feat(slice): add ForAll & Exists funcs

README.md

@@ -121,6 +121,8 @@ Supported helpers for slices:
 - [IsSorted](#issorted)
 - [IsSortedByKey](#issortedbykey)
 - [Splice](#Splice)
+- [ForAll](#ForAll)
+- [Exists](#Exists)
 
 Supported helpers for maps:
 
@@ -1041,6 +1043,32 @@ result = lo.Splice([]string{"a", "b"}, 42, "1", "2")
 
 [[play](https://go.dev/play/p/G5_GhkeSUBA)]
 
+### ForAll
+
+ForAll returns true if all a slice items satisfy the predicate.
+
+```go
+result := ForAll([]int{2, 4, 6, 8}, func(x int) bool {
+	return x%2 == 0
+})
+    // true
+```
+
+[[play](https://go.dev/play/p/K9Jt5gZ0HW4)]
+
+### Exists
+
+Exists returns true if at least one element satisfies the predicate.
+
+```go
+result := Exists([]int{2, 4, 6, 8, 9}, func(x int) bool {
+	return x == 8
+})
+    // true
+```
+
+[[play](https://go.dev/play/p/2lCKJ_hFUWV)]
+
 ### Keys
 
 Creates a slice of the map keys.
@@ -1062,7 +1090,7 @@ keys := lo.Keys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"bar": 3})
 
 ### UniqKeys
 
-Creates an array of unique map keys. 
+Creates an array of unique map keys.
 
 ```go
 keys := lo.UniqKeys(map[string]int{"foo": 1, "bar": 2}, map[string]int{"baz": 3})

slice.go

@@ -693,3 +693,27 @@ func Splice[T any, Slice ~[]T](collection Slice, i int, elements ...T) Slice {
 
 	return append(append(append(output, collection[:i]...), elements...), collection[i:]...)
 }
+
+// ForAll returns true if all a slice items satisfy the predicate.
+// Play: https://go.dev/play/p/K9Jt5gZ0HW4
+func ForAll[T any, Slice ~[]T](collection Slice, predicate func(item T) bool) bool {
+	for i := range collection {
+		if !predicate(collection[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Exists returns true if at least one element satisfies the predicate.
+// Play: https://go.dev/play/p/2lCKJ_hFUWV
+func Exists[T any, Slice ~[]T](collection Slice, predicate func(item T) bool) bool {
+	for i := range collection {
+		if predicate(collection[i]) {
+			return true
+		}
+	}
+
+	return false
+}

slice_test.go

@@ -1029,3 +1029,38 @@ func TestSplice(t *testing.T) {
 	nonempty := Splice(allStrings, 1, "1", "2")
 	is.IsType(nonempty, allStrings, "type preserved")
 }
+
+func TestForAll(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
+	r1 := ForAll([]int{2, 4, 6, 8}, func(x int) bool {
+		return x%2 == 0
+	})
+	is.True(r1)
+
+	r2 := ForAll([]int{}, func(x int) bool {
+		return x%2 == 0
+	})
+	is.True(r2)
+
+	r3 := ForAll([]int{2, 4, 6, 8, 9}, func(x int) bool {
+		return x%2 == 0
+	})
+	is.False(r3)
+}
+
+func TestExists(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
+	r1 := Exists([]string{"one", "two", "three"}, func(x string) bool {
+		return x == "two"
+	})
+	is.True(r1)
+
+	r2 := Exists([]int{2, 4, 6, 8, 9}, func(x int) bool {
+		return x == 10
+	})
+	is.False(r2)
+}