feature: added filter method to array list

pkg/collections/array_list/array_list_methods.go

@@ -208,3 +208,21 @@ func (self *ArrayList[T]) Find(filter func(T) bool) *optional.Optional[T] {
 
 	return optional.Empty[T]()
 }
+
+func (self *ArrayList[T]) Filter(filter func(T) bool) *ArrayList[T] {
+	return self.FilterTo(filter, NewArrayList[T]())
+}
+
+func (self *ArrayList[T]) FilterTo(filter func(T) bool, resultList *ArrayList[T]) *ArrayList[T] {
+	if resultList == nil {
+		panic(fmt.Errorf("can not filter %v to nil list", self))
+	}
+
+	self.ForEach(func(value T) {
+		if filter(value) {
+			resultList.Add(value)
+		}
+	})
+
+	return resultList
+}