Add type param R to Reduce() and ReduceRgiht()

jiaxwu · Dec 23, 2021 · 77641a8 · 77641a8
1 parent f7c9333
commit 77641a8
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Showing 4 changed files with 68 additions and 2 deletions.
diff --git a/reduce.go b/reduce.go
@@ -1,7 +1,7 @@
 package slices
 
 // Reduce slice to a value
-func Reduce[T any](slice []T, reduce func(total T, item T, index int, slice []T) T, init T) T {
+func Reduce[T any, R any](slice []T, reduce func(total R, item T, index int, slice []T) R, init R) R {
 	for index := 0; index < len(slice); index++ {
 		init = reduce(init, slice[index], index, slice)
 	}

diff --git a/reduce_right.go b/reduce_right.go
@@ -1,7 +1,7 @@
 package slices
 
 // ReduceRight slice to a value
-func ReduceRight[T any](slice []T, reduce func(total T, item T, index int, slice []T) T, init T) T {
+func ReduceRight[T any, R any](slice []T, reduce func(total R, item T, index int, slice []T) R, init R) R {
 	for index := len(slice) - 1; index >= 0; index-- {
 		init = reduce(init, slice[index], index, slice)
 	}

diff --git a/reduce_right_test.go b/reduce_right_test.go
@@ -2,6 +2,7 @@ package slices
 
 import (
 	"reflect"
+	"strconv"
 	"testing"
 )
 
@@ -36,3 +37,35 @@ func TestReduceRight(t *testing.T) {
 		})
 	}
 }
+
+func TestReduceRight2(t *testing.T) {
+	type args struct {
+		slice  []int
+		reduce func(total string, item int, index int, slice []int) string
+		init   string
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			name: "number1",
+			args: args{
+				slice: []int{1, 2, 3, 4, 5},
+				reduce: func(total string, item int, index int, slice []int) string {
+					return total + strconv.Itoa(item)
+				},
+				init: "",
+			},
+			want: "54321",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := ReduceRight(tt.args.slice, tt.args.reduce, tt.args.init); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("ReduceRight() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
diff --git a/reduce_test.go b/reduce_test.go
@@ -2,6 +2,7 @@ package slices
 
 import (
 	"reflect"
+	"strconv"
 	"testing"
 )
 
@@ -36,3 +37,35 @@ func TestReduce(t *testing.T) {
 		})
 	}
 }
+
+func TestReduce2(t *testing.T) {
+	type args struct {
+		slice  []int
+		reduce func(total string, item int, index int, slice []int) string
+		init   string
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			name: "numberToString",
+			args: args{
+				slice: []int{1, 2, 3, 4, 5},
+				reduce: func(total string, item int, index int, slice []int) string {
+					return total + strconv.Itoa(item)
+				},
+				init: "",
+			},
+			want: "12345",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := Reduce(tt.args.slice, tt.args.reduce, tt.args.init); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("Reduce() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}