ap

commit bb8d6330c84e9863c286eab715ac19773cf7076d
parent 7790fb401e46238565b651c05d019988bd549ae3
Author: Jacob R. Edwards <n/a>
Date:   Sun, 11 Dec 2022 17:58:48 -0600

Add regex negation flag

By appending an exclaimation point ('!') to a regular expression
(/regex/!) it's result is inverted. This is a very useful ability
(even if regular expressions themselves should have the functionality);
well worth the addition.

Diffstat:
M
aps/find.c
 | 
9
+++++++--
M
aps/find.h
 | 
1
+

2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/aps/find.c b/aps/find.c
@@ -86,10 +86,11 @@ prepsearch(struct search *state, struct item *start, char *pattern)
 		c = *pattern;
 		pattern += 1;
 		p = strrchr(pattern, c);
-		if (!p || p[1])
+		if (!p || (p[1] && (p[1] != '!' || p[2])))
 			return "Unterminated regular expression";
 		if (p - pattern >= sizeof(reg))
 			return "Regular expression too long";
+		state->inv = p[1] == '!';
 		memcpy(reg, pattern, p - pattern);
 		reg[p - pattern] = 0;
 		if (!reg[0])
@@ -122,6 +123,7 @@ prepsearch(struct search *state, struct item *start, char *pattern)
 			 */
 			return "Ranges spanning from negative to positive indexes not yet implemented";
 		}
+		state->inv = 0;
 		state->inc = nextitem;
 		state->reg = 0;
 	}
@@ -163,9 +165,12 @@ findnext(struct search *state)
 		} else if (state->reg) { /* One could do something like "match = state->match(state->cur);" instead. */
 			switch (regexec(&state->u.reg, state->cur->path, 0, NULL, 0)) {
 			case 0:
-				match = state->cur;
+				if (!state->inv)
+					match = state->cur;
 				break;
 			case REG_NOMATCH:
+				if (state->inv)
+					match = state->cur;
 				break;
 			default:
 				bug("Regex failed to execute");
diff --git a/aps/find.h b/aps/find.h
@@ -2,6 +2,7 @@ struct search {
 	int fin;
 	int new;
 	int reg;
+	int inv;
 	struct item *(*inc)(struct item *);
 	struct item *cur, *end;
 	union {