(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
	typeof define === 'function' && define.amd ? define(factory) :
	(global = global || self, global.esquery = factory());
}(this, (function () { 'use strict';

	var commonjsGlobal = typeof globalThis !== 'undefined' ? globalThis : typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : {};

	function createCommonjsModule(fn, module) {
		return module = { exports: {} }, fn(module, module.exports), module.exports;
	}

	var estraverse = createCommonjsModule(function (module, exports) {
	/*
	  Copyright (C) 2012-2013 Yusuke Suzuki <utatane.tea@gmail.com>
	  Copyright (C) 2012 Ariya Hidayat <ariya.hidayat@gmail.com>

	  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 HOLDERS AND CONTRIBUTORS "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 <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.
	*/
	/*jslint vars:false, bitwise:true*/
	/*jshint indent:4*/
	/*global exports:true*/
	(function clone(exports) {

	    var Syntax,
	        VisitorOption,
	        VisitorKeys,
	        BREAK,
	        SKIP,
	        REMOVE;

	    function deepCopy(obj) {
	        var ret = {}, key, val;
	        for (key in obj) {
	            if (obj.hasOwnProperty(key)) {
	                val = obj[key];
	                if (typeof val === 'object' && val !== null) {
	                    ret[key] = deepCopy(val);
	                } else {
	                    ret[key] = val;
	                }
	            }
	        }
	        return ret;
	    }

	    // based on LLVM libc++ upper_bound / lower_bound
	    // MIT License

	    function upperBound(array, func) {
	        var diff, len, i, current;

	        len = array.length;
	        i = 0;

	        while (len) {
	            diff = len >>> 1;
	            current = i + diff;
	            if (func(array[current])) {
	                len = diff;
	            } else {
	                i = current + 1;
	                len -= diff + 1;
	            }
	        }
	        return i;
	    }

	    Syntax = {
	        AssignmentExpression: 'AssignmentExpression',
	        AssignmentPattern: 'AssignmentPattern',
	        ArrayExpression: 'ArrayExpression',
	        ArrayPattern: 'ArrayPattern',
	        ArrowFunctionExpression: 'ArrowFunctionExpression',
	        AwaitExpression: 'AwaitExpression', // CAUTION: It's deferred to ES7.
	        BlockStatement: 'BlockStatement',
	        BinaryExpression: 'BinaryExpression',
	        BreakStatement: 'BreakStatement',
	        CallExpression: 'CallExpression',
	        CatchClause: 'CatchClause',
	        ClassBody: 'ClassBody',
	        ClassDeclaration: 'ClassDeclaration',
	        ClassExpression: 'ClassExpression',
	        ComprehensionBlock: 'ComprehensionBlock',  // CAUTION: It's deferred to ES7.
	        ComprehensionExpression: 'ComprehensionExpression',  // CAUTION: It's deferred to ES7.
	        ConditionalExpression: 'ConditionalExpression',
	        ContinueStatement: 'ContinueStatement',
	        DebuggerStatement: 'DebuggerStatement',
	        DirectiveStatement: 'DirectiveStatement',
	        DoWhileStatement: 'DoWhileStatement',
	        EmptyStatement: 'EmptyStatement',
	        ExportAllDeclaration: 'ExportAllDeclaration',
	        ExportDefaultDeclaration: 'ExportDefaultDeclaration',
	        ExportNamedDeclaration: 'ExportNamedDeclaration',
	        ExportSpecifier: 'ExportSpecifier',
	        ExpressionStatement: 'ExpressionStatement',
	        ForStatement: 'ForStatement',
	        ForInStatement: 'ForInStatement',
	        ForOfStatement: 'ForOfStatement',
	        FunctionDeclaration: 'FunctionDeclaration',
	        FunctionExpression: 'FunctionExpression',
	        GeneratorExpression: 'GeneratorExpression',  // CAUTION: It's deferred to ES7.
	        Identifier: 'Identifier',
	        IfStatement: 'IfStatement',
	        ImportExpression: 'ImportExpression',
	        ImportDeclaration: 'ImportDeclaration',
	        ImportDefaultSpecifier: 'ImportDefaultSpecifier',
	        ImportNamespaceSpecifier: 'ImportNamespaceSpecifier',
	        ImportSpecifier: 'ImportSpecifier',
	        Literal: 'Literal',
	        LabeledStatement: 'LabeledStatement',
	        LogicalExpression: 'LogicalExpression',
	        MemberExpression: 'MemberExpression',
	        MetaProperty: 'MetaProperty',
	        MethodDefinition: 'MethodDefinition',
	        ModuleSpecifier: 'ModuleSpecifier',
	        NewExpression: 'NewExpression',
	        ObjectExpression: 'ObjectExpression',
	        ObjectPattern: 'ObjectPattern',
	        Program: 'Program',
	        Property: 'Property',
	        RestElement: 'RestElement',
	        ReturnStatement: 'ReturnStatement',
	        SequenceExpression: 'SequenceExpression',
	        SpreadElement: 'SpreadElement',
	        Super: 'Super',
	        SwitchStatement: 'SwitchStatement',
	        SwitchCase: 'SwitchCase',
	        TaggedTemplateExpression: 'TaggedTemplateExpression',
	        TemplateElement: 'TemplateElement',
	        TemplateLiteral: 'TemplateLiteral',
	        ThisExpression: 'ThisExpression',
	        ThrowStatement: 'ThrowStatement',
	        TryStatement: 'TryStatement',
	        UnaryExpression: 'UnaryExpression',
	        UpdateExpression: 'UpdateExpression',
	        VariableDeclaration: 'VariableDeclaration',
	        VariableDeclarator: 'VariableDeclarator',
	        WhileStatement: 'WhileStatement',
	        WithStatement: 'WithStatement',
	        YieldExpression: 'YieldExpression'
	    };

