Replace build system with a faster new one that uses Node and UglifyJS and generates...
[jquery.git] / build / lib / parse-js.js
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+/***********************************************************************
+
+  A JavaScript tokenizer / parser / beautifier / compressor.
+
+  This version is suitable for Node.js.  With minimal changes (the
+  exports stuff) it should work on any JS platform.
+
+  This file contains the tokenizer/parser.  It is a port to JavaScript
+  of parse-js [1], a JavaScript parser library written in Common Lisp
+  by Marijn Haverbeke.  Thank you Marijn!
+
+  [1] http://marijn.haverbeke.nl/parse-js/
+
+  Exported functions:
+
+    - tokenizer(code) -- returns a function.  Call the returned
+      function to fetch the next token.
+
+    - parse(code) -- returns an AST of the given JavaScript code.
+
+  -------------------------------- (C) ---------------------------------
+
+                           Author: Mihai Bazon
+                         <mihai.bazon@gmail.com>
+                       http://mihai.bazon.net/blog
+
+  Distributed under the BSD license:
+
+    Copyright 2010 (c) Mihai Bazon <mihai.bazon@gmail.com>
+    Based on parse-js (http://marijn.haverbeke.nl/parse-js/).
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+        * Redistributions of source code must retain the above
+          copyright notice, this list of conditions and the following
+          disclaimer.
+
+        * Redistributions in binary form must reproduce the above
+          copyright notice, this list of conditions and the following
+          disclaimer in the documentation and/or other materials
+          provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
+    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+    OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+    TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+    THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+ ***********************************************************************/
+
+/* -----[ Tokenizer (constants) ]----- */
+
+var KEYWORDS = array_to_hash([
+        "break",
+        "case",
+        "catch",
+        "const",
+        "continue",
+        "default",
+        "delete",
+        "do",
+        "else",
+        "finally",
+        "for",
+        "function",
+        "if",
+        "in",
+        "instanceof",
+        "new",
+        "return",
+        "switch",
+        "throw",
+        "try",
+        "typeof",
+        "var",
+        "void",
+        "while",
+        "with"
+]);
+
+var RESERVED_WORDS = array_to_hash([
+        "abstract",
+        "boolean",
+        "byte",
+        "char",
+        "class",
+        "debugger",
+        "double",
+        "enum",
+        "export",
+        "extends",
+        "final",
+        "float",
+        "goto",
+        "implements",
+        "import",
+        "int",
+        "interface",
+        "long",
+        "native",
+        "package",
+        "private",
+        "protected",
+        "public",
+        "short",
+        "static",
+        "super",
+        "synchronized",
+        "throws",
+        "transient",
+        "volatile"
+]);
+
+var KEYWORDS_BEFORE_EXPRESSION = array_to_hash([
+        "return",
+        "new",
+        "delete",
+        "throw",
+        "else",
+        "case"
+]);
+
+var KEYWORDS_ATOM = array_to_hash([
+        "false",
+        "null",
+        "true",
+        "undefined"
+]);
+
+var OPERATOR_CHARS = array_to_hash(characters("+-*&%=<>!?|~^"));
+
+var RE_HEX_NUMBER = /^0x[0-9a-f]+$/i;
+var RE_OCT_NUMBER = /^0[0-7]+$/;
+var RE_DEC_NUMBER = /^\d*\.?\d*(?:e[+-]?\d*(?:\d\.?|\.?\d)\d*)?$/i;
+
+var OPERATORS = array_to_hash([
+        "in",
+        "instanceof",
+        "typeof",
+        "new",
+        "void",
+        "delete",
+        "++",
+        "--",
+        "+",
+        "-",
+        "!",
+        "~",
+        "&",
+        "|",
+        "^",
+        "*",
+        "/",
+        "%",
+        ">>",
+        "<<",
+        ">>>",
+        "<",
+        ">",
+        "<=",
+        ">=",
+        "==",
+        "===",
+        "!=",
+        "!==",
+        "?",
+        "=",
+        "+=",
+        "-=",
+        "/=",
+        "*=",
+        "%=",
+        ">>=",
+        "<<=",
+        ">>>=",
+        "~=",
+        "%=",
+        "|=",
+        "^=",
+        "&=",
+        "&&",
+        "||"
+]);
+
+var WHITESPACE_CHARS = array_to_hash(characters(" \n\r\t"));
+
+var PUNC_BEFORE_EXPRESSION = array_to_hash(characters("[{}(,.;:"));
+
+var PUNC_CHARS = array_to_hash(characters("[]{}(),;:"));
+
+var REGEXP_MODIFIERS = array_to_hash(characters("gmsiy"));
+
+/* -----[ Tokenizer ]----- */
+
+function is_alphanumeric_char(ch) {
+        ch = ch.charCodeAt(0);
+        return (ch >= 48 && ch <= 57) ||
+                (ch >= 65 && ch <= 90) ||
+                (ch >= 97 && ch <= 122);
+};
+
+function is_identifier_char(ch) {
+        return is_alphanumeric_char(ch) || ch == "$" || ch == "_";
+};
+
+function is_digit(ch) {
+        ch = ch.charCodeAt(0);
+        return ch >= 48 && ch <= 57;
+};
+
+function parse_js_number(num) {
+        if (RE_HEX_NUMBER.test(num)) {
