[Emacs-diffs] Changes to emacs/src/character.c [emacs-unicode-2]

[Kenichi Handa]

Index: emacs/src/character.c
diff -c /dev/null emacs/src/character.c:1.1.4.1
*** /dev/null   Mon Sep  8 08:48:33 2003
--- emacs/src/character.c       Mon Sep  8 08:48:10 2003
***************
*** 0 ****
--- 1,975 ----
+ /* 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 a character not less than 256 can't have modifier bits, we
+        just ignore the bits.  */
+       if (SINGLE_BYTE_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.  */
+ 
+ int
+ translate_char (table, c)
+      Lisp_Object table;
+      int c;
+ {
+   Lisp_Object ch;
+ 
+   if (! CHAR_TABLE_P (table))
+     return c;
+   ch = CHAR_TABLE_REF (table, c);
+   if (! CHARACTERP (ch))
+     return c;
+   return XINT (ch);
+ }
+ 
+ /* 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;
+       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 */