	    VisitorKeys = {
	        AssignmentExpression: ['left', 'right'],
	        AssignmentPattern: ['left', 'right'],
	        ArrayExpression: ['elements'],
	        ArrayPattern: ['elements'],
	        ArrowFunctionExpression: ['params', 'body'],
	        AwaitExpression: ['argument'], // CAUTION: It's deferred to ES7.
	        BlockStatement: ['body'],
	        BinaryExpression: ['left', 'right'],
	        BreakStatement: ['label'],
	        CallExpression: ['callee', 'arguments'],
	        CatchClause: ['param', 'body'],
	        ClassBody: ['body'],
	        ClassDeclaration: ['id', 'superClass', 'body'],
	        ClassExpression: ['id', 'superClass', 'body'],
	        ComprehensionBlock: ['left', 'right'],  // CAUTION: It's deferred to ES7.
	        ComprehensionExpression: ['blocks', 'filter', 'body'],  // CAUTION: It's deferred to ES7.
	        ConditionalExpression: ['test', 'consequent', 'alternate'],
	        ContinueStatement: ['label'],
	        DebuggerStatement: [],
	        DirectiveStatement: [],
	        DoWhileStatement: ['body', 'test'],
	        EmptyStatement: [],
	        ExportAllDeclaration: ['source'],
	        ExportDefaultDeclaration: ['declaration'],
	        ExportNamedDeclaration: ['declaration', 'specifiers', 'source'],
	        ExportSpecifier: ['exported', 'local'],
	        ExpressionStatement: ['expression'],
	        ForStatement: ['init', 'test', 'update', 'body'],
	        ForInStatement: ['left', 'right', 'body'],
	        ForOfStatement: ['left', 'right', 'body'],
	        FunctionDeclaration: ['id', 'params', 'body'],
	        FunctionExpression: ['id', 'params', 'body'],
	        GeneratorExpression: ['blocks', 'filter', 'body'],  // CAUTION: It's deferred to ES7.
	        Identifier: [],
	        IfStatement: ['test', 'consequent', 'alternate'],
	        ImportExpression: ['source'],
	        ImportDeclaration: ['specifiers', 'source'],
	        ImportDefaultSpecifier: ['local'],
	        ImportNamespaceSpecifier: ['local'],
	        ImportSpecifier: ['imported', 'local'],
	        Literal: [],
	        LabeledStatement: ['label', 'body'],
	        LogicalExpression: ['left', 'right'],
	        MemberExpression: ['object', 'property'],
	        MetaProperty: ['meta', 'property'],
	        MethodDefinition: ['key', 'value'],
	        ModuleSpecifier: [],
	        NewExpression: ['callee', 'arguments'],
	        ObjectExpression: ['properties'],
	        ObjectPattern: ['properties'],
	        Program: ['body'],
	        Property: ['key', 'value'],
	        RestElement: [ 'argument' ],
	        ReturnStatement: ['argument'],
	        SequenceExpression: ['expressions'],
	        SpreadElement: ['argument'],
	        Super: [],
	        SwitchStatement: ['discriminant', 'cases'],
	        SwitchCase: ['test', 'consequent'],
	        TaggedTemplateExpression: ['tag', 'quasi'],
	        TemplateElement: [],
	        TemplateLiteral: ['quasis', 'expressions'],
	        ThisExpression: [],
	        ThrowStatement: ['argument'],
	        TryStatement: ['block', 'handler', 'finalizer'],
	        UnaryExpression: ['argument'],
	        UpdateExpression: ['argument'],
	        VariableDeclaration: ['declarations'],
	        VariableDeclarator: ['id', 'init'],
	        WhileStatement: ['test', 'body'],
	        WithStatement: ['object', 'body'],
	        YieldExpression: ['argument']
	    };

