| // Copyright Istio 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 sets |
| |
| import ( |
| "sort" |
| ) |
| |
| type Set map[string]struct{} |
| |
| // NewWithLength returns an empty Set with the given capacity. |
| // It's only a hint, not a limitation. |
| func NewWithLength(l int) Set { |
| return make(Set, l) |
| } |
| |
| // New creates a new Set with the given items. |
| func New(items ...string) Set { |
| s := NewWithLength(len(items)) |
| return s.InsertAll(items...) |
| } |
| |
| // Insert a single item to this Set. |
| func (s Set) Insert(item string) Set { |
| s[item] = struct{}{} |
| return s |
| } |
| |
| // InsertAll adds the items to this Set. |
| func (s Set) InsertAll(items ...string) Set { |
| for _, item := range items { |
| s[item] = struct{}{} |
| } |
| return s |
| } |
| |
| // Delete removes an item from the set. |
| func (s Set) Delete(item string) Set { |
| delete(s, item) |
| return s |
| } |
| |
| // Delete removes items from the set. |
| func (s Set) DeleteAll(items ...string) Set { |
| for _, item := range items { |
| delete(s, item) |
| } |
| return s |
| } |
| |
| // Merge a set of objects that are in s2 into s |
| // For example: |
| // s = {a1, a2, a3} |
| // s2 = {a3, a4, a5} |
| // s.Merge(s2) = {a1, a2, a3, a4, a5} |
| func (s Set) Merge(s2 Set) Set { |
| for item := range s2 { |
| s[item] = struct{}{} |
| } |
| |
| return s |
| } |
| |
| // Copy this set. |
| func (s Set) Copy() Set { |
| result := New() |
| for key := range s { |
| result.Insert(key) |
| } |
| return result |
| } |
| |
| // Union returns a set of objects that are in s or s2 |
| // For example: |
| // s = {a1, a2, a3} |
| // s2 = {a1, a2, a4, a5} |
| // s.Union(s2) = s2.Union(s) = {a1, a2, a3, a4, a5} |
| func (s Set) Union(s2 Set) Set { |
| result := s.Copy() |
| for key := range s2 { |
| result.Insert(key) |
| } |
| return result |
| } |
| |
| // Difference returns a set of objects that are not in s2 |
| // For example: |
| // s = {a1, a2, a3} |
| // s2 = {a1, a2, a4, a5} |
| // s.Difference(s2) = {a3} |
| // s2.Difference(s) = {a4, a5} |
| func (s Set) Difference(s2 Set) Set { |
| result := New() |
| for key := range s { |
| if !s2.Contains(key) { |
| result.Insert(key) |
| } |
| } |
| return result |
| } |
| |
| // Intersection returns a set of objects that are common between s and s2 |
| // For example: |
| // s = {a1, a2, a3} |
| // s2 = {a1, a2, a4, a5} |
| // s.Intersection(s2) = {a1, a2} |
| func (s Set) Intersection(s2 Set) Set { |
| result := New() |
| for key := range s { |
| if s2.Contains(key) { |
| result.Insert(key) |
| } |
| } |
| return result |
| } |
| |
| // SupersetOf returns true if s contains all elements of s2 |
| // For example: |
| // s = {a1, a2, a3} |
| // s2 = {a1, a2, a3, a4, a5} |
| // s.SupersetOf(s2) = false |
| // s2.SupersetOf(s) = true |
| func (s Set) SupersetOf(s2 Set) bool { |
| return s2.Difference(s).IsEmpty() |
| } |
| |
| // UnsortedList returns the slice with contents in random order. |
| func (s Set) UnsortedList() []string { |
| res := make([]string, 0, s.Len()) |
| for key := range s { |
| res = append(res, key) |
| } |
| return res |
| } |
| |
| // SortedList returns the slice with contents sorted. |
| func (s Set) SortedList() []string { |
| res := s.UnsortedList() |
| sort.Strings(res) |
| return res |
| } |
| |
| // Contains returns whether the given item is in the set. |
| func (s Set) Contains(item string) bool { |
| _, ok := s[item] |
| return ok |
| } |
| |
| // Equals checks whether the given set is equal to the current set. |
| func (s Set) Equals(other Set) bool { |
| if s.Len() != other.Len() { |
| return false |
| } |
| |
| for key := range s { |
| if !other.Contains(key) { |
| return false |
| } |
| } |
| |
| return true |
| } |
| |
| // Len returns the number of elements in this Set. |
| func (s Set) Len() int { |
| return len(s) |
| } |
| |
| // IsEmpty indicates whether the set is the empty set. |
| func (s Set) IsEmpty() bool { |
| return len(s) == 0 |
| } |
| |
| // Diff takes a pair of Sets, and returns the elements that occur only on the left and right set. |
| func (s Set) Diff(other Set) (left []string, right []string) { |
| for k := range s { |
| if _, f := other[k]; !f { |
| left = append(left, k) |
| } |
| } |
| for k := range other { |
| if _, f := s[k]; !f { |
| right = append(right, k) |
| } |
| } |
| return |
| } |