diff --git a/lexer.go b/lexer/lexer.go
similarity index 59%
rename from lexer.go
rename to lexer/lexer.go
index 9b756dc..e074b09 100644
--- a/lexer.go
+++ b/lexer/lexer.go
@@ -1,9 +1,9 @@
-package glob
+package lexer
 
 import (
 	"bytes"
 	"fmt"
-	"github.com/gobwas/glob/runes"
+	"github.com/gobwas/glob/util/runes"
 	"unicode/utf8"
 )
 
@@ -30,123 +30,24 @@ var specials = []byte{
 	char_terms_close,
 }
 
-func special(c byte) bool {
+func Special(c byte) bool {
 	return bytes.IndexByte(specials, c) != -1
 }
 
-type itemType int
+type tokens []Token
 
-const (
-	item_eof itemType = iota
-	item_error
-	item_text
-	item_char
-	item_any
-	item_super
-	item_single
-	item_not
-	item_separator
-	item_range_open
-	item_range_close
-	item_range_lo
-	item_range_hi
-	item_range_between
-	item_terms_open
-	item_terms_close
-)
-
-func (i itemType) String() string {
-	switch i {
-	case item_eof:
-		return "eof"
-
-	case item_error:
-		return "error"
-
-	case item_text:
-		return "text"
-
-	case item_char:
-		return "char"
-
-	case item_any:
-		return "any"
-
-	case item_super:
-		return "super"
-
-	case item_single:
-		return "single"
-
-	case item_not:
-		return "not"
-
-	case item_separator:
-		return "separator"
-
-	case item_range_open:
-		return "range_open"
-
-	case item_range_close:
-		return "range_close"
-
-	case item_range_lo:
-		return "range_lo"
-
-	case item_range_hi:
-		return "range_hi"
-
-	case item_range_between:
-		return "range_between"
-
-	case item_terms_open:
-		return "terms_open"
-
-	case item_terms_close:
-		return "terms_close"
-
-	default:
-		return "undef"
-	}
-}
-
-type item struct {
-	t itemType
-	s string
-}
-
-func (i item) String() string {
-	return fmt.Sprintf("%v<%q>", i.t, i.s)
-}
-
-type stubLexer struct {
-	Items []item
-	pos   int
-}
-
-func (s *stubLexer) nextItem() (ret item) {
-	if s.pos == len(s.Items) {
-		return item{item_eof, ""}
-	}
-	ret = s.Items[s.pos]
-	s.pos++
-	return
-}
-
-type items []item
-
-func (i *items) shift() (ret item) {
+func (i *tokens) shift() (ret Token) {
 	ret = (*i)[0]
 	copy(*i, (*i)[1:])
 	*i = (*i)[:len(*i)-1]
 	return
 }
 
-func (i *items) push(v item) {
+func (i *tokens) push(v Token) {
 	*i = append(*i, v)
 }
 
-func (i *items) empty() bool {
+func (i *tokens) empty() bool {
 	return len(*i) == 0
 }
 
@@ -157,7 +58,7 @@ type lexer struct {
 	pos  int
 	err  error
 
-	items      items
+	tokens     tokens
 	termsLevel int
 
 	lastRune     rune
@@ -167,8 +68,8 @@ type lexer struct {
 
 func newLexer(source string) *lexer {
 	l := &lexer{
-		data:  source,
-		items: items(make([]item, 0, 4)),
+		data:   source,
+		tokens: tokens(make([]Token, 0, 4)),
 	}
 	return l
 }
@@ -233,12 +134,12 @@ func (l *lexer) termsLeave() {
 	l.termsLevel--
 }
 
-func (l *lexer) nextItem() item {
+func (l *lexer) nextItem() Token {
 	if l.err != nil {
-		return item{item_error, l.err.Error()}
+		return Token{Error, l.err.Error()}
 	}
-	if !l.items.empty() {
-		return l.items.shift()
+	if !l.tokens.empty() {
+		return l.tokens.shift()
 	}
 
 	l.fetchItem()
@@ -252,32 +153,32 @@ func (l *lexer) fetchItem() {
 	r := l.read()
 	switch {
 	case r == eof:
-		l.items.push(item{item_eof, ""})
+		l.tokens.push(Token{EOF, ""})
 
 	case r == char_terms_open:
 		l.termsEnter()
-		l.items.push(item{item_terms_open, string(r)})
+		l.tokens.push(Token{TermsOpen, string(r)})
 
 	case r == char_comma && l.inTerms():
-		l.items.push(item{item_separator, string(r)})
+		l.tokens.push(Token{Separator, string(r)})
 
 	case r == char_terms_close && l.inTerms():
-		l.items.push(item{item_terms_close, string(r)})
+		l.tokens.push(Token{TermsClose, string(r)})
 		l.termsLeave()
 
 	case r == char_range_open:
-		l.items.push(item{item_range_open, string(r)})
+		l.tokens.push(Token{RangeOpen, string(r)})
 		l.fetchRange()
 
 	case r == char_single:
-		l.items.push(item{item_single, string(r)})
+		l.tokens.push(Token{Single, string(r)})
 
 	case r == char_any:
 		if l.read() == char_any {
-			l.items.push(item{item_super, string(r) + string(r)})
+			l.tokens.push(Token{Super, string(r) + string(r)})
 		} else {
 			l.unread()
-			l.items.push(item{item_any, string(r)})
+			l.tokens.push(Token{Any, string(r)})
 		}
 
 	default:
@@ -308,27 +209,27 @@ func (l *lexer) fetchRange() {
 			if r != char_range_close {
 				l.errorf("expected close range character")
 			} else {
-				l.items.push(item{item_range_close, string(r)})
+				l.tokens.push(Token{RangeClose, string(r)})
 			}
 			return
 		}
 
 		if wantHi {
-			l.items.push(item{item_range_hi, string(r)})
+			l.tokens.push(Token{RangeHi, string(r)})
 			wantClose = true
 			continue
 		}
 