	    // unique id
	    BREAK = {};
	    SKIP = {};
	    REMOVE = {};

	    VisitorOption = {
	        Break: BREAK,
	        Skip: SKIP,
	        Remove: REMOVE
	    };

	    function Reference(parent, key) {
	        this.parent = parent;
	        this.key = key;
	    }

	    Reference.prototype.replace = function replace(node) {
	        this.parent[this.key] = node;
	    };

	    Reference.prototype.remove = function remove() {
	        if (Array.isArray(this.parent)) {
	            this.parent.splice(this.key, 1);
	            return true;
	        } else {
	            this.replace(null);
	            return false;
	        }
	    };

	    function Element(node, path, wrap, ref) {
	        this.node = node;
	        this.path = path;
	        this.wrap = wrap;
	        this.ref = ref;
	    }

	    function Controller() { }

	    // API:
	    // return property path array from root to current node
	    Controller.prototype.path = function path() {
	        var i, iz, j, jz, result, element;

	        function addToPath(result, path) {
	            if (Array.isArray(path)) {
	                for (j = 0, jz = path.length; j < jz; ++j) {
	                    result.push(path[j]);
	                }
	            } else {
	                result.push(path);
	            }
	        }

	        // root node
	        if (!this.__current.path) {
	            return null;
	        }

	        // first node is sentinel, second node is root element
	        result = [];
	        for (i = 2, iz = this.__leavelist.length; i < iz; ++i) {
	            element = this.__leavelist[i];
	            addToPath(result, element.path);
	        }
	        addToPath(result, this.__current.path);
	        return result;
	    };

	    // API:
	    // return type of current node
	    Controller.prototype.type = function () {
	        var node = this.current();
	        return node.type || this.__current.wrap;
	    };

	    // API:
	    // return array of parent elements
	    Controller.prototype.parents = function parents() {
	        var i, iz, result;

	        // first node is sentinel
	        result = [];
	        for (i = 1, iz = this.__leavelist.length; i < iz; ++i) {
	            result.push(this.__leavelist[i].node);
	        }

	        return result;
	    };

	    // API:
	    // return current node
	    Controller.prototype.current = function current() {
	        return this.__current.node;
	    };

