diff --git a/compiler.go b/compiler.go
index 381e9a7..215117c 100644
--- a/compiler.go
+++ b/compiler.go
@@ -26,7 +26,7 @@ func optimize(matcher match.Matcher) match.Matcher {
 		rightNil := m.Right == nil
 
 		if leftNil && rightNil {
-			return match.Raw{r.Str}
+			return match.NewRaw(r.Str)
 		}
 
 		_, leftSuper := m.Left.(match.Super)
@@ -93,15 +93,20 @@ func glueAsRow(matchers []match.Matcher) match.Matcher {
 		return nil
 	}
 
-	row := match.Row{}
+	var (
+		c []match.Matcher
+		l int
+	)
 	for _, matcher := range matchers {
-		err := row.Add(matcher)
-		if err != nil {
+		if ml := matcher.Len(); ml == -1 {
 			return nil
+		} else {
+			c = append(c, matcher)
+			l += ml
 		}
 	}
 
-	return row
+	return match.Row{c, l}
 }
 
 func glueAsEvery(matchers []match.Matcher) match.Matcher {
@@ -187,7 +192,7 @@ func glueAsEvery(matchers []match.Matcher) match.Matcher {
 	return every
 }
 
-func convertMatchers(matchers []match.Matcher) []match.Matcher {
+func minimizeMatchers(matchers []match.Matcher) []match.Matcher {
 	var done match.Matcher
 	var left, right, count int
 
@@ -201,7 +206,6 @@ func convertMatchers(matchers []match.Matcher) []match.Matcher {
 				} else {
 					cl, gl := done.Len(), glued.Len()
 					swap = cl > -1 && gl > -1 && gl > cl
-
 					swap = swap || count < r-l
 				}
 
@@ -228,7 +232,7 @@ func convertMatchers(matchers []match.Matcher) []match.Matcher {
 		return next
 	}
 
-	return convertMatchers(next)
+	return minimizeMatchers(next)
 }
 
 func compileMatchers(matchers []match.Matcher) (match.Matcher, error) {
@@ -258,36 +262,29 @@ func compileMatchers(matchers []match.Matcher) (match.Matcher, error) {
 		}
 	}
 
-	//	_, ok := val.(match.BTree)
-	//	fmt.Println("a tree", ok)
-
 	left := matchers[:idx]
 	var right []match.Matcher
 	if len(matchers) > idx+1 {
 		right = matchers[idx+1:]
 	}
 
-	tree := match.BTree{Value: val}
-
+	var l, r match.Matcher
+	var err error
 	if len(left) > 0 {
-		l, err := compileMatchers(left)
+		l, err = compileMatchers(left)
 		if err != nil {
 			return nil, err
 		}
-
-		tree.Left = l
 	}
 
 	if len(right) > 0 {
-		r, err := compileMatchers(right)
+		r, err = compileMatchers(right)
 		if err != nil {
 			return nil, err
 		}
-
-		tree.Right = r
 	}
 
-	return tree, nil
+	return match.NewBTree(val, l, r), nil
 }
 
 func do(node node, s string) (m match.Matcher, err error) {
@@ -306,7 +303,7 @@ func do(node node, s string) (m match.Matcher, err error) {
 		if _, ok := node.(*nodeAnyOf); ok {
 			m = match.AnyOf{matchers}
 		} else {
-			m, err = compileMatchers(convertMatchers(matchers))
+			m, err = compileMatchers(minimizeMatchers(matchers))
 			if err != nil {
 				return nil, err
 			}
@@ -328,7 +325,7 @@ func do(node node, s string) (m match.Matcher, err error) {
 		m = match.Single{s}
 
 	case *nodeText:
-		m = match.Raw{n.text}
+		m = match.NewRaw(n.text)
 
 	default:
 		return nil, fmt.Errorf("could not compile tree: unknown node type")
@@ -370,7 +367,7 @@ func do2(node node, s string) ([]match.Matcher, error) {
 		}
 
 		for _, matchers := range ways {
-			c, err := compileMatchers(convertMatchers(matchers))
+			c, err := compileMatchers(minimizeMatchers(matchers))
 			if err != nil {
 				return nil, err
 			}
@@ -404,7 +401,7 @@ func do2(node node, s string) ([]match.Matcher, error) {
 		}
 
