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/* See LICENSE file for copyright and license details. */
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "utf.h"
#include "util.h"
/* tokens, one-character operators represent themselves */
enum {
VAL = CHAR_MAX + 1, GE, LE, NE
};
struct val {
char *str;
long long num;
};
static void
enan(struct val *v)
{
if (!v->str)
return;
enprintf(2, "syntax error: expected integer, got %s\n", v->str);
}
static void
ezero(struct val *v)
{
if (v->num != 0)
return;
enprintf(2, "division by zero\n");
}
static int
valcmp(struct val *a, struct val *b)
{
int ret;
char buf[BUFSIZ];
if (!a->str && !b->str) {
ret = (a->num > b->num) - (a->num < b->num);
} else if (a->str && !b->str) {
snprintf(buf, sizeof(buf), "%lld", b->num);
ret = strcmp(a->str, buf);
} else if (!a->str && b->str) {
snprintf(buf, sizeof(buf), "%lld", a->num);
ret = strcmp(buf, b->str);
} else {
ret = strcmp(a->str, b->str);
}
return ret;
}
static void
match(struct val *vstr, struct val *vregx, struct val *ret)
{
regex_t re;
regmatch_t matches[2];
long long d;
size_t anchlen;
char strbuf[BUFSIZ], regxbuf[BUFSIZ],
*s, *p, *anchreg, *str, *regx;
const char *errstr;
if (!vstr->str) {
snprintf(strbuf, sizeof(strbuf), "%lld", vstr->num);
str = strbuf;
} else {
str = vstr->str;
}
if (!vregx->str) {
snprintf(regxbuf, sizeof(regxbuf), "%lld", vregx->num);
regx = regxbuf;
} else {
regx = vregx->str;
}
/* anchored regex */
anchlen = strlen(regx) + 1 + 1;
anchreg = emalloc(anchlen);
estrlcpy(anchreg, "^", anchlen);
estrlcat(anchreg, regx, anchlen);
enregcomp(3, &re, anchreg, 0);
free(anchreg);
if (regexec(&re, str, 2, matches, 0)) {
regfree(&re);
ret->str = re.re_nsub ? "" : NULL;
return;
} else if (re.re_nsub) {
regfree(&re);
s = str + matches[1].rm_so;
p = str + matches[1].rm_eo;
*p = '\0';
d = strtonum(s, LLONG_MIN, LLONG_MAX, &errstr);
if (!errstr) {
ret->num = d;
return;
} else {
ret->str = enstrdup(3, s);
return;
}
} else {
regfree(&re);
str += matches[0].rm_so;
ret->num = utfnlen(str, matches[0].rm_eo - matches[0].rm_so);
return;
}
}
static void
doop(int *ophead, int *opp, struct val *valhead, struct val *valp)
{
struct val ret = { .str = NULL, .num = 0 }, *a, *b;
int op;
/* an operation "a op b" needs an operator and two values */
if (opp[-1] == '(')
enprintf(2, "syntax error: extra (\n");
if (valp - valhead < 2)
enprintf(2, "syntax error: missing expression or extra operator\n");
a = valp - 2;
b = valp - 1;
op = opp[-1];
switch (op) {
case '|':
if ( a->str && *a->str) ret.str = a->str;
else if (!a->str && a->num) ret.num = a->num;
else if ( b->str && *b->str) ret.str = b->str;
else ret.num = b->num;
break;
case '&':
if (((a->str && *a->str) || a->num) &&
((b->str && *b->str) || b->num)) {
ret.str = a->str;
ret.num = a->num;
}
break;
case '=': ret.num = (valcmp(a, b) == 0); break;
case '>': ret.num = (valcmp(a, b) > 0); break;
case GE : ret.num = (valcmp(a, b) >= 0); break;
case '<': ret.num = (valcmp(a, b) < 0); break;
case LE : ret.num = (valcmp(a, b) <= 0); break;
case NE : ret.num = (valcmp(a, b) != 0); break;
case '+': enan(a); enan(b); ret.num = a->num + b->num; break;
case '-': enan(a); enan(b); ret.num = a->num - b->num; break;
case '*': enan(a); enan(b); ret.num = a->num * b->num; break;
case '/': enan(a); enan(b); ezero(b); ret.num = a->num / b->num; break;
case '%': enan(a); enan(b); ezero(b); ret.num = a->num % b->num; break;
case ':': match(a, b, &ret); break;
}
valp[-2] = ret;
}
static int
lex(char *s, struct val *v)
{
long long d;
int type = VAL;
char *ops = "|&=><+-*/%():";
const char *errstr;
d = strtonum(s, LLONG_MIN, LLONG_MAX, &errstr);
if (!errstr) {
/* integer */
v->num = d;
} else if (s[0] && strchr(ops, s[0]) && !s[1]) {
/* one-char operand */
type = s[0];
} else if (s[0] && strchr("><!", s[0]) && s[1] == '=' && !s[2]) {
/* two-char operand */
type = (s[0] == '>') ? GE : (s[0] == '<') ? LE : NE;
} else {
/* string */
v->str = s;
}
return type;
}
static int
parse(char *expr[], int numexpr)
{
struct val *valhead, *valp, v = { .str = NULL, .num = 0 };
int *ophead, *opp, type, lasttype = 0;
char prec[] = {
[ 0 ] = 0, [VAL] = 0, ['('] = 0, [')'] = 0,
['|'] = 1,
['&'] = 2,
['='] = 3, ['>'] = 3, [GE] = 3, ['<'] = 3, [LE] = 3, [NE] = 3,
['+'] = 4, ['-'] = 4,
['*'] = 5, ['/'] = 5, ['%'] = 5,
[':'] = 6,
};
valp = valhead = enreallocarray(3, NULL, numexpr, sizeof(*valp));
opp = ophead = enreallocarray(3, NULL, numexpr, sizeof(*opp));
for (; *expr; expr++) {
switch ((type = lex(*expr, &v))) {
case VAL:
valp->str = v.str;
valp->num = v.num;
valp++;
break;
case '(':
*opp++ = type;
break;
case ')':
if (lasttype == '(')
enprintf(2, "syntax error: empty ( )\n");
while (opp > ophead && opp[-1] != '(')
doop(ophead, opp--, valhead, valp--);
if (opp == ophead)
enprintf(2, "syntax error: extra )\n");
opp--;
break;
default: /* operator */
if (prec[lasttype])
enprintf(2, "syntax error: extra operator\n");
while (opp > ophead && prec[opp[-1]] >= prec[type])
doop(ophead, opp--, valhead, valp--);
*opp++ = type;
break;
}
lasttype = type;
v.str = NULL;
v.num = 0;
}
while (opp > ophead)
doop(ophead, opp--, valhead, valp--);
if (valp == valhead)
enprintf(2, "syntax error: missing expression\n");
if (--valp > valhead)
enprintf(2, "syntax error: extra expression\n");
if (valp->str)
puts(valp->str);
else
printf("%lld\n", valp->num);
return (valp->str && *valp->str) || valp->num;
}
int
main(int argc, char *argv[])
{
int ret;
argv0 = *argv, argv0 ? (argc--, argv++) : (void *)0;
ret = !parse(argv, argc);
if (fshut(stdout, "<stdout>"))
ret = 3;
return ret;
}