da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/***********************************************************************
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* This software is part of the ast package *
3e14f97f673e8a630f076077de35afdd43dc1587Roger A. Faulkner* Copyright (c) 1985-2010 AT&T Intellectual Property *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* and is licensed under the *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Common Public License, Version 1.0 *
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin* by AT&T Intellectual Property *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* A copy of the License is available at *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Information and Software Systems Research *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* AT&T Research *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Florham Park NJ *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Glenn Fowler <gsf@research.att.com> *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* David Korn <dgk@research.att.com> *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Phong Vo <kpv@research.att.com> *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin***********************************************************************/
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * G. S. Fowler
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * D. G. Korn
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * AT&T Bell Laboratories
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * long integer arithmetic expression evaluator
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * long constants may be represented as:
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * 0ooo octal
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * 0[xX]hhh hexadecimal
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * ddd decimal
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * n#ccc base n, 2 <= b <= 36
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * NOTE: all operands are evaluated as both the parse
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * and evaluation are done on the fly
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chintypedef struct /* expression handle */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * set error message string
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic long
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * evaluate a subexpression with precedence
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstatic long
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin register int c;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin register long n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin register long x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin switch (c)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (!precedence) return(0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (!n) n = x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin n = n || x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin n = n && x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (peekchr(ex) != '=') error(ex, "operator syntax error");
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (c == '=') n = n == x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else n = n != x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (c == '<') n <<= x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else n >>= x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (c == '<') n = n <= x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else n = n >= x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (c == '<') n = n < x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else n = n > x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (c == '+') n += x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else n -= x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (c == '*') n *= x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else if (c == '/') n /= x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else n %= x;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (isspace(c)) continue;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if (isdigit(c)) n = strton(ex->nextchr, &ex->nextchr, NiL, 0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else if (ex->convert) n = (*ex->convert)(ex->nextchr, &ex->nextchr, ex->handle);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(n);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * evaluate an integer arithmetic expression in s
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * (long)(*convert)(const char* string, char** end, void* handle)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * is a user supplied conversion routine that is called when unknown
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * chars are encountered; string points to the part to be
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * converted and end is adjusted to point to the next non-converted
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * character; if string is 0 then end points to an error message string
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * NOTE: (*convert)() may call strexpr(ex, )
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinstrexpr(const char* s, char** end, long(*convert)(const char*, char**, void*), void* handle)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(n);