diff --git a/lib/index.js b/lib/index.js
index ef845265..b78bfa8c 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -3,6 +3,8 @@ var names = require('./utils/names');
 
 module.exports = {
     List: require('./utils/list'),
+    Scanner: require('./parser/scanner'),
+
     syntax: require('./syntax'),
     property: names.property,
     keyword: names.keyword,
diff --git a/lib/parser/const.js b/lib/parser/const.js
index 28c1c0c1..775657b9 100644
--- a/lib/parser/const.js
+++ b/lib/parser/const.js
@@ -1,10 +1,10 @@
-// token types (note: value shouldn't intersect with using char codes)
+// token types (note: value shouldn't intersect with used char codes)
 var WHITESPACE = 1;
 var IDENTIFIER = 2;
 var NUMBER = 3;
 var STRING = 4;
 var COMMENT = 5;
-var PUNCTUATION = 6;
+var PUNCTUATOR = 6;
 
 var TAB = 9;
 var N = 10;
@@ -12,121 +12,121 @@ var F = 12;
 var R = 13;
 var SPACE = 32;
 
-var TokenType = {
+var TYPE = {
     Whitespace:   WHITESPACE,
     Identifier:   IDENTIFIER,
     Number:           NUMBER,
     String:           STRING,
     Comment:         COMMENT,
-    Punctuation: PUNCTUATION,
+    Punctuator:   PUNCTUATOR,
 
-    ExclamationMark:    33,  // !
-    QuotationMark:      34,  // "
-    NumberSign:         35,  // #
-    DollarSign:         36,  // $
-    PercentSign:        37,  // %
-    Ampersand:          38,  // &
-    Apostrophe:         39,  // '
-    LeftParenthesis:    40,  // (
-    RightParenthesis:   41,  // )
-    Asterisk:           42,  // *
-    PlusSign:           43,  // +
-    Comma:              44,  // ,
-    HyphenMinus:        45,  // -
-    FullStop:           46,  // .
-    Solidus:            47,  // /
-    Colon:              58,  // :
-    Semicolon:          59,  // ;
-    LessThanSign:       60,  // <
-    EqualsSign:         61,  // =
-    GreaterThanSign:    62,  // >
-    QuestionMark:       63,  // ?
-    CommercialAt:       64,  // @
-    LeftSquareBracket:  91,  // [
-    RightSquareBracket: 93,  // ]
-    CircumflexAccent:   94,  // ^
-    LowLine:            95,  // _
-    LeftCurlyBracket:  123,  // {
-    VerticalLine:      124,  // |
-    RightCurlyBracket: 125,  // }
-    Tilde:             126   // ~
+    ExclamationMark:      33,  // !
+    QuotationMark:        34,  // "
+    NumberSign:           35,  // #
+    DollarSign:           36,  // $
+    PercentSign:          37,  // %
+    Ampersand:            38,  // &
+    Apostrophe:           39,  // '
+    LeftParenthesis:      40,  // (
+    RightParenthesis:     41,  // )
+    Asterisk:             42,  // *
+    PlusSign:             43,  // +
+    Comma:                44,  // ,
+    HyphenMinus:          45,  // -
+    FullStop:             46,  // .
+    Solidus:              47,  // /
+    Colon:                58,  // :
+    Semicolon:            59,  // ;
+    LessThanSign:         60,  // <
+    EqualsSign:           61,  // =
+    GreaterThanSign:      62,  // >
+    QuestionMark:         63,  // ?
+    CommercialAt:         64,  // @
+    LeftSquareBracket:    91,  // [
+    RightSquareBracket:   93,  // ]
+    CircumflexAccent:     94,  // ^
+    LowLine:              95,  // _
+    LeftCurlyBracket:    123,  // {
+    VerticalLine:        124,  // |
+    RightCurlyBracket:   125,  // }
+    Tilde:               126   // ~
 };
 
-var TokenName = Object.keys(TokenType).reduce(function(result, key) {
-    result[TokenType[key]] = key;
+var NAME = Object.keys(TYPE).reduce(function(result, key) {
+    result[TYPE[key]] = key;
     return result;
 }, {});
 