 		if !seenNot && r == char_range_not {
-			l.items.push(item{item_not, string(r)})
+			l.tokens.push(Token{Not, string(r)})
 			seenNot = true
 			continue
 		}
 
 		if n, w := l.peek(); n == char_range_between {
 			l.seek(w)
-			l.items.push(item{item_range_lo, string(r)})
-			l.items.push(item{item_range_between, string(n)})
+			l.tokens.push(Token{RangeLo, string(r)})
+			l.tokens.push(Token{RangeBetween, string(n)})
 			wantHi = true
 			continue
 		}
@@ -367,6 +268,6 @@ reading:
 	}
 
 	if len(data) > 0 {
-		l.items.push(item{item_text, string(data)})
+		l.tokens.push(Token{Text, string(data)})
 	}
 }
diff --git a/lexer/lexer_test.go b/lexer/lexer_test.go
new file mode 100644
index 0000000..8af3aa6
--- /dev/null
+++ b/lexer/lexer_test.go
@@ -0,0 +1,192 @@
+package lexer
+
+import (
+	"testing"
+)
+
+func TestLexGood(t *testing.T) {
+	for id, test := range []struct {
+		pattern string
+		items   []Token
+	}{
+		{
+			pattern: "",
+			items: []Token{
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "hello",
+			items: []Token{
+				Token{Text, "hello"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "/{rate,[0-9]]}*",
+			items: []Token{
+				Token{Text, "/"},
+				Token{TermsOpen, "{"},
+				Token{Text, "rate"},
+				Token{Separator, ","},
+				Token{RangeOpen, "["},
+				Token{RangeLo, "0"},
+				Token{RangeBetween, "-"},
+				Token{RangeHi, "9"},
+				Token{RangeClose, "]"},
+				Token{Text, "]"},
+				Token{TermsClose, "}"},
+				Token{Any, "*"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "hello,world",
+			items: []Token{
+				Token{Text, "hello,world"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "hello\\,world",
+			items: []Token{
+				Token{Text, "hello,world"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "hello\\{world",
+			items: []Token{
+				Token{Text, "hello{world"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "hello?",
+			items: []Token{
+				Token{Text, "hello"},
+				Token{Single, "?"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "hellof*",
+			items: []Token{
+				Token{Text, "hellof"},
+				Token{Any, "*"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "hello**",
+			items: []Token{
+				Token{Text, "hello"},
+				Token{Super, "**"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "[日-語]",
+			items: []Token{
+				Token{RangeOpen, "["},
+				Token{RangeLo, "日"},
+				Token{RangeBetween, "-"},
+				Token{RangeHi, "語"},
+				Token{RangeClose, "]"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "[!日-語]",
+			items: []Token{
+				Token{RangeOpen, "["},
+				Token{Not, "!"},
+				Token{RangeLo, "日"},
+				Token{RangeBetween, "-"},
+				Token{RangeHi, "語"},
+				Token{RangeClose, "]"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "[日本語]",
+			items: []Token{
+				Token{RangeOpen, "["},
+				Token{Text, "日本語"},
+				Token{RangeClose, "]"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "[!日本語]",
+			items: []Token{
+				Token{RangeOpen, "["},
+				Token{Not, "!"},
+				Token{Text, "日本語"},
+				Token{RangeClose, "]"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "{a,b}",
+			items: []Token{
+				Token{TermsOpen, "{"},
+				Token{Text, "a"},
+				Token{Separator, ","},
+				Token{Text, "b"},
+				Token{TermsClose, "}"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "/{z,ab}*",
+			items: []Token{
+				Token{Text, "/"},
+				Token{TermsOpen, "{"},
+				Token{Text, "z"},
+				Token{Separator, ","},
+				Token{Text, "ab"},
+				Token{TermsClose, "}"},
+				Token{Any, "*"},
+				Token{EOF, ""},
+			},
+		},
+		{
+			pattern: "{[!日-語],*,?,{a,b,\\c}}",
+			items: []Token{
+				Token{TermsOpen, "{"},
+				Token{RangeOpen, "["},
+				Token{Not, "!"},
+				Token{RangeLo, "日"},
+				Token{RangeBetween, "-"},
+				Token{RangeHi, "語"},
+				Token{RangeClose, "]"},
+				Token{Separator, ","},
+				Token{Any, "*"},
+				Token{Separator, ","},
+				Token{Single, "?"},
+				Token{Separator, ","},
+				Token{TermsOpen, "{"},
+				Token{Text, "a"},
+				Token{Separator, ","},
+				Token{Text, "b"},
+				Token{Separator, ","},
+				Token{Text, "c"},
+				Token{TermsClose, "}"},
+				Token{TermsClose, "}"},
+				Token{EOF, ""},
+			},
+		},
+	} {
+		lexer := newLexer(test.pattern)
+		for i, exp := range test.items {
+			act := lexer.nextItem()
+			if act.Type != exp.Type {
+				t.Errorf("#%d %q: wrong %d-th item type: exp: %q; act: %q\n\t(%s vs %s)", id, test.pattern, i, exp.Type, act.Type, exp, act)
+			}
+			if act.Raw != exp.Raw {
+				t.Errorf("#%d %q: wrong %d-th item contents: exp: %q; act: %q\n\t(%s vs %s)", id, test.pattern, i, exp.Raw, act.Raw, exp, act)
+			}
+		}
+	}
+}
diff --git a/lexer/token.go b/lexer/token.go
new file mode 100644
index 0000000..2797c4e
--- /dev/null
+++ b/lexer/token.go
@@ -0,0 +1,88 @@
+package lexer
+
+import "fmt"
+
+type TokenType int