+                return parseInt(num.substr(2), 16);
+        } else if (RE_OCT_NUMBER.test(num)) {
+                return parseInt(num.substr(1), 8);
+        } else if (RE_DEC_NUMBER.test(num)) {
+                return parseFloat(num);
+        }
+};
+
+function JS_Parse_Error(message, line, col, pos) {
+        this.message = message;
+        this.line = line;
+        this.col = col;
+        this.pos = pos;
+        try {
+                ({})();
+        } catch(ex) {
+                this.stack = ex.stack;
+        };
+};
+
+JS_Parse_Error.prototype.toString = function() {
+        return this.message + " (line: " + this.line + ", col: " + this.col + ", pos: " + this.pos + ")" + "\n\n" + this.stack;
+};
+
+function js_error(message, line, col, pos) {
+        throw new JS_Parse_Error(message, line, col, pos);
+};
+
+function is_token(token, type, val) {
+        return token.type == type && (val == null || token.value == val);
+};
+
+var EX_EOF = {};
+
+function tokenizer($TEXT, skip_comments) {
+
+        var S = {
+                text           : $TEXT.replace(/\r\n?|[\n\u2028\u2029]/g, "\n").replace(/^\uFEFF/, ''),
+                pos            : 0,
+                tokpos         : 0,
+                line           : 0,
+                tokline        : 0,
+                col            : 0,
+                tokcol         : 0,
+                newline_before : false,
+                regex_allowed  : false
+        };
+
+        function peek() { return S.text.charAt(S.pos); };
+
+        function next(signal_eof) {
+                var ch = S.text.charAt(S.pos++);
+                if (signal_eof && !ch)
+                        throw EX_EOF;
+                if (ch == "\n") {
+                        S.newline_before = true;
+                        ++S.line;
+                        S.col = 0;
+                } else {
+                        ++S.col;
+                }
+                return ch;
+        };
+
+        function eof() {
+                return !S.peek();
+        };
+
+        function find(what, signal_eof) {
+                var pos = S.text.indexOf(what, S.pos);
+                if (signal_eof && pos == -1) throw EX_EOF;
+                return pos;
+        };
+
+        function start_token() {
+                S.tokline = S.line;
+                S.tokcol = S.col;
+                S.tokpos = S.pos;
+        };
+
+        function token(type, value) {
+                S.regex_allowed = ((type == "operator" && !HOP(UNARY_POSTFIX, value)) ||
+                                   (type == "keyword" && HOP(KEYWORDS_BEFORE_EXPRESSION, value)) ||
+                                   (type == "punc" && HOP(PUNC_BEFORE_EXPRESSION, value)));
+                var ret = {
+                        type  : type,
+                        value : value,
+                        line  : S.tokline,
+                        col   : S.tokcol,
+                        pos   : S.tokpos,
+                        nlb   : S.newline_before
+                };
+                S.newline_before = false;
+                return ret;
+        };
+
+        function skip_whitespace() {
+                while (HOP(WHITESPACE_CHARS, peek()))
+                        next();
+        };
+
+        function read_while(pred) {
+                var ret = "", ch = peek(), i = 0;
+                while (ch && pred(ch, i++)) {
+                        ret += next();
+                        ch = peek();
+                }
+                return ret;
+        };
+
+        function parse_error(err) {
+                js_error(err, S.tokline, S.tokcol, S.tokpos);
+        };
+
+        function read_num(prefix) {
+                var has_e = false, after_e = false, has_x = false, has_dot = prefix == ".";
+                var num = read_while(function(ch, i){
+                        if (ch == "x" || ch == "X") {
+                                if (has_x) return false;
+                                return has_x = true;
+                        }
+                        if (!has_x && (ch == "E" || ch == "e")) {
+                                if (has_e) return false;
+                                return has_e = after_e = true;
+                        }
+                        if (ch == "-") {
+                                if (after_e || (i == 0 && !prefix)) return true;
+                                return false;
+                        }
+                        if (ch == "+") return after_e;
+                        after_e = false;
+                        if (ch == ".") {
+                                if (!has_dot)
+                                        return has_dot = true;
+                                return false;
+                        }
+                        return is_alphanumeric_char(ch);
+                });
+                if (prefix)
+                        num = prefix + num;
+                var valid = parse_js_number(num);
+                if (!isNaN(valid)) {
+                        return token("num", valid);
+                } else {
+                        parse_error("Invalid syntax: " + num);
+                }
+        };
+
+        function read_escaped_char() {
+                var ch = next(true);
