (str, len, -1, NULL, NULL);
}

/* Return width of Lisp string STRING when displayed in the current
   buffer.  The width is measured by how many columns it occupies on
   the screen while paying attention to compositions.  If PRECISION >
   0, return the width of longest substring that doesn't exceed
   PRECISION, and set number of characters and bytes of the substring
   in *NCHARS and *NBYTES respectively.  */

int
lisp_string_width (string, precision, nchars, nbytes)
     Lisp_Object string;
     int precision, *nchars, *nbytes;
{
  int len = SCHARS (string);
  unsigned char *str = SDATA (string);
  int i = 0, i_byte = 0;
  int width = 0;
  struct Lisp_Char_Table *dp = buffer_display_table ();

  while (i < len)
    {
      int chars, bytes, thiswidth;
      Lisp_Object val;
      int cmp_id;
      EMACS_INT ignore, end;

      if (find_composition (i, -1, &ignore, &end, &val, string)
	  && ((cmp_id = get_composition_id (i, i_byte, end - i, val, string))
	      >= 0))
	{
	  thiswidth = composition_table[cmp_id]->width;
	  chars = end - i;
	  bytes = string_char_to_byte (string, end) - i_byte;
	}
      else if (dp)
	{
	  int c = STRING_CHAR_AND_LENGTH (str + i_byte, len - i_byte, bytes);

	  chars = 1;
	  val = DISP_CHAR_VECTOR (dp, c);
	  if (VECTORP (val))
	    thiswidth = XVECTOR (val)->size;
	  else
	    thiswidth = CHAR_WIDTH (c);
	}
      else
	{
	  int c = STRING_CHAR_AND_LENGTH (str + i_byte, len - i_byte, bytes);

	  chars = 1;
	  thiswidth = CHAR_WIDTH (c);
	}

      if (precision > 0
	  && (width + thiswidth > precision))
	{
	  *nchars = i;
	  *nbytes = i_byte;
	  return width;
	}
      i += chars;
      i_byte += bytes;
      width += thiswidth;
  }

  if (precision > 0)
    {
      *nchars = i;
      *nbytes = i_byte;
    }

  return width;
}

DEFUN ("string-width", Fstring_width, Sstring_width, 1, 1, 0,
       doc: /* Return width of STRING when displayed in the current buffer.
Width is measured by how many columns it occupies on the screen.
When calculating width of a multibyte character in STRING,
only the base leading-code is considered; the validity of
the following bytes is not checked.  Tabs in STRING are always
taken to occupy `tab-width' columns.  */)
     (str)
     Lisp_Object str;
{
  Lisp_Object val;

  CHECK_STRING (str);
  XSETFASTINT (val, lisp_string_width (str, -1, NULL, NULL));
  return val;
}

DEFUN ("char-direction", Fchar_direction, Schar_direction, 1, 1, 0,
       doc: /* Return the direction of CHAR.
The returned value is 0 for left-to-right and 1 for right-to-left.  */)
     (ch)
     Lisp_Object ch;
{
  int c;

  CHECK_CHARACTER (ch);
  c = XINT (ch);
  return CHAR_TABLE_REF (Vchar_direction_table, c);
}

DEFUN ("chars-in-region", Fchars_in_region, Schars_in_region, 2, 2, 0,
       doc: /* Return number of characters between BEG and END.
This is now an obsolete function.  We keep it just for backward compatibility.  */)
     (beg, end)
     Lisp_Object beg, end;
{
  int from, to;

  CHECK_NUMBER_COERCE_MARKER (beg);
  CHECK_NUMBER_COERCE_MARKER (end);

  from = min (XFASTINT (beg), XFASTINT (end));
  to = max (XFASTINT (beg), XFASTINT (end));

  return make_number (to - from);
}

/* Return the number of characters in the NBYTES bytes at PTR.
   This works by looking at the contents and checking for multibyte
   sequences while assuming that there's no invalid sequence.
   However, if the current buffer has enable-multibyte-characters =
   nil, we treat each byte as a character.  */

int
chars_in_text (ptr, nbytes)
     const unsigned char *ptr;
     int nbytes;
{
  /* current_buffer is null at early stages of Emacs initialization.  */
  if (current_buffer == 0
      || NILP (current_buffer->enable_multibyte_characters))
    return nbytes;

