59 lines
987 B
Go
59 lines
987 B
Go
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package dag
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import (
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"sync"
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)
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// set is an internal Set data structure that is based on simply using
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// pointers as the hash key into a map.
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type set struct {
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m map[interface{}]struct{}
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once sync.Once
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}
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// Add adds an item to the set
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func (s *set) Add(v interface{}) {
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s.once.Do(s.init)
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s.m[v] = struct{}{}
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}
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// Delete removes an item from the set.
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func (s *set) Delete(v interface{}) {
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s.once.Do(s.init)
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delete(s.m, v)
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}
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// Include returns true/false of whether a value is in the set.
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func (s *set) Include(v interface{}) bool {
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s.once.Do(s.init)
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_, ok := s.m[v]
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return ok
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}
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// Len is the number of items in the set.
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func (s *set) Len() int {
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if s == nil {
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return 0
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}
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return len(s.m)
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}
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// List returns the list of set elements.
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func (s *set) List() []interface{} {
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if s == nil {
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return nil
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}
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r := make([]interface{}, 0, len(s.m))
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for k, _ := range s.m {
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r = append(r, k)
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}
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return r
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}
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func (s *set) init() {
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s.m = make(map[interface{}]struct{})
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}
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