parse-css.js

(function (root, factory) {
    // Universal Module Definition (UMD) to support AMD, CommonJS/Node.js,
    // Rhino, and plain browser loading.
    if (typeof define === 'function' && define.amd) {
        define(['exports'], factory);
    } else if (typeof exports !== 'undefined') {
        factory(exports);
    } else {
        factory(root);
    }
}(this, function (exports) {

var between = function (num, first, last) { return num >= first && num <= last; }
function digit(code) { return between(code, 0x30,0x39); }
function hexdigit(code) { return digit(code) || between(code, 0x41,0x46) || between(code, 0x61,0x66); }
function uppercaseletter(code) { return between(code, 0x41,0x5a); }
function lowercaseletter(code) { return between(code, 0x61,0x7a); }
function letter(code) { return uppercaseletter(code) || lowercaseletter(code); }
function nonascii(code) { return code >= 0x80; }
function namestartchar(code) { return letter(code) || nonascii(code) || code == 0x5f; }
function namechar(code) { return namestartchar(code) || digit(code) || code == 0x2d; }
function nonprintable(code) { return between(code, 0,8) || code == 0xb || between(code, 0xe,0x1f) || code == 0x7f; }
function newline(code) { return code == 0xa || code == 0xc; }
function whitespace(code) { return newline(code) || code == 9 || code == 0x20; }
function badescape(code) { return newline(code) || isNaN(code); }

var maximumallowedcodepoint = 0x10ffff;

var InvalidCharacterError = function(message) {
	this.message = message;
};
InvalidCharacterError.prototype = new Error;
InvalidCharacterError.prototype.name = 'InvalidCharacterError';

function preprocess(str) {
	// Turn a string into an array of code points,
	// following the preprocessing cleanup rules.
	var codepoints = [];
	for(var i = 0; i < str.length; i++) {
		var code = str.charCodeAt(i);
		if(code == 0xd && str.charCodeAt(i+1) == 0xa) {
			code = 0xa; i++;
		}
		if(code == 0xd || code == 0xc) code = 0xa;
		if(code == 0x0) code = 0xfffd;
		if(between(code, 0xd800, 0xdbff) && between(str.charCodeAt(i+1), 0xdc00, 0xdfff)) {
			// Decode a surrogate pair into an astral codepoint.
			var lead = code - 0xd800;
			var trail = str.charCodeAt(i+1) - 0xdc00;
			code = Math.pow(2, 21) + lead * Math.pow(2, 10) + trail;
		}
		codepoints.push(code);
	}
	return codepoints;
}

function stringFromCode(code) {
	if(code <= 0xffff) return String.fromCharCode(code);
	// Otherwise, encode astral char as surrogate pair.
	code -= Math.pow(2, 21);
	var lead = Math.floor(code/Math.pow(2, 10)) + 0xd800;
	var trail = code % Math.pow(2, 10); + 0xdc00;
	return String.fromCharCode(lead) + String.fromCharCode(trail);
}

function tokenize(str) {
	str = preprocess(str);
	var i = -1;
	var tokens = [];
	var code;

	// Line number information.
	var line = 0;
	var column = 0;
	// The only use of lastLineLength is in reconsume().
	var lastLineLength = 0;
	var incrLineno = function() {
		line += 1;
		lastLineLength = column;
		column = 0;
	};
	var locStart = {line:line, column:column};

	var codepoint = function(i) {
		if(i >= str.length) {
			return -1;
		}
		return str[i];
	}
	var next = function(num) {
		if(num === undefined)
			num = 1;
		if(num > 3)
			throw "Spec Error: no more than three codepoints of lookahead.";
		return codepoint(i+num);
	};
	var consume = function(num) {
		if(num === undefined)
			num = 1;
		i += num;
		code = codepoint(i);
		if(newline(code)) incrLineno();
		else column += num;
		//console.log('Consume '+i+' '+String.fromCharCode(code) + ' 0x' + code.toString(16));
		return true;
	};
	var reconsume = function() {
		i -= 1;
		if (newline(code)) {
			line -= 1;
			column = lastLineLength;
		} else {
			column -= 1;
		}
		locStart.line = line;
		locStart.column = column;
		return true;
	};
	var eof = function(codepoint) {
		if(codepoint === undefined) codepoint = code;
		return codepoint == -1;
	};
	var donothing = function() {};
	var parseerror = function() { console.log("Parse error at index " + i + ", processing codepoint 0x" + code.toString(16) + ".");return true; };