-var punctuation = [
-    TokenType.ExclamationMark,    // '!'
-    TokenType.QuotationMark,      // '"'
-    TokenType.NumberSign,         // '#'
-    TokenType.DollarSign,         // '$'
-    TokenType.PercentSign,        // '%'
-    TokenType.Ampersand,          // '&'
-    TokenType.Apostrophe,         // '\''
-    TokenType.LeftParenthesis,    // '('
-    TokenType.RightParenthesis,   // ')'
-    TokenType.Asterisk,           // '*'
-    TokenType.PlusSign,           // '+'
-    TokenType.Comma,              // ','
-    TokenType.HyphenMinus,        // '-'
-    TokenType.FullStop,           // '.'
-    TokenType.Solidus,            // '/'
-    TokenType.Colon,              // ':'
-    TokenType.Semicolon,          // ';'
-    TokenType.LessThanSign,       // '<'
-    TokenType.EqualsSign,         // '='
-    TokenType.GreaterThanSign,    // '>'
-    TokenType.QuestionMark,       // '?'
-    TokenType.CommercialAt,       // '@'
-    TokenType.LeftSquareBracket,  // '['
-    TokenType.RightSquareBracket, // ']'
-    TokenType.CircumflexAccent,   // '^'
-    TokenType.LeftCurlyBracket,   // '{'
-    TokenType.VerticalLine,       // '|'
-    TokenType.RightCurlyBracket,  // '}'
-    TokenType.Tilde               // '~'
-];
-var SYMBOL_CATEGORY_LENGTH = Math.max.apply(null, punctuation) + 1;
-var SYMBOL_CATEGORY = new Uint32Array(SYMBOL_CATEGORY_LENGTH);
-var IS_PUNCTUATION = new Uint32Array(SYMBOL_CATEGORY_LENGTH);
+var SafeUint32Array = typeof Uint32Array !== 'undefined' ? Uint32Array : Array; // fallback on Array when TypedArray is not supported
+var SYMBOL_TYPE = new SafeUint32Array(Math.max.apply(null, Object.keys(NAME).map(Number)) + 1);
+var PUNCTUATION = new SafeUint32Array(SYMBOL_TYPE.length);
 
-for (var i = 0; i < SYMBOL_CATEGORY.length; i++) {
-    SYMBOL_CATEGORY[i] = IDENTIFIER;
+for (var i = 0; i < SYMBOL_TYPE.length; i++) {
+    SYMBOL_TYPE[i] = IDENTIFIER;
 }
 
 // fill categories
-punctuation.forEach(function(key) {
-    SYMBOL_CATEGORY[Number(key)] = PUNCTUATION;
-    IS_PUNCTUATION[Number(key)] = PUNCTUATION;
-}, SYMBOL_CATEGORY);
-
-IS_PUNCTUATION[TokenType.HyphenMinus] = 0;
-// whitespace is punctuator
-IS_PUNCTUATION[SPACE] = PUNCTUATION;
-IS_PUNCTUATION[TAB] = PUNCTUATION;
-IS_PUNCTUATION[N] = PUNCTUATION;
-IS_PUNCTUATION[R] = PUNCTUATION;
-IS_PUNCTUATION[F] = PUNCTUATION;
+[
+    TYPE.ExclamationMark,    // '!'
+    TYPE.QuotationMark,      // '"'
+    TYPE.NumberSign,         // '#'
+    TYPE.DollarSign,         // '$'
+    TYPE.PercentSign,        // '%'
+    TYPE.Ampersand,          // '&'
+    TYPE.Apostrophe,         // '\''
+    TYPE.LeftParenthesis,    // '('
+    TYPE.RightParenthesis,   // ')'
+    TYPE.Asterisk,           // '*'
+    TYPE.PlusSign,           // '+'
+    TYPE.Comma,              // ','
+    TYPE.HyphenMinus,        // '-'
+    TYPE.FullStop,           // '.'
+    TYPE.Solidus,            // '/'
+    TYPE.Colon,              // ':'
+    TYPE.Semicolon,          // ';'
+    TYPE.LessThanSign,       // '<'
+    TYPE.EqualsSign,         // '='
+    TYPE.GreaterThanSign,    // '>'
+    TYPE.QuestionMark,       // '?'
+    TYPE.CommercialAt,       // '@'
+    TYPE.LeftSquareBracket,  // '['
+    TYPE.RightSquareBracket, // ']'
+    TYPE.CircumflexAccent,   // '^'
+    TYPE.LeftCurlyBracket,   // '{'
+    TYPE.VerticalLine,       // '|'
+    TYPE.RightCurlyBracket,  // '}'
+    TYPE.Tilde               // '~'
+].forEach(function(key) {
+    SYMBOL_TYPE[Number(key)] = PUNCTUATOR;
+    PUNCTUATION[Number(key)] = PUNCTUATOR;
+}, SYMBOL_TYPE);
 
 for (var i = 48; i <= 57; i++) {
-    SYMBOL_CATEGORY[i] = NUMBER;
+    SYMBOL_TYPE[i] = NUMBER;
 }
 