+
+const (
+	EOF TokenType = iota
+	Error
+	Text
+	Char
+	Any
+	Super
+	Single
+	Not
+	Separator
+	RangeOpen
+	RangeClose
+	RangeLo
+	RangeHi
+	RangeBetween
+	TermsOpen
+	TermsClose
+)
+
+func (tt TokenType) String() string {
+	switch tt {
+	case EOF:
+		return "eof"
+
+	case Error:
+		return "error"
+
+	case Text:
+		return "text"
+
+	case Char:
+		return "char"
+
+	case Any:
+		return "any"
+
+	case Super:
+		return "super"
+
+	case Single:
+		return "single"
+
+	case Not:
+		return "not"
+
+	case Separator:
+		return "separator"
+
+	case RangeOpen:
+		return "range_open"
+
+	case RangeClose:
+		return "range_close"
+
+	case RangeLo:
+		return "range_lo"
+
+	case RangeHi:
+		return "range_hi"
+
+	case RangeBetween:
+		return "range_between"
+
+	case TermsOpen:
+		return "terms_open"
+
+	case TermsClose:
+		return "terms_close"
+
+	default:
+		return "undef"
+	}
+}
+
+type Token struct {
+	Type TokenType
+	Raw  string
+}
+
+func (t Token) String() string {
+	return fmt.Sprintf("%v<%q>", t.Type, t.Raw)
+}
diff --git a/lexer_test.go b/lexer_test.go
deleted file mode 100644
index 8ede767..0000000
--- a/lexer_test.go
+++ /dev/null
@@ -1,192 +0,0 @@
-package glob
-
-import (
-	"testing"
-)
-
-func TestLexGood(t *testing.T) {
-	for id, test := range []struct {
-		pattern string
-		items   []item
-	}{
-		{
-			pattern: "",
-			items: []item{
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "hello",
-			items: []item{
-				item{item_text, "hello"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "/{rate,[0-9]]}*",
-			items: []item{
-				item{item_text, "/"},
-				item{item_terms_open, "{"},
-				item{item_text, "rate"},
-				item{item_separator, ","},
-				item{item_range_open, "["},
-				item{item_range_lo, "0"},
-				item{item_range_between, "-"},
-				item{item_range_hi, "9"},
-				item{item_range_close, "]"},
-				item{item_text, "]"},
-				item{item_terms_close, "}"},
-				item{item_any, "*"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "hello,world",
-			items: []item{
-				item{item_text, "hello,world"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "hello\\,world",
-			items: []item{
-				item{item_text, "hello,world"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "hello\\{world",
-			items: []item{
-				item{item_text, "hello{world"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "hello?",
-			items: []item{
-				item{item_text, "hello"},
-				item{item_single, "?"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "hellof*",
-			items: []item{
-				item{item_text, "hellof"},
-				item{item_any, "*"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "hello**",
-			items: []item{
-				item{item_text, "hello"},
-				item{item_super, "**"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "[日-語]",
-			items: []item{
-				item{item_range_open, "["},
-				item{item_range_lo, "日"},
-				item{item_range_between, "-"},
-				item{item_range_hi, "語"},
-				item{item_range_close, "]"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "[!日-語]",
-			items: []item{
-				item{item_range_open, "["},
-				item{item_not, "!"},
-				item{item_range_lo, "日"},
-				item{item_range_between, "-"},
-				item{item_range_hi, "語"},
-				item{item_range_close, "]"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "[日本語]",
-			items: []item{
-				item{item_range_open, "["},
-				item{item_text, "日本語"},
-				item{item_range_close, "]"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "[!日本語]",
-			items: []item{
-				item{item_range_open, "["},
-				item{item_not, "!"},
-				item{item_text, "日本語"},
-				item{item_range_close, "]"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "{a,b}",
-			items: []item{
-				item{item_terms_open, "{"},
-				item{item_text, "a"},
-				item{item_separator, ","},
-				item{item_text, "b"},
-				item{item_terms_close, "}"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "/{z,ab}*",
-			items: []item{
-				item{item_text, "/"},
-				item{item_terms_open, "{"},
-				item{item_text, "z"},
-				item{item_separator, ","},
-				item{item_text, "ab"},
-				item{item_terms_close, "}"},
-				item{item_any, "*"},
-				item{item_eof, ""},
-			},
-		},
-		{
-			pattern: "{[!日-語],*,?,{a,b,\\c}}",
-			items: []item{
-				item{item_terms_open, "{"},
-				item{item_range_open, "["},
-				item{item_not, "!"},
-				item{item_range_lo, "日"},
-				item{item_range_between, "-"},
-				item{item_range_hi, "語"},
-				item{item_range_close, "]"},
-				item{item_separator, ","},
-				item{item_any, "*"},
-				item{item_separator, ","},
-				item{item_single, "?"},
-				item{item_separator, ","},
-				item{item_terms_open, "{"},
-				item{item_text, "a"},
-				item{item_separator, ","},
-				item{item_text, "b"},
-				item{item_separator, ","},
-				item{item_text, "c"},
-				item{item_terms_close, "}"},
