Add .Exclude for iterator method chaining

Author: William-Young-97

iter/filter_test.go

@@ -64,6 +64,18 @@ func ExampleExclude() {
 	// None
 }
 
+func ExampleExclude_method() {
+	filtered := iter.Lift([]int{0, 1, 0, 2}).Exclude(filters.IsZero[int])
+	fmt.Println(filtered.Next())
+	fmt.Println(filtered.Next())
+	fmt.Println(filtered.Next())
+
+	// Output:
+	// Some(1)
+	// Some(2)
+	// None
+}
+
 func TestFilter(t *testing.T) {
 	evens := iter.Filter[int](iter.Count(), filters.IsEven[int])
 	assert.Equal(t, evens.Next().Unwrap(), 0)

iter/iter.go

@@ -154,3 +154,9 @@ func (iter *BaseIter[T]) Enumerate() *EnumerateIter[T] {
 func (iter *BaseIter[T]) Transform(op func(T) T) *MapIter[T, T] {
 	return Transform[T](iter, op)
 }
+
+// Exclude is a convenience method for [Exclude], providing this iterator
+// as an argument.
+func (iter *BaseIter[T]) Exclude(fun func(T) bool) *FilterIter[T] {
+	return Exclude[T](iter, fun)
+}

iter/iter_test.go

@@ -217,3 +217,9 @@ func TestBaseIteratorEnumerate(t *testing.T) {
 	assert.Equal(t, iterator.Next(), option.Some(iter.Pair[uint, string]{1, "Friend"}))
 	assert.True(t, iterator.Next().IsNone())
 }
+
+func TestBaseIteratorExclude(t *testing.T) {
+	evens := iter.Count().Exclude(filters.IsEven[int])
+	assert.Equal(t, evens.Next().Unwrap(), 1)
+	assert.Equal(t, evens.Next().Unwrap(), 3)
+}