-SYMBOL_CATEGORY[SPACE] = WHITESPACE;
-SYMBOL_CATEGORY[TAB] = WHITESPACE;
-SYMBOL_CATEGORY[N] = WHITESPACE;
-SYMBOL_CATEGORY[R] = WHITESPACE;
-SYMBOL_CATEGORY[F] = WHITESPACE;
+SYMBOL_TYPE[SPACE] = WHITESPACE;
+SYMBOL_TYPE[TAB] = WHITESPACE;
+SYMBOL_TYPE[N] = WHITESPACE;
+SYMBOL_TYPE[R] = WHITESPACE;
+SYMBOL_TYPE[F] = WHITESPACE;
+
+SYMBOL_TYPE[TYPE.Apostrophe] = STRING;
+SYMBOL_TYPE[TYPE.QuotationMark] = STRING;
 
-SYMBOL_CATEGORY[TokenType.Apostrophe] = STRING;
-SYMBOL_CATEGORY[TokenType.QuotationMark] = STRING;
+// whitespace is punctuation ...
+PUNCTUATION[SPACE] = PUNCTUATOR;
+PUNCTUATION[TAB] = PUNCTUATOR;
+PUNCTUATION[N] = PUNCTUATOR;
+PUNCTUATION[R] = PUNCTUATOR;
+PUNCTUATION[F] = PUNCTUATOR;
+// ... hyper minus is not
+PUNCTUATION[TYPE.HyphenMinus] = 0;
 
 module.exports = {
-    TokenType: TokenType,
-    TokenName: TokenName,
+    TYPE: TYPE,
+    NAME: NAME,
 
-    SYMBOL_CATEGORY: SYMBOL_CATEGORY,
-    IS_PUNCTUATION: IS_PUNCTUATION
+    SYMBOL_TYPE: SYMBOL_TYPE,
+    PUNCTUATION: PUNCTUATION
 };
diff --git a/lib/parser/index.js b/lib/parser/index.js
index 55e8fcfd..90dede54 100644
--- a/lib/parser/index.js
+++ b/lib/parser/index.js
@@ -1,49 +1,49 @@
 'use strict';
 
-var TokenType = require('./const').TokenType;
-var Scanner = require('./scanner');
 var List = require('../utils/list');
-var cmpChar = require('./utils').cmpChar;
-var cmpStr = require('./utils').cmpStr;
-var endsWith = require('./utils').endsWith;
-var isHex = require('./utils').isHex;
+var Scanner = require('./scanner');
+
+var scanner = new Scanner();
+var cmpChar = Scanner.cmpChar;
+var cmpStr = Scanner.cmpStr;
+var endsWith = Scanner.endsWith;
+var isHex = Scanner.isHex;
 var needPositions;
 var filename;
-var scanner;
 
 var DESCENDANT_COMBINATOR = {};
 var SPACE_NODE = { type: 'Space' };
 
