restructure main loop

regex.c

@@ -73,14 +73,12 @@ char *next_char(char *needle)
 	int db;
 	if (*needle && *needle != '[')
 		return needle + 1;
-	for (db = (*needle == '[' ? 2 : 0);
+	for (db = 1;
 			*needle && (*needle != ']' || db);
 			needle++)
-	{
-		if (db > 1)
+		if (db)
 			db--;
-	}
-	return needle;
+	return needle + 1;
 }
 
 // Find first character behind the closing parenthesis of the current group, or end of string
@@ -153,7 +151,18 @@ bool regex_match(char *haystack, char *needle)
 			if (!bv[st])
 				continue;
 			fprintf(stderr, "prepr %lu: \"%s\"\n", st, needle + st);
-			if (needle[st] == '|')
+			if (needle[st] == '(')
+			{
+				// at start of group, look at variants and quantifier
+				for (var = needle + st + 1; *var && *var != ')'; var = next_var(var))
+						bv[var - needle] = true;
+				if (*var == ')')
+					var++;
+				q = quant(*var);
+				if (strchr("*?", q))
+					bv[var + 1 - needle] = true;
+			}
+			else if (needle[st] == '|')
 			{
 				// at end of variant, look at end of group
 				bv[st] = false;
@@ -173,7 +182,7 @@ bool regex_match(char *haystack, char *needle)
 				fprintf(stderr, "quant %c\n", q);
 				fprintf(stderr, "suffix \"%s\"\n", needle + (q ? st + 2 : st + 1));
 				nneedl = start_of_group(needle, needle + st);
-				if ((q == '+' || q == '*') && !bv[nneedl - needle])
+				if (strchr("+*", q) && !bv[nneedl - needle])
 				{
 					// spicy: if the quantifier allows multiple occurences, we have to activate a previous state
 					fprintf(stderr, "start of group: \"%s\"\n", nneedl);
@@ -183,23 +192,12 @@ bool regex_match(char *haystack, char *needle)
 				else
 					bv[nneedl - needle] = false;
 			}
-			else if (needle[st] == '(')
-			{
-				// at start of group, look at variants and quantifier
-				for (var = needle + st + 1; *var && *var != ')'; var = next_var(var))
-						bv[var - needle] = true;
-				if (*var == ')')
-					var++;
-				q = quant(*var);
-				if (q == '*' || q == '?')
-					bv[var + 1 - needle] = true;
-			}
 			else
 			{
 				// check if current needle is optional
 				nneedl = next_char(needle + st);
 				q = *nneedl;
-				if (q == '*' || q == '?')
+				if (strchr("?*", q))
 					bv[nneedl + 1 - needle] = true;
 			}
 		}
@@ -220,7 +218,7 @@ bool regex_match(char *haystack, char *needle)
 				na = false;
 				if (q)
 					nneedl++;
-				if (q == '*' || q == '+')
+				if (strchr("*+", q))
 					bv[st-1] = true;
 				bv[nneedl - needle] = true;
 			}