	var consumeAToken = function() {
		consumeComments();
		consume();
		if(whitespace(code)) {
			while(whitespace(next())) consume();
			return new WhitespaceToken;
		}
		else if(code == 0x22) return consumeAStringToken();
		else if(code == 0x23) {
			if(namechar(next()) || areAValidEscape(next(1), next(2))) {
				var token = new HashToken();
				if(wouldStartAnIdentifier(next(1), next(2), next(3))) token.type = "id";
				token.value = consumeAName();
				return token;
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x24) {
			if(next() == 0x3d) {
				consume();
				return new SuffixMatchToken();
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x27) return consumeAStringToken();
		else if(code == 0x28) return new OpenParenToken();
		else if(code == 0x29) return new CloseParenToken();
		else if(code == 0x2a) {
			if(next() == 0x3d) {
				consume();
				return new SubstringMatchToken();
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x2b) {
			if(startsWithANumber()) {
				reconsume();
				return consumeANumericToken();
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x2c) return new CommaToken();
		else if(code == 0x2d) {
			if(startsWithANumber()) {
				reconsume();
				return consumeANumericToken();
			} else if(next(1) == 0x2d && next(2) == 0x3e) {
				consume(2);
				return new CDCToken();
			} else if(startsWithAnIdentifier()) {
				reconsume();
				return consumeAnIdentlikeToken();
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x2e) {
			if(startsWithANumber()) {
				reconsume();
				return consumeANumericToken();
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x3a) return new ColonToken;
		else if(code == 0x3b) return new SemicolonToken;
		else if(code == 0x3c) {
			if(next(1) == 0x21 && next(2) == 0x2d && next(3) == 0x2d) {
				consume(3);
				return new CDOToken();
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x40) {
			if(wouldStartAnIdentifier(next(1), next(2), next(3))) {
				return new AtKeywordToken(consumeAName());
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x5b) return new OpenSquareToken();
		else if(code == 0x5c) {
			if(startsWithAValidEscape()) {
				reconsume();
				return consumeAnIdentlikeToken();
			} else {
				parseerror();
				return new DelimToken(code);
			}
		}
		else if(code == 0x5d) return new CloseSquareToken();
		else if(code == 0x5e) {
			if(next() == 0x3d) {
				consume();
				return new PrefixMatchToken();
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x7b) return new OpenCurlyToken();
		else if(code == 0x7c) {
			if(next() == 0x3d) {
				consume();
				return new DashMatchToken();
			} else if(next() == 0x7c) {
				consume();
				return new ColumnToken();
			} else {
				return new DelimToken(code);
			}
		}
		else if(code == 0x7d) return new CloseCurlyToken();
		else if(code == 0x7e) {
			if(next() == 0x3d) {
				consume();
				return new IncludeMatchToken();
			} else {
				return new DelimToken(code);
			}
		}
		else if(digit(code)) {
			reconsume();
			return consumeANumericToken();
		}
		else if(namestartchar(code)) {
			reconsume();
			return consumeAnIdentlikeToken();
		}
		else if(eof()) return new EOFToken();
		else return new DelimToken(code);
	};

	var consumeComments = function() {
		while(next(1) == 0x2f && next(2) == 0x2a) {
			consume(2);
			while(true) {
				consume();
				if(code == 0x2a && next() == 0x2f) {
					consume();
					break;
				} else if(eof()) {
					parseerror();
					return;
				}
			}
		}
	};

	var consumeANumericToken = function() {
		var num = consumeANumber();
		if(wouldStartAnIdentifier(next(1), next(2), next(3))) {
			var token = new DimensionToken();
			console.log(num);
			token.value = num.value;
			token.repr = num.repr;
			token.type = num.type;
			token.unit = consumeAName();
			return token;
		} else if(next() == 0x25) {
			consume();
			var token = new PercentageToken();
			token.value = num.value;
			token.repr = num.repr;
			return token;
		} else {
			var token = new NumberToken();
			token.value = num.value;
			token.repr = num.repr;
			token.type = num.type;
			return token;
		}
	};

	var consumeAnIdentlikeToken = function() {
		var str = consumeAName();
		if(str.toLowerCase() == "url" && next() == 0x28) {
			consume();
			while(whitespace(next(1)) && whitespace(next(2))) consume();
			if(next() == 0x22 || next() == 0x27) {
				return new FunctionToken(str);
			} else if(whitespace(next()) && (next(2) == 0x22 || next(2) == 0x27)) {
				return new FunctionToken(str);
			} else {
				return consumeAURLToken();
			}
		} else if(next() == 0x28) {
			consume();
			return new FunctionToken(str);
		} else {
			return new IdentToken(str);
		}
	};

	var consumeAStringToken = function(endingCodePoint) {
		if(endingCodePoint === undefined) endingCodePoint = code;
		var string = "";
		while(consume()) {
			if(code == endingCodePoint || eof()) {
				return new StringToken(string);
			} else if(newline(code)) {
				parseerror();
				reconsume();
				return new BadStringToken();
			} else if(code == 0x5c) {
				if(eof(next())) {
					donothing();
				} else if(newline(next())) {
					consume();
				} else {
					string += stringFromCode(consumeEscape())
				}
			} else {
				string += stringFromCode(code);
			}
		}
	};