-var WHITESPACE = TokenType.Whitespace;
-var IDENTIFIER = TokenType.Identifier;
-var NUMBER = TokenType.Number;
-var STRING = TokenType.String;
-var COMMENT = TokenType.Comment;
-var EXCLAMATIONMARK = TokenType.ExclamationMark;
-var NUMBERSIGN = TokenType.NumberSign;
-var DOLLARSIGN = TokenType.DollarSign;
-var PERCENTSIGN = TokenType.PercentSign;
-var LEFTPARENTHESIS = TokenType.LeftParenthesis;
-var RIGHTPARENTHESIS = TokenType.RightParenthesis;
-var ASTERISK = TokenType.Asterisk;
-var PLUSSIGN = TokenType.PlusSign;
-var COMMA = TokenType.Comma;
-var HYPHENMINUS = TokenType.HyphenMinus;
-var FULLSTOP = TokenType.FullStop;
-var SOLIDUS = TokenType.Solidus;
-var COLON = TokenType.Colon;
-var SEMICOLON = TokenType.Semicolon;
-var EQUALSSIGN = TokenType.EqualsSign;
-var GREATERTHANSIGN = TokenType.GreaterThanSign;
-var QUESTIONMARK = TokenType.QuestionMark;
-var COMMERCIALAT = TokenType.CommercialAt;
-var LEFTSQUAREBRACKET = TokenType.LeftSquareBracket;
-var RIGHTSQUAREBRACKET = TokenType.RightSquareBracket;
-var CIRCUMFLEXACCENT = TokenType.CircumflexAccent;
-var LEFTCURLYBRACKET = TokenType.LeftCurlyBracket;
-var VERTICALLINE = TokenType.VerticalLine;
-var RIGHTCURLYBRACKET = TokenType.RightCurlyBracket;
-var TILDE = TokenType.Tilde;
+var WHITESPACE = Scanner.TYPE.Whitespace;
+var IDENTIFIER = Scanner.TYPE.Identifier;
+var NUMBER = Scanner.TYPE.Number;
+var STRING = Scanner.TYPE.String;
+var COMMENT = Scanner.TYPE.Comment;
+var EXCLAMATIONMARK = Scanner.TYPE.ExclamationMark;
+var NUMBERSIGN = Scanner.TYPE.NumberSign;
+var DOLLARSIGN = Scanner.TYPE.DollarSign;
+var PERCENTSIGN = Scanner.TYPE.PercentSign;
+var LEFTPARENTHESIS = Scanner.TYPE.LeftParenthesis;
+var RIGHTPARENTHESIS = Scanner.TYPE.RightParenthesis;
+var ASTERISK = Scanner.TYPE.Asterisk;
+var PLUSSIGN = Scanner.TYPE.PlusSign;
+var COMMA = Scanner.TYPE.Comma;
+var HYPHENMINUS = Scanner.TYPE.HyphenMinus;
+var FULLSTOP = Scanner.TYPE.FullStop;
+var SOLIDUS = Scanner.TYPE.Solidus;
+var COLON = Scanner.TYPE.Colon;
+var SEMICOLON = Scanner.TYPE.Semicolon;
+var EQUALSSIGN = Scanner.TYPE.EqualsSign;
+var GREATERTHANSIGN = Scanner.TYPE.GreaterThanSign;
+var QUESTIONMARK = Scanner.TYPE.QuestionMark;
+var COMMERCIALAT = Scanner.TYPE.CommercialAt;
+var LEFTSQUAREBRACKET = Scanner.TYPE.LeftSquareBracket;
+var RIGHTSQUAREBRACKET = Scanner.TYPE.RightSquareBracket;
+var CIRCUMFLEXACCENT = Scanner.TYPE.CircumflexAccent;
+var LEFTCURLYBRACKET = Scanner.TYPE.LeftCurlyBracket;
+var VERTICALLINE = Scanner.TYPE.VerticalLine;
+var RIGHTCURLYBRACKET = Scanner.TYPE.RightCurlyBracket;
+var TILDE = Scanner.TYPE.Tilde;
 var N = 110; // 'n'.charCodeAt(0)
 
 var SCOPE_ATRULE_EXPRESSION = {
@@ -59,7 +59,7 @@ var SCOPE_VALUE = {
     var: getVarFunction
 };
 
-var initialContext = {
+var CONTEXT = {
     stylesheet: getStylesheet,
     atrule: getAtrule,
     atruleExpression: getAtruleExpression,
@@ -1729,20 +1729,18 @@ function parse(source, options) {
     needPositions = Boolean(options.positions);
     filename = options.filename || '<unknown>';
 
-    if (!initialContext.hasOwnProperty(context)) {
+    if (!CONTEXT.hasOwnProperty(context)) {
         throw new Error('Unknown context `' + context + '`');
     }
 
-    scanner = new Scanner(source, options.line, options.column);
+    scanner.setSource(source, options.line, options.column);
 
     if (context === 'value') {
         ast = getValue(false, options.property ? String(options.property) : null);
     } else {
-        ast = initialContext[context]();
+        ast = CONTEXT[context]();
     }
 
-    scanner = null;
-
     // console.log(JSON.stringify(ast, null, 4));
     return ast;
 };
diff --git a/lib/parser/scanner.js b/lib/parser/scanner.js
index 2cd5f259..c193982f 100644
--- a/lib/parser/scanner.js
+++ b/lib/parser/scanner.js
@@ -1,34 +1,40 @@
 'use strict';
 