+                switch (ch) {
+                    case "n" : return "\n";
+                    case "r" : return "\r";
+                    case "t" : return "\t";
+                    case "b" : return "\b";
+                    case "v" : return "\v";
+                    case "f" : return "\f";
+                    case "0" : return "\0";
+                    case "x" : return String.fromCharCode(hex_bytes(2));
+                    case "u" : return String.fromCharCode(hex_bytes(4));
+                    default  : return ch;
+                }
+        };
+
+        function hex_bytes(n) {
+                var num = 0;
+                for (; n > 0; --n) {
+                        var digit = parseInt(next(true), 16);
+                        if (isNaN(digit))
+                                parse_error("Invalid hex-character pattern in string");
+                        num = (num << 4) | digit;
+                }
+                return num;
+        };
+
+        function read_string() {
+                return with_eof_error("Unterminated string constant", function(){
+                        var quote = next(), ret = "";
+                        for (;;) {
+                                var ch = next(true);
+                                if (ch == "\\") ch = read_escaped_char();
+                                else if (ch == quote) break;
+                                ret += ch;
+                        }
+                        return token("string", ret);
+                });
+        };
+
+        function read_line_comment() {
+                next();
+                var i = find("\n"), ret;
+                if (i == -1) {
+                        ret = S.text.substr(S.pos);
+                        S.pos = S.text.length;
+                } else {
+                        ret = S.text.substring(S.pos, i);
+                        S.pos = i;
+                }
+                return token("comment1", ret);
+        };
+
+        function read_multiline_comment() {
+                next();
+                return with_eof_error("Unterminated multiline comment", function(){
+                        var i = find("*/", true),
+                            text = S.text.substring(S.pos, i),
+                            tok = token("comment2", text);
+                        S.pos = i + 2;
+                        S.line += text.split("\n").length - 1;
+                        S.newline_before = text.indexOf("\n") >= 0;
+                        return tok;
+                });
+        };
+
+        function read_regexp() {
+                return with_eof_error("Unterminated regular expression", function(){
+                        var prev_backslash = false, regexp = "", ch, in_class = false;
+                        while ((ch = next(true))) if (prev_backslash) {
+                                regexp += "\\" + ch;
+                                prev_backslash = false;
+                        } else if (ch == "[") {
+                                in_class = true;
+                                regexp += ch;
+                        } else if (ch == "]" && in_class) {
+                                in_class = false;
+                                regexp += ch;
+                        } else if (ch == "/" && !in_class) {
+                                break;
+                        } else if (ch == "\\") {
+                                prev_backslash = true;
+                        } else {
+                                regexp += ch;
+                        }
+                        var mods = read_while(function(ch){
+                                return HOP(REGEXP_MODIFIERS, ch);
+                        });
+                        return token("regexp", [ regexp, mods ]);
+                });
+        };
+
+        function read_operator(prefix) {
+                function grow(op) {
+                        var bigger = op + peek();
+                        if (HOP(OPERATORS, bigger)) {
+                                next();
+                                return grow(bigger);
+                        } else {
+                                return op;
+                        }
+                };
+                return token("operator", grow(prefix || next()));
+        };
+
+        var handle_slash = skip_comments ? function() {
+                next();
+                var regex_allowed = S.regex_allowed;
+                switch (peek()) {
+                    case "/": read_line_comment(); S.regex_allowed = regex_allowed; return next_token();
+                    case "*": read_multiline_comment(); S.regex_allowed = regex_allowed; return next_token();
+                }
+                return S.regex_allowed ? read_regexp() : read_operator("/");
+        } : function() {
+                next();
+                switch (peek()) {
+                    case "/": return read_line_comment();
+                    case "*": return read_multiline_comment();
+                }
+                return S.regex_allowed ? read_regexp() : read_operator("/");
+        };
+
+        function handle_dot() {
+                next();
+                return is_digit(peek())
+                        ? read_num(".")