 		for _, matchers := range ways {
-			c, err := compileMatchers(convertMatchers(matchers))
+			c, err := compileMatchers(minimizeMatchers(matchers))
 			if err != nil {
 				return nil, err
 			}
@@ -427,7 +424,7 @@ func do2(node node, s string) ([]match.Matcher, error) {
 		result = append(result, match.Single{s})
 
 	case *nodeText:
-		result = append(result, match.Raw{n.text})
+		result = append(result, match.NewRaw(n.text))
 
 	default:
 		return nil, fmt.Errorf("could not compile tree: unknown node type")
diff --git a/compiler_test.go b/compiler_test.go
index 3b56b43..15a52ec 100644
--- a/compiler_test.go
+++ b/compiler_test.go
@@ -74,42 +74,47 @@ func TestCompileMatchers(t *testing.T) {
 			[]match.Matcher{
 				match.Super{},
 				match.Single{separators},
-				match.Raw{"c"},
+				match.Raw{"c", 1},
 			},
-			match.BTree{
-				Left: match.BTree{
-					Left:  match.Super{},
-					Value: match.Single{separators},
+			match.NewBTree(
+				match.Raw{"c", 1},
+				match.NewBTree(
+					match.Single{separators},
+					match.Super{},
+					nil,
+				),
+				nil,
+			),
+		},
+		{
+			[]match.Matcher{
+				match.Any{},
+				match.Raw{"c", 1},
+				match.Any{},
+			},
+			match.NewBTree(
+				match.Raw{"c", 1},
+				match.Any{},
+				match.Any{},
+			),
+		},
+		{
+			[]match.Matcher{
+				match.Range{'a', 'c', true},
+				match.List{"zte", false},
+				match.Raw{"c", 1},
+				match.Single{},
+			},
+			match.Row{
+				Matchers: match.Matchers{
+					match.Range{'a', 'c', true},
+					match.List{"zte", false},
+					match.Raw{"c", 1},
+					match.Single{},
 				},
-				Value: match.Raw{"c"},
+				Length: 4,
 			},
 		},
-		{
-			[]match.Matcher{
-				match.Any{},
-				match.Raw{"c"},
-				match.Any{},
-			},
-			match.BTree{
-				Left:  match.Any{},
-				Value: match.Raw{"c"},
-				Right: match.Any{},
-			},
-		},
-		{
-			[]match.Matcher{
-				match.Range{'a', 'c', true},
-				match.List{"zte", false},
-				match.Raw{"c"},
-				match.Single{},
-			},
-			match.Row{Matchers: match.Matchers{
-				match.Range{'a', 'c', true},
-				match.List{"zte", false},
-				match.Raw{"c"},
-				match.Single{},
-			}},
-		},
 	} {
 		act, err := compileMatchers(test.in)
 		if err != nil {
@@ -132,17 +137,20 @@ func TestConvertMatchers(t *testing.T) {
 			[]match.Matcher{
 				match.Range{'a', 'c', true},
 				match.List{"zte", false},
-				match.Raw{"c"},
+				match.Raw{"c", 1},
 				match.Single{},
 				match.Any{},
 			},
 			[]match.Matcher{
-				match.Row{Matchers: match.Matchers{
-					match.Range{'a', 'c', true},
-					match.List{"zte", false},
-					match.Raw{"c"},
-					match.Single{},
-				}},
+				match.Row{
+					Matchers: match.Matchers{
+						match.Range{'a', 'c', true},
+						match.List{"zte", false},
+						match.Raw{"c", 1},
+						match.Single{},
+					},
+					Length: 4,
+				},
 				match.Any{},
 			},
 		},
@@ -150,7 +158,7 @@ func TestConvertMatchers(t *testing.T) {
 			[]match.Matcher{
 				match.Range{'a', 'c', true},
 				match.List{"zte", false},
-				match.Raw{"c"},
+				match.Raw{"c", 1},
 				match.Single{},
 				match.Any{},
 				match.Single{},
@@ -158,16 +166,19 @@ func TestConvertMatchers(t *testing.T) {
 				match.Any{},
 			},
 			[]match.Matcher{
-				match.Row{Matchers: match.Matchers{
-					match.Range{'a', 'c', true},
-					match.List{"zte", false},
-					match.Raw{"c"},
-				}},
+				match.Row{
+					Matchers: match.Matchers{
+						match.Range{'a', 'c', true},
+						match.List{"zte", false},
+						match.Raw{"c", 1},
+					},
+					Length: 3,
+				},
 				match.Min{3},
 			},
 		},
 	} {
-		act := convertMatchers(test.in)
+		act := minimizeMatchers(test.in)
 		if !reflect.DeepEqual(act, test.exp) {
 			t.Errorf("#%d unexpected convert matchers 2 result:\nact: %s;\nexp: %s", id, act, test.exp)
 			continue
@@ -197,7 +208,7 @@ func TestCompiler(t *testing.T) {
 	}{
 		{
 			ast:    pattern(&nodeText{text: "abc"}),
-			result: match.Raw{"abc"},
+			result: match.Raw{"abc", 3},