-				item{item_terms_close, "}"},
-				item{item_eof, ""},
-			},
-		},
-	} {
-		lexer := newLexer(test.pattern)
-		for i, exp := range test.items {
-			act := lexer.nextItem()
-			if act.t != exp.t {
-				t.Errorf("#%d %q: wrong %d-th item type: exp: %q; act: %q\n\t(%s vs %s)", id, test.pattern, i, exp.t, act.t, exp, act)
-			}
-			if act.s != exp.s {
-				t.Errorf("#%d %q: wrong %d-th item contents: exp: %q; act: %q\n\t(%s vs %s)", id, test.pattern, i, exp.s, act.s, exp, act)
-			}
-		}
-	}
-}
diff --git a/parser.go b/parser.go
deleted file mode 100644
index 760ec96..0000000
--- a/parser.go
+++ /dev/null
@@ -1,230 +0,0 @@
-package glob
-
-import (
-	"errors"
-	"fmt"
-	"unicode/utf8"
-)
-
-type node interface {
-	children() []node
-	append(node)
-}
-
-// todo may be split it into another package
-type lexerIface interface {
-	nextItem() item
-}
-
-type nodeImpl struct {
-	desc []node
-}
-
-func (n *nodeImpl) append(c node) {
-	n.desc = append(n.desc, c)
-}
-func (n *nodeImpl) children() []node {
-	return n.desc
-}
-
-type nodeList struct {
-	nodeImpl
-	not   bool
-	chars string
-}
-type nodeRange struct {
-	nodeImpl
-	not    bool
-	lo, hi rune
-}
-type nodeText struct {
-	nodeImpl
-	text string
-}
-
-type nodePattern struct{ nodeImpl }
-type nodeAny struct{ nodeImpl }
-type nodeSuper struct{ nodeImpl }
-type nodeSingle struct{ nodeImpl }
-type nodeAnyOf struct{ nodeImpl }
-
-type tree struct {
-	root    node
-	current node
-	path    []node
-}
-
-func (t *tree) enter(c node) {
-	if t.root == nil {
-		t.root = c
-		t.current = c
-		return
-	}
-
-	t.current.append(c)
-	t.path = append(t.path, c)
-	t.current = c
-}
-
-func (t *tree) leave() {
-	if len(t.path)-1 <= 0 {
-		t.current = t.root
-		t.path = nil
-		return
-	}
-
-	t.path = t.path[:len(t.path)-1]
-	t.current = t.path[len(t.path)-1]
-}
-
-type parseFn func(*tree, lexerIface) (parseFn, error)
-
-func parse(lexer lexerIface) (*nodePattern, error) {
-	var parser parseFn
-
-	root := &nodePattern{}
-	tree := &tree{}
-	tree.enter(root)
-
-	for parser = parserMain; ; {
-		next, err := parser(tree, lexer)
-		if err != nil {
-			return nil, err
-		}
-
-		if next == nil {
-			break
-		}
-
-		parser = next
-	}
-
-	return root, nil
-}
-
-func parserMain(tree *tree, lexer lexerIface) (parseFn, error) {
-	for stop := false; !stop; {
-		item := lexer.nextItem()
-
-		switch item.t {
-		case item_eof:
-			stop = true
-			continue
-
-		case item_error:
-			return nil, errors.New(item.s)
-
-		case item_text:
-			tree.current.append(&nodeText{text: item.s})
-			return parserMain, nil
-
-		case item_any:
-			tree.current.append(&nodeAny{})
-			return parserMain, nil
-
-		case item_super:
-			tree.current.append(&nodeSuper{})
-			return parserMain, nil
-
-		case item_single:
-			tree.current.append(&nodeSingle{})
-			return parserMain, nil
-
-		case item_range_open:
-			return parserRange, nil
-
-		case item_terms_open:
-			tree.enter(&nodeAnyOf{})
-			tree.enter(&nodePattern{})
-			return parserMain, nil
-
-		case item_separator:
-			tree.leave()
-			tree.enter(&nodePattern{})
-			return parserMain, nil
-
-		case item_terms_close:
-			tree.leave()
-			tree.leave()
-			return parserMain, nil
-
-		default:
-			return nil, fmt.Errorf("unexpected token: %s", item)
-		}
-	}
-
-	return nil, nil
-}
-
-func parserRange(tree *tree, lexer lexerIface) (parseFn, error) {
-	var (
-		not   bool
-		lo    rune
-		hi    rune
-		chars string
-	)
-
-	for {
-		item := lexer.nextItem()
-
-		switch item.t {
-		case item_eof:
-			return nil, errors.New("unexpected end")
-
-		case item_error:
-			return nil, errors.New(item.s)
-
-		case item_not:
-			not = true
-
-		case item_range_lo:
-			r, w := utf8.DecodeRuneInString(item.s)
-			if len(item.s) > w {
-				return nil, fmt.Errorf("unexpected length of lo character")
-			}
-
-			lo = r
-
-		case item_range_between:
-			//
-
-		case item_range_hi:
-			r, w := utf8.DecodeRuneInString(item.s)
-			if len(item.s) > w {
-				return nil, fmt.Errorf("unexpected length of lo character")
-			}
-
-			hi = r
-
-			if hi < lo {
-				return nil, fmt.Errorf("hi character '%s' should be greater than lo '%s'", string(hi), string(lo))
-			}
-
-		case item_text:
-			chars = item.s
-
-		case item_range_close:
-			isRange := lo != 0 && hi != 0
-			isChars := chars != ""
-
-			if isChars == isRange {
-				return nil, fmt.Errorf("could not parse range")
-			}
-
-			if isRange {
-				tree.current.append(&nodeRange{
-					lo:  lo,
-					hi:  hi,
-					not: not,
-				})
-			} else {
-				tree.current.append(&nodeList{
-					chars: chars,
-					not:   not,
-				})
-			}
-
-			return parserMain, nil
-		}
-	}
-}
diff --git a/parser/ast.go b/parser/ast.go
new file mode 100644
index 0000000..588a45c
--- /dev/null
+++ b/parser/ast.go
@@ -0,0 +1,48 @@
+package parser
+
+type Node interface {
+	Children() []Node
