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mirror of https://github.com/duke-git/lancet.git synced 2026-02-04 12:52:28 +08:00

feat: add FindLast func

This commit is contained in:
dudaodong
2022-01-24 15:28:47 +08:00
parent 8bb102cb6e
commit 1ad990ce9d
2 changed files with 43 additions and 1 deletions

View File

@@ -367,6 +367,34 @@ func Find(slice, function interface{}) (interface{}, bool) {
return sv.Index(index).Interface(), true
}
// FindLast iterates over elements of slice from end to begin, returning the first one that passes a truth test on function.
// The function signature should be func(index int, value interface{}) bool .
func FindLast(slice, function interface{}) (interface{}, bool) {
sv := sliceValue(slice)
fn := functionValue(function)
elemType := sv.Type().Elem()
if checkSliceCallbackFuncSignature(fn, elemType, reflect.ValueOf(true).Type()) {
panic("function param should be of type func(int, " + elemType.String() + ")" + reflect.ValueOf(true).Type().String())
}
index := -1
for i := sv.Len() - 1; i >= 0; i-- {
flag := fn.Call([]reflect.Value{reflect.ValueOf(i), sv.Index(i)})[0]
if flag.Bool() {
index = i
break
}
}
if index == -1 {
var none interface{}
return none, false
}
return sv.Index(index).Interface(), true
}
// FlattenDeep flattens slice recursive
func FlattenDeep(slice interface{}) interface{} {
sv := sliceValue(slice)

View File

@@ -172,6 +172,20 @@ func TestFind(t *testing.T) {
assert.Equal(2, res)
}
func TestFindLast(t *testing.T) {
nums := []int{1, 2, 3, 4, 5}
even := func(i, num int) bool {
return num%2 == 0
}
res, ok := FindLast(nums, even)
if !ok {
t.Fatal("found nothing")
}
assert := internal.NewAssert(t, "TestFind")
assert.Equal(4, res)
}
func TestFindFoundNothing(t *testing.T) {
nums := []int{1, 1, 1, 1, 1, 1}
findFunc := func(i, num int) bool {
@@ -443,7 +457,7 @@ func TestDifferenceBy(t *testing.T) {
assert := internal.NewAssert(t, "TestDifferenceBy")
s1 := []int{1, 2, 3, 4, 5} //after add one: 2 3 4 5 6
s2 := []int{3, 4, 5} //after add one: 4 5 6
s2 := []int{3, 4, 5} //after add one: 4 5 6
addOne := func(i int, v int) int {
return v + 1
}