Return loop index in regex iterator.

core/text/regex/regex.odin

@@ -73,6 +73,7 @@ Match_Iterator :: struct {
 	offset:   int,
 	regex:    Regular_Expression,
 	capture:  Capture,
+	idx:      int,
 	temp:     runtime.Allocator,
 }
 
@@ -442,7 +443,7 @@ Returns:
 - result: `Capture` for this iteration.
 - ok:     A bool indicating if there was a match, stopping the iteration on `false`.
 */
-match_iterator :: proc(it: ^Match_Iterator) -> (result: Capture, ok: bool) {
+match_iterator :: proc(it: ^Match_Iterator) -> (result: Capture, index: int, ok: bool) {
 	runtime.DEFAULT_TEMP_ALLOCATOR_TEMP_GUARD()
 	num_groups: int
 	num_groups, ok = match_with_preallocated_capture(
@@ -452,6 +453,10 @@ match_iterator :: proc(it: ^Match_Iterator) -> (result: Capture, ok: bool) {
 		it.temp,
 	)
 
+	defer if ok {
+		it.idx += 1
+	}
+
 	if num_groups > 0 {
 		for i in 0..<num_groups {
 			it.capture.pos[i] += it.offset
@@ -459,7 +464,7 @@ match_iterator :: proc(it: ^Match_Iterator) -> (result: Capture, ok: bool) {
 		it.offset = it.capture.pos[0][1]
 		result = {it.capture.pos[:num_groups], it.capture.groups[:num_groups]}
 	}
-	return
+	return result, it.idx, ok
 }
 
 match :: proc {
@@ -468,6 +473,11 @@ match :: proc {
 	match_iterator,
 }
 
+reset :: proc(it: ^Match_Iterator) {
+	it.offset = 0
+	it.idx    = 0
+}
+
 /*
 Allocate a `Capture` in advance for use with `match`. This can save some time
 if you plan on performing several matches at once and only need the results

tests/core/text/regex/test_core_text_regex.odin

@@ -1127,13 +1127,12 @@ test_match_iterator :: proc(t: ^testing.T) {
 		(err == nil) or_continue
 
 		count: int
-		for capture in regex.match(&it) {
+		for capture, idx in regex.match(&it) {
 			if count > len(test.expected) {
 				break
 			}
-			check_capture(t, capture, test.expected[count])
-			count += 1
+			check_capture(t, capture, test.expected[idx])
 		}
-		testing.expect_value(t, count, len(test.expected))
+		testing.expect_value(t, it.idx, len(test.expected))
 	}
 }