+	Parent() Node
+	append(Node) Node
+}
+
+type node struct {
+	parent   Node
+	children []Node
+}
+
+func (n *node) Children() []Node {
+	return n.children
+}
+
+func (n *node) Parent() Node {
+	return n.parent
+}
+
+func (n *node) append(c Node) Node {
+	n.children = append(n.children, c)
+	return c
+}
+
+type ListNode struct {
+	node
+	Not   bool
+	Chars string
+}
+
+type RangeNode struct {
+	node
+	Not    bool
+	Lo, Hi rune
+}
+
+type TextNode struct {
+	node
+	Text string
+}
+
+type PatternNode struct{ node }
+type AnyNode struct{ node }
+type SuperNode struct{ node }
+type SingleNode struct{ node }
+type AnyOfNode struct{ node }
diff --git a/parser/parser.go b/parser/parser.go
new file mode 100644
index 0000000..6adea39
--- /dev/null
+++ b/parser/parser.go
@@ -0,0 +1,144 @@
+package parser
+
+import (
+	"errors"
+	"fmt"
+	"github.com/gobwas/glob/lexer"
+	"unicode/utf8"
+)
+
+type Lexer interface {
+	Next() lexer.Token
+}
+
+type parseFn func(Node, Lexer) (parseFn, Node, error)
+
+func Parse(lexer Lexer) (*PatternNode, error) {
+	var parser parseFn
+
+	root := &PatternNode{}
+
+	var (
+		tree Node
+		err  error
+	)
+	for parser, tree = parserMain, root; parser != nil; {
+		parser, tree, err = parser(tree, lexer)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return root, nil
+}
+
+func parserMain(tree Node, lex Lexer) (parseFn, Node, error) {
+	for {
+		token := lex.Next()
+		switch token.Type {
+		case lexer.EOF:
+			return nil, tree, nil
+
+		case lexer.Error:
+			return nil, tree, errors.New(token.Raw)
+
+		case lexer.Text:
+			return parserMain, tree.append(&TextNode{Text: token.Raw}), nil
+
+		case lexer.Any:
+			return parserMain, tree.append(&AnyNode{}), nil
+
+		case lexer.Super:
+			return parserMain, tree.append(&SuperNode{}), nil
+
+		case lexer.Single:
+			return parserMain, tree.append(&SingleNode{}), nil
+
+		case lexer.RangeOpen:
+			return parserRange, tree, nil
+
+		case lexer.TermsOpen:
+			return parserMain, tree.append(&AnyOfNode{}).append(&PatternNode{}), nil
+
+		case lexer.Separator:
+			return parserMain, tree.Parent().append(&PatternNode{}), nil
+
+		case lexer.TermsClose:
+			return parserMain, tree.Parent().Parent(), nil
+
+		default:
+			return nil, tree, fmt.Errorf("unexpected token: %s", token)
+		}
+	}
+	return nil, tree, fmt.Errorf("unknown error")
+}
+
+func parserRange(tree Node, lex Lexer) (parseFn, Node, error) {
+	var (
+		not   bool
+		lo    rune
+		hi    rune
+		chars string
+	)
+	for {
+		token := lex.Next()
+		switch token.Type {
+		case lexer.EOF:
+			return nil, tree, errors.New("unexpected end")
+
+		case lexer.Error:
+			return nil, tree, errors.New(token.Raw)
+
+		case lexer.Not:
+			not = true
+
+		case lexer.RangeLo:
+			r, w := utf8.DecodeRuneInString(token.Raw)
+			if len(token.Raw) > w {
+				return nil, tree, fmt.Errorf("unexpected length of lo character")
+			}
+			lo = r
+
+		case lexer.RangeBetween:
+			//
+
+		case lexer.RangeHi:
+			r, w := utf8.DecodeRuneInString(token.Raw)
+			if len(token.Raw) > w {
+				return nil, tree, fmt.Errorf("unexpected length of lo character")
+			}
+
+			hi = r
+
+			if hi < lo {
+				return nil, tree, fmt.Errorf("hi character '%s' should be greater than lo '%s'", string(hi), string(lo))
+			}
+
+		case lexer.Text:
+			chars = token.Raw
+
+		case lexer.RangeClose:
+			isRange := lo != 0 && hi != 0
+			isChars := chars != ""
+
+			if isChars == isRange {
+				return nil, tree, fmt.Errorf("could not parse range")
+			}
+
+			if isRange {
+				tree = tree.append(&RangeNode{
+					Lo:  lo,
+					Hi:  hi,
+					Not: not,
+				})
+			} else {
+				tree = tree.append(&ListNode{
+					Chars: chars,
+					Not:   not,
+				})
+			}
+
+			return parserMain, tree, nil
+		}
+	}
+}
diff --git a/parser/parser_test.go b/parser/parser_test.go
new file mode 100644
index 0000000..177d7bf
--- /dev/null
+++ b/parser/parser_test.go
@@ -0,0 +1,332 @@
+package parser
+
+import (
+	"fmt"
+	"github.com/gobwas/glob/lexer"
+	"reflect"
+	"testing"
+)
+
+type stubLexer struct {
+	tokens []lexer.Token
+	pos    int
+}
+
+func (s *stubLexer) Next() (ret lexer.Token) {
+	if s.pos == len(s.tokens) {
+		return lexer.Token{lexer.EOF, ""}
+	}
+	ret = s.tokens[s.pos]
+	s.pos++
+	return
+}
+
+func TestParseString(t *testing.T) {
+	for id, test := range []struct {
+		tokens []lexer.Token
+		tree   Node
+	}{
+		{
+			//pattern: "abc",
+			tokens: []lexer.Token{
+				lexer.Token{lexer.Text, "abc"},
+				lexer.Token{lexer.EOF, ""},
+			},
+			tree: &PatternNode{
+				node: node{
+					children: []Node{
+						&TextNode{Text: "abc"},
+					},
+				},
+			},
+		},
+		{
+			//pattern: "a*c",
+			tokens: []lexer.Token{
+				lexer.Token{lexer.Text, "a"},
+				lexer.Token{lexer.Any, "*"},
+				lexer.Token{lexer.Text, "c"},
+				lexer.Token{lexer.EOF, ""},
+			},
+			tree: &PatternNode{