+                        : token("punc", ".");
+        };
+
+        function read_word() {
+                var word = read_while(is_identifier_char);
+                return !HOP(KEYWORDS, word)
+                        ? token("name", word)
+                        : HOP(OPERATORS, word)
+                        ? token("operator", word)
+                        : HOP(KEYWORDS_ATOM, word)
+                        ? token("atom", word)
+                        : token("keyword", word);
+        };
+
+        function with_eof_error(eof_error, cont) {
+                try {
+                        return cont();
+                } catch(ex) {
+                        if (ex === EX_EOF) parse_error(eof_error);
+                        else throw ex;
+                }
+        };
+
+        function next_token(force_regexp) {
+                if (force_regexp)
+                        return read_regexp();
+                skip_whitespace();
+                start_token();
+                var ch = peek();
+                if (!ch) return token("eof");
+                if (is_digit(ch)) return read_num();
+                if (ch == '"' || ch == "'") return read_string();
+                if (HOP(PUNC_CHARS, ch)) return token("punc", next());
+                if (ch == ".") return handle_dot();
+                if (ch == "/") return handle_slash();
+                if (HOP(OPERATOR_CHARS, ch)) return read_operator();
+                if (is_identifier_char(ch)) return read_word();
+                parse_error("Unexpected character '" + ch + "'");
+        };
+
+        next_token.context = function(nc) {
+                if (nc) S = nc;
+                return S;
+        };
+
+        return next_token;
+
+};
+
+/* -----[ Parser (constants) ]----- */
+
+var UNARY_PREFIX = array_to_hash([
+        "typeof",
+        "void",
+        "delete",
+        "--",
+        "++",
+        "!",
+        "~",
+        "-",
+        "+"
+]);
+
+var UNARY_POSTFIX = array_to_hash([ "--", "++" ]);
+
+var ASSIGNMENT = (function(a, ret, i){
+        while (i < a.length) {
+                ret[a[i]] = a[i].substr(0, a[i].length - 1);
+                i++;
+        }
+        return ret;
+})(
+        ["+=", "-=", "/=", "*=", "%=", ">>=", "<<=", ">>>=", "~=", "%=", "|=", "^=", "&="],
+        { "=": true },
+        0
+);
+
+var PRECEDENCE = (function(a, ret){
+        for (var i = 0, n = 1; i < a.length; ++i, ++n) {
+                var b = a[i];
+                for (var j = 0; j < b.length; ++j) {
+                        ret[b[j]] = n;
+                }
+        }
+        return ret;
+})(
+        [
+                ["||"],
+                ["&&"],
+                ["|"],
+                ["^"],
+                ["&"],
+                ["==", "===", "!=", "!=="],
+                ["<", ">", "<=", ">=", "in", "instanceof"],
+                [">>", "<<", ">>>"],
+                ["+", "-"],
+                ["*", "/", "%"]
+        ],
+        {}
+);
+
+var STATEMENTS_WITH_LABELS = array_to_hash([ "for", "do", "while", "switch" ]);
+
+var ATOMIC_START_TOKEN = array_to_hash([ "atom", "num", "string", "regexp", "name" ]);
+
+/* -----[ Parser ]----- */
+
+function NodeWithToken(str, start, end) {
+        this.name = str;
+        this.start = start;
+        this.end = end;
+};
+
+NodeWithToken.prototype.toString = function() { return this.name; };
+
+function parse($TEXT, strict_mode, embed_tokens) {
+
+        var S = {
+                input: tokenizer($TEXT, true),
+                token: null,
+                prev: null,
+                peeked: null,
+                in_function: 0,
+                in_loop: 0,
+                labels: []
+        };
+
+        S.token = next();
+
+        function is(type, value) {
+                return is_token(S.token, type, value);
+        };
+
+        function peek() { return S.peeked || (S.peeked = S.input()); };
+
+        function next() {
+                S.prev = S.token;
+                if (S.peeked) {
+                        S.token = S.peeked;
+                        S.peeked = null;
+                } else {
+                        S.token = S.input();
+                }
+                return S.token;
+        };
+
+        function prev() {
+                return S.prev;
+        };
+
+        function croak(msg, line, col, pos) {
+                var ctx = S.input.context();
+                js_error(msg,
+                         line != null ? line : ctx.tokline,
+                         col != null ? col : ctx.tokcol,
+                         pos != null ? pos : ctx.tokpos);
+        };
+
+        function token_error(token, msg) {
+                croak(msg, token.line, token.col);
+        };
+
+        function unexpected(token) {
+                if (token == null)
+                        token = S.token;
+                token_error(token, "Unexpected token: " + token.type + " (" + token.value + ")");
+        };
+
+        function expect_token(type, val) {
+                if (is(type, val)) {
+                        return next();
+                }
+                token_error(S.token, "Unexpected token " + S.token.type + ", expected " + type);
+        };
+
+        function expect(punc) { return expect_token("punc", punc); };
+
