Restore coverage to 100%

it/exhausted_test.go

@@ -4,7 +4,9 @@ import (
 	"fmt"
 	"maps"
 	"slices"
+	"testing"
 
+	"github.com/BooleanCat/go-functional/v2/internal/assert"
 	"github.com/BooleanCat/go-functional/v2/it"
 )
 
@@ -17,3 +19,23 @@ func ExampleExhausted2() {
 	fmt.Println(len(maps.Collect(it.Exhausted2[int, string]())))
 	// Output: 0
 }
+
+func TestEnumerateYieldFalse(t *testing.T) {
+	t.Parallel()
+
+	iterator := it.Enumerate(slices.Values([]int{1, 2, 3, 4, 5}))
+
+	var (
+		index  int
+		number int
+	)
+
+	iterator(func(i int, n int) bool {
+		index = i
+		number = n
+		return false
+	})
+
+	assert.Equal(t, index, 0)
+	assert.Equal(t, number, 1)
+}

it/filter.go

@@ -17,15 +17,7 @@ func Filter[V any](delegate iter.Seq[V], predicate func(V) bool) iter.Seq[V] {
 
 // Exclude yields values from an iterator that do not satisfy a predicate.
 func Exclude[V any](delegate iter.Seq[V], predicate func(V) bool) iter.Seq[V] {
-	return func(yield func(V) bool) {
-		for value := range delegate {
-			if !predicate(value) {
-				if !yield(value) {
-					return
-				}
-			}
-		}
-	}
+	return Filter(delegate, not(predicate))
 }
 
 // Filter2 yields values from an iterator that satisfy a predicate.
@@ -43,13 +35,17 @@ func Filter2[V, W any](delegate iter.Seq2[V, W], predicate func(V, W) bool) iter
 
 // Exclude2 yields values from an iterator that do not satisfy a predicate.
 func Exclude2[V, W any](delegate iter.Seq2[V, W], predicate func(V, W) bool) iter.Seq2[V, W] {
-	return func(yield func(V, W) bool) {
-		for k, v := range delegate {
-			if !predicate(k, v) {
-				if !yield(k, v) {
-					return
-				}
-			}
-		}
+	return Filter2(delegate, not2(predicate))
+}
+
+func not[V any](predicate func(V) bool) func(V) bool {
+	return func(value V) bool {
+		return !predicate(value)
+	}
+}
+
+func not2[V, W any](predicate func(V, W) bool) func(V, W) bool {
+	return func(k V, v W) bool {
+		return !predicate(k, v)
 	}
 }

it/filter_test.go

@@ -2,7 +2,6 @@ package it_test
 
 import (
 	"fmt"
-	"iter"
 	"maps"
 	"slices"
 	"testing"
@@ -28,11 +27,19 @@ func TestFilterEmpty(t *testing.T) {
 	assert.Empty[int](t, slices.Collect(it.Filter(it.Exhausted[int](), filter.IsEven)))
 }
 
-func TestFilterTerminateEarly(t *testing.T) {
+func TestFilterYieldsFalse(t *testing.T) {
 	t.Parallel()
 
-	_, stop := iter.Pull(it.Filter(slices.Values([]int{1, 2, 3}), filter.IsEven))
-	stop()
+	seq := it.Filter(slices.Values([]int{1, 2, 3, 4, 5}), filter.IsEven)
+
+	var value int
+
+	seq(func(v int) bool {
+		value = v
+		return false
+	})
+
+	assert.Equal(t, value, 2)
 }
 
 func ExampleExclude() {
@@ -63,11 +70,25 @@ func TestFilter2Empty(t *testing.T) {
 	assert.Equal(t, len(maps.Collect(it.Filter2(it.Exhausted2[int, int](), filter.Passthrough2))), 0)
 }
 
-func TestFilter2TerminateEarly(t *testing.T) {
+func TestFilter2YieldsFalse(t *testing.T) {
 	t.Parallel()
 
-	_, stop := iter.Pull2(it.Filter2(maps.All(map[int]string{1: "one", 2: "two"}), filter.Passthrough2))
-	stop()
+	seq := it.Filter2(maps.All(map[int]string{1: "one", 2: "two"}), filter.Passthrough2)
+
+	var (
+		key   int
+		value string
+	)
+
+	seq(func(k int, v string) bool {
+		key = k
+		value = v
+		return false
+	})
+
+	assert.Equal(t, key, 1)
+	assert.Equal(t, value, "one")
+
 }
 
 func ExampleExclude2() {
@@ -86,10 +107,3 @@ func TestExclude2Empty(t *testing.T) {
 
 	assert.Equal(t, len(maps.Collect(it.Exclude2(it.Exhausted2[int, int](), filter.Passthrough2))), 0)
 }
-
-func TestExclude2TerminateEarly(t *testing.T) {
-	t.Parallel()
-
-	_, stop := iter.Pull2(it.Exclude2(it.Exhausted2[int, int](), filter.Passthrough2))
-	stop()
-}