	    Controller.prototype.__execute = function __execute(callback, element) {
	        var previous, result;

	        result = undefined;

	        previous  = this.__current;
	        this.__current = element;
	        this.__state = null;
	        if (callback) {
	            result = callback.call(this, element.node, this.__leavelist[this.__leavelist.length - 1].node);
	        }
	        this.__current = previous;

	        return result;
	    };

	    // API:
	    // notify control skip / break
	    Controller.prototype.notify = function notify(flag) {
	        this.__state = flag;
	    };

	    // API:
	    // skip child nodes of current node
	    Controller.prototype.skip = function () {
	        this.notify(SKIP);
	    };

	    // API:
	    // break traversals
	    Controller.prototype['break'] = function () {
	        this.notify(BREAK);
	    };

	    // API:
	    // remove node
	    Controller.prototype.remove = function () {
	        this.notify(REMOVE);
	    };

	    Controller.prototype.__initialize = function(root, visitor) {
	        this.visitor = visitor;
	        this.root = root;
	        this.__worklist = [];
	        this.__leavelist = [];
	        this.__current = null;
	        this.__state = null;
	        this.__fallback = null;
	        if (visitor.fallback === 'iteration') {
	            this.__fallback = Object.keys;
	        } else if (typeof visitor.fallback === 'function') {
	            this.__fallback = visitor.fallback;
	        }

	        this.__keys = VisitorKeys;
	        if (visitor.keys) {
	            this.__keys = Object.assign(Object.create(this.__keys), visitor.keys);
	        }
	    };

	    function isNode(node) {
	        if (node == null) {
	            return false;
	        }
	        return typeof node === 'object' && typeof node.type === 'string';
	    }

	    function isProperty(nodeType, key) {
	        return (nodeType === Syntax.ObjectExpression || nodeType === Syntax.ObjectPattern) && 'properties' === key;
	    }

	    Controller.prototype.traverse = function traverse(root, visitor) {
	        var worklist,
	            leavelist,
	            element,
	            node,
	            nodeType,
	            ret,
	            key,
	            current,
	            current2,
	            candidates,
	            candidate,
	            sentinel;

	        this.__initialize(root, visitor);

	        sentinel = {};

	        // reference
	        worklist = this.__worklist;
	        leavelist = this.__leavelist;

	        // initialize
	        worklist.push(new Element(root, null, null, null));
	        leavelist.push(new Element(null, null, null, null));

	        while (worklist.length) {
	            element = worklist.pop();

	            if (element === sentinel) {
	                element = leavelist.pop();

	                ret = this.__execute(visitor.leave, element);

	                if (this.__state === BREAK || ret === BREAK) {
	                    return;
	                }
	                continue;
	            }

	            if (element.node) {

	                ret = this.__execute(visitor.enter, element);

	                if (this.__state === BREAK || ret === BREAK) {
	                    return;
	                }

	                worklist.push(sentinel);
	                leavelist.push(element);

	                if (this.__state === SKIP || ret === SKIP) {
	                    continue;
	                }

	                node = element.node;
	                nodeType = node.type || element.wrap;
	                candidates = this.__keys[nodeType];
	                if (!candidates) {
	                    if (this.__fallback) {
	                        candidates = this.__fallback(node);
	                    } else {
	                        throw new Error('Unknown node type ' + nodeType + '.');
	                    }
	                }

	                current = candidates.length;
	                while ((current -= 1) >= 0) {
	                    key = candidates[current];
	                    candidate = node[key];
	                    if (!candidate) {
	                        continue;
	                    }

	                    if (Array.isArray(candidate)) {
	                        current2 = candidate.length;
	                        while ((current2 -= 1) >= 0) {
	                            if (!candidate[current2]) {
	                                continue;
	                            }
	                            if (isProperty(nodeType, candidates[current])) {
	                                element = new Element(candidate[current2], [key, current2], 'Property', null);
	                            } else if (isNode(candidate[current2])) {
	                                element = new Element(candidate[current2], [key, current2], null, null);
	                            } else {
	                                continue;
	                            }
	                            worklist.push(element);
	                        }
	                    } else if (isNode(candidate)) {
	                        worklist.push(new Element(candidate, key, null, null));
	                    }
	                }
	            }
	        }
	    };

