feat: add FromSlicePtr (#217)

* feat: add FromSlicePtr

* Update README.md

---------

Co-authored-by: Samuel Berthe <dev@samuel-berthe.fr>

README.md

@@ -254,6 +254,7 @@ Type manipulation helpers:
 - [FromPtr](#fromptr)
 - [FromPtrOr](#fromptror)
 - [ToSlicePtr](#tosliceptr)
+- [FromSlicePtr](#fromsliceptr)
 - [ToAnySlice](#toanyslice)
 - [FromAnySlice](#fromanyslice)
 - [Empty](#empty)
@@ -2681,6 +2682,24 @@ ptr := lo.ToSlicePtr([]string{"hello", "world"})
 // []*string{"hello", "world"}
 ```
 
+### FromSlicePtr
+
+Returns a slice with the pointer values.
+Returns a zero value in case of a nil pointer element.
+
+```go
+str1 := "hello"
+str2 := "world"
+
+ptr := lo.FromSlicePtr[string]([]*string{&str1, &str2, nil})
+// []string{"hello", "world", ""}
+
+ptr := lo.Compact(
+ lo.FromSlicePtr[string]([]*string{&str1, &str2, nil}),
+)
+// []string{"hello", "world"}
+```
+
 ### ToAnySlice
 
 Returns a slice with all elements mapped to `any` type.

type_manipulation.go

@@ -58,6 +58,17 @@ func ToSlicePtr[T any](collection []T) []*T {
  return result
 }
 
+// FromSlicePtr returns a slice with the pointer values.
+// Returns a zero value in case of a nil pointer element.
+func FromSlicePtr[T any](collection []*T) []T {
+ return Map(collection, func(x *T, _ int) T {
+ if x == nil {
+ return Empty[T]()
+ }
+ return *x
+ })
+}
+
 // ToAnySlice returns a slice with all elements mapped to `any` type
 func ToAnySlice[T any](collection []T) []any {
  result := make([]any, len(collection))

type_manipulation_test.go

@@ -121,6 +121,16 @@ func TestToSlicePtr(t *testing.T) {
  is.Equal(result1, []*string{&str1, &str2})
 }
 
+func TestFromSlicePtr(t *testing.T) {
+ is := assert.New(t)
+
+ str1 := "foo"
+ str2 := "bar"
+ result1 := FromSlicePtr([]*string{&str1, &str2, nil})
+
+ is.Equal(result1, []string{str1, str2, ""})
+}
+
 func TestToAnySlice(t *testing.T) {
  t.Parallel()
  is := assert.New(t)