dragonfly/pkg/slices/slices.go

110 lines
2.4 KiB
Go

/*
* Copyright 2022 The Dragonfly Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package slices
import "slices"
// Contains returns true if elements is present in a collection.
func Contains[T comparable](s []T, els ...T) bool {
ss := make(map[T]struct{}, len(s))
for _, el := range s {
ss[el] = struct{}{}
}
for _, el := range els {
if _, found := ss[el]; !found {
return false
}
}
return true
}
// FindDuplicate returns duplicate element in a collection.
func FindDuplicate[T comparable](s []T) (T, bool) {
visited := make(map[T]struct{})
for _, v := range s {
if _, ok := visited[v]; ok {
return v, true
}
visited[v] = struct{}{}
}
var zero T
return zero, false
}
// RemoveDuplicates removes duplicate element in a collection.
func RemoveDuplicates[T comparable](s []T) []T {
var result []T
visited := make(map[T]bool, len(s))
for _, v := range s {
if !visited[v] {
visited[v] = true
result = append(result, v)
}
}
return result
}
// Remove removes an element from a collection.
func Remove[T comparable](s []T, i int) []T {
return slices.Delete(s, i, i+1)
}
// Reverse reverses elements in a collection.
func Reverse[S ~[]T, T any](s S) {
for i, j := 0, len(s)-1; i < j; i, j = i+1, j-1 {
s[i], s[j] = s[j], s[i]
}
}
// Difference returns the difference between two slices.
// The first value is the collection of element absent of l2.
// The second value is the collection of element absent of l1.
func Difference[T comparable](l1 []T, l2 []T) ([]T, []T) {
left := []T{}
right := []T{}
visitedLeft := map[T]struct{}{}
visitedRight := map[T]struct{}{}
for _, e := range l1 {
visitedLeft[e] = struct{}{}
}
for _, e := range l2 {
visitedRight[e] = struct{}{}
}
for _, e := range l1 {
if _, ok := visitedRight[e]; !ok {
left = append(left, e)
}
}
for _, e := range l2 {
if _, ok := visitedLeft[e]; !ok {
right = append(right, e)
}
}
return left, right
}