 var CssSyntaxError = require('./error');
-var TokenType = require('./const').TokenType;
-var TokenName = require('./const').TokenName;
-var IS_PUNCTUATION = require('./const').IS_PUNCTUATION;
-var SYMBOL_CATEGORY = require('./const').SYMBOL_CATEGORY;
-var SYMBOL_CATEGORY_LENGTH = SYMBOL_CATEGORY.length;
-var cmpStr = require('./utils').cmpStr;
-var isHex = require('./utils').isHex;
+
+var constants = require('./const');
+var TYPE = constants.TYPE;
+var NAME = constants.NAME;
+var SYMBOL_TYPE = constants.SYMBOL_TYPE;
+var SYMBOL_TYPE_LENGTH = SYMBOL_TYPE.length;
+
+var utils = require('./utils');
+var firstCharOffset = utils.firstCharOffset;
+var cmpStr = utils.cmpStr;
+var isNumber = utils.isNumber;
+var findLastNonSpaceLocation = utils.findLastNonSpaceLocation;
+var findWhitespaceEnd = utils.findWhitespaceEnd;
+var findCommentEnd = utils.findCommentEnd;
+var findStringEnd = utils.findStringEnd;
+var findNumberEnd = utils.findNumberEnd;
+var findIdentifierEnd = utils.findIdentifierEnd;
 
 var NULL = 0;
-var WHITESPACE = TokenType.Whitespace;
-var IDENTIFIER = TokenType.Identifier;
-var NUMBER = TokenType.Number;
-var STRING = TokenType.String;
-var COMMENT = TokenType.Comment;
-var PUNCTUATION = TokenType.Punctuation;
-
-var TAB = 9;
+var WHITESPACE = TYPE.Whitespace;
+var IDENTIFIER = TYPE.Identifier;
+var NUMBER = TYPE.Number;
+var STRING = TYPE.String;
+var COMMENT = TYPE.Comment;
+var PUNCTUATOR = TYPE.Punctuator;
+
 var N = 10;
 var F = 12;
 var R = 13;
-var SPACE = 32;
 var STAR = 42;
 var SLASH = 47;
-var BACK_SLASH = 92;
-var FULLSTOP = TokenType.FullStop;
-var PLUSSIGN = TokenType.PlusSign;
-var HYPHENMINUS = TokenType.HyphenMinus;
-var E = 101; // 'e'.charCodeAt(0)
+var FULLSTOP = TYPE.FullStop;
+var PLUSSIGN = TYPE.PlusSign;
+var HYPHENMINUS = TYPE.HyphenMinus;
 
 var MIN_BUFFER_SIZE = 16 * 1024;
 var OFFSET_MASK = 0x00FFFFFF;
@@ -36,20 +42,10 @@ var TYPE_OFFSET = 24;
 var SafeUint32Array = typeof Uint32Array !== 'undefined' ? Uint32Array : Array; // fallback on Array when TypedArray is not supported
 var lastIndexOf = Array.prototype.lastIndexOf; // some browser implementations have no TypedArray#lastIndexOf
 
-var offsetAndType = new SafeUint32Array(MIN_BUFFER_SIZE);
-var lines = null;
-
-function firstCharOffset(source) {
-    return source.charCodeAt(0) === 0xFEFF ? 1 : 0;
-}
-
-function isNumber(code) {
-    return code >= 48 && code <= 57;
-}
-
 function computeLines(scanner, source) {
     var sourceLength = source.length;
     var start = firstCharOffset(source);
+    var lines = scanner.lines;
     var line = scanner.initLine;
 
     if (lines === null || lines.length < sourceLength + 1) {
@@ -72,174 +68,31 @@ function computeLines(scanner, source) {
 
     lines[i] = line;
 
