diff --git a/parser.go b/parser.go
index e4ff88b..6ae246e 100644
--- a/parser.go
+++ b/parser.go
@@ -10,6 +10,8 @@ import (
 	"text/scanner"
 )
 
+//go:generate stringer -type=tokenType
+
 type tokenType int
 
 const (
@@ -23,33 +25,46 @@ const (
 	tokenStatementEnd
 )
 
-// Rule is a string type that represents a CSS rule.
-type Rule string
-
 type tokenEntry struct {
 	value string
 	pos   scanner.Position
 }
 
-type tokenizer struct {
-	s *scanner.Scanner
-}
-
-// Type returns the rule type, which can be a class, id or a tag.
-func (rule Rule) Type() string {
-	if strings.HasPrefix(string(rule), ".") {
-		return "class"
+func newTokenType(typ string) tokenType {
+	types := map[string]tokenType{
+		"{": tokenBlockStart,
+		"}": tokenBlockEnd,
+		":": tokenStyleSeparator,
+		";": tokenStatementEnd,
+		".": tokenSelector,
+		"#": tokenSelector,
 	}
-	if strings.HasPrefix(string(rule), "#") {
-		return "id"
+
+	result, ok := types[typ]
+	if ok {
+		return result
 	}
-	return "tag"
+
+	return tokenValue
 }
 
 func (e tokenEntry) typ() tokenType {
 	return newTokenType(e.value)
 }
 
+type tokenizer struct {
+	s *scanner.Scanner
+}
+
+func newTokenizer(r io.Reader) *tokenizer {
+	s := &scanner.Scanner{}
+	s.Init(r)
+
+	return &tokenizer{
+		s: s,
+	}
+}
+
 func (t *tokenizer) next() (tokenEntry, error) {
 	token := t.s.Scan()
 	if token == scanner.EOF {
@@ -57,7 +72,7 @@ func (t *tokenizer) next() (tokenEntry, error) {
 	}
 	value := t.s.TokenText()
 	pos := t.s.Pos()
-	if newTokenType(value).String() == "STYLE_SEPARATOR" {
+	if newTokenType(value) == tokenStyleSeparator {
 		t.s.IsIdentRune = func(ch rune, i int) bool { // property value can contain spaces
 			if ch == -1 || ch == '\n' || ch == '\r' || ch == '\t' || ch == ':' || ch == ';' {
 				return false
@@ -78,44 +93,18 @@ func (t *tokenizer) next() (tokenEntry, error) {
 	}, nil
 }
 
-func (t tokenType) String() string {
-	switch t {
-	case tokenBlockStart:
-		return "BLOCK_START"
-	case tokenBlockEnd:
-		return "BLOCK_END"
-	case tokenStyleSeparator:
-		return "STYLE_SEPARATOR"
-	case tokenStatementEnd:
-		return "STATEMENT_END"
-	case tokenSelector:
-		return "SELECTOR"
-	}
-	return "VALUE"
-}
+// Rule is a string type that represents a CSS rule.
+type Rule string
 
-func newTokenType(typ string) tokenType {
-	switch typ {
-	case "{":
-		return tokenBlockStart
-	case "}":
-		return tokenBlockEnd
-	case ":":
-		return tokenStyleSeparator
-	case ";":
-		return tokenStatementEnd
-	case ".", "#":
-		return tokenSelector
+// Type returns the rule type, which can be a class, id or a tag.
+func (rule Rule) Type() string {
+	if strings.HasPrefix(string(rule), ".") {
+		return "class"
 	}
-	return tokenValue
-}
-
-func newTokenizer(r io.Reader) *tokenizer {
-	s := &scanner.Scanner{}
-	s.Init(r)
-	return &tokenizer{
-		s: s,
+	if strings.HasPrefix(string(rule), "#") {
+		return "id"
 	}
+	return "tag"
 }
 
 func buildList(r io.Reader) *list.List {
diff --git a/parser_test.go b/parser_test.go
index 938aa11..16ad22a 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -78,7 +78,7 @@ rule1 {
 	}
 
 	for _, tt := range cases {
-		t.Run("GoodCSS", func(t *testing.T) {
+		t.Run(tt.name, func(t *testing.T) {
 			css, err := Unmarshal([]byte(tt.CSS))
 			if err != nil {
 				t.Fatal(err)
diff --git a/tokentype_string.go b/tokentype_string.go
new file mode 100644
index 0000000..c6840e4
--- /dev/null
+++ b/tokentype_string.go
@@ -0,0 +1,31 @@
+// Code generated by "stringer -type=tokenType"; DO NOT EDIT.
+
+package css
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[tokenFirstToken - -1]
+	_ = x[tokenBlockStart-0]
+	_ = x[tokenBlockEnd-1]
+	_ = x[tokenRuleName-2]
+	_ = x[tokenValue-3]
+	_ = x[tokenSelector-4]
+	_ = x[tokenStyleSeparator-5]
+	_ = x[tokenStatementEnd-6]
+}
+
+const _tokenType_name = "tokenFirstTokentokenBlockStarttokenBlockEndtokenRuleNametokenValuetokenSelectortokenStyleSeparatortokenStatementEnd"
+
+var _tokenType_index = [...]uint8{0, 15, 30, 43, 56, 66, 79, 98, 115}
+
+func (i tokenType) String() string {
+	i -= -1
+	if i < 0 || i >= tokenType(len(_tokenType_index)-1) {
+		return "tokenType(" + strconv.FormatInt(int64(i+-1), 10) + ")"
+	}
+	return _tokenType_name[_tokenType_index[i]:_tokenType_index[i+1]]
+}