	var consumeAURLToken = function() {
		var token = new URLToken("");
		while(whitespace(next())) consume();
		if(eof(next())) return token;
		while(consume()) {
			if(code == 0x29 || eof()) {
				return token;
			} else if(whitespace(code)) {
				while(whitespace(next())) consume();
				if(next() == 0x29 || eof(next())) {
					consume();
					return token;
				} else {
					consumeTheRemnantsOfABadURL();
					return new BadURLToken();
				}
			} else if(code == 0x22 || code == 0x27 || code == 0x28 || nonprintable(code)) {
				parseerror();
				consumeTheRemnantsOfABadURL();
				return new BadURLToken();
			} else if(code == 0x5c) {
				if(startsWithAValidEscape()) {
					token.value += stringFromCode(consumeEscape());
				} else {
					parseerror();
					consumeTheRemnantsOfABadURL();
					return new BadURLToken();
				}
			} else {
				token.value += stringFromCode(code);
			}
		}
	};

	var consumeEscape = function() {
		// Assume the the current character is the \
		// and the next code point is not a newline.
		consume();
		if(hexdigit(code)) {
			// Consume 1-6 hex digits
			var digits = [code];
			for(var total = 0; total < 5; total++) {
				if(hexdigit(next())) {
					consume();
					digits.push(code);
				} else {
					break;
				}
			}
			if(whitespace(next())) consume();
			var value = parseInt(digits.map(function(x){return String.fromCharCode(x);}).join(''), 16);
			if( value > maximumallowedcodepoint ) value = 0xfffd;
			return value;
		} else if(eof()) {
			return 0xfffd;
		} else {
			return code;
		}
	};

	var areAValidEscape = function(c1, c2) {
		if(c1 != 0x5c) return false;
		if(newline(c2)) return false;
		return true;
	};
	var startsWithAValidEscape = function() {
		return areAValidEscape(code, next());
	};

	var wouldStartAnIdentifier = function(c1, c2, c3) {
		if(c1 == 0x2d) {
			return namestartchar(c2) || c2 == 0x2d || areAValidEscape(c2, c3);
		} else if(namestartchar(c1)) {
			return true;
		} else if(c1 == 0x5c) {
			return areAValidEscape(c1, c2);
		} else {
			return false;
		}
	};
	var startsWithAnIdentifier = function() {
		return wouldStartAnIdentifier(code, next(1), next(2));
	};

	var wouldStartANumber = function(c1, c2, c3) {
		if(c1 == 0x2b || c1 == 0x2d) {
			if(digit(c2)) return true;
			if(c2 == 0x2e && digit(c3)) return true;
			return false;
		} else if(c1 == 0x2e) {
			if(digit(c2)) return true;
			return false;
		} else if(digit(c1)) {
			return true;
		} else {
			return false;
		}
	};
	var startsWithANumber = function() {
		return wouldStartANumber(code, next(1), next(2));
	};

	var consumeAName = function() {
		var result = "";
		while(consume()) {
			if(namechar(code)) {
				result += stringFromCode(code);
			} else if(startsWithAValidEscape()) {
				result += stringFromCode(consumeEscape());
			} else {
				reconsume();
				return result;
			}
		}
	};

	var consumeANumber = function() {
		var repr = [];
		var type = "integer";
		if(next() == 0x2b || next() == 0x2d) {
			consume();
			repr += stringFromCode(code);
		}
		while(digit(next())) {
			consume();
			repr += stringFromCode(code);
		}
		if(next(1) == 0x2e && digit(next(2))) {
			consume();
			repr += stringFromCode(code);
			consume();
			repr += stringFromCode(code);
			type = "number";
			while(digit(next())) {
				consume();
				repr += stringFromCode(code);
			}
		}
		var c1 = next(1), c2 = next(2), c3 = next(3);
		if((c1 == 0x45 || c1 == 0x65) && digit(c2)) {
			consume();
			repr += stringFromCode(code);
			consume();
			repr += stringFromCode(code);
			type = "number";
			while(digit(next())) {
				consume();
				repr += stringFromCode(code);
			}
		} else if((c1 == 0x45 || c1 == 0x65) && (c2 == 0x2b || c2 == 0x2d) && digit(c3)) {
			consume();
			repr += stringFromCode(code);
			consume();
			repr += stringFromCode(code);
			consume();
			repr += stringFromCode(code);
			type = "number";
			while(digit(next())) {
				consume();
				repr += stringFromCode(code);
			}
		}
		var value = convertAStringToANumber(repr);
		return {type:type, value:value, repr:repr};
	};

	var convertAStringToANumber = function(string) {
		// CSS's number rules are identical to JS, afaik.
		return +string;
	};

	var consumeTheRemnantsOfABadURL = function() {
		while(consume()) {
			if(code == 0x2d || eof()) {
				return;
			} else if(startsWithAValidEscape()) {
				consumeEscape();
				donothing();
			} else {
				donothing();
			}
		}
	};



	var iterationCount = 0;
	while(!eof(next())) {
		tokens.push(consumeAToken());
		iterationCount++;
		if(iterationCount > str.length*2) return "I'm infinite-looping!";
	}
	return tokens;
}

