/* Multibyte character data type.
   Copyright (C) 2001, 2005-2007, 2009-2010, 2021,2024 Free Software Foundation, Inc.

   This program 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 3 of the License, or
   (at your option) any later version.

   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Written by Bruno Haible <bruno@clisp.org>.  */

#ifndef _SHMBCHAR_H
#define _SHMBCHAR_H 1

#if defined (HANDLE_MULTIBYTE)

#include <string.h>

/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
   <wchar.h>.
   BSD/OS 4.1 has a bug: <stdio.h> and <time.h> must be included before
   <wchar.h>.  */
#include <stdio.h>
#include <time.h>
#include <wchar.h>
#include <wctype.h>

/* is_basic(c) tests whether the single-byte character c is
   - in the ISO C "basic character set" or is one of '@', '$', and '`'
     which ISO C 23 § 5.2.1.1.(1) guarantees to be single-byte and in
     practice are safe to treat as basic in the execution character set,
     or 
   - in the POSIX "portable character set", which
     <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap06.html>
     equally guarantees to be single-byte. */
                               
#if (' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
    && ('$' == 36) && ('%' == 37) && ('&' == 38) && ('\'' == 39) \
    && ('(' == 40) && (')' == 41) && ('*' == 42) && ('+' == 43) \
    && (',' == 44) && ('-' == 45) && ('.' == 46) && ('/' == 47) \
    && ('0' == 48) && ('1' == 49) && ('2' == 50) && ('3' == 51) \
    && ('4' == 52) && ('5' == 53) && ('6' == 54) && ('7' == 55) \
    && ('8' == 56) && ('9' == 57) && (':' == 58) && (';' == 59) \
    && ('<' == 60) && ('=' == 61) && ('>' == 62) && ('?' == 63) \
    && ('@' == 64) && ('A' == 65) && ('B' == 66) && ('C' == 67) \
    && ('D' == 68) && ('E' == 69) && ('F' == 70) && ('G' == 71) \
    && ('H' == 72) && ('I' == 73) && ('J' == 74) && ('K' == 75) \
    && ('L' == 76) && ('M' == 77) && ('N' == 78) && ('O' == 79) \
    && ('P' == 80) && ('Q' == 81) && ('R' == 82) && ('S' == 83) \
    && ('T' == 84) && ('U' == 85) && ('V' == 86) && ('W' == 87) \
    && ('X' == 88) && ('Y' == 89) && ('Z' == 90) && ('[' == 91) \
    && ('\\' == 92) && (']' == 93) && ('^' == 94) && ('_' == 95) \
    && ('`' == 96) && ('a' == 97) && ('b' == 98) && ('c' == 99) \
    && ('d' == 100) && ('e' == 101) && ('f' == 102) && ('g' == 103) \
    && ('h' == 104) && ('i' == 105) && ('j' == 106) && ('k' == 107) \
    && ('l' == 108) && ('m' == 109) && ('n' == 110) && ('o' == 111) \
    && ('p' == 112) && ('q' == 113) && ('r' == 114) && ('s' == 115) \
    && ('t' == 116) && ('u' == 117) && ('v' == 118) && ('w' == 119) \
    && ('x' == 120) && ('y' == 121) && ('z' == 122) && ('{' == 123) \
    && ('|' == 124) && ('}' == 125) && ('~' == 126)
/* The character set is ISO-646, not EBCDIC. */
# define IS_BASIC_ASCII 1

extern const unsigned int is_basic_table[];

static inline int
is_basic (char c)
{
  return (is_basic_table [(unsigned char) c >> 5] >> ((unsigned char) c & 31))
         & 1;
}

#if 0
/* XXX - FUTURE */
/* All locale encodings (see localcharset.h) map the characters 0x00..0x7F
   to U+0000..U+007F, like ASCII, except for
     CP864      different mapping of '%'
     SHIFT_JIS  different mappings of 0x5C, 0x7E
     JOHAB      different mapping of 0x5C
   However, these characters in the range 0x20..0x7E are in the ISO C
   "basic character set" and in the POSIX "portable character set", which
   ISO C and POSIX guarantee to be single-byte.  Thus, locales with these
   encodings are not POSIX compliant.  And they are most likely not in use
   any more (as of 2023).  */
#define is_basic(c) ((unsigned char) (c) < 0x80)
#endif

#else

static inline int
is_basic (char c)
{
  switch (c)
    {
    case '\b': case '\r': case '\n':
    case '\t': case '\v': case '\f':
    case ' ': case '!': case '"': case '#': case '$': case '%':
    case '&': case '\'': case '(': case ')': case '*':
    case '+': case ',': case '-': case '.': case '/':
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9':
    case ':': case ';': case '<': case '=': case '>':
    case '?': case '@':
    case 'A': case 'B': case 'C': case 'D': case 'E':
    case 'F': case 'G': case 'H': case 'I': case 'J':
    case 'K': case 'L': case 'M': case 'N': case 'O':
    case 'P': case 'Q': case 'R': case 'S': case 'T':
    case 'U': case 'V': case 'W': case 'X': case 'Y':
    case 'Z':
    case '[': case '\\': case ']': case '^': case '_': case '`':
    case 'a': case 'b': case 'c': case 'd': case 'e':
    case 'f': case 'g': case 'h': case 'i': case 'j':
    case 'k': case 'l': case 'm': case 'n': case 'o':
    case 'p': case 'q': case 'r': case 's': case 't':
    case 'u': case 'v': case 'w': case 'x': case 'y':
    case 'z': case '{': case '|': case '}': case '~':
      return 1;
    default:
      return 0;
    }
}

#endif

#endif /* HANDLE_MULTIBYTE */
#endif /* _SHMBCHAR_H */
