[bpt/guile.git] / lib / unistr / u8-mbtouc.c

/* Look at first character in UTF-8 string.
   Copyright (C) 1999-2002, 2006-2007, 2009 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2001.

   This program is free software: you can redistribute it and/or modify it
   under the terms of the GNU Lesser 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

#if defined IN_LIBUNISTRING
/* Tell unistr.h to declare u8_mbtouc as 'extern', not 'static inline'.  */
# include "unistring-notinline.h"
#endif

/* Specification.  */
#include "unistr.h"

#if !HAVE_INLINE

int
u8_mbtouc (ucs4_t *puc, const uint8_t *s, size_t n)
{
  uint8_t c = *s;

  if (c < 0x80)
    {
      *puc = c;
      return 1;
    }
  else if (c >= 0xc2)
    {
      if (c < 0xe0)
	{
	  if (n >= 2)
	    {
	      if ((s[1] ^ 0x80) < 0x40)
		{
		  *puc = ((unsigned int) (c & 0x1f) << 6)
		         | (unsigned int) (s[1] ^ 0x80);
		  return 2;
		}
	      /* invalid multibyte character */
	    }
	  else
	    {
	      /* incomplete multibyte character */
	      *puc = 0xfffd;
	      return n;
	    }
	}
      else if (c < 0xf0)
	{
	  if (n >= 3)
	    {
	      if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
		  && (c >= 0xe1 || s[1] >= 0xa0)
		  && (c != 0xed || s[1] < 0xa0))
		{
		  *puc = ((unsigned int) (c & 0x0f) << 12)
		         | ((unsigned int) (s[1] ^ 0x80) << 6)
		         | (unsigned int) (s[2] ^ 0x80);
		  return 3;
		}
	      /* invalid multibyte character */
	    }
	  else
	    {
	      /* incomplete multibyte character */
	      *puc = 0xfffd;
	      return n;
	    }
	}
      else if (c < 0xf8)
	{
	  if (n >= 4)
	    {
	      if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
		  && (s[3] ^ 0x80) < 0x40
		  && (c >= 0xf1 || s[1] >= 0x90)
#if 1
		  && (c < 0xf4 || (c == 0xf4 && s[1] < 0x90))
#endif
		 )
		{
		  *puc = ((unsigned int) (c & 0x07) << 18)
		         | ((unsigned int) (s[1] ^ 0x80) << 12)
		         | ((unsigned int) (s[2] ^ 0x80) << 6)
		         | (unsigned int) (s[3] ^ 0x80);
		  return 4;
		}
	      /* invalid multibyte character */
	    }
	  else
	    {
	      /* incomplete multibyte character */
	      *puc = 0xfffd;
	      return n;
	    }
	}
#if 0
      else if (c < 0xfc)
	{
	  if (n >= 5)
	    {
	      if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
		  && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
		  && (c >= 0xf9 || s[1] >= 0x88))
		{
		  *puc = ((unsigned int) (c & 0x03) << 24)
		         | ((unsigned int) (s[1] ^ 0x80) << 18)
		         | ((unsigned int) (s[2] ^ 0x80) << 12)
		         | ((unsigned int) (s[3] ^ 0x80) << 6)
		         | (unsigned int) (s[4] ^ 0x80);
		  return 5;
		}
	      /* invalid multibyte character */
	    }
	  else
	    {
	      /* incomplete multibyte character */
	      *puc = 0xfffd;
	      return n;
	    }
	}
      else if (c < 0xfe)
	{
	  if (n >= 6)
	    {
	      if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
		  && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
		  && (s[5] ^ 0x80) < 0x40
		  && (c >= 0xfd || s[1] >= 0x84))
		{
		  *puc = ((unsigned int) (c & 0x01) << 30)
		         | ((unsigned int) (s[1] ^ 0x80) << 24)
		         | ((unsigned int) (s[2] ^ 0x80) << 18)
		         | ((unsigned int) (s[3] ^ 0x80) << 12)
		         | ((unsigned int) (s[4] ^ 0x80) << 6)
		         | (unsigned int) (s[5] ^ 0x80);
		  return 6;
		}
	      /* invalid multibyte character */
	    }
	  else
	    {
	      /* incomplete multibyte character */
	      *puc = 0xfffd;
	      return n;
	    }
	}
#endif
    }
  /* invalid multibyte character */
  *puc = 0xfffd;
  return 1;
}