+				node: node{
+					children: []Node{
+						&TextNode{Text: "a"},
+						&AnyNode{},
+						&TextNode{Text: "c"},
+					},
+				},
+			},
+		},
+		{
+			//pattern: "a**c",
+			tokens: []lexer.Token{
+				lexer.Token{lexer.Text, "a"},
+				lexer.Token{lexer.Super, "**"},
+				lexer.Token{lexer.Text, "c"},
+				lexer.Token{lexer.EOF, ""},
+			},
+			tree: &PatternNode{
+				node: node{
+					children: []Node{
+						&TextNode{Text: "a"},
+						&SuperNode{},
+						&TextNode{Text: "c"},
+					},
+				},
+			},
+		},
+		{
+			//pattern: "a?c",
+			tokens: []lexer.Token{
+				lexer.Token{lexer.Text, "a"},
+				lexer.Token{lexer.Single, "?"},
+				lexer.Token{lexer.Text, "c"},
+				lexer.Token{lexer.EOF, ""},
+			},
+			tree: &PatternNode{
+				node: node{
+					children: []Node{
+						&TextNode{Text: "a"},
+						&SingleNode{},
+						&TextNode{Text: "c"},
+					},
+				},
+			},
+		},
+		{
+			//pattern: "[!a-z]",
+			tokens: []lexer.Token{
+				lexer.Token{lexer.RangeOpen, "["},
+				lexer.Token{lexer.Not, "!"},
+				lexer.Token{lexer.RangeLo, "a"},
+				lexer.Token{lexer.RangeBetween, "-"},
+				lexer.Token{lexer.RangeHi, "z"},
+				lexer.Token{lexer.RangeClose, "]"},
+				lexer.Token{lexer.EOF, ""},
+			},
+			tree: &PatternNode{
+				node: node{
+					children: []Node{
+						&RangeNode{Lo: 'a', Hi: 'z', Not: true},
+					},
+				},
+			},
+		},
+		{
+			//pattern: "[az]",
+			tokens: []lexer.Token{
+				lexer.Token{lexer.RangeOpen, "["},
+				lexer.Token{lexer.Text, "az"},
+				lexer.Token{lexer.RangeClose, "]"},
+				lexer.Token{lexer.EOF, ""},
+			},
+			tree: &PatternNode{
+				node: node{
+					children: []Node{
+						&ListNode{Chars: "az"},
+					},
+				},
+			},
+		},
+		{
+			//pattern: "{a,z}",
+			tokens: []lexer.Token{
+				lexer.Token{lexer.TermsOpen, "{"},
+				lexer.Token{lexer.Text, "a"},
+				lexer.Token{lexer.Separator, ","},
+				lexer.Token{lexer.Text, "z"},
+				lexer.Token{lexer.TermsClose, "}"},
+				lexer.Token{lexer.EOF, ""},
+			},
+			tree: &PatternNode{
+				node: node{
+					children: []Node{
+						&AnyOfNode{node: node{children: []Node{
+							&PatternNode{
+								node: node{children: []Node{
+									&TextNode{Text: "a"},
+								}},
+							},
+							&PatternNode{
+								node: node{children: []Node{
+									&TextNode{Text: "z"},
+								}},
+							},
+						}}},
+					},
+				},
+			},
+		},
+		{
+			//pattern: "/{z,ab}*",
+			tokens: []lexer.Token{
+				lexer.Token{lexer.Text, "/"},
+				lexer.Token{lexer.TermsOpen, "{"},
+				lexer.Token{lexer.Text, "z"},
+				lexer.Token{lexer.Separator, ","},
+				lexer.Token{lexer.Text, "ab"},
+				lexer.Token{lexer.TermsClose, "}"},
+				lexer.Token{lexer.Any, "*"},
+				lexer.Token{lexer.EOF, ""},
+			},
+			tree: &PatternNode{
+				node: node{
+					children: []Node{
+						&TextNode{Text: "/"},
+						&AnyOfNode{node: node{children: []Node{
+							&PatternNode{
+								node: node{children: []Node{
+									&TextNode{Text: "z"},
+								}},
+							},
+							&PatternNode{
+								node: node{children: []Node{
+									&TextNode{Text: "ab"},
+								}},
+							},
+						}}},
+						&AnyNode{},
+					},
+				},
+			},
+		},
+		{
+			//pattern: "{a,{x,y},?,[a-z],[!qwe]}",
+			tokens: []lexer.Token{
+				lexer.Token{lexer.TermsOpen, "{"},
+				lexer.Token{lexer.Text, "a"},
+				lexer.Token{lexer.Separator, ","},
+				lexer.Token{lexer.TermsOpen, "{"},
+				lexer.Token{lexer.Text, "x"},
+				lexer.Token{lexer.Separator, ","},
+				lexer.Token{lexer.Text, "y"},
+				lexer.Token{lexer.TermsClose, "}"},
+				lexer.Token{lexer.Separator, ","},
+				lexer.Token{lexer.Single, "?"},
+				lexer.Token{lexer.Separator, ","},
+				lexer.Token{lexer.RangeOpen, "["},
+				lexer.Token{lexer.RangeLo, "a"},
+				lexer.Token{lexer.RangeBetween, "-"},
+				lexer.Token{lexer.RangeHi, "z"},
+				lexer.Token{lexer.RangeClose, "]"},
+				lexer.Token{lexer.Separator, ","},
+				lexer.Token{lexer.RangeOpen, "["},
+				lexer.Token{lexer.Not, "!"},
+				lexer.Token{lexer.Text, "qwe"},
+				lexer.Token{lexer.RangeClose, "]"},
+				lexer.Token{lexer.TermsClose, "}"},
+				lexer.Token{lexer.EOF, ""},
+			},
+			tree: &PatternNode{
+				node: node{
+					children: []Node{
+						&AnyOfNode{node: node{children: []Node{
+							&PatternNode{
+								node: node{children: []Node{
+									&TextNode{Text: "a"},
+								}},
+							},
+							&PatternNode{
+								node: node{children: []Node{
+									&AnyOfNode{node: node{children: []Node{
+										&PatternNode{
+											node: node{children: []Node{
+												&TextNode{Text: "x"},
+											}},
+										},
+										&PatternNode{
+											node: node{children: []Node{
+												&TextNode{Text: "y"},
+											}},
+										},
+									}}},
+								}},
+							},
+							&PatternNode{