function CSSParserToken() { throw "Abstract Base Class"; }
CSSParserToken.prototype.toJSON = function() {
	return {token: this.tokenType};
}
CSSParserToken.prototype.toString = function() { return this.tokenType; }
CSSParserToken.prototype.toSource = function() { return ''+this; }

function BadStringToken() { return this; }
BadStringToken.prototype = Object.create(CSSParserToken.prototype);
BadStringToken.prototype.tokenType = "BADSTRING";

function BadURLToken() { return this; }
BadURLToken.prototype = Object.create(CSSParserToken.prototype);
BadURLToken.prototype.tokenType = "BADURL";

function WhitespaceToken() { return this; }
WhitespaceToken.prototype = Object.create(CSSParserToken.prototype);
WhitespaceToken.prototype.tokenType = "WHITESPACE";
WhitespaceToken.prototype.toString = function() { return "WS"; }
WhitespaceToken.prototype.toSource = function() { return " "; }

function CDOToken() { return this; }
CDOToken.prototype = Object.create(CSSParserToken.prototype);
CDOToken.prototype.tokenType = "CDO";
CDOToken.prototype.toSource = function() { return "<!--"; }

function CDCToken() { return this; }
CDCToken.prototype = Object.create(CSSParserToken.prototype);
CDCToken.prototype.tokenType = "CDC";
CDCToken.prototype.toSource = function() { return "-->"; }

function ColonToken() { return this; }
ColonToken.prototype = Object.create(CSSParserToken.prototype);
ColonToken.prototype.tokenType = ":";

function SemicolonToken() { return this; }
SemicolonToken.prototype = Object.create(CSSParserToken.prototype);
SemicolonToken.prototype.tokenType = ";";

function CommaToken() { return this; }
CommaToken.prototype = Object.create(CSSParserToken.prototype);
CommaToken.prototype.tokenType = ",";

function GroupingToken() { throw "Abstract Base Class"; }
GroupingToken.prototype = Object.create(CSSParserToken.prototype);

function OpenCurlyToken() { this.value = "{"; this.mirror = "}"; return this; }
OpenCurlyToken.prototype = Object.create(GroupingToken.prototype);
OpenCurlyToken.prototype.tokenType = "{";

function CloseCurlyToken() { this.value = "}"; this.mirror = "{"; return this; }
CloseCurlyToken.prototype = Object.create(GroupingToken.prototype);
CloseCurlyToken.prototype.tokenType = "}";

function OpenSquareToken() { this.value = "["; this.mirror = "]"; return this; }
OpenSquareToken.prototype = Object.create(GroupingToken.prototype);
OpenSquareToken.prototype.tokenType = "[";

function CloseSquareToken() { this.value = "]"; this.mirror = "["; return this; }
CloseSquareToken.prototype = Object.create(GroupingToken.prototype);
CloseSquareToken.prototype.tokenType = "]";

function OpenParenToken() { this.value = "("; this.mirror = ")"; return this; }
OpenParenToken.prototype = Object.create(GroupingToken.prototype);
OpenParenToken.prototype.tokenType = "(";

function CloseParenToken() { this.value = ")"; this.mirror = "("; return this; }
CloseParenToken.prototype = Object.create(GroupingToken.prototype);
CloseParenToken.prototype.tokenType = ")";

function IncludeMatchToken() { return this; }
IncludeMatchToken.prototype = Object.create(CSSParserToken.prototype);
IncludeMatchToken.prototype.tokenType = "~=";

function DashMatchToken() { return this; }
DashMatchToken.prototype = Object.create(CSSParserToken.prototype);
DashMatchToken.prototype.tokenType = "|=";

function PrefixMatchToken() { return this; }
PrefixMatchToken.prototype = Object.create(CSSParserToken.prototype);
PrefixMatchToken.prototype.tokenType = "^=";

function SuffixMatchToken() { return this; }
SuffixMatchToken.prototype = Object.create(CSSParserToken.prototype);
SuffixMatchToken.prototype.tokenType = "$=";

function SubstringMatchToken() { return this; }
SubstringMatchToken.prototype = Object.create(CSSParserToken.prototype);
SubstringMatchToken.prototype.tokenType = "*=";

function ColumnToken() { return this; }
ColumnToken.prototype = Object.create(CSSParserToken.prototype);
ColumnToken.prototype.tokenType = "||";

function EOFToken() { return this; }
EOFToken.prototype = Object.create(CSSParserToken.prototype);
EOFToken.prototype.tokenType = "EOF";
EOFToken.prototype.toSource = function() { return ""; }

function DelimToken(code) {
	this.value = stringFromCode(code);
	return this;
}
DelimToken.prototype = Object.create(CSSParserToken.prototype);
DelimToken.prototype.tokenType = "DELIM";
DelimToken.prototype.toString = function() { return "DELIM("+this.value+")"; }
DelimToken.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.value = this.value;
	return json;
}
DelimToken.prototype.toSource = function() {
	if(this.value == "\\")
		return "\\\n";
	else
		return this.value;
}