+        function can_insert_semicolon() {
+                return !strict_mode && (
+                        S.token.nlb || is("eof") || is("punc", "}")
+                );
+        };
+
+        function semicolon() {
+                if (is("punc", ";")) next();
+                else if (!can_insert_semicolon()) unexpected();
+        };
+
+        function as() {
+                return slice(arguments);
+        };
+
+        function parenthesised() {
+                expect("(");
+                var ex = expression();
+                expect(")");
+                return ex;
+        };
+
+        function add_tokens(str, start, end) {
+                return new NodeWithToken(str, start, end);
+        };
+
+        var statement = embed_tokens ? function() {
+                var start = S.token;
+                var stmt = $statement();
+                stmt[0] = add_tokens(stmt[0], start, prev());
+                return stmt;
+        } : $statement;
+
+        function $statement() {
+                if (is("operator", "/")) {
+                        S.peeked = null;
+                        S.token = S.input(true); // force regexp
+                }
+                switch (S.token.type) {
+                    case "num":
+                    case "string":
+                    case "regexp":
+                    case "operator":
+                    case "atom":
+                        return simple_statement();
+
+                    case "name":
+                        return is_token(peek(), "punc", ":")
+                                ? labeled_statement(prog1(S.token.value, next, next))
+                                : simple_statement();
+
+                    case "punc":
+                        switch (S.token.value) {
+                            case "{":
+                                return as("block", block_());
+                            case "[":
+                            case "(":
+                                return simple_statement();
+                            case ";":
+                                next();
+                                return as("block");
+                            default:
+                                unexpected();
+                        }
+
+                    case "keyword":
+                        switch (prog1(S.token.value, next)) {
+                            case "break":
+                                return break_cont("break");
+
+                            case "continue":
+                                return break_cont("continue");
+
+                            case "debugger":
+                                semicolon();
+                                return as("debugger");
+
+                            case "do":
+                                return (function(body){
+                                        expect_token("keyword", "while");
+                                        return as("do", prog1(parenthesised, semicolon), body);
+                                })(in_loop(statement));
+
+                            case "for":
+                                return for_();
+
+                            case "function":
+                                return function_(true);
+
+                            case "if":
+                                return if_();
+
+                            case "return":
+                                if (S.in_function == 0)
+                                        croak("'return' outside of function");
+                                return as("return",
+                                          is("punc", ";")
+                                          ? (next(), null)
+                                          : can_insert_semicolon()
+                                          ? null
+                                          : prog1(expression, semicolon));
+
+                            case "switch":
+                                return as("switch", parenthesised(), switch_block_());
+
+                            case "throw":
+                                return as("throw", prog1(expression, semicolon));
+
+                            case "try":
+                                return try_();
+
+                            case "var":
+                                return prog1(var_, semicolon);
+
+                            case "const":
+                                return prog1(const_, semicolon);
+
+                            case "while":
+                                return as("while", parenthesised(), in_loop(statement));
+
+                            case "with":
+                                return as("with", parenthesised(), statement());
+
+                            default:
+                                unexpected();
+                        }
+                }
+        };
+
+        function labeled_statement(label) {
+                S.labels.push(label);
+                var start = S.token, stat = statement();
+                if (strict_mode && !HOP(STATEMENTS_WITH_LABELS, stat[0]))
+                        unexpected(start);
+                S.labels.pop();
+                return as("label", label, stat);
+        };
+
+        function simple_statement() {
+                return as("stat", prog1(expression, semicolon));