  return multibyte_chars_in_text (ptr, nbytes);
}

/* Return the number of characters in the NBYTES bytes at PTR.
   This works by looking at the contents and checking for multibyte
   sequences while assuming that there's no invalid sequence.  It
   ignores enable-multibyte-characters.  */

int
multibyte_chars_in_text (ptr, nbytes)
     const unsigned char *ptr;
     int nbytes;
{
  const unsigned char *endp = ptr + nbytes;
  int chars = 0;

  while (ptr < endp)
    {
      int len = MULTIBYTE_LENGTH (ptr, endp);

      if (len == 0)
	abort ();
      ptr += len;
      chars++;
    }

  return chars;
}

/* Parse unibyte text at STR of LEN bytes as a multibyte text, count
   characters and bytes in it, and store them in *NCHARS and *NBYTES
   respectively.  On counting bytes, pay attention to that 8-bit
   characters not constructing a valid multibyte sequence are
   represented by 2-byte in a multibyte text.  */

void
parse_str_as_multibyte (str, len, nchars, nbytes)
     const unsigned char *str;
     int len, *nchars, *nbytes;
{
  const unsigned char *endp = str + len;
  int n, chars = 0, bytes = 0;

  if (len >= MAX_MULTIBYTE_LENGTH)
    {
      const unsigned char *adjusted_endp = endp - MAX_MULTIBYTE_LENGTH;
      while (str < adjusted_endp)
	{
	  if ((n = MULTIBYTE_LENGTH_NO_CHECK (str)) > 0)
	    str += n, bytes += n;
	  else
	    str++, bytes += 2;
	  chars++;
	}
    }
  while (str < endp)
    {
      if ((n = MULTIBYTE_LENGTH (str, endp)) > 0)
	str += n, bytes += n;
      else
	str++, bytes += 2;
      chars++;
    }

  *nchars = chars;
  *nbytes = bytes;
  return;
}

/* Arrange unibyte text at STR of NBYTES bytes as a multibyte text.
   It actually converts only such 8-bit characters that don't contruct
   a multibyte sequence to multibyte forms of Latin-1 characters.  If
   NCHARS is nonzero, set *NCHARS to the number of characters in the
   text.  It is assured that we can use LEN bytes at STR as a work
   area and that is enough.  Return the number of bytes of the
   resulting text.  */

int
str_as_multibyte (str, len, nbytes, nchars)
     unsigned char *str;
     int len, nbytes, *nchars;
{
  unsigned char *p = str, *endp = str + nbytes;
  unsigned char *to;
  int chars = 0;
  int n;

  if (nbytes >= MAX_MULTIBYTE_LENGTH)
    {
      unsigned char *adjusted_endp = endp - MAX_MULTIBYTE_LENGTH;
      while (p < adjusted_endp
	     && (n = MULTIBYTE_LENGTH_NO_CHECK (p)) > 0)
	p += n, chars++;
    }
  while ((n = MULTIBYTE_LENGTH (p, endp)) > 0)
    p += n, chars++;
  if (nchars)
    *nchars = chars;
  if (p == endp)
    return nbytes;

  to = p;
  nbytes = endp - p;
  endp = str + len;
  safe_bcopy ((char *) p, (char *) (endp - nbytes), nbytes);
  p = endp - nbytes;

  if (nbytes >= MAX_MULTIBYTE_LENGTH)
    {
      unsigned char *adjusted_endp = endp - MAX_MULTIBYTE_LENGTH;
      while (p < adjusted_endp)
	{
	  if ((n = MULTIBYTE_LENGTH_NO_CHECK (p)) > 0)
	    {
	      while (n--)
		*to++ = *p++;
	    }
	  else
	    {
	      int c = *p++;
	      c = BYTE8_TO_CHAR (c);
	      to += CHAR_STRING (c, to);
	    }
	}
      chars++;
    }
  while (p < endp)
    {
      if ((n = MULTIBYTE_LENGTH (p, endp)) > 0)
	{
	  while (n--)
	    *to++ = *p++;
	}
      else
	{
	  int c = *p++;
	  c = BYTE8_TO_CHAR (c);
	  to += CHAR_STRING (c, to);
	}
      chars++;
    }
  if (nchars)
    *nchars = chars;
  return (to - str);
}