function StringValuedToken() { throw "Abstract Base Class"; }
StringValuedToken.prototype = Object.create(CSSParserToken.prototype);
StringValuedToken.prototype.ASCIIMatch = function(str) {
	return this.value.toLowerCase() == str.toLowerCase();
}
StringValuedToken.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.value = this.value;
	return json;
}

function IdentToken(val) {
	this.value = val;
}
IdentToken.prototype = Object.create(StringValuedToken.prototype);
IdentToken.prototype.tokenType = "IDENT";
IdentToken.prototype.toString = function() { return "IDENT("+this.value+")"; }
IdentToken.prototype.toSource = function() {
	return escapeIdent(this.value);
}

function FunctionToken(val) {
	this.value = val;
	this.mirror = ")";
}
FunctionToken.prototype = Object.create(StringValuedToken.prototype);
FunctionToken.prototype.tokenType = "FUNCTION";
FunctionToken.prototype.toString = function() { return "FUNCTION("+this.value+")"; }
FunctionToken.prototype.toSource = function() {
	return escapeIdent(this.value) + "(";
}

function AtKeywordToken(val) {
	this.value = val;
}
AtKeywordToken.prototype = Object.create(StringValuedToken.prototype);
AtKeywordToken.prototype.tokenType = "AT-KEYWORD";
AtKeywordToken.prototype.toString = function() { return "AT("+this.value+")"; }
AtKeywordToken.prototype.toSource = function() {
	return "@" + escapeIdent(this.value);
}

function HashToken(val) {
	this.value = val;
	this.type = "unrestricted";
}
HashToken.prototype = Object.create(StringValuedToken.prototype);
HashToken.prototype.tokenType = "HASH";
HashToken.prototype.toString = function() { return "HASH("+this.value+")"; }
HashToken.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.value = this.value;
	json.type = this.type;
	return json;
}
HashToken.prototype.toSource = function() {
	if(this.type == "id") {
		return "#" + escapeIdent(this.value);
	} else {
		return "#" + escapeHash(this.value);
	}
}

function StringToken(val) {
	this.value = val;
}
StringToken.prototype = Object.create(StringValuedToken.prototype);
StringToken.prototype.tokenType = "STRING";
StringToken.prototype.toString = function() {
	return '"' + escapeString(this.value) + '"';
}

function URLToken(val) {
	this.value = val;
}
URLToken.prototype = Object.create(StringValuedToken.prototype);
URLToken.prototype.tokenType = "URL";
URLToken.prototype.toString = function() { return "URL("+this.value+")"; }
URLToken.prototype.toSource = function() {
	return 'url("' + escapeString(this.value) + '")';
}

function NumberToken() {
	this.value = null;
	this.type = "integer";
	this.repr = "";
}
NumberToken.prototype = Object.create(CSSParserToken.prototype);
NumberToken.prototype.tokenType = "NUMBER";
NumberToken.prototype.toString = function() {
	if(this.type == "integer")
		return "INT("+this.value+")";
	return "NUMBER("+this.value+")";
}
NumberToken.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.value = this.value;
	json.type = this.type;
	json.repr = this.repr;
	return json;
}
NumberToken.prototype.toSource = function() { return this.repr; };

function PercentageToken() {
	this.value = null;
	this.repr = "";
}
PercentageToken.prototype = Object.create(CSSParserToken.prototype);
PercentageToken.prototype.tokenType = "PERCENTAGE";
PercentageToken.prototype.toString = function() { return "PERCENTAGE("+this.value+")"; }
PercentageToken.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.value = this.value;
	json.repr = this.repr;
	return json;
}
PercentageToken.prototype.toSource = function() { return this.repr + "%"; }

function DimensionToken() {
	this.value = null;
	this.type = "integer";
	this.repr = "";
	this.unit = "";
}
DimensionToken.prototype = Object.create(CSSParserToken.prototype);
DimensionToken.prototype.tokenType = "DIMENSION";
DimensionToken.prototype.toString = function() { return "DIM("+this.value+","+this.unit+")"; }
DimensionToken.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.value = this.value;
	json.type = this.type;
	json.repr = this.repr;
	json.unit = this.unit;
	return json;
}
DimensionToken.prototype.toSource = function() {
	var source = this.repr;
	var unit = escapeIdent(this.unit);
	if(unit[0].toLowerCase() == "e" && (unit[1] == "-" || between(unit.charCodeAt(1), 0x30, 0x39))) {
		// Unit is ambiguous with scinot
		// Remove the leading "e", replace with escape.
		unit = "\\65 " + unit.slice(1, unit.length);
	}
	return source+unit;
}

function escapeIdent(string) {
	string = ''+string;
	var result = '';
	var firstcode = string.charCodeAt(0);
	for(var i = 0; i < string.length; i++) {
		var code = string.charCodeAt(i);
		if(code == 0x0) {
			throw new InvalidCharacterError('Invalid character: the input contains U+0000.');
		}

