feat: add Limit method of stream

stream/stream.go

@@ -167,7 +167,7 @@ func (s stream[T]) Peek(consumer func(item T)) stream[T] {
 	return s
 }
 
-// Skip Returns a stream consisting of the remaining elements of this stream after discarding the first n elements of the stream. If this stream contains fewer than n elements then an empty stream will be returned.
+// Skip returns a stream consisting of the remaining elements of this stream after discarding the first n elements of the stream. If this stream contains fewer than n elements then an empty stream will be returned.
 func (s stream[T]) Skip(n int) stream[T] {
 	if n <= 0 {
 		return s
@@ -180,8 +180,6 @@ func (s stream[T]) Skip(n int) stream[T] {
 		return FromSlice(source)
 	}
 
-	// source = make([]T, l-n+1, l-n+1)
-
 	for i := n; i < l; i++ {
 		source = append(source, s.source[i])
 	}
@@ -189,6 +187,25 @@ func (s stream[T]) Skip(n int) stream[T] {
 	return FromSlice(source)
 }
 
+// Limit returns a stream consisting of the elements of this stream, truncated to be no longer than maxSize in length.
+func (s stream[T]) Limit(maxSize int) stream[T] {
+	if s.source == nil {
+		return s
+	}
+
+	if maxSize < 0 {
+		return FromSlice([]T{})
+	}
+
+	source := make([]T, 0, maxSize)
+
+	for i := 0; i < len(s.source) && i < maxSize; i++ {
+		source = append(source, s.source[i])
+	}
+
+	return FromSlice(source)
+}
+
 // Count returns the count of elements in the stream.
 func (s stream[T]) Count() int {
 	return len(s.source)

stream/stream_test.go

@@ -151,8 +151,23 @@ func TestStream_Skip(t *testing.T) {
 
 	s1 := stream.Skip(-1)
 	s2 := stream.Skip(0)
-	// s2 := stream.Skip(0)
 
 	assert.Equal([]int{1, 2, 3, 4, 5, 6}, s1.ToSlice())
 	assert.Equal([]int{1, 2, 3, 4, 5, 6}, s2.ToSlice())
 }
+
+func TestStream_Limit(t *testing.T) {
+	assert := internal.NewAssert(t, "TestStream_Limit")
+
+	stream := FromSlice([]int{1, 2, 3, 4, 5, 6})
+
+	s1 := stream.Limit(-1)
+	s2 := stream.Limit(0)
+	s3 := stream.Limit(1)
+	s4 := stream.Limit(6)
+
+	assert.Equal([]int{}, s1.ToSlice())
+	assert.Equal([]int{}, s2.ToSlice())
+	assert.Equal([]int{1}, s3.ToSlice())
+	assert.Equal([]int{1, 2, 3, 4, 5, 6}, s4.ToSlice())
+}