+        };
+
+        function break_cont(type) {
+                var name = is("name") ? S.token.value : null;
+                if (name != null) {
+                        next();
+                        if (!member(name, S.labels))
+                                croak("Label " + name + " without matching loop or statement");
+                }
+                else if (S.in_loop == 0)
+                        croak(type + " not inside a loop or switch");
+                semicolon();
+                return as(type, name);
+        };
+
+        function for_() {
+                expect("(");
+                var has_var = is("keyword", "var");
+                if (has_var)
+                        next();
+                if (is("name") && is_token(peek(), "operator", "in")) {
+                        // for (i in foo)
+                        var name = S.token.value;
+                        next(); next();
+                        var obj = expression();
+                        expect(")");
+                        return as("for-in", has_var, name, obj, in_loop(statement));
+                } else {
+                        // classic for
+                        var init = is("punc", ";") ? null : has_var ? var_() : expression();
+                        expect(";");
+                        var test = is("punc", ";") ? null : expression();
+                        expect(";");
+                        var step = is("punc", ")") ? null : expression();
+                        expect(")");
+                        return as("for", init, test, step, in_loop(statement));
+                }
+        };
+
+        function function_(in_statement) {
+                var name = is("name") ? prog1(S.token.value, next) : null;
+                if (in_statement && !name)
+                        unexpected();
+                expect("(");
+                return as(in_statement ? "defun" : "function",
+                          name,
+                          // arguments
+                          (function(first, a){
+                                  while (!is("punc", ")")) {
+                                          if (first) first = false; else expect(",");
+                                          if (!is("name")) unexpected();
+                                          a.push(S.token.value);
+                                          next();
+                                  }
+                                  next();
+                                  return a;
+                          })(true, []),
+                          // body
+                          (function(){
+                                  ++S.in_function;
+                                  var loop = S.in_loop;
+                                  S.in_loop = 0;
+                                  var a = block_();
+                                  --S.in_function;
+                                  S.in_loop = loop;
+                                  return a;
+                          })());
+        };
+
+        function if_() {
+                var cond = parenthesised(), body = statement(), belse;
+                if (is("keyword", "else")) {
+                        next();
+                        belse = statement();
+                }
+                return as("if", cond, body, belse);
+        };
+
+        function block_() {
+                expect("{");
+                var a = [];
+                while (!is("punc", "}")) {
+                        if (is("eof")) unexpected();
+                        a.push(statement());
+                }
+                next();
+                return a;
+        };
+
+        var switch_block_ = curry(in_loop, function(){
+                expect("{");
+                var a = [], cur = null;
+                while (!is("punc", "}")) {
+                        if (is("eof")) unexpected();
+                        if (is("keyword", "case")) {
+                                next();
+                                cur = [];
+                                a.push([ expression(), cur ]);
+                                expect(":");
+                        }
+                        else if (is("keyword", "default")) {
+                                next();
+                                expect(":");
+                                cur = [];
+                                a.push([ null, cur ]);
+                        }
+                        else {
+                                if (!cur) unexpected();
+                                cur.push(statement());
+                        }
+                }
+                next();
+                return a;
+        });
+
+        function try_() {
+                var body = block_(), bcatch, bfinally;
+                if (is("keyword", "catch")) {
+                        next();
+                        expect("(");
+                        if (!is("name"))
+                                croak("Name expected");
+                        var name = S.token.value;
+                        next();
+                        expect(")");
+                        bcatch = [ name, block_() ];
+                }
+                if (is("keyword", "finally")) {
+                        next();