	    Controller.prototype.replace = function replace(root, visitor) {
	        var worklist,
	            leavelist,
	            node,
	            nodeType,
	            target,
	            element,
	            current,
	            current2,
	            candidates,
	            candidate,
	            sentinel,
	            outer,
	            key;

	        function removeElem(element) {
	            var i,
	                key,
	                nextElem,
	                parent;

	            if (element.ref.remove()) {
	                // When the reference is an element of an array.
	                key = element.ref.key;
	                parent = element.ref.parent;

	                // If removed from array, then decrease following items' keys.
	                i = worklist.length;
	                while (i--) {
	                    nextElem = worklist[i];
	                    if (nextElem.ref && nextElem.ref.parent === parent) {
	                        if  (nextElem.ref.key < key) {
	                            break;
	                        }
	                        --nextElem.ref.key;
	                    }
	                }
	            }
	        }

	        this.__initialize(root, visitor);

	        sentinel = {};

	        // reference
	        worklist = this.__worklist;
	        leavelist = this.__leavelist;

	        // initialize
	        outer = {
	            root: root
	        };
	        element = new Element(root, null, null, new Reference(outer, 'root'));
	        worklist.push(element);
	        leavelist.push(element);

	        while (worklist.length) {
	            element = worklist.pop();

	            if (element === sentinel) {
	                element = leavelist.pop();

	                target = this.__execute(visitor.leave, element);

	                // node may be replaced with null,
	                // so distinguish between undefined and null in this place
	                if (target !== undefined && target !== BREAK && target !== SKIP && target !== REMOVE) {
	                    // replace
	                    element.ref.replace(target);
	                }

	                if (this.__state === REMOVE || target === REMOVE) {
	                    removeElem(element);
	                }

	                if (this.__state === BREAK || target === BREAK) {
	                    return outer.root;
	                }
	                continue;
	            }

	            target = this.__execute(visitor.enter, element);

	            // node may be replaced with null,
	            // so distinguish between undefined and null in this place
	            if (target !== undefined && target !== BREAK && target !== SKIP && target !== REMOVE) {
	                // replace
	                element.ref.replace(target);
	                element.node = target;
	            }

	            if (this.__state === REMOVE || target === REMOVE) {
	                removeElem(element);
	                element.node = null;
	            }

	            if (this.__state === BREAK || target === BREAK) {
	                return outer.root;
	            }

	            // node may be null
	            node = element.node;
	            if (!node) {
	                continue;
	            }

	            worklist.push(sentinel);
	            leavelist.push(element);

	            if (this.__state === SKIP || target === SKIP) {
	                continue;
	            }

	            nodeType = node.type || element.wrap;
	            candidates = this.__keys[nodeType];
	            if (!candidates) {
	                if (this.__fallback) {
	                    candidates = this.__fallback(node);
	                } else {
	                    throw new Error('Unknown node type ' + nodeType + '.');
	                }
	            }

	            current = candidates.length;
	            while ((current -= 1) >= 0) {
	                key = candidates[current];
	                candidate = node[key];
	                if (!candidate) {
	                    continue;
	                }

	                if (Array.isArray(candidate)) {
	                    current2 = candidate.length;
	                    while ((current2 -= 1) >= 0) {
	                        if (!candidate[current2]) {
	                            continue;
	                        }
	                        if (isProperty(nodeType, candidates[current])) {
	                            element = new Element(candidate[current2], [key, current2], 'Property', new Reference(candidate, current2));
	                        } else if (isNode(candidate[current2])) {
	                            element = new Element(candidate[current2], [key, current2], null, new Reference(candidate, current2));
	                        } else {
	                            continue;
	                        }
	                        worklist.push(element);
	                    }
	                } else if (isNode(candidate)) {
	                    worklist.push(new Element(candidate, key, null, new Reference(node, key)));
	                }
	            }
	        }