 		},
 		{
 			ast:    pattern(&nodeAny{}),
@@ -247,25 +258,33 @@ func TestCompiler(t *testing.T) {
 		{
 			ast: pattern(&nodeAny{}, &nodeText{text: "abc"}, &nodeSingle{}),
 			sep: separators,
-			result: match.BTree{
-				Left: match.Any{separators},
-				Value: match.Row{Matchers: match.Matchers{
-					match.Raw{"abc"},
-					match.Single{separators},
-				}},
-			},
+			result: match.NewBTree(
+				match.Row{
+					Matchers: match.Matchers{
+						match.Raw{"abc", 3},
+						match.Single{separators},
+					},
+					Length: 4,
+				},
+				match.Any{separators},
+				nil,
+			),
 		},
 		{
 			ast: pattern(&nodeSuper{}, &nodeSingle{}, &nodeText{text: "abc"}, &nodeSingle{}),
 			sep: separators,
-			result: match.BTree{
-				Left: match.Super{},
-				Value: match.Row{Matchers: match.Matchers{
-					match.Single{separators},
-					match.Raw{"abc"},
-					match.Single{separators},
-				}},
-			},
+			result: match.NewBTree(
+				match.Row{
+					Matchers: match.Matchers{
+						match.Single{separators},
+						match.Raw{"abc", 3},
+						match.Single{separators},
+					},
+					Length: 5,
+				},
+				match.Super{},
+				nil,
+			),
 		},
 		{
 			ast:    pattern(&nodeAny{}, &nodeText{text: "abc"}),
@@ -284,29 +303,33 @@ func TestCompiler(t *testing.T) {
 			result: match.Contains{"abc", false},
 		},
 		{
-			ast:    pattern(&nodeAny{}, &nodeAny{}, &nodeAny{}, &nodeText{text: "abc"}, &nodeAny{}, &nodeAny{}),
-			sep:    separators,
-			result: match.BTree{Left: match.Any{separators}, Value: match.Raw{"abc"}, Right: match.Any{separators}},
+			ast: pattern(&nodeAny{}, &nodeAny{}, &nodeAny{}, &nodeText{text: "abc"}, &nodeAny{}, &nodeAny{}),
+			sep: separators,
+			result: match.NewBTree(
+				match.Raw{"abc", 3},
+				match.Any{separators},
+				match.Any{separators},
+			),
 		},
 		{
 			ast: pattern(&nodeSuper{}, &nodeSingle{}, &nodeText{text: "abc"}, &nodeSuper{}, &nodeSingle{}),
-			result: match.BTree{
-				Left:  match.Min{1},
-				Value: match.Raw{"abc"},
-				Right: match.Min{1},
-			},
+			result: match.NewBTree(
+				match.Raw{"abc", 3},
+				match.Min{1},
+				match.Min{1},
+			),
 		},
 		{
 			ast: pattern(anyOf(&nodeText{text: "abc"})),
 			result: match.AnyOf{match.Matchers{
-				match.Raw{"abc"},
+				match.Raw{"abc", 3},
 			}},
 		},
 		{
 			ast: pattern(anyOf(pattern(anyOf(pattern(&nodeText{text: "abc"}))))),
 			result: match.AnyOf{match.Matchers{
 				match.AnyOf{match.Matchers{
-					match.Raw{"abc"},
+					match.Raw{"abc", 3},
 				}},
 			}},
 		},
@@ -316,13 +339,17 @@ func TestCompiler(t *testing.T) {
 				&nodeRange{lo: 'a', hi: 'x', not: true},
 				&nodeAny{},
 			),
-			result: match.BTree{
-				Value: match.Row{Matchers: match.Matchers{
-					match.Range{Lo: 'a', Hi: 'z'},
-					match.Range{Lo: 'a', Hi: 'x', Not: true},
-				}},
-				Right: match.Super{},
-			},
+			result: match.NewBTree(
+				match.Row{
+					Matchers: match.Matchers{
+						match.Range{Lo: 'a', Hi: 'z'},
+						match.Range{Lo: 'a', Hi: 'x', Not: true},
+					},
+					Length: 2,
+				},
+				nil,
+				match.Super{},
+			),
 		},
 		//		{
 		//			ast: pattern(
@@ -330,9 +357,9 @@ func TestCompiler(t *testing.T) {
 		//				anyOf(&nodeText{text: "c"}, &nodeText{text: "d"}),
 		//			),
 		//			result: match.AnyOf{Matchers: match.Matchers{
-		//				match.Row{Matchers: match.Matchers{match.Raw{"a"}, match.Raw{"c"}}},
+		//				match.Row{Matchers: match.Matchers{match.Raw{"a"}, match.Raw{"c", 1}}},
 		//				match.Row{Matchers: match.Matchers{match.Raw{"a"}, match.Raw{"d"}}},
-		//				match.Row{Matchers: match.Matchers{match.Raw{"b"}, match.Raw{"c"}}},
+		//				match.Row{Matchers: match.Matchers{match.Raw{"b"}, match.Raw{"c", 1}}},
 		//				match.Row{Matchers: match.Matchers{match.Raw{"b"}, match.Raw{"d"}}},
 		//			}},
 		//		},
diff --git a/match/any.go b/match/any.go
index f554b6a..ba13645 100644
--- a/match/any.go
+++ b/match/any.go
@@ -36,7 +36,7 @@ func (self Any) Index(s string) (int, []int) {
 }
 
