Test Repeat success and next state

gigaparsec.go

@@ -379,25 +379,26 @@ func Pipe[In, Ignore, Through any](p Parser[In, Ignore]) func(Through) Parser[In
 // It succeeds if and only if p succeeds at least minCount times.
 // It consumes if and only if at least one of the applications of p consumes.
 func Repeat[In, Out any](minCount int, p Parser[In, Out]) Parser[In, []Out] {
-	return func(s State[In]) (Result[In, []Out], error) {
+	return func(state State[In]) (Result[In, []Out], error) {
 		var values []Out
 		var consumed bool
-		next := s
+		currState := state
 		for {
-			result, err := p(next)
+			result, err := p(currState)
 			if err != nil {
 				return Result[In, []Out]{}, fmt.Errorf("AtLeastN: %w", err)
 			}
 			consumed = consumed || result.Consumed()
 			var value Out
 			var success bool
-			success, value, next = result.Status()
+			success, value, nextState := result.Status()
 			if !success {
 				if len(values) >= minCount {
-					return Succeed(consumed, values, next, MessageOK(s.Pos())), nil
+					return Succeed(consumed, values, currState, MessageOK(state.Pos())), nil
 				}
 				return Fail[In, []Out](consumed, result.Message()), nil
 			}
+			currState = nextState
 			values = append(values, value)
 		}
 	}

parser_test.go

@@ -138,24 +138,25 @@ func TestEnd(t *testing.T) {
 }
 
 func TestRepeat(t *testing.T) {
+	const maxParses = 100
 	t.Run("succeeds iff number of successes ≥ minCount", rapid.MakeCheck(func(t *rapid.T) {
-		const good byte = 'o'
-		const bad byte = 'x'
-		const maxParses = 100
-
 		minCount := rapid.IntRange(0, maxParses).Draw(t, "minCount")
 		successes := rapid.IntRange(0, maxParses).Draw(t, "successes")
+		shouldSucceed := successes >= minCount
 
-		input := append(ptest.SliceOfN(good, successes), bad)
-		p := gigaparsec.Repeat(minCount, gigaparsec.Match(good))
-		result, err := p(gigaparsec.MakeState(bytes.NewReader(input)))
+		input := append(ptest.SliceOfN(true, successes), false)
+		p := gigaparsec.Repeat(minCount, gigaparsec.Match(true))
+		result, err := p(gigaparsec.MakeState(gigaparsec.SliceReaderAt[bool](input)))
 
 		must.NoError(t, err)
-		success, _, _ := result.Status()
-		test.EqOp(t, successes >= minCount, success, test.Sprint("expected successes ≥ minCount"))
+		success, _, next := result.Status()
+		test.EqOp(t, shouldSucceed, success)
+		if success {
+			test.EqOp(t, uint64(successes), next.Pos())
+		}
+	}))
+	t.Run("consumes iff at least one application consumes", rapid.MakeCheck(func(t *rapid.T) {
+
 	}))
-	t.Run("consumes iff at least one application consumes", Todo)
 	t.Run("fails on error", Todo)
-	t.Run("position is unchanged on failure", Todo)
-	t.Run("position follows last success on overall success", Todo)
 }