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)