		if(
			between(code, 0x1, 0x1f) || code == 0x7f ||
			(i == 0 && between(code, 0x30, 0x39)) ||
			(i == 1 && between(code, 0x30, 0x39) && firstcode == 0x2d)
		) {
			result += '\\' + code.toString(16) + ' ';
		} else if(
			code >= 0x80 ||
			code == 0x2d ||
			code == 0x5f ||
			between(code, 0x30, 0x39) ||
			between(code, 0x41, 0x5a) ||
			between(code, 0x61, 0x7a)
		) {
			result += string[i];
		} else {
			result += '\\' + string[i];
		}
	}
	return result;
}

function escapeHash(string) {
	// Escapes the contents of "unrestricted"-type hash tokens.
	// Won't preserve the ID-ness of "id"-type hash tokens;
	// use escapeIdent() for that.
	string = ''+string;
	var result = '';
	var firstcode = string.charCodeAt(0);
	for(var i = 0; i < string.length; i++) {
		var code = string.charCodeAt(i);
		if(code == 0x0) {
			throw new InvalidCharacterError('Invalid character: the input contains U+0000.');
		}

		if(
			code >= 0x80 ||
			code == 0x2d ||
			code == 0x5f ||
			between(code, 0x30, 0x39) ||
			between(code, 0x41, 0x5a) ||
			between(code, 0x61, 0x7a)
		) {
			result += string[i];
		} else {
			result += '\\' + code.toString(16) + ' ';
		}
	}
	return result;
}

function escapeString(string) {
	string = ''+string;
	var result = '';
	for(var i = 0; i < string.length; i++) {
		var code = string.charCodeAt(i);

		if(code == 0x0) {
			throw new InvalidCharacterError('Invalid character: the input contains U+0000.');
		}

		if(between(code, 0x1, 0x1f) || code == 0x7f) {
			result += '\\' + code.toString(16) + ' ';
		} else if(code == 0x22 || code == 0x5c) {
			result += '\\' + string[i];
		} else {
			result += string[i];
		}
	}
	return result;
}

// Exportation.
exports.tokenize = tokenize;
exports.IdentToken = IdentToken;
exports.FunctionToken = FunctionToken;
exports.AtKeywordToken = AtKeywordToken;
exports.HashToken = HashToken;
exports.StringToken = StringToken;
exports.BadStringToken = BadStringToken;
exports.URLToken = URLToken;
exports.BadURLToken = BadURLToken;
exports.DelimToken = DelimToken;
exports.NumberToken = NumberToken;
exports.PercentageToken = PercentageToken;
exports.DimensionToken = DimensionToken;
exports.IncludeMatchToken = IncludeMatchToken;
exports.DashMatchToken = DashMatchToken;
exports.PrefixMatchToken = PrefixMatchToken;
exports.SuffixMatchToken = SuffixMatchToken;
exports.SubstringMatchToken = SubstringMatchToken;
exports.ColumnToken = ColumnToken;
exports.WhitespaceToken = WhitespaceToken;
exports.CDOToken = CDOToken;
exports.CDCToken = CDCToken;
exports.ColonToken = ColonToken;
exports.SemicolonToken = SemicolonToken;
exports.CommaToken = CommaToken;
exports.OpenParenToken = OpenParenToken;
exports.CloseParenToken = CloseParenToken;
exports.OpenSquareToken = OpenSquareToken;
exports.CloseSquareToken = CloseSquareToken;
exports.OpenCurlyToken = OpenCurlyToken;
exports.CloseCurlyToken = CloseCurlyToken;
exports.EOFToken = EOFToken;
exports.CSSParserToken = CSSParserToken;
exports.GroupingToken = GroupingToken;

function TokenStream(tokens) {
	// Assume that tokens is an array.
	this.tokens = tokens;
	this.i = -1;
}
TokenStream.prototype.tokenAt = function(i) {
	if(i < this.tokens.length)
		return this.tokens[i];
	return new EOFToken();
}
TokenStream.prototype.consume = function(num) {
	if(num === undefined) num = 1;
	this.i += num;
	this.token = this.tokenAt(this.i);
	//console.log(this.i, this.token);
	return true;
}
TokenStream.prototype.next = function() {
	return this.tokenAt(this.i+1);
}
TokenStream.prototype.reconsume = function() {
	this.i--;
}

function parseerror(s, msg) {
	console.log("Parse error at token " + s.i + ": " + s.token + ".\n" + msg);
	return true;
}
function donothing(){ return true; };

function consumeAListOfRules(s, topLevel) {
	var rules = [];
	var rule;
	while(s.consume()) {
		if(s.token instanceof WhitespaceToken) {
			continue;
		} else if(s.token instanceof EOFToken) {
			return rules;
		} else if(s.token instanceof CDOToken || s.token instanceof CDCToken) {
			if(topLevel == "top-level") continue;
			s.reconsume();
			if(rule = consumeAQualifiedRule(s)) rules.push(rule);
		} else if(s.token instanceof AtKeywordToken) {
			s.reconsume();
			if(rule = consumeAnAtRule(s)) rules.push(rule);
		} else {
			s.reconsume();
			if(rule = consumeAQualifiedRule(s)) rules.push(rule);
		}
	}
}

