chresc.c revision da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2007 AT&T Knowledge Ventures *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Knowledge Ventures *
* *
* A copy of the License is available at *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* return the next character in the string s
* \ character constants are converted
* p is updated to point to the next character in s
*/
#include <ast.h>
#include <ctype.h>
#include <ccode.h>
#if !_PACKAGE_astsa
#include <regex.h>
#endif
int
chresc(register const char* s, char** p)
{
register const char* q;
register int c;
const char* e;
#if !_PACKAGE_astsa
int n;
char buf[64];
#endif
switch (c = mbchar(s))
{
case 0:
s--;
break;
case '\\':
switch (c = *s++)
{
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
c -= '0';
q = s + 2;
while (s < q)
switch (*s)
{
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
c = (c << 3) + *s++ - '0';
break;
default:
q = s;
break;
}
break;
case 'a':
c = CC_bel;
break;
case 'b':
c = '\b';
break;
case 'c':
if (c = *s)
{
s++;
if (islower(c))
c = toupper(c);
}
c ^= 0x40;
break;
case 'C':
if (*s == '-' && *(s + 1))
{
s++;
goto control;
}
#if !_PACKAGE_astsa
{
if (n == 1)
c = buf[0];
s = e;
}
#endif
break;
case 'e':
case 'E':
c = CC_esc;
break;
case 'f':
c = '\f';
break;
case 'M':
if (*s == '-')
{
s++;
c = CC_esc;
}
break;
case 'n':
c = '\n';
break;
case 'r':
c = '\r';
break;
case 't':
c = '\t';
break;
case 'v':
c = CC_vt;
break;
case 'u':
case 'U':
case 'x':
c = 0;
q = c == 'u' ? (s + 4) : c == 'U' ? (s + 8) : (char*)0;
e = s;
while (!e || !q || s < q)
{
switch (*s)
{
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
c = (c << 4) + *s++ - 'a' + 10;
continue;
case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
c = (c << 4) + *s++ - 'A' + 10;
continue;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
c = (c << 4) + *s++ - '0';
continue;
case '{':
case '[':
if (s != e)
break;
e = 0;
s++;
continue;
case '}':
case ']':
if (!e)
s++;
break;
default:
break;
}
break;
}
break;
case 0:
s--;
break;
}
break;
}
if (p)
*p = (char*)s;
return c;
}