Merge branch 'set' into 'main'

add StrSet type

See merge request CRThaze/sugar!2

sugar.go

@@ -137,3 +137,32 @@ func CheckExit(err error) {
 		os.Exit(1)
 	}
 }
+
+/*
+ * Sets
+ */
+
+// StrSet a set type for strings.
+type StrSet map[string]struct{}
+
+// Add adds a new key to the set if it does not already exist.
+func (s *StrSet) Add(str string) {
+	(*s)[str] = struct{}{}
+}
+
+// Has checks if the given string is present in the set.
+func (s *StrSet) Has(str string) bool {
+	if _, ok := (*s)[str]; ok {
+		return true
+	}
+	return false
+}
+
+// AddHas behaves like Add, but returns true if the key already existed.
+func (s *StrSet) AddHas(str string) bool {
+	if ok := s.Has(str); ok {
+		return ok
+	}
+	s.Add(str)
+	return false
+}