package vendor

// union returns the union of a and b.
func union(a, b map[string]bool) map[string]bool {
	r := make(map[string]bool)
	for k := range a {
		r[k] = true
	}
	for k := range b {
		r[k] = true
	}
	return r
}

// intersection returns the intersection of a and b.
func intersection(a, b map[string]bool) map[string]bool {
	r := make(map[string]bool)
	for k := range a {
		if b[k] {
			r[k] = true
		}
	}
	return r
}

// difference returns the symetric difference of a and b.
func difference(a, b map[string]bool) map[string]bool {
	r := make(map[string]bool)
	for k := range a {
		if !b[k] {
			r[k] = true
		}
	}
	for k := range b {
		if !a[k] {
			r[k] = true
		}
	}
	return r
}

// contains returns true if a contains all the elements in s.
func contains(a map[string]bool, s ...string) bool {
	var r bool
	for _, e := range s {
		if !a[e] {
			return false
		}
		r = true
	}
	return r
}