-    return lines;
-}
-
-function findLastNonSpaceLocation(scanner) {
-    for (var i = scanner.source.length - 1; i >= 0; i--) {
-        var code = scanner.source.charCodeAt(i);
-
-        if (code !== SPACE && code !== TAB && code !== R && code !== N && code !== F) {
-            break;
-        }
-    }
-
-    return scanner.getLocation(i + 1);
-};
-
-function isNewline(source, offset, code) {
-    if (code === N || code === F || code === R) {
-        if (code === R && offset + 1 < source.length && source.charCodeAt(offset + 1) === N) {
-            return 2;
-        }
-
-        return 1;
-    }
-
-    return 0;
-}
-
-function findWhitespaceEnd(source, offset) {
-    for (; offset < source.length; offset++) {
-        var code = source.charCodeAt(offset);
-
-        if (code !== SPACE && code !== TAB && code !== R && code !== N && code !== F) {
-            break;
-        }
-    }
-
-    return offset;
-}
-
-function findCommentEnd(source, offset) {
-    var commentEnd = source.indexOf('*/', offset);
-
-    if (commentEnd === -1) {
-        return source.length;
-    }
-
-    return commentEnd + 2;
-}
-
-function findStringEnd(source, offset, quote) {
-    for (; offset < source.length; offset++) {
-        var code = source.charCodeAt(offset);
-
-        // TODO: bad string
-        if (code === BACK_SLASH) {
-            offset++;
-        } else if (code === quote) {
-            offset++;
-            break;
-        }
-    }
-
-    return offset;
-}
-
-function findDecimalNumberEnd(source, offset) {
-    for (; offset < source.length; offset++) {
-        var code = source.charCodeAt(offset);
-
-        if (code < 48 || code > 57) {  // not a 0 .. 9
-            break;
-        }
-    }
-
-    return offset;
-}
-
-function findNumberEnd(source, offset, allowFraction) {
-    var code;
-
-    offset = findDecimalNumberEnd(source, offset);
-
-    // fraction: .\d+
-    if (allowFraction && offset + 1 < source.length && source.charCodeAt(offset) === FULLSTOP) {
-        code = source.charCodeAt(offset + 1);
-
-        if (isNumber(code)) {
-            offset = findDecimalNumberEnd(source, offset + 1);
-        }
-    }
-
-    // exponent: e[+-]\d+
-    if (offset + 1 < source.length) {
-        if ((source.charCodeAt(offset) | 32) === E) { // case insensitive check for `e`
-            code = source.charCodeAt(offset + 1);
-
-            if (code === PLUSSIGN || code === HYPHENMINUS) {
-                if (offset + 2 < source.length) {
-                    code = source.charCodeAt(offset + 2);
-                }
-            }
-
-            if (isNumber(code)) {
-                offset = findDecimalNumberEnd(source, offset + 2);
-            }
-        }
-    }
-
-    return offset;
-}
-
-// skip escaped unicode sequence that can ends with space
-// [0-9a-f]{1,6}(\r\n|[ \n\r\t\f])?
-function findEscaseEnd(source, offset) {
-    for (var i = 0; i < 7 && offset + i < source.length; i++) {
-        var code = source.charCodeAt(offset + i);
-
-        if (i !== 6 && isHex(code)) {
-            continue;
-        }
-
-        if (i > 0) {
-            offset += i - 1 + isNewline(source, offset + i, code);
-            if (code === SPACE || code === TAB) {
-                offset++;
-            }
-        }
-
-        break;
-    }
-
-    return offset;
-}
-
-function findIdentifierEnd(source, offset) {
-    for (; offset < source.length; offset++) {
-        var code = source.charCodeAt(offset);
-
-        if (code === BACK_SLASH) {
-            offset = findEscaseEnd(source, offset + 1);
-        } else if (code < SYMBOL_CATEGORY_LENGTH && IS_PUNCTUATION[code] === PUNCTUATION) {
-            break;
-        }
-    }
-
-    return offset;
+    scanner.lineComputed = true;
+    scanner.lines = lines;
 }
 
 function tokenLayout(scanner, source, startPos) {
     var sourceLength = source.length;
+    var offsetAndType = scanner.offsetAndType;
     var tokenCount = 0;
     var prevType = 0;
     var offset = startPos;
 
-    if (offsetAndType.length < sourceLength + 1) {
+    if (offsetAndType === null || offsetAndType.length < sourceLength + 1) {
         offsetAndType = new SafeUint32Array(sourceLength + 1024);
     }
 
     while (offset < sourceLength) {
         var code = source.charCodeAt(offset);
-        var type = code < SYMBOL_CATEGORY_LENGTH ? SYMBOL_CATEGORY[code] : IDENTIFIER;
+        var type = code < SYMBOL_TYPE_LENGTH ? SYMBOL_TYPE[code] : IDENTIFIER;
 
         switch (type) {
             case WHITESPACE:
                 offset = findWhitespaceEnd(source, offset + 1);
                 break;
 
-            case PUNCTUATION:
+            case PUNCTUATOR:
                 if (code === STAR && prevType === SLASH) { // /*
                     type = COMMENT;
                     offset = findCommentEnd(source, offset + 1);
@@ -293,26 +146,33 @@ function tokenLayout(scanner, source, startPos) {
 //
 
 var Scanner = function(source, initLine, initColumn) {
-    var start = firstCharOffset(source);
-
-    this.source = source;
-    this.initLine = typeof initLine === 'undefined' ? 1 : initLine;
-    this.initColumn = (typeof initColumn === 'undefined' ? 1 : initColumn) - start;
-    this.lastLocationLine = this.initLine;
-    this.lastLocationLineOffset = 1 - this.initColumn;
+    this.offsetAndType = null;
     this.lines = null;
 