function consumeAnAtRule(s) {
	s.consume();
	var rule = new AtRule(s.token.value);
	while(s.consume()) {
		if(s.token instanceof SemicolonToken || s.token instanceof EOFToken) {
			return rule;
		} else if(s.token instanceof OpenCurlyToken) {
			rule.value = consumeASimpleBlock(s);
			return rule;
		} else if(s.token instanceof SimpleBlock && s.token.name == "{") {
			rule.value = s.token;
			return rule;
		} else {
			s.reconsume();
			rule.prelude.push(consumeAComponentValue(s));
		}
	}
}

function consumeAQualifiedRule(s) {
	var rule = new QualifiedRule();
	while(s.consume()) {
		if(s.token instanceof EOFToken) {
			parseerror(s, "Hit EOF when trying to parse the prelude of a qualified rule.");
			return;
		} else if(s.token instanceof OpenCurlyToken) {
			rule.value = consumeASimpleBlock(s);
			return rule;
		} else if(s.token instanceof SimpleBlock && s.token.name == "{") {
			rule.value = token;
			return rule;
		} else {
			s.reconsume();
			rule.prelude.push(consumeAComponentValue(s));
		}
	}
}

function consumeAListOfDeclarations(s) {
	var decls = [];
	while(s.consume()) {
		if(s.token instanceof WhitespaceToken || s.token instanceof SemicolonToken) {
			donothing();
		} else if(s.token instanceof EOFToken) {
			return decls;
		} else if(s.token instanceof AtKeywordToken) {
			s.reconsume();
			decls.push(consumeAnAtRule(s));
		} else if(s.token instanceof IdentToken) {
			var temp = [s.token];
			while(!(s.next() instanceof SemicolonToken || s.next() instanceof EOFToken))
				temp.push(consumeAComponentValue(s));
			var decl;
			if(decl = consumeADeclaration(new TokenStream(temp))) decls.push(decl);
		} else {
			parseerror(s);
			reconsume();
			while(!(s.next() instanceof SemicolonToken || s.next() instanceof EOFToken))
				consumeAComponentValue(s);
		}
	}
}

function consumeADeclaration(s) {
	// Assumes that the next input token will be an ident token.
	s.consume();
	var decl = new Declaration(s.token.value);
	while(s.next() instanceof WhitespaceToken) s.consume();
	if(!(s.next() instanceof ColonToken)) {
		parseerror(s);
		return;
	} else {
		s.consume();
	}
	while(!(s.next() instanceof EOFToken)) {
		decl.value.push(consumeAComponentValue(s));
	}
	var foundImportant = false;
	for(var i = decl.value.length - 1; i >= 0; i--) {
		if(decl.value[i] instanceof WhitespaceToken) {
			continue;
		} else if(decl.value[i] instanceof IdentToken && decl.value[i].ASCIIMatch("important")) {
			foundImportant = true;
		} else if(foundImportant && decl.value[i] instanceof DelimToken && decl.value[i].value == "!") {
			decl.value.splice(i, decl.value.length);
			decl.important = true;
			break;
		} else {
			break;
		}
	}
	return decl;
}

function consumeAComponentValue(s) {
	s.consume();
	if(s.token instanceof OpenCurlyToken || s.token instanceof OpenSquareToken || s.token instanceof OpenParenToken)
		return consumeASimpleBlock(s);
	if(s.token instanceof FunctionToken)
		return consumeAFunction(s);
	return s.token;
}

function consumeASimpleBlock(s) {
	var mirror = s.token.mirror;
	var block = new SimpleBlock(s.token.value);
	while(s.consume()) {
		if(s.token instanceof EOFToken || (s.token instanceof GroupingToken && s.token.value == mirror))
			return block;
		else {
			s.reconsume();
			block.value.push(consumeAComponentValue(s));
		}
	}
}

function consumeAFunction(s) {
	var func = new Func(s.token.value);
	while(s.consume()) {
		if(s.token instanceof EOFToken || s.token instanceof CloseParenToken)
			return func;
		else {
			s.reconsume();
			func.value.push(consumeAComponentValue(s));
		}
	}
}

function normalizeInput(input) {
	if(typeof input == "string")
		return new TokenStream(tokenize(input));
	if(input instanceof TokenStream)
		return input;
	if(input.length !== undefined)
		return new TokenStream(input);
	else throw SyntaxError(input);
}

function parseAStylesheet(s) {
	s = normalizeInput(s);
	var sheet = new Stylesheet();
	sheet.value = consumeAListOfRules(s, "top-level");
	return sheet;
}

function parseAListOfRules(s) {
	s = normalizeInput(s);
	return consumeAListOfRules(s);
}