+								node: node{children: []Node{
+									&SingleNode{},
+								}},
+							},
+							&PatternNode{
+								node: node{
+									children: []Node{
+										&RangeNode{Lo: 'a', Hi: 'z', Not: false},
+									},
+								},
+							},
+							&PatternNode{
+								node: node{
+									children: []Node{
+										&ListNode{Chars: "qwe", Not: true},
+									},
+								},
+							},
+						}}},
+					},
+				},
+			},
+		},
+	} {
+		lexer := &stubLexer{tokens: test.tokens}
+		result, err := Parse(lexer)
+		if err != nil {
+			t.Errorf("[%d] unexpected error: %s", id, err)
+		}
+		if !reflect.DeepEqual(test.tree, result) {
+			t.Errorf("[%d] Parse():\nact:\t%s\nexp:\t%s\n", id, result, test.tree)
+		}
+	}
+}
+
+const abstractNodeImpl = "nodeImpl"
+
+func nodeEqual(a, b Node) error {
+	if (a == nil || b == nil) && a != b {
+		return fmt.Errorf("nodes are not equal: exp %s, act %s", a, b)
+	}
+
+	aValue, bValue := reflect.Indirect(reflect.ValueOf(a)), reflect.Indirect(reflect.ValueOf(b))
+	aType, bType := aValue.Type(), bValue.Type()
+	if aType != bType {
+		return fmt.Errorf("nodes are not equal: exp %s, act %s", aValue.Type(), bValue.Type())
+	}
+
+	for i := 0; i < aType.NumField(); i++ {
+		var eq bool
+
+		f := aType.Field(i).Name
+		if f == abstractNodeImpl {
+			continue
+		}
+
+		af, bf := aValue.FieldByName(f), bValue.FieldByName(f)
+
+		switch af.Kind() {
+		case reflect.String:
+			eq = af.String() == bf.String()
+		case reflect.Bool:
+			eq = af.Bool() == bf.Bool()
+		default:
+			eq = fmt.Sprint(af) == fmt.Sprint(bf)
+		}
+
+		if !eq {
+			return fmt.Errorf("nodes<%s> %q fields are not equal: exp %q, act %q", aType, f, af, bf)
+		}
+	}
+
+	for i, aDesc := range a.Children() {
+		if len(b.Children())-1 < i {
+			return fmt.Errorf("node does not have enough children (got %d children, wanted %d-th token)", len(b.Children()), i)
+		}
+
+		bDesc := b.Children()[i]
+
+		if err := nodeEqual(aDesc, bDesc); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/parser_test.go b/parser_test.go
deleted file mode 100644
index 0e9312f..0000000
--- a/parser_test.go
+++ /dev/null
@@ -1,324 +0,0 @@
-package glob
-
-import (
-	"fmt"
-	"reflect"
-	"testing"
-)
-
-func TestParseString(t *testing.T) {
-	for id, test := range []struct {
-		items []item
-		tree  node
-	}{
-		{
-			//pattern: "abc",
-			items: []item{
-				item{item_text, "abc"},
-				item{item_eof, ""},
-			},
-			tree: &nodePattern{
-				nodeImpl: nodeImpl{
-					desc: []node{
-						&nodeText{text: "abc"},
-					},
-				},
-			},
-		},
-		{
-			//pattern: "a*c",
-			items: []item{
-				item{item_text, "a"},
-				item{item_any, "*"},
-				item{item_text, "c"},
-				item{item_eof, ""},
-			},
-			tree: &nodePattern{
-				nodeImpl: nodeImpl{
-					desc: []node{
-						&nodeText{text: "a"},
-						&nodeAny{},
-						&nodeText{text: "c"},
-					},
-				},
-			},
-		},
-		{
-			//pattern: "a**c",
-			items: []item{
-				item{item_text, "a"},
-				item{item_super, "**"},
-				item{item_text, "c"},
-				item{item_eof, ""},
-			},
-			tree: &nodePattern{
-				nodeImpl: nodeImpl{
-					desc: []node{
-						&nodeText{text: "a"},
-						&nodeSuper{},
-						&nodeText{text: "c"},
-					},
-				},
-			},
-		},
-		{
-			//pattern: "a?c",
-			items: []item{
-				item{item_text, "a"},
-				item{item_single, "?"},
-				item{item_text, "c"},
-				item{item_eof, ""},
-			},
-			tree: &nodePattern{
-				nodeImpl: nodeImpl{
-					desc: []node{
-						&nodeText{text: "a"},
-						&nodeSingle{},
-						&nodeText{text: "c"},
-					},
-				},
-			},
-		},
-		{
-			//pattern: "[!a-z]",
-			items: []item{
-				item{item_range_open, "["},
-				item{item_not, "!"},
-				item{item_range_lo, "a"},
-				item{item_range_between, "-"},
-				item{item_range_hi, "z"},
-				item{item_range_close, "]"},
-				item{item_eof, ""},
-			},
-			tree: &nodePattern{
-				nodeImpl: nodeImpl{
-					desc: []node{
-						&nodeRange{lo: 'a', hi: 'z', not: true},
-					},
-				},
-			},
-		},
-		{
-			//pattern: "[az]",
-			items: []item{
-				item{item_range_open, "["},
-				item{item_text, "az"},
-				item{item_range_close, "]"},
-				item{item_eof, ""},
-			},
-			tree: &nodePattern{
-				nodeImpl: nodeImpl{
-					desc: []node{
-						&nodeList{chars: "az"},
-					},
-				},
-			},
-		},
-		{
-			//pattern: "{a,z}",
-			items: []item{
-				item{item_terms_open, "{"},
-				item{item_text, "a"},
-				item{item_separator, ","},
-				item{item_text, "z"},
-				item{item_terms_close, "}"},
-				item{item_eof, ""},
-			},
-			tree: &nodePattern{
-				nodeImpl: nodeImpl{
-					desc: []node{
-						&nodeAnyOf{nodeImpl: nodeImpl{desc: []node{
-							&nodePattern{
-								nodeImpl: nodeImpl{desc: []node{
-									&nodeText{text: "a"},
-								}},
-							},
-							&nodePattern{
-								nodeImpl: nodeImpl{desc: []node{