 func (self Any) Len() int {
-	return -1
+	return lenNo
 }
 
 func (self Any) Kind() Kind {
diff --git a/match/btree.go b/match/btree.go
index 9c3534d..d9ce037 100644
--- a/match/btree.go
+++ b/match/btree.go
@@ -7,38 +7,50 @@ import (
 
 type BTree struct {
 	Value, Left, Right Matcher
+	VLen, LLen, RLen   int
+	Length             int
+}
+
+func NewBTree(Value, Left, Right Matcher) (tree BTree) {
+	tree.Value = Value
+	tree.Left = Left
+	tree.Right = Right
+
+	lenOk := true
+	if tree.VLen = Value.Len(); tree.VLen == -1 {
+		lenOk = false
+	}
+
+	if Left != nil {
+		if tree.LLen = Left.Len(); tree.LLen == -1 {
+			lenOk = false
+		}
+	}
+
+	if Right != nil {
+		if tree.RLen = Right.Len(); tree.RLen == -1 {
+			lenOk = false
+		}
+	}
+
+	if lenOk {
+		tree.Length = tree.LLen + tree.VLen + tree.RLen
+	} else {
+		tree.Length = -1
+	}
+
+	return tree
 }
 
 func (self BTree) Kind() Kind {
 	return KindBTree
 }
 
-func (self BTree) len() (l, v, r int, ok bool) {
-	v = self.Value.Len()
-
-	if self.Left != nil {
-		l = self.Left.Len()
-	}
-
-	if self.Right != nil {
-		r = self.Right.Len()
-	}
-
-	ok = l > -1 && v > -1 && r > -1
-
-	return
-}
-
 func (self BTree) Len() int {
-	l, v, r, ok := self.len()
-	if ok {
-		return l + v + r
-	}
-
-	return -1
+	return self.Length
 }
 
-// todo
+// todo?
 func (self BTree) Index(s string) (int, []int) {
 	return -1, nil
 }
@@ -46,17 +58,16 @@ func (self BTree) Index(s string) (int, []int) {
 func (self BTree) Match(s string) bool {
 	inputLen := len(s)
 
-	lLen, vLen, rLen, ok := self.len()
-	if ok && lLen+vLen+rLen > inputLen {
+	if self.Length != -1 && self.Length > inputLen {
 		return false
 	}
 
 	var offset, limit int
-	if lLen >= 0 {
-		offset = lLen
+	if self.LLen >= 0 {
+		offset = self.LLen
 	}
-	if rLen >= 0 {
-		limit = inputLen - rLen
+	if self.RLen >= 0 {
+		limit = inputLen - self.RLen
 	} else {
 		limit = inputLen
 	}
@@ -79,7 +90,7 @@ func (self BTree) Match(s string) bool {
 			for i := len(segments) - 1; i >= 0; i-- {
 				length := segments[i]
 