	        return outer.root;
	    };

	    function traverse(root, visitor) {
	        var controller = new Controller();
	        return controller.traverse(root, visitor);
	    }

	    function replace(root, visitor) {
	        var controller = new Controller();
	        return controller.replace(root, visitor);
	    }

	    function extendCommentRange(comment, tokens) {
	        var target;

	        target = upperBound(tokens, function search(token) {
	            return token.range[0] > comment.range[0];
	        });

	        comment.extendedRange = [comment.range[0], comment.range[1]];

	        if (target !== tokens.length) {
	            comment.extendedRange[1] = tokens[target].range[0];
	        }

	        target -= 1;
	        if (target >= 0) {
	            comment.extendedRange[0] = tokens[target].range[1];
	        }

	        return comment;
	    }

	    function attachComments(tree, providedComments, tokens) {
	        // At first, we should calculate extended comment ranges.
	        var comments = [], comment, len, i, cursor;

	        if (!tree.range) {
	            throw new Error('attachComments needs range information');
	        }

	        // tokens array is empty, we attach comments to tree as 'leadingComments'
	        if (!tokens.length) {
	            if (providedComments.length) {
	                for (i = 0, len = providedComments.length; i < len; i += 1) {
	                    comment = deepCopy(providedComments[i]);
	                    comment.extendedRange = [0, tree.range[0]];
	                    comments.push(comment);
	                }
	                tree.leadingComments = comments;
	            }
	            return tree;
	        }

	        for (i = 0, len = providedComments.length; i < len; i += 1) {
	            comments.push(extendCommentRange(deepCopy(providedComments[i]), tokens));
	        }

	        // This is based on John Freeman's implementation.
	        cursor = 0;
	        traverse(tree, {
	            enter: function (node) {
	                var comment;

	                while (cursor < comments.length) {
	                    comment = comments[cursor];
	                    if (comment.extendedRange[1] > node.range[0]) {
	                        break;
	                    }

	                    if (comment.extendedRange[1] === node.range[0]) {
	                        if (!node.leadingComments) {
	                            node.leadingComments = [];
	                        }
	                        node.leadingComments.push(comment);
	                        comments.splice(cursor, 1);
	                    } else {
	                        cursor += 1;
	                    }
	                }

	                // already out of owned node
	                if (cursor === comments.length) {
	                    return VisitorOption.Break;
	                }

	                if (comments[cursor].extendedRange[0] > node.range[1]) {
	                    return VisitorOption.Skip;
	                }
	            }
	        });

	        cursor = 0;
	        traverse(tree, {
	            leave: function (node) {
	                var comment;

	                while (cursor < comments.length) {
	                    comment = comments[cursor];
	                    if (node.range[1] < comment.extendedRange[0]) {
	                        break;
	                    }

	                    if (node.range[1] === comment.extendedRange[0]) {
	                        if (!node.trailingComments) {
	                            node.trailingComments = [];
	                        }
	                        node.trailingComments.push(comment);
	                        comments.splice(cursor, 1);
	                    } else {
	                        cursor += 1;
	                    }
	                }

