badguardhome/internal/aghstrings/set.go

72 lines
1.4 KiB
Go

package aghstrings
// unit is a convenient alias for struct{}
type unit = struct{}
// Set is a set of strings.
type Set struct {
m map[string]unit
}
// NewSet returns a new string set containing strs.
func NewSet(strs ...string) (set *Set) {
set = &Set{
m: make(map[string]unit, len(strs)),
}
for _, s := range strs {
set.Add(s)
}
return set
}
// Add adds s to the set. Add panics if the set is a nil set, just like a nil
// map does.
func (set *Set) Add(s string) {
set.m[s] = unit{}
}
// Del deletes s from the set. Calling Del on a nil set has no effect, just
// like delete on an empty map doesn't.
func (set *Set) Del(s string) {
if set != nil {
delete(set.m, s)
}
}
// Has returns true if s is in the set. Calling Has on a nil set returns false,
// just like indexing on an empty map does.
func (set *Set) Has(s string) (ok bool) {
if set != nil {
_, ok = set.m[s]
}
return ok
}
// Len returns the length of the set. A nil set has a length of zero, just like
// an empty map.
func (set *Set) Len() (n int) {
if set == nil {
return 0
}
return len(set.m)
}
// Values returns all values in the set. The order of the values is undefined.
// Values returns nil if the set is nil.
func (set *Set) Values() (strs []string) {
if set == nil {
return nil
}
strs = make([]string, 0, len(set.m))
for s := range set.m {
strs = append(strs, s)
}
return strs
}