-				if rLen >= 0 && inputLen-(offset+index+length) != rLen {
+				if self.RLen >= 0 && inputLen-(offset+index+length) != self.RLen {
 					continue
 				}
 
diff --git a/match/contains.go b/match/contains.go
index d7b2154..a9ff543 100644
--- a/match/contains.go
+++ b/match/contains.go
@@ -53,7 +53,7 @@ func (self Contains) Index(s string) (int, []int) {
 }
 
 func (self Contains) Len() int {
-	return -1
+	return lenNo
 }
 
 func (self Contains) Kind() Kind {
diff --git a/match/list.go b/match/list.go
index 2ff1e1f..06068a5 100644
--- a/match/list.go
+++ b/match/list.go
@@ -16,17 +16,12 @@ func (self List) Kind() Kind {
 }
 
 func (self List) Match(s string) bool {
-	if utf8.RuneCountInString(s) > 1 {
-		return false
-	}
-
 	inList := strings.Index(self.List, s) != -1
-
 	return inList == !self.Not
 }
 
 func (self List) Len() int {
-	return 1
+	return lenOne
 }
 
 func (self List) Index(s string) (int, []int) {
diff --git a/match/match.go b/match/match.go
index d16f9a9..39989b8 100644
--- a/match/match.go
+++ b/match/match.go
@@ -27,6 +27,9 @@ const (
 	KindContains
 )
 
+const lenOne = 1
+const lenNo = -1
+
 type Matcher interface {
 	Match(string) bool
 	Index(string) (int, []int)
diff --git a/match/max.go b/match/max.go
index 67e5378..cc7244a 100644
--- a/match/max.go
+++ b/match/max.go
@@ -10,12 +10,19 @@ type Max struct {
 }
 
 func (self Max) Match(s string) bool {
-	return utf8.RuneCountInString(s) <= self.Limit
+	var l int
+	for range s {
+		l += 1
+		if l > self.Limit {
+			return false
+		}
+	}
+
+	return true
 }
 
 func (self Max) Index(s string) (int, []int) {
-	c := utf8.RuneCountInString(s)
-	if c < self.Limit {
+	if !self.Match(s) {
 		return -1, nil
 	}
 
@@ -34,7 +41,7 @@ func (self Max) Index(s string) (int, []int) {
 }
 
 func (self Max) Len() int {
-	return -1
+	return lenNo
 }
 
 func (self Max) Search(s string) (int, int, bool) {
diff --git a/match/min.go b/match/min.go
index 5bba994..1df3072 100644
--- a/match/min.go
+++ b/match/min.go
@@ -10,7 +10,15 @@ type Min struct {
 }
 
 func (self Min) Match(s string) bool {
-	return utf8.RuneCountInString(s) >= self.Limit
+	var l int
+	for range s {
+		l += 1
+		if l >= self.Limit {
+			return true
+		}
+	}
+
+	return false
 }
 
 func (self Min) Index(s string) (int, []int) {
@@ -33,7 +41,7 @@ func (self Min) Index(s string) (int, []int) {
 }
 
 func (self Min) Len() int {
-	return -1
+	return lenNo
 }
 
 func (self Min) Search(s string) (int, int, bool) {
diff --git a/match/prefix.go b/match/prefix.go
index 49b22e6..097e316 100644
--- a/match/prefix.go
+++ b/match/prefix.go
@@ -38,7 +38,7 @@ func (self Prefix) Index(s string) (int, []int) {
 }
 
 func (self Prefix) Len() int {
-	return -1
+	return lenNo
 }
 
 func (self Prefix) Search(s string) (i int, l int, ok bool) {
diff --git a/match/prefix_suffix.go b/match/prefix_suffix.go
index 9efffea..6d3af9e 100644
--- a/match/prefix_suffix.go
+++ b/match/prefix_suffix.go
@@ -44,7 +44,7 @@ func (self PrefixSuffix) Index(s string) (int, []int) {
 }
 
 func (self PrefixSuffix) Len() int {
-	return -1
+	return lenNo
 }
 
 func (self PrefixSuffix) Search(s string) (i int, l int, ok bool) {
diff --git a/match/range.go b/match/range.go
index e771285..42453c6 100644
--- a/match/range.go
+++ b/match/range.go
@@ -15,7 +15,7 @@ func (self Range) Kind() Kind {
 }
 
 func (self Range) Len() int {
-	return 1
+	return lenOne
 }
 
 func (self Range) Match(s string) bool {
diff --git a/match/raw.go b/match/raw.go
index 5cac636..12c86fa 100644
--- a/match/raw.go
+++ b/match/raw.go
@@ -3,11 +3,20 @@ package match
 import (
 	"fmt"
 	"strings"
+	"unicode/utf8"
 )
 
