Files
tidb/pkg/util/set/string_set.go
2025-05-08 12:51:50 +00:00

93 lines
2.1 KiB
Go

// Copyright 2018 PingCAP, Inc.
//
// 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 set
import (
"strings"
)
// StringSet is a string set.
type StringSet map[string]struct{}
// NewStringSet builds a string set.
func NewStringSet(ss ...string) StringSet {
set := make(StringSet, len(ss))
for _, s := range ss {
set.Insert(s)
}
return set
}
// Exist checks whether `val` exists in `s`.
func (s StringSet) Exist(val string) bool {
_, ok := s[val]
return ok
}
// Insert inserts `val` into `s`.
func (s StringSet) Insert(val string) {
s[val] = struct{}{}
}
// Intersection returns the intersection of two sets
func (s StringSet) Intersection(rhs StringSet) StringSet {
newSet := NewStringSet()
for elt := range s {
if rhs.Exist(elt) {
newSet.Insert(elt)
}
}
return newSet
}
// IntersectionWithLower returns the intersection of two sets with different case of string.
func (s StringSet) IntersectionWithLower(rhs StringSet, toLower bool) StringSet {
newSet := NewStringSet()
for origElt := range rhs {
var elt string
if toLower {
elt = strings.ToLower(origElt)
} else {
elt = strings.ToUpper(origElt)
}
if s.Exist(elt) {
newSet.Insert(origElt)
}
}
return newSet
}
// Count returns the number in Set s.
func (s StringSet) Count() int {
return len(s)
}
// Empty returns whether s is empty.
func (s StringSet) Empty() bool {
return len(s) == 0
}
// Clear clears the set.
func (s StringSet) Clear() {
clear(s)
}
// IterateWith iterate items in StringSet and pass it to `fn`.
func (s StringSet) IterateWith(fn func(string)) {
for k := range s {
fn(k)
}
}