-									&nodeText{text: "z"},
-								}},
-							},
-						}}},
-					},
-				},
-			},
-		},
-		{
-			//pattern: "/{z,ab}*",
-			items: []item{
-				item{item_text, "/"},
-				item{item_terms_open, "{"},
-				item{item_text, "z"},
-				item{item_separator, ","},
-				item{item_text, "ab"},
-				item{item_terms_close, "}"},
-				item{item_any, "*"},
-				item{item_eof, ""},
-			},
-			tree: &nodePattern{
-				nodeImpl: nodeImpl{
-					desc: []node{
-						&nodeText{text: "/"},
-						&nodeAnyOf{nodeImpl: nodeImpl{desc: []node{
-							&nodePattern{
-								nodeImpl: nodeImpl{desc: []node{
-									&nodeText{text: "z"},
-								}},
-							},
-							&nodePattern{
-								nodeImpl: nodeImpl{desc: []node{
-									&nodeText{text: "ab"},
-								}},
-							},
-						}}},
-						&nodeAny{},
-					},
-				},
-			},
-		},
-		{
-			//pattern: "{a,{x,y},?,[a-z],[!qwe]}",
-			items: []item{
-				item{item_terms_open, "{"},
-				item{item_text, "a"},
-				item{item_separator, ","},
-				item{item_terms_open, "{"},
-				item{item_text, "x"},
-				item{item_separator, ","},
-				item{item_text, "y"},
-				item{item_terms_close, "}"},
-				item{item_separator, ","},
-				item{item_single, "?"},
-				item{item_separator, ","},
-				item{item_range_open, "["},
-				item{item_range_lo, "a"},
-				item{item_range_between, "-"},
-				item{item_range_hi, "z"},
-				item{item_range_close, "]"},
-				item{item_separator, ","},
-				item{item_range_open, "["},
-				item{item_not, "!"},
-				item{item_text, "qwe"},
-				item{item_range_close, "]"},
-				item{item_terms_close, "}"},
-				item{item_eof, ""},
-			},
-			tree: &nodePattern{
-				nodeImpl: nodeImpl{
-					desc: []node{
-						&nodeAnyOf{nodeImpl: nodeImpl{desc: []node{
-							&nodePattern{
-								nodeImpl: nodeImpl{desc: []node{
-									&nodeText{text: "a"},
-								}},
-							},
-							&nodePattern{
-								nodeImpl: nodeImpl{desc: []node{
-									&nodeAnyOf{nodeImpl: nodeImpl{desc: []node{
-										&nodePattern{
-											nodeImpl: nodeImpl{desc: []node{
-												&nodeText{text: "x"},
-											}},
-										},
-										&nodePattern{
-											nodeImpl: nodeImpl{desc: []node{
-												&nodeText{text: "y"},
-											}},
-										},
-									}}},
-								}},
-							},
-							&nodePattern{
-								nodeImpl: nodeImpl{desc: []node{
-									&nodeSingle{},
-								}},
-							},
-							&nodePattern{
-								nodeImpl: nodeImpl{
-									desc: []node{
-										&nodeRange{lo: 'a', hi: 'z', not: false},
-									},
-								},
-							},
-							&nodePattern{
-								nodeImpl: nodeImpl{
-									desc: []node{
-										&nodeList{chars: "qwe", not: true},
-									},
-								},
-							},
-						}}},
-					},
-				},
-			},
-		},
-	} {
-		lexer := &stubLexer{Items: test.items}
-		pattern, err := parse(lexer)
-
-		if err != nil {
-			t.Errorf("#%d %s", id, err)
-			continue
-		}
-
-		if !reflect.DeepEqual(test.tree, pattern) {
-			t.Errorf("#%d tries are not equal", id)
-			if err = nodeEqual(test.tree, pattern); err != nil {
-				t.Errorf("#%d %s", id, err)
-				continue
-			}
-		}
-	}
-}
-
-const abstractNodeImpl = "nodeImpl"
-
-func nodeEqual(a, b node) error {
-	if (a == nil || b == nil) && a != b {
-		return fmt.Errorf("nodes are not equal: exp %s, act %s", a, b)
-	}
-
-	aValue, bValue := reflect.Indirect(reflect.ValueOf(a)), reflect.Indirect(reflect.ValueOf(b))
-	aType, bType := aValue.Type(), bValue.Type()
-	if aType != bType {
-		return fmt.Errorf("nodes are not equal: exp %s, act %s", aValue.Type(), bValue.Type())
-	}
-
-	for i := 0; i < aType.NumField(); i++ {
-		var eq bool
-
-		f := aType.Field(i).Name
-		if f == abstractNodeImpl {
-			continue
-		}
-
-		af, bf := aValue.FieldByName(f), bValue.FieldByName(f)
-
-		switch af.Kind() {
-		case reflect.String:
-			eq = af.String() == bf.String()
-		case reflect.Bool:
-			eq = af.Bool() == bf.Bool()
-		default:
-			eq = fmt.Sprint(af) == fmt.Sprint(bf)
-		}
-
-		if !eq {
-			return fmt.Errorf("nodes<%s> %q fields are not equal: exp %q, act %q", aType, f, af, bf)
-		}
-	}
-
-	for i, aDesc := range a.children() {
-		if len(b.children())-1 < i {
-			return fmt.Errorf("node does not have enough children (got %d children, wanted %d-th token)", len(b.children()), i)
-		}
-
-		bDesc := b.children()[i]
-
-		if err := nodeEqual(aDesc, bDesc); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
diff --git a/runes/runes.go b/util/runes/runes.go
similarity index 100%
rename from runes/runes.go
rename to util/runes/runes.go
diff --git a/runes/runes_test.go b/util/runes/runes_test.go
similarity index 100%
rename from runes/runes_test.go
rename to util/runes/runes_test.go
diff --git a/strings/strings.go b/util/strings/strings.go
similarity index 100%
rename from strings/strings.go
rename to util/strings/strings.go