 // raw represents raw string to match
 type Raw struct {
-	Str string
+	Str    string
+	Length int
+}
+
+func NewRaw(s string) Raw {
+	return Raw{
+		Str:    s,
+		Length: utf8.RuneCountInString(s),
+	}
 }
 
 func (self Raw) Match(s string) bool {
@@ -15,7 +24,7 @@ func (self Raw) Match(s string) bool {
 }
 
 func (self Raw) Len() int {
-	return len(self.Str)
+	return self.Length
 }
 
 func (self Raw) Kind() Kind {
@@ -28,7 +37,7 @@ func (self Raw) Index(s string) (index int, segments []int) {
 		return
 	}
 
-	segments = []int{len(self.Str)}
+	segments = []int{self.Length}
 
 	return
 }
diff --git a/match/row.go b/match/row.go
index 2c337df..9982ed4 100644
--- a/match/row.go
+++ b/match/row.go
@@ -2,27 +2,15 @@ package match
 
 import (
 	"fmt"
+	"unicode/utf8"
 )
 
 type Row struct {
 	Matchers Matchers
-	len      int
+	Length   int
 }
 
-func (self *Row) Add(m Matcher) error {
-	if l := m.Len(); l == -1 {
-		return fmt.Errorf("matcher should have fixed length")
-	}
-
-	self.Matchers = append(self.Matchers, m)
-	return nil
-}
-
-func (self Row) Match(s string) bool {
-	if len(s) < self.Len() {
-		return false
-	}
-
+func (self Row) matchAll(s string) bool {
 	var idx int
 	for _, m := range self.Matchers {
 		l := m.Len()
@@ -36,21 +24,33 @@ func (self Row) Match(s string) bool {
 	return true
 }
 
-func (self Row) Len() (l int) {
-	if self.len == 0 {
-		for _, m := range self.Matchers {
-			self.len += m.Len()
-		}
+func (self Row) Match(s string) bool {
+	if utf8.RuneCountInString(s) < self.Length {
+		return false
 	}
 
-	return self.len
+	return self.matchAll(s)
+}
+
+func (self Row) Len() (l int) {
+	return self.Length
 }
 
 func (self Row) Index(s string) (int, []int) {
+	l := utf8.RuneCountInString(s)
+	if l < self.Length {
+		return -1, nil
+	}
+
 	for i := range s {
 		sub := s[i:]
-		if self.Match(sub) {
-			return i, []int{self.Len()}
+		if self.matchAll(sub) {
+			return i, []int{self.Length}
+		}
+
+		l -= 1
+		if l < self.Length {
+			return -1, nil
 		}
 	}
 
@@ -62,5 +62,5 @@ func (self Row) Kind() Kind {
 }
 
 func (self Row) String() string {
-	return fmt.Sprintf("<row:[%s]>", self.Matchers)
+	return fmt.Sprintf("<row_%d:[%s]>", self.Length, self.Matchers)
 }
diff --git a/match/single.go b/match/single.go
index 833f4c7..b35e80b 100644
--- a/match/single.go
+++ b/match/single.go
@@ -12,11 +12,11 @@ type Single struct {
 }
 
 func (self Single) Match(s string) bool {
-	return utf8.RuneCountInString(s) == 1 && strings.IndexAny(s, self.Separators) == -1
+	return strings.IndexAny(s, self.Separators) == -1
 }
 
 func (self Single) Len() int {
-	return 1
+	return lenOne
 }
 
 func (self Single) Index(s string) (int, []int) {
diff --git a/match/suffix.go b/match/suffix.go
index c9e0425..670724a 100644
--- a/match/suffix.go
+++ b/match/suffix.go
@@ -23,7 +23,7 @@ func (self Suffix) Index(s string) (int, []int) {
 }
 
 func (self Suffix) Len() int {
-	return -1
+	return lenNo
 }
 
 func (self Suffix) Search(s string) (i int, l int, ok bool) {
diff --git a/match/super.go b/match/super.go
index ad50d43..a7e0979 100644
--- a/match/super.go
+++ b/match/super.go
@@ -12,7 +12,7 @@ func (self Super) Match(s string) bool {
 }
 
 func (self Super) Len() int {
-	return -1
+	return lenNo
 }
 
 func (self Super) Index(s string) (int, []int) {