sbase

commit e50d533d598dbe284e225e2ee52ed5f76a6e6f6a
parent 7d5b113423ae72b2edbd8433871ad8a819bfadca
Author: Randy Palamar <randy@rnpnr.xyz>
Date:   Sun,  7 Jan 2024 11:02:17 -0700

expr: treat expressions as strs until evaluation

Comparison operations (>, <, =, etc.) and matching operations must
operate originally provided string not one that has gone back and
forth through string formatting. This caused operations such as
the following to give incorrect results:

./expr 00003 : '.*'
Before: 1
After: 5

This commit fixes that issue.

Diffstat:
M
expr.c
 | 
73
+++++++++++++++++++++++++------------------------------------------------

1 file changed, 25 insertions(+), 48 deletions(-)
diff --git a/expr.c b/expr.c
@@ -18,11 +18,13 @@ struct val {
 };
 
 static void
-enan(struct val *v)
+tonum(struct val *v)
 {
-	if (!v->str)
-		return;
-	enprintf(2, "syntax error: expected integer, got %s\n", v->str);
+	const char *errstr;
+	long long d = strtonum(v->str, LLONG_MIN, LLONG_MAX, &errstr);
+	if (errstr)
+		enprintf(2, "error: expected integer, got %s\n", v->str);
+	v->num = d;
 }
 
 static void
@@ -37,16 +39,14 @@ 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);
+	const char *err1, *err2;
+	long long d1, d2;
+
+	d1 = strtonum(a->str, LLONG_MIN, LLONG_MAX, &err1);
+	d2 = strtonum(b->str, LLONG_MIN, LLONG_MAX, &err2);
+
+	if (!err1 && !err2) {
+		ret = (d1 > d2) - (d1 < d2);
 	} else {
 		ret = strcmp(a->str, b->str);
 	}
@@ -61,24 +61,10 @@ match(struct val *vstr, struct val *vregx, struct val *ret)
 	regmatch_t matches[2];
 	long long d;
 	size_t anchlen;
-	char strbuf[BUFSIZ], regxbuf[BUFSIZ],
-	     *s, *p, *anchreg, *str, *regx;
+	char *s, *p, *anchreg;
+	char *str = vstr->str, *regx = vregx->str;
 	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);
@@ -152,11 +138,11 @@ doop(int *ophead, int *opp, struct val *valhead, struct val *valp)
 	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 '+': tonum(a); tonum(b);           ret.num = a->num + b->num; break;
+	case '-': tonum(a); tonum(b);           ret.num = a->num - b->num; break;
+	case '*': tonum(a); tonum(b);           ret.num = a->num * b->num; break;
+	case '/': tonum(a); tonum(b); ezero(b); ret.num = a->num / b->num; break;
+	case '%': tonum(a); tonum(b); ezero(b); ret.num = a->num % b->num; break;
 
 	case ':': match(a, b, &ret); break;
 	}
@@ -167,25 +153,15 @@ doop(int *ophead, int *opp, struct val *valhead, struct val *valp)
 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]) {
+	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;
@@ -211,8 +187,9 @@ parse(char *expr[], int numexpr)
 	for (; *expr; expr++) {
 		switch ((type = lex(*expr, &v))) {
 		case VAL:
-			valp->str = v.str;
-			valp->num = v.num;
+			/* treatment of *expr is not known until
+			 * doop(); treat as a string for now */
+			valp->str = *expr;
 			valp++;
 			break;
 		case '(':