+                        bfinally = block_();
+                }
+                if (!bcatch && !bfinally)
+                        croak("Missing catch/finally blocks");
+                return as("try", body, bcatch, bfinally);
+        };
+
+        function vardefs() {
+                var a = [];
+                for (;;) {
+                        if (!is("name"))
+                                unexpected();
+                        var name = S.token.value;
+                        next();
+                        if (is("operator", "=")) {
+                                next();
+                                a.push([ name, expression(false) ]);
+                        } else {
+                                a.push([ name ]);
+                        }
+                        if (!is("punc", ","))
+                                break;
+                        next();
+                }
+                return a;
+        };
+
+        function var_() {
+                return as("var", vardefs());
+        };
+
+        function const_() {
+                return as("const", vardefs());
+        };
+
+        function new_() {
+                var newexp = expr_atom(false), args;
+                if (is("punc", "(")) {
+                        next();
+                        args = expr_list(")");
+                } else {
+                        args = [];
+                }
+                return subscripts(as("new", newexp, args), true);
+        };
+
+        function expr_atom(allow_calls) {
+                if (is("operator", "new")) {
+                        next();
+                        return new_();
+                }
+                if (is("operator") && HOP(UNARY_PREFIX, S.token.value)) {
+                        return make_unary("unary-prefix",
+                                          prog1(S.token.value, next),
+                                          expr_atom(allow_calls));
+                }
+                if (is("punc")) {
+                        switch (S.token.value) {
+                            case "(":
+                                next();
+                                return subscripts(prog1(expression, curry(expect, ")")), allow_calls);
+                            case "[":
+                                next();
+                                return subscripts(array_(), allow_calls);
+                            case "{":
+                                next();
+                                return subscripts(object_(), allow_calls);
+                        }
+                        unexpected();
+                }
+                if (is("keyword", "function")) {
+                        next();
+                        return subscripts(function_(false), allow_calls);
+                }
+                if (HOP(ATOMIC_START_TOKEN, S.token.type)) {
+                        var atom = S.token.type == "regexp"
+                                ? as("regexp", S.token.value[0], S.token.value[1])
+                                : as(S.token.type, S.token.value);
+                        return subscripts(prog1(atom, next), allow_calls);
+                }
+                unexpected();
+        };
+
+        function expr_list(closing, allow_trailing_comma) {
+                var first = true, a = [];
+                while (!is("punc", closing)) {
+                        if (first) first = false; else expect(",");
+                        if (allow_trailing_comma && is("punc", closing))
+                                break;
+                        a.push(expression(false));
+                }
+                next();
+                return a;
+        };
+
+        function array_() {
+                return as("array", expr_list("]", !strict_mode));
+        };
+
+        function object_() {
+                var first = true, a = [];
+                while (!is("punc", "}")) {
+                        if (first) first = false; else expect(",");
+                        if (!strict_mode && is("punc", "}"))
+                                // allow trailing comma
+                                break;
+                        var type = S.token.type;
+                        var name = as_property_name();
+                        if (type == "name" && (name == "get" || name == "set") && !is("punc", ":")) {
+                                a.push([ as_name(), function_(false), name ]);
+                        } else {
+                                expect(":");
+                                a.push([ name, expression(false) ]);
+                        }
+                }
+                next();
+                return as("object", a);
+        };
+
+        function as_property_name() {
+                switch (S.token.type) {
+                    case "num":
+                    case "string":
+                        return prog1(S.token.value, next);
+                }
+                return as_name();
+        };
+
+        function as_name() {
+                switch (S.token.type) {
+                    case "name":
+                    case "operator":
+                    case "keyword":
+                    case "atom":
+                        return prog1(S.token.value, next);
