add SliceToSeq2

go.mod

@@ -1,6 +1,6 @@
 module github.com/samber/lo
 
-go 1.18
+go 1.25
 
 //
 // Dev dependencies are excluded from releases. Please check CI.

slice.go

@@ -1,12 +1,32 @@
 package lo
 
 import (
+	"iter"
 	"sort"
 
 	"github.com/samber/lo/internal/constraints"
 	"github.com/samber/lo/mutable"
 )
 
+// SliceToSeq2 converts a slice into a sequence of pairs (key, value).
+// Elements are paired consecutively: s[0] with s[1], s[2] with s[3], etc.
+// If the slice has an odd number of elements, the last element is paired with the zero value of type E.
+func SliceToSeq2[Slice ~[]E, E any](collection Slice) iter.Seq2[E, E] {
+	return func(yield func(E, E) bool) {
+		n := len(collection)
+		var zero E
+		for i := 0; i < n; i += 2 {
+			v := zero
+			if i+1 < n {
+				v = collection[i+1]
+			}
+			if !yield(collection[i], v) {
+				return
+			}
+		}
+	}
+}
+
 // Filter iterates over elements of collection, returning a slice of all elements predicate returns true for.
 // Play: https://go.dev/play/p/Apjg3WeSi7K
 func Filter[T any, Slice ~[]T](collection Slice, predicate func(item T, index int) bool) Slice {

slice_test.go

@@ -2,7 +2,9 @@ package lo
 
 import (
 	"fmt"
+	"maps"
 	"math"
+	"reflect"
 	"sort"
 	"strconv"
 	"strings"
@@ -11,6 +13,69 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestSliceToSeq2(t *testing.T) {
+	t.Run("Even length slice", func(t *testing.T) {
+		data := []string{"a", "1", "b", "2"}
+		expected := map[string]string{"a": "1", "b": "2"}
+
+		got := maps.Collect(SliceToSeq2(data))
+
+		if !reflect.DeepEqual(got, expected) {
+			t.Errorf("expected %v, got %v", expected, got)
+		}
+	})
+
+	t.Run("Odd length slice", func(t *testing.T) {
+		data := []string{"a", "1", "b"}
+		// 最后一个元素 b 应该对应零值 ""
+		expected := map[string]string{"a": "1", "b": ""}
+
+		got := maps.Collect(SliceToSeq2(data))
+
+		if !reflect.DeepEqual(got, expected) {
+			t.Errorf("expected %v, got %v", expected, got)
+		}
+	})
+
+	t.Run("Empty slice", func(t *testing.T) {
+		data := []string{}
+		got := maps.Collect(SliceToSeq2(data))
+
+		if len(got) != 0 {
+			t.Errorf("expected empty map, got %v", got)
+		}
+	})
+
+	t.Run("Early termination (Break)", func(t *testing.T) {
+		data := []string{"a", "1", "b", "2", "c", "3"}
+		count := 0
+
+		// 模拟只取前两个键值对的情况
+		for k, v := range SliceToSeq2(data) {
+			count++
+			if k == "b" {
+				break // 触发 yield 返回 false
+			}
+			_ = v
+		}
+
+		if count != 2 {
+			t.Errorf("expected to iterate 2 times, but got %d", count)
+		}
+	})
+
+	t.Run("Integer slice", func(t *testing.T) {
+		data := []int{1, 10, 2, 20}
+		expected := map[int]int{1: 10, 2: 20}
+
+		got := maps.Collect(SliceToSeq2(data))
+
+		if !reflect.DeepEqual(got, expected) {
+			t.Errorf("expected %v, got %v", expected, got)
+		}
+	})
+}
+
 func TestFilter(t *testing.T) {
 	t.Parallel()
 	is := assert.New(t)