/* Parse unibyte string at STR of LEN bytes, and return the number of
   bytes it may ocupy when converted to multibyte string by
   `str_to_multibyte'.  */

int
parse_str_to_multibyte (str, len)
     unsigned char *str;
     int len;
{
  unsigned char *endp = str + len;
  int bytes;

  for (bytes = 0; str < endp; str++)
    bytes += (*str < 0x80) ? 1 : 2;
  return bytes;
}


/* Convert unibyte text at STR of NBYTES bytes to a multibyte text
   that contains the same single-byte characters.  It actually
   converts all 8-bit characters to multibyte forms.  It is assured
   that we can use LEN bytes at STR as a work area and that is
   enough.  */

int
str_to_multibyte (str, len, bytes)
     unsigned char *str;
     int len, bytes;
{
  unsigned char *p = str, *endp = str + bytes;
  unsigned char *to;

  while (p < endp && *p < 0x80) p++;
  if (p == endp)
    return bytes;
  to = p;
  bytes = endp - p;
  endp = str + len;
  safe_bcopy ((char *) p, (char *) (endp - bytes), bytes);
  p = endp - bytes;
  while (p < endp)
    {
      int c = *p++;

      if (c >= 0x80)
	c = BYTE8_TO_CHAR (c);
      to += CHAR_STRING (c, to);
    }
  return (to - str);
}

/* Arrange multibyte text at STR of LEN bytes as a unibyte text.  It
   actually converts characters in the range 0x80..0xFF to
   unibyte.  */

int
str_as_unibyte (str, bytes)
     unsigned char *str;
     int bytes;
{
  const unsigned char *p = str, *endp = str + bytes;
  unsigned char *to;
  int c, len;

  while (p < endp)
    {
      c = *p;
      len = BYTES_BY_CHAR_HEAD (c);
      if (CHAR_BYTE8_HEAD_P (c))
	break;
      p += len;
    }
  to = str + (p - str);
  while (p < endp)
    {
      c = *p;
      len = BYTES_BY_CHAR_HEAD (c);
      if (CHAR_BYTE8_HEAD_P (c))
	{
	  c = STRING_CHAR_ADVANCE (p);
	  *to++ = CHAR_TO_BYTE8 (c);
	}
      else
	{
	  while (len--) *to++ = *p++;
	}
    }
  return (to - str);
}

int
string_count_byte8 (string)
     Lisp_Object string;
{
  int multibyte = STRING_MULTIBYTE (string);
  int nbytes = SBYTES (string);
  unsigned char *p = SDATA (string);
  unsigned char *pend = p + nbytes;
  int count = 0;
  int c, len;

  if (multibyte)
    while (p < pend)
      {
	c = *p;
	len = BYTES_BY_CHAR_HEAD (c);

	if (CHAR_BYTE8_HEAD_P (c))
	  count++;
	p += len;
      }
  else
    while (p < pend)
      {
	if (*p++ >= 0x80)
	  count++;
      }
  return count;
}


Lisp_Object
string_escape_byte8 (string)
     Lisp_Object string;
{
  int nchars = SCHARS (string);
  int nbytes = SBYTES (string);
  int multibyte = STRING_MULTIBYTE (string);
  int byte8_count;
  const unsigned char *src, *src_end;
  unsigned char *dst;
  Lisp_Object val;
  int c, len;

  if (multibyte && nchars == nbytes)
    return string;

  byte8_count = string_count_byte8 (string);

  if (byte8_count == 0)
    return string;

  if (multibyte)
    /* Convert 2-byte sequence of byte8 chars to 4-byte octal.  */
    val = make_uninit_multibyte_string (nchars + byte8_count * 3,
					nbytes + byte8_count * 2);
  else
    /* Convert 1-byte sequence of byte8 chars to 4-byte octal.  */
    val = make_uninit_string (nbytes + byte8_count * 3);

  src = SDATA (string);
  src_end = src + nbytes;
  dst = SDATA (val);
  if (multibyte)
    while (src < src_end)
      {
	c = *src;
	len = BYTES_BY_CHAR_HEAD (c);

	if (CHAR_BYTE8_HEAD_P (c))
	  {
	    c = STRING_CHAR_ADVANCE (src);
	    c = CHAR_TO_BYTE8 (c);
	    sprintf ((char *) dst, "\\%03o", c);
	    dst += 4;
	  }
	else
	  while (len--) *dst++ = *src++;
      }
  else
    while (src < src_end)
      {
	c = *src++;
	if (c >= 0x80)
	  {
	    sprintf ((char *) dst, "\\%03o", c);
	    dst += 4;
	  }
	else
	  *dst++ = c;
      }
  return val;
}