#endif
Commit	Line	Data
24d56127 LC	1	/* Look at first character in UTF-8 string.
	2	Copyright (C) 1999-2002, 2006-2007, 2009 Free Software Foundation, Inc.
	3	Written by Bruno Haible <bruno@clisp.org>, 2001.
	4
	5	This program is free software: you can redistribute it and/or modify it
	6	under the terms of the GNU Lesser General Public License as published
	7	by the Free Software Foundation; either version 3 of the License, or
	8	(at your option) any later version.
	9
	10	This program is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public License
	16	along with this program. If not, see <http://www.gnu.org/licenses/>. */
	17
	18	#include <config.h>
	19
	20	#if defined IN_LIBUNISTRING
	21	/* Tell unistr.h to declare u8_mbtouc as 'extern', not 'static inline'. */
	22	# include "unistring-notinline.h"
	23	#endif
	24
	25	/* Specification. */
	26	#include "unistr.h"
	27
	28	#if !HAVE_INLINE
	29
	30	int
	31	u8_mbtouc (ucs4_t puc, const uint8_t s, size_t n)
	32	{
	33	uint8_t c = *s;
	34
	35	if (c < 0x80)
	36	{
	37	*puc = c;
	38	return 1;
	39	}
	40	else if (c >= 0xc2)
	41	{
	42	if (c < 0xe0)
	43	{
	44	if (n >= 2)
	45	{
	46	if ((s[1] ^ 0x80) < 0x40)
	47	{
	48	*puc = ((unsigned int) (c & 0x1f) << 6)
	49	\| (unsigned int) (s[1] ^ 0x80);
	50	return 2;
	51	}
	52	/* invalid multibyte character */
	53	}
	54	else
	55	{
	56	/* incomplete multibyte character */
	57	*puc = 0xfffd;
	58	return n;
	59	}
	60	}
	61	else if (c < 0xf0)
	62	{
	63	if (n >= 3)
	64	{
65	if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
66	&& (c >= 0xe1 \|\| s[1] >= 0xa0)
67	&& (c != 0xed \|\| s[1] < 0xa0))
68	{
69	*puc = ((unsigned int) (c & 0x0f) << 12)
70	\| ((unsigned int) (s[1] ^ 0x80) << 6)
71	\| (unsigned int) (s[2] ^ 0x80);
72	return 3;
73	}
74	/* invalid multibyte character */
75	}
76	else
77	{
78	/* incomplete multibyte character */
79	*puc = 0xfffd;
80	return n;
81	}
82	}
83	else if (c < 0xf8)
84	{
85	if (n >= 4)
86	{
87	if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
88	&& (s[3] ^ 0x80) < 0x40
89	&& (c >= 0xf1 \|\| s[1] >= 0x90)
90	#if 1
91	&& (c < 0xf4 \|\| (c == 0xf4 && s[1] < 0x90))
92	#endif
93	)
94	{
95	*puc = ((unsigned int) (c & 0x07) << 18)
96	\| ((unsigned int) (s[1] ^ 0x80) << 12)
97	\| ((unsigned int) (s[2] ^ 0x80) << 6)
98	\| (unsigned int) (s[3] ^ 0x80);
99	return 4;
100	}
101	/* invalid multibyte character */
102	}
103	else
104	{
105	/* incomplete multibyte character */
106	*puc = 0xfffd;
107	return n;
108	}
109	}
110	#if 0
111	else if (c < 0xfc)
112	{
113	if (n >= 5)
114	{
115	if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
116	&& (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
117	&& (c >= 0xf9 \|\| s[1] >= 0x88))
118	{
119	*puc = ((unsigned int) (c & 0x03) << 24)
120	\| ((unsigned int) (s[1] ^ 0x80) << 18)
121	\| ((unsigned int) (s[2] ^ 0x80) << 12)
122	\| ((unsigned int) (s[3] ^ 0x80) << 6)
123	\| (unsigned int) (s[4] ^ 0x80);
124	return 5;
125	}
126	/* invalid multibyte character */
127	}
128	else
129	{
130	/* incomplete multibyte character */
131	*puc = 0xfffd;
132	return n;
133	}
134	}
135	else if (c < 0xfe)
136	{
137	if (n >= 6)
138	{
139	if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
140	&& (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
141	&& (s[5] ^ 0x80) < 0x40
142	&& (c >= 0xfd \|\| s[1] >= 0x84))
143	{
144	*puc = ((unsigned int) (c & 0x01) << 30)
145	\| ((unsigned int) (s[1] ^ 0x80) << 24)
146	\| ((unsigned int) (s[2] ^ 0x80) << 18)
147	\| ((unsigned int) (s[3] ^ 0x80) << 12)
148	\| ((unsigned int) (s[4] ^ 0x80) << 6)
149	\| (unsigned int) (s[5] ^ 0x80);
150	return 6;
151	}
152	/* invalid multibyte character */
153	}
154	else
155	{
156	/* incomplete multibyte character */
157	*puc = 0xfffd;
158	return n;
159	}
160	}
161	#endif
162	}
163	/* invalid multibyte character */
164	*puc = 0xfffd;
165	return 1;
166	}
167
168	#endif