+                    default:
+                        unexpected();
+                }
+        };
+
+        function subscripts(expr, allow_calls) {
+                if (is("punc", ".")) {
+                        next();
+                        return subscripts(as("dot", expr, as_name()), allow_calls);
+                }
+                if (is("punc", "[")) {
+                        next();
+                        return subscripts(as("sub", expr, prog1(expression, curry(expect, "]"))), allow_calls);
+                }
+                if (allow_calls && is("punc", "(")) {
+                        next();
+                        return subscripts(as("call", expr, expr_list(")")), true);
+                }
+                if (allow_calls && is("operator") && HOP(UNARY_POSTFIX, S.token.value)) {
+                        return prog1(curry(make_unary, "unary-postfix", S.token.value, expr),
+                                     next);
+                }
+                return expr;
+        };
+
+        function make_unary(tag, op, expr) {
+                if ((op == "++" || op == "--") && !is_assignable(expr))
+                        croak("Invalid use of " + op + " operator");
+                return as(tag, op, expr);
+        };
+
+        function expr_op(left, min_prec) {
+                var op = is("operator") ? S.token.value : null;
+                var prec = op != null ? PRECEDENCE[op] : null;
+                if (prec != null && prec > min_prec) {
+                        next();
+                        var right = expr_op(expr_atom(true), prec);
+                        return expr_op(as("binary", op, left, right), min_prec);
+                }
+                return left;
+        };
+
+        function expr_ops() {
+                return expr_op(expr_atom(true), 0);
+        };
+
+        function maybe_conditional() {
+                var expr = expr_ops();
+                if (is("operator", "?")) {
+                        next();
+                        var yes = expression(false);
+                        expect(":");
+                        return as("conditional", expr, yes, expression(false));
+                }
+                return expr;
+        };
+
+        function is_assignable(expr) {
+                switch (expr[0]) {
+                    case "dot":
+                    case "sub":
+                        return true;
+                    case "name":
+                        return expr[1] != "this";
+                }
+        };
+
+        function maybe_assign() {
+                var left = maybe_conditional(), val = S.token.value;
+                if (is("operator") && HOP(ASSIGNMENT, val)) {
+                        if (is_assignable(left)) {
+                                next();
+                                return as("assign", ASSIGNMENT[val], left, maybe_assign());
+                        }
+                        croak("Invalid assignment");
+                }
+                return left;
+        };
+
+        function expression(commas) {
+                if (arguments.length == 0)
+                        commas = true;
+                var expr = maybe_assign();
+                if (commas && is("punc", ",")) {
+                        next();
+                        return as("seq", expr, expression());
+                }
+                return expr;
+        };
+
+        function in_loop(cont) {
+                try {
+                        ++S.in_loop;
+                        return cont();
+                } finally {
+                        --S.in_loop;
+                }
+        };
+
+        return as("toplevel", (function(a){
+                while (!is("eof"))
+                        a.push(statement());
+                return a;
+        })([]));
+
+};
+
+/* -----[ Utilities ]----- */
+
+function curry(f) {
+        var args = slice(arguments, 1);
+        return function() { return f.apply(this, args.concat(slice(arguments))); };
+};
+
+function prog1(ret) {
+        if (ret instanceof Function)
+                ret = ret();
+        for (var i = 1, n = arguments.length; --n > 0; ++i)
+                arguments[i]();
+        return ret;
+};
+
+function array_to_hash(a) {
+        var ret = {};
+        for (var i = 0; i < a.length; ++i)
+                ret[a[i]] = true;
+        return ret;
+};
+
+function slice(a, start) {
+        return Array.prototype.slice.call(a, start == null ? 0 : start);
+};
+
+function characters(str) {
+        return str.split("");
+};
+
+function member(name, array) {
+        for (var i = array.length; --i >= 0;)
+                if (array[i] === name)
+                        return true;
+        return false;
+};
+
+function HOP(obj, prop) {
+        return Object.prototype.hasOwnProperty.call(obj, prop);
+};
+
+/* -----[ Exports ]----- */
+
+exports.tokenizer = tokenizer;
+exports.parse = parse;
+exports.slice = slice;
+exports.curry = curry;
+exports.member = member;
+exports.array_to_hash = array_to_hash;
+exports.PRECEDENCE = PRECEDENCE;
+exports.KEYWORDS_ATOM = KEYWORDS_ATOM;
+exports.RESERVED_WORDS = RESERVED_WORDS;
+exports.KEYWORDS = KEYWORDS;
+exports.ATOMIC_START_TOKEN = ATOMIC_START_TOKEN;
+exports.OPERATORS = OPERATORS;
+exports.is_alphanumeric_char = is_alphanumeric_char;