-    this.eof = false;
-    this.currentToken = -1;
-    this.tokenType = 0;
-    this.tokenStart = start;
-    this.tokenEnd = start;
-
-    tokenLayout(this, source, start);
-    this.next();
+    this.setSource(source || '', initLine, initColumn);
 };
 
 Scanner.prototype = {
+    setSource: function(source, initLine, initColumn) {
+        var start = firstCharOffset(source);
+
+        this.source = source;
+        this.initLine = typeof initLine === 'undefined' ? 1 : initLine;
+        this.initColumn = (typeof initColumn === 'undefined' ? 1 : initColumn) - start;
+        this.lastLocationLine = this.initLine;
+        this.lastLocationLineOffset = 1 - this.initColumn;
+        this.lineComputed = false;
+
+        this.eof = false;
+        this.currentToken = -1;
+        this.tokenType = 0;
+        this.tokenStart = start;
+        this.tokenEnd = start;
+
+        tokenLayout(this, source, start);
+        this.next();
+    },
+
     lookupType: function(offset) {
         offset += this.currentToken;
 
@@ -377,7 +237,7 @@ Scanner.prototype = {
 
     eat: function(tokenType) {
         if (this.tokenType !== tokenType) {
-            this.error(TokenName[tokenType] + ' is expected');
+            this.error(NAME[tokenType] + ' is expected');
         }
 
         this.next();
@@ -391,8 +251,8 @@ Scanner.prototype = {
     },
 
     getLocation: function(offset, source) {
-        if (this.lines === null) {
-            this.lines = computeLines(this, this.source);
+        if (!this.lineComputed) {
+            computeLines(this, this.source);
         }
 
         var line = this.lines[offset];
@@ -441,11 +301,21 @@ Scanner.prototype = {
 
     getTypes: function() {
         return Array.prototype.slice.call(this.offsetAndType, 0, this.tokenCount).map(function(item) {
-            return TokenName[item >> TYPE_OFFSET];
+            return NAME[item >> TYPE_OFFSET];
         });
     }
 };
 
+// extend scanner with constants
+Object.keys(constants).forEach(function(key) {
+    Scanner[key] = constants[key];
+});
+
+// extend scanner with static methods from utils
+Object.keys(utils).forEach(function(key) {
+    Scanner[key] = utils[key];
+});
+
 // warm up tokenizer to elimitate code branches that never execute
 // fix soft deoptimizations (insufficient type feedback)
 new Scanner('\n\r\r\n\f//""\'\'/*\r\n\f*/1a;.\\31\t\+2{url(a);+1.2e3 -.4e-5 .6e+7}');
diff --git a/lib/parser/utils.js b/lib/parser/utils.js
index dde2c7a5..9e8bf296 100644
--- a/lib/parser/utils.js
+++ b/lib/parser/utils.js
@@ -1,9 +1,46 @@
+var constants = require('./const');
+var PUNCTUATION = constants.PUNCTUATION;
+var SYMBOL_TYPE = constants.SYMBOL_TYPE;
+var SYMBOL_TYPE_LENGTH = SYMBOL_TYPE.length;
+var TYPE = constants.TYPE;
+var FULLSTOP = TYPE.FullStop;
+var PLUSSIGN = TYPE.PlusSign;
+var HYPHENMINUS = TYPE.HyphenMinus;
+var PUNCTUATOR = TYPE.Punctuator;
+var TAB = 9;
+var N = 10;
+var F = 12;
+var R = 13;
+var SPACE = 32;
+var BACK_SLASH = 92;
+var E = 101; // 'e'.charCodeAt(0)
+
+function firstCharOffset(source) {
+    return source.charCodeAt(0) === 0xFEFF ? 1 : 0;
+}
+
 function isHex(code) {
     return (code >= 48 && code <= 57) || // 0 .. 9
            (code >= 65 && code <= 70) || // A .. F
            (code >= 97 && code <= 102);  // a .. f
 }
 
+function isNumber(code) {
+    return code >= 48 && code <= 57;
+}
+
+function isNewline(source, offset, code) {
+    if (code === N || code === F || code === R) {
+        if (code === R && offset + 1 < source.length && source.charCodeAt(offset + 1) === N) {
+            return 2;
+        }
+
+        return 1;
+    }
+
+    return 0;
+}
+
 function cmpChar(testStr, offset, referenceCode) {
     var code = testStr.charCodeAt(offset);
 
@@ -45,9 +82,156 @@ function endsWith(testStr, referenceStr) {
     return cmpStr(testStr, testStr.length - referenceStr.length, testStr.length, referenceStr);
 }
 
