| // Copyright 2015 The LUCI 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 stringset |
| |
| import "sort" |
| |
| // Set is the base type. make(Set) can be used too. |
| type Set map[string]struct{} |
| |
| // New returns a new string Set implementation. |
| func New(sizeHint int) Set { |
| return make(Set, sizeHint) |
| } |
| |
| // NewFromSlice returns a new string Set implementation, |
| // initialized with the values in the provided slice. |
| func NewFromSlice(vals ...string) Set { |
| ret := make(Set, len(vals)) |
| for _, k := range vals { |
| ret[k] = struct{}{} |
| } |
| return ret |
| } |
| |
| // Has returns true iff the Set contains value. |
| func (s Set) Has(value string) bool { |
| _, ret := s[value] |
| return ret |
| } |
| |
| // HasAll returns true iff the Set contains all the given values. |
| func (s Set) HasAll(values ...string) bool { |
| for _, v := range values { |
| if !s.Has(v) { |
| return false |
| } |
| } |
| return true |
| } |
| |
| // Add ensures that Set contains value, and returns true if it was added (i.e. |
| // it returns false if the Set already contained the value). |
| func (s Set) Add(value string) bool { |
| if _, ok := s[value]; ok { |
| return false |
| } |
| s[value] = struct{}{} |
| return true |
| } |
| |
| // AddAll ensures that Set contains all values. |
| func (s Set) AddAll(values []string) { |
| for _, value := range values { |
| s[value] = struct{}{} |
| } |
| } |
| |
| // Del removes value from the set, and returns true if it was deleted (i.e. it |
| // returns false if the Set did not already contain the value). |
| func (s Set) Del(value string) bool { |
| if _, ok := s[value]; !ok { |
| return false |
| } |
| delete(s, value) |
| return true |
| } |
| |
| // DelAll ensures that Set contains none of values. |
| func (s Set) DelAll(values []string) { |
| for _, value := range values { |
| delete(s, value) |
| } |
| } |
| |
| // Peek returns an arbitrary element from the set. If the set was empty, this |
| // returns ("", false). |
| func (s Set) Peek() (string, bool) { |
| for k := range s { |
| return k, true |
| } |
| return "", false |
| } |
| |
| // Pop removes and returns an arbitrary element from the set and removes it from the |
| // set. If the set was empty, this returns ("", false). |
| func (s Set) Pop() (string, bool) { |
| for k := range s { |
| delete(s, k) |
| return k, true |
| } |
| return "", false |
| } |
| |
| // Iter calls `cb` for each item in the set. If `cb` returns false, the |
| // iteration stops. |
| func (s Set) Iter(cb func(string) bool) { |
| for k := range s { |
| if !cb(k) { |
| break |
| } |
| } |
| } |
| |
| // Len returns the number of items in this set. |
| func (s Set) Len() int { |
| return len(s) |
| } |
| |
| // Dup returns a duplicate set. |
| func (s Set) Dup() Set { |
| ret := make(Set, len(s)) |
| for k := range s { |
| ret[k] = struct{}{} |
| } |
| return ret |
| } |
| |
| // ToSlice renders this set to a slice of all values. |
| func (s Set) ToSlice() []string { |
| ret := make([]string, 0, len(s)) |
| for k := range s { |
| ret = append(ret, k) |
| } |
| return ret |
| } |
| |
| // ToSortedSlice renders this set to a sorted slice of all values, ascending. |
| func (s Set) ToSortedSlice() []string { |
| ret := s.ToSlice() |
| sort.Strings(ret) |
| return ret |
| } |
| |
| // Intersect returns a new Set which is the intersection of this set with the |
| // other set. |
| func (s Set) Intersect(other Set) Set { |
| smallLen := len(s) |
| if lo := len(other); lo < smallLen { |
| smallLen = lo |
| } |
| ret := make(Set, smallLen) |
| for k := range s { |
| if _, ok := other[k]; ok { |
| ret[k] = struct{}{} |
| } |
| } |
| return ret |
| } |
| |
| // Difference returns a new Set which is this set with all elements from other |
| // removed (i.e. `self - other`). |
| func (s Set) Difference(other Set) Set { |
| ret := make(Set) |
| for k := range s { |
| if _, ok := other[k]; !ok { |
| ret[k] = struct{}{} |
| } |
| } |
| return ret |
| } |
| |
| // Union returns a new Set which contains all element from this set, as well |
| // as all elements from the other set. |
| func (s Set) Union(other Set) Set { |
| ret := make(Set, len(s)) |
| for k := range s { |
| ret[k] = struct{}{} |
| } |
| for k := range other { |
| ret[k] = struct{}{} |
| } |
| return ret |
| } |
| |
| // Contains returns true iff the given set contains all elements from the other set. |
| func (s Set) Contains(other Set) bool { |
| for k := range other { |
| if !s.Has(k) { |
| return false |
| } |
| } |
| return true |
| } |