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yap-6.3/os/getw.h
Vítor Santos Costa f7d23f9deb Simplify Input/Output
get rid of string I/O, did not add much
getc is never actually used by Prolog
try to use system I/O, even if it may be slower, at least for now.
extend IO C-interface to allow reading clauses
2016-02-21 19:06:25 +00:00

204 lines
5.3 KiB
C

/// compose a wide char from a sequence of getchars
/// this is a slow lane routine, called if no specialised code
/// isavailable.
static int GETW(int sno) {
StreamDesc *st = GLOBAL_Stream + sno;
int ch = GETC();
if (ch == -1)
return post_process_weof(st);
switch (st->encoding) {
case ENC_OCTET:
// no error detection, all characters are ok.
case ENC_ISO_LATIN1:
return post_process_read_wchar(ch, 1, st);
// 7 bits code, anything above is bad news
case ENC_ISO_ASCII:
if (ch & 0x80) {
/* error */
}
return post_process_read_wchar(ch, 1, st);
// default OS encoding, depends on locale.
case ENC_ISO_ANSI: {
char buf[8];
int out;
int wch;
mbstate_t mbstate;
memset((void *)&(mbstate), 0, sizeof(mbstate_t));
buf[0] = ch;
int n=1;
while ((out = mbrtowc(&wch, buf, 1, &(mbstate))) != 1) {
int ch = buf[0] = GETC();
n++;
if (ch == -1)
return post_process_weof(st);
}
return post_process_read_wchar(wch, n, st);
}
// UTF-8 works o 8 bits.
case ENC_ISO_UTF8: {
int wch;
unsigned char buf[8];
if (ch < 0x80) {
return post_process_read_wchar(ch, 1, st);
}
// if ((ch - 0xc2) > (0xf4-0xc2)) return UTF8PROC_ERROR_INVALIDUTF8;
if (ch < 0xe0) { // 2-byte sequence
// Must have valid continuation character
int c1 = buf[0] = GETC();
if (c1 == -1)
return post_process_weof(st);
// if (!utf_cont(*str)) return UTF8PROC_ERROR_INVALIDUTF8;
wch = ((ch & 0x1f)<<6) | (c1 & 0x3f);
return post_process_read_wchar(wch, 2, st);
}
if (ch < 0xf0) { // 3-byte sequence
//if ((str + 1 >= end) || !utf_cont(*str) || !utf_cont(str[1]))
// return UTF8PROC_ERROR_INVALIDUTF8;
// Check for surrogate chars
//if (ch == 0xed && *str > 0x9f)
// return UTF8PROC_ERROR_INVALIDUTF8;
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
int c2 = GETC();
if (c2 == -1)
return post_process_weof(st);
wch = ((ch & 0xf)<<12) | ((c1 & 0x3f)<<6) | (c2 & 0x3f);
return post_process_read_wchar(wch, 3, st);
} else {
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
int c2 = GETC();
if (c2 == -1)
return post_process_weof(st);
int c3 = GETC();
if (c3 == -1)
return post_process_weof(st);
wch = ((ch & 7)<<18) | ((c1 & 0x3f)<<12) | ((c2 & 0x3f)<<6) | (c3 & 0x3f);
return post_process_read_wchar(wch, 4, st);
}
}
case ENC_UTF16_LE: // check http://unicode.org/faq/utf_bom.html#utf16-3
// little-endian: start with big shot
{
int wch;
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch = (c1 << 8) + ch;
if (wch >= 0xd800 && wch < 0xdc00) {
int c2 = GETC();
if (c2 == -1)
return post_process_weof(st);
int c3 = GETC();
if (c3 == -1)
return post_process_weof(st);
wch = wch + (((c3 << 8) + c2)<<wch) + SURROGATE_OFFSET;
return post_process_read_wchar(wch, 4, st);
}
return post_process_read_wchar(wch, 2, st);
}
case ENC_UTF16_BE: // check http://unicode.org/faq/utf_bom.html#utf16-3
// little-endian: start with big shot
{
int wch;
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch = (c1) + (ch<<8);
if (wch >= 0xd800 && wch < 0xdc00) {
int c3 = GETC();
if (c3 == -1)
return post_process_weof(st);
int c2 = GETC();
if (c2 == -1)
return post_process_weof(st);
wch = (((c3 << 8) + c2) << 10) + wch + SURROGATE_OFFSET;
return post_process_read_wchar(wch, 4, st);
}
return post_process_read_wchar(wch, 2, st);
}
case ENC_UCS2_BE: // check http://unicode.org/faq/utf_bom.html#utf16-3
// little-endian: start with big shot
{
int wch;
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch = (c1) + (ch<<8);
return post_process_read_wchar(wch, 2, st);
}
case ENC_UCS2_LE: // check http://unicode.org/faq/utf_bom.html#utf16-3
// little-endian: start with big shot
{
int wch;
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch = (c1 << 8) + ch;
return post_process_read_wchar(wch, 2, st);
}
case ENC_ISO_UTF32_BE: // check http://unicode.org/faq/utf_bom.html#utf16-3
// little-endian: start with big shot
{
int wch = ch;
{
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch = wch + c1;
}
{
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch = (wch << 8 )+c1;
}
{
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch = (wch << 8) +c1;
}
return post_process_read_wchar(wch, 4, st);
}
case ENC_ISO_UTF32_LE: // check http://unicode.org/faq/utf_bom.html#utf16-3
// little-endian: start with big shot
{
int wch = ch;
{
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch += c1<<8;
}
{
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch += c1<<16;
}
{
int c1 = GETC();
if (c1 == -1)
return post_process_weof(st);
wch += c1<<24;
}
return post_process_read_wchar(wch, 4, st);
}
}
}