	                // already out of owned node
	                if (cursor === comments.length) {
	                    return VisitorOption.Break;
	                }

	                if (comments[cursor].extendedRange[0] > node.range[1]) {
	                    return VisitorOption.Skip;
	                }
	            }
	        });

	        return tree;
	    }

	    exports.Syntax = Syntax;
	    exports.traverse = traverse;
	    exports.replace = replace;
	    exports.attachComments = attachComments;
	    exports.VisitorKeys = VisitorKeys;
	    exports.VisitorOption = VisitorOption;
	    exports.Controller = Controller;
	    exports.cloneEnvironment = function () { return clone({}); };

	    return exports;
	}(exports));
	/* vim: set sw=4 ts=4 et tw=80 : */
	});

	var parser = createCommonjsModule(function (module) {
	/*
	 * Generated by PEG.js 0.10.0.
	 *
	 * http://pegjs.org/
	 */
	(function(root, factory) {
	  if ( module.exports) {
	    module.exports = factory();
	  }
	})(commonjsGlobal, function() {

	  function peg$subclass(child, parent) {
	    function ctor() { this.constructor = child; }
	    ctor.prototype = parent.prototype;
	    child.prototype = new ctor();
	  }

	  function peg$SyntaxError(message, expected, found, location) {
	    this.message  = message;
	    this.expected = expected;
	    this.found    = found;
	    this.location = location;
	    this.name     = "SyntaxError";

	    if (typeof Error.captureStackTrace === "function") {
	      Error.captureStackTrace(this, peg$SyntaxError);
	    }
	  }

	  peg$subclass(peg$SyntaxError, Error);

	  peg$SyntaxError.buildMessage = function(expected, found) {
	    var DESCRIBE_EXPECTATION_FNS = {
	          literal: function(expectation) {
	            return "\"" + literalEscape(expectation.text) + "\"";
	          },

	          "class": function(expectation) {
	            var escapedParts = "",
	                i;

	            for (i = 0; i < expectation.parts.length; i++) {
	              escapedParts += expectation.parts[i] instanceof Array
	                ? classEscape(expectation.parts[i][0]) + "-" + classEscape(expectation.parts[i][1])
	                : classEscape(expectation.parts[i]);
	            }

	            return "[" + (expectation.inverted ? "^" : "") + escapedParts + "]";
	          },

	          any: function(expectation) {
	            return "any character";
	          },

	          end: function(expectation) {
	            return "end of input";
	          },

	          other: function(expectation) {
	            return expectation.description;
	          }
	        };

	    function hex(ch) {
	      return ch.charCodeAt(0).toString(16).toUpperCase();
	    }

	    function literalEscape(s) {
	      return s
	        .replace(/\\/g, '\\\\')
	        .replace(/"/g,  '\\"')
	        .replace(/\0/g, '\\0')
	        .replace(/\t/g, '\\t')
	        .replace(/\n/g, '\\n')
	        .replace(/\r/g, '\\r')
	        .replace(/[\x00-\x0F]/g,          function(ch) { return '\\x0' + hex(ch); })
	        .replace(/[\x10-\x1F\x7F-\x9F]/g, function(ch) { return '\\x'  + hex(ch); });
	    }

	    function classEscape(s) {
	      return s
	        .replace(/\\/g, '\\\\')
	        .replace(/\]/g, '\\]')
	        .replace(/\^/g, '\\^')
	        .replace(/-/g,  '\\-')
	        .replace(/\0/g, '\\0')
	        .replace(/\t/g, '\\t')
	        .replace(/\n/g, '\\n')
	        .replace(/\r/g, '\\r')
	        .replace(/[\x00-\x0F]/g,          function(ch) { return '\\x0' + hex(ch); })
	        .replace(/[\x10-\x1F\x7F-\x9F]/g, function(ch) { return '\\x'  + hex(ch); });
	    }

	    function describeExpectation(expectation) {
	      return DESCRIBE_EXPECTATION_FNS[expectation.type](expectation);
	    }

	    function describeExpected(expected) {
	      var descriptions = new Array(expected.length),
	          i, j;

	      for (i = 0; i < expected.length; i++) {
	        descriptions[i] = describeExpectation(expected[i]);
	      }

	      descriptions.sort();

	      if (descriptions.length > 0) {
	        for (i = 1, j = 1; i < descriptions.length; i++) {
	          if (descriptions[i - 1] !== descriptions[i]) {
	            descriptions[j] = descriptions[i];
	            j++;
	          }
	        }