DEFUN ("string", Fstring, Sstring, 0, MANY, 0,
       doc: /*
Concatenate all the argument characters and make the result a string.
usage: (string &rest CHARACTERS)  */)
     (n, args)
     int n;
     Lisp_Object *args;
{
  int i;
  unsigned char *buf = (unsigned char *) alloca (MAX_MULTIBYTE_LENGTH * n);
  unsigned char *p = buf;
  int c;

  for (i = 0; i < n; i++)
    {
      CHECK_CHARACTER (args[i]);
      c = XINT (args[i]);
      p += CHAR_STRING (c, p);
    }

  return make_string_from_bytes ((char *) buf, n, p - buf);
}

void
init_character_once ()
{
}

#ifdef emacs

void
syms_of_character ()
{
  DEFSYM (Qcharacterp, "characterp");
  DEFSYM (Qauto_fill_chars, "auto-fill-chars");

  staticpro (&Vchar_unify_table);
  Vchar_unify_table = Qnil;

  defsubr (&Smax_char);
  defsubr (&Scharacterp);
  defsubr (&Sunibyte_char_to_multibyte);
  defsubr (&Smultibyte_char_to_unibyte);
  defsubr (&Schar_bytes);
  defsubr (&Schar_width);
  defsubr (&Sstring_width);
  defsubr (&Schar_direction);
  defsubr (&Schars_in_region);
  defsubr (&Sstring);

  DEFVAR_LISP ("translation-table-vector",  &Vtranslation_table_vector,
	       doc: /*
Vector recording all translation tables ever defined.
Each element is a pair (SYMBOL . TABLE) relating the table to the
symbol naming it.  The ID of a translation table is an index into this vector.  */);
  Vtranslation_table_vector = Fmake_vector (make_number (16), Qnil);

  DEFVAR_LISP ("auto-fill-chars", &Vauto_fill_chars,
	       doc: /*
A char-table for characters which invoke auto-filling.
Such characters have value t in this table.  */);
  Vauto_fill_chars = Fmake_char_table (Qauto_fill_chars, Qnil);
  CHAR_TABLE_SET (Vauto_fill_chars, ' ', Qt);
  CHAR_TABLE_SET (Vauto_fill_chars, '\n', Qt);

  DEFVAR_LISP ("char-width-table", &Vchar_width_table,
	       doc: /*
A char-table for width (columns) of each character.  */);
  Vchar_width_table = Fmake_char_table (Qnil, make_number (1));
  char_table_set_range (Vchar_width_table, 0x80, 0x9F, make_number (4));
  char_table_set_range (Vchar_width_table, MAX_5_BYTE_CHAR + 1, MAX_CHAR,
			make_number (4));

  DEFVAR_LISP ("char-direction-table", &Vchar_direction_table,
	       doc: /* A char-table for direction of each character.  */);
  Vchar_direction_table = Fmake_char_table (Qnil, make_number (1));

  DEFVAR_LISP ("printable-chars", &Vprintable_chars,
	       doc: /* A char-table for each printable character.  */);
  Vprintable_chars = Fmake_char_table (Qnil, Qnil);
  Fset_char_table_range (Vprintable_chars,
			 Fcons (make_number (32), make_number (126)), Qt);
  Fset_char_table_range (Vprintable_chars,
			 Fcons (make_number (160),
				make_number (MAX_5_BYTE_CHAR)), Qt);

  DEFVAR_LISP ("char-script-table", &Vchar_script_table,
	       doc: /* Char table of script symbols.
It has one extra slot whose value is a list of script symbols.  */);

  /* Intern this now in case it isn't already done.
     Setting this variable twice is harmless.
     But don't staticpro it here--that is done in alloc.c.  */
  Qchar_table_extra_slots = intern ("char-table-extra-slots");
  DEFSYM (Qchar_script_table, "char-script-table");
  Fput (Qchar_script_table, Qchar_table_extra_slots, make_number (1));
  Vchar_script_table = Fmake_char_table (Qchar_script_table, Qnil);
}

#endif /* emacs */