function parseARule(s) {
	s = normalizeInput(s);
	while(s.next() instanceof WhitespaceToken) s.consume();
	if(s.next() instanceof EOFToken) throw SyntaxError();
	if(s.next() instanceof AtKeywordToken) {
		var rule = consumeAnAtRule(s);
	} else {
		var rule = consumeAQualifiedRule(s);
		if(!rule) throw SyntaxError();
	}
	while(s.next() instanceof WhitespaceToken) s.consume();
	if(s.next() instanceof EOFToken)
		return rule;
	throw SyntaxError();
}

function parseADeclaration(s) {
	s = normalizeInput(s);
	while(s.next() instanceof WhitespaceToken) s.consume();
	if(!(s.next() instanceof IdentToken)) throw SyntaxError();
	var decl = consumeADeclaration(s);
	if(decl)
		return decl
	else
		throw SyntaxError();
}

function parseAListOfDeclarations(s) {
	s = normalizeInput(s);
	return consumeAListOfDeclarations(s);
}

function parseAComponentValue(s) {
	s = normalizeInput(s);
	while(s.next() instanceof WhitespaceToken) s.consume();
	if(s.next() instanceof EOFToken) throw SyntaxError();
	var val = consumeAComponentValue(s);
	if(!val) throw SyntaxError();
	while(s.next() instanceof WhitespaceToken) s.consume();
	if(s.next() instanceof EOFToken)
		return val;
	throw SyntaxError();
}

function parseAListOfComponentValues(s) {
	s = normalizeInput(s);
	var vals = [];
	while(true) {
		var val = consumeAComponentValue(s);
		if(val instanceof EOFToken)
			return vals
		else
			vals.push(val);
	}
}

function parseACommaSeparatedListOfComponentValues(s) {
	s = normalizeInput(s);
	var listOfCVLs = [];
	while(true) {
		var vals = [];
		while(true) {
			var val = consumeAComponentValue(s);
			if(val instanceof EOFToken) {
				listOfCVLs.push(vals);
				return listOfCVLs;
			} else if(val instanceof CommaToken) {
				listOfCVLs.push(vals);
				break;
			} else {
				vals.push(val);
			}
		}
	}
}


function CSSParserRule() { throw "Abstract Base Class"; }
CSSParserRule.prototype.toString = function(indent) {
	return JSON.stringify(this,null,indent);
}
CSSParserRule.prototype.toJSON = function() {
	return {type:this.type, value:this.value};
}

function Stylesheet() {
	this.value = [];
	return this;
}
Stylesheet.prototype = Object.create(CSSParserRule.prototype);
Stylesheet.prototype.type = "STYLESHEET";

function AtRule(name) {
	this.name = name;
	this.prelude = [];
	this.value = null;
	return this;
}
AtRule.prototype = Object.create(CSSParserRule.prototype);
AtRule.prototype.type = "AT-RULE";
AtRule.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.name = this.name;
	json.prelude = this.prelude;
	return json;
}

function QualifiedRule() {
	this.prelude = [];
	this.value = [];
	return this;
}
QualifiedRule.prototype = Object.create(CSSParserRule.prototype);
QualifiedRule.prototype.type = "QUALIFIED-RULE";
QualifiedRule.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.prelude = this.prelude;
	return json;
}

function Declaration(name) {
	this.name = name;
	this.value = [];
	this.important = false;
	return this;
}
Declaration.prototype = Object.create(CSSParserRule.prototype);
Declaration.prototype.type = "DECLARATION";
Declaration.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.name = this.name;
	json.important = this.important;
	return json;
}

function SimpleBlock(type) {
	this.name = type;
	this.value = [];
	return this;
}
SimpleBlock.prototype = Object.create(CSSParserRule.prototype);
SimpleBlock.prototype.type = "BLOCK";
SimpleBlock.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.name = this.name;
	return json;
}

function Func(name) {
	this.name = name;
	this.value = [];
	return this;
}
Func.prototype = Object.create(CSSParserRule.prototype);
Func.prototype.type = "FUNCTION";
Func.prototype.toJSON = function() {
	var json = this.constructor.prototype.constructor.prototype.toJSON.call(this);
	json.name = this.name;
	return json;
}

// Exportation.
exports.CSSParserRule = CSSParserRule;
exports.Stylesheet = Stylesheet;
exports.AtRule = AtRule;
exports.QualifiedRule = QualifiedRule;
exports.Declaration = Declaration;
exports.SimpleBlock = SimpleBlock;
exports.Func = Func;
exports.parseAStylesheet = parseAStylesheet;
exports.parseAListOfRules = parseAListOfRules;
exports.parseARule = parseARule;
exports.parseADeclaration = parseADeclaration;
exports.parseAListOfDeclarations = parseAListOfDeclarations;
exports.parseAComponentValue = parseAComponentValue;
exports.parseAListOfComponentValues = parseAListOfComponentValues;
exports.parseACommaSeparatedListOfComponentValues = parseACommaSeparatedListOfComponentValues;

}));