+function findLastNonSpaceLocation(scanner) {
+    for (var i = scanner.source.length - 1; i >= 0; i--) {
+        var code = scanner.source.charCodeAt(i);
+
+        if (code !== SPACE && code !== TAB && code !== R && code !== N && code !== F) {
+            break;
+        }
+    }
+
+    return scanner.getLocation(i + 1);
+}
+
+function findWhitespaceEnd(source, offset) {
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        if (code !== SPACE && code !== TAB && code !== R && code !== N && code !== F) {
+            break;
+        }
+    }
+
+    return offset;
+}
+
+function findCommentEnd(source, offset) {
+    var commentEnd = source.indexOf('*/', offset);
+
+    if (commentEnd === -1) {
+        return source.length;
+    }
+
+    return commentEnd + 2;
+}
+
+function findStringEnd(source, offset, quote) {
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        // TODO: bad string
+        if (code === BACK_SLASH) {
+            offset++;
+        } else if (code === quote) {
+            offset++;
+            break;
+        }
+    }
+
+    return offset;
+}
+
+function findDecimalNumberEnd(source, offset) {
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        if (code < 48 || code > 57) {  // not a 0 .. 9
+            break;
+        }
+    }
+
+    return offset;
+}
+
+function findNumberEnd(source, offset, allowFraction) {
+    var code;
+
+    offset = findDecimalNumberEnd(source, offset);
+
+    // fraction: .\d+
+    if (allowFraction && offset + 1 < source.length && source.charCodeAt(offset) === FULLSTOP) {
+        code = source.charCodeAt(offset + 1);
+
+        if (isNumber(code)) {
+            offset = findDecimalNumberEnd(source, offset + 1);
+        }
+    }
+
+    // exponent: e[+-]\d+
+    if (offset + 1 < source.length) {
+        if ((source.charCodeAt(offset) | 32) === E) { // case insensitive check for `e`
+            code = source.charCodeAt(offset + 1);
+
+            if (code === PLUSSIGN || code === HYPHENMINUS) {
+                if (offset + 2 < source.length) {
+                    code = source.charCodeAt(offset + 2);
+                }
+            }
+
+            if (isNumber(code)) {
+                offset = findDecimalNumberEnd(source, offset + 2);
+            }
+        }
+    }
+
+    return offset;
+}
+
+// skip escaped unicode sequence that can ends with space
+// [0-9a-f]{1,6}(\r\n|[ \n\r\t\f])?
+function findEscaseEnd(source, offset) {
+    for (var i = 0; i < 7 && offset + i < source.length; i++) {
+        var code = source.charCodeAt(offset + i);
+
+        if (i !== 6 && isHex(code)) {
+            continue;
+        }
+
+        if (i > 0) {
+            offset += i - 1 + isNewline(source, offset + i, code);
+            if (code === SPACE || code === TAB) {
+                offset++;
+            }
+        }
+
+        break;
+    }
+
+    return offset;
+}
+
+function findIdentifierEnd(source, offset) {
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        if (code === BACK_SLASH) {
+            offset = findEscaseEnd(source, offset + 1);
+        } else if (code < SYMBOL_TYPE_LENGTH && PUNCTUATION[code] === PUNCTUATOR) {
+            break;
+        }
+    }
+
+    return offset;
+}
+
 module.exports = {
+    firstCharOffset: firstCharOffset,
+
     isHex: isHex,
+    isNumber: isNumber,
+    isNewline: isNewline,
+
     cmpChar: cmpChar,
     cmpStr: cmpStr,
-    endsWith: endsWith
+    endsWith: endsWith,
+
+    findLastNonSpaceLocation: findLastNonSpaceLocation,
+    findWhitespaceEnd: findWhitespaceEnd,
+    findCommentEnd: findCommentEnd,
+    findStringEnd: findStringEnd,
+    findDecimalNumberEnd: findDecimalNumberEnd,
+    findNumberEnd: findNumberEnd,
+    findEscaseEnd: findEscaseEnd,
+    findIdentifierEnd: findIdentifierEnd
 };
diff --git a/test/scanner.js b/test/scanner.js
index 3aa0c752..9e26f977 100644
--- a/test/scanner.js
+++ b/test/scanner.js
@@ -1,6 +1,6 @@
 var assert = require('assert');
 var Scanner = require('../lib/parser/scanner');
-var TokenName = require('../lib/parser/const').TokenName;
+var TokenName = require('../lib/parser/const').NAME;
 
 describe('parser/scanner', function() {
     var css = '.test\n{\n  prop: url(foo/bar.jpg);\n}';