package stringset
import (
	"fmt"
	"strings"
)
type Set map[string]struct{}
func New() Set {
	return Set{}
}
func NewFromSlice(l []string) Set {
	s := New()
	for _, i := range l {
		s[i] = struct{}{}
	}
	return s
}
func (s Set) String() string {
	ret := strings.Builder{}
	ret.WriteByte('{')
	i := len(s)
	for k := range s {
		ret.WriteString(fmt.Sprintf("%q", k))
		i--
		if i != 0 {
			ret.WriteString(", ")
		}
	}
	ret.WriteByte('}')
	return ret.String()
}
func (s Set) IsEmpty() bool {
	if len(s) == 0 {
		return true
	}
	return false
}
func (s Set) Has(elem string) bool {
	_, ok := s[elem]
	return ok
}
func (s Set) Add(elem string) {
	s[elem] = struct{}{}
}
func Subset(s1, s2 Set) bool {
	for k := range s1 {
		_, ok := s2[k]
		if !ok {
			return false
		}
	}
	return true
}
func Disjoint(s1, s2 Set) bool {
	for k := range s1 {
		_, ok := s2[k]
		if ok {
			return false
		}
	}
	return true
}
func Equal(s1, s2 Set) bool {
	for k := range s1 {
		_, ok := s2[k]
		if !ok {
			return false
		}
	}
	for k := range s2 {
		_, ok := s1[k]
		if !ok {
			return false
		}
	}
	return true
}
func Intersection(s1, s2 Set) Set {
	ret := New()
	for k := range s1 {
		_, ok := s2[k]
		if ok {
			ret[k] = struct{}{}
		}
	}
	return ret
}
func Difference(s1, s2 Set) Set {
	ret := New()
	for k := range s1 {
		_, ok := s2[k]
		if !ok {
			ret[k] = struct{}{}
		}
	}
	return ret
}
func Union(s1, s2 Set) Set {
	ret := New()
	for k := range s1 {
		ret[k] = struct{}{}
	}
	for k := range s2 {
		ret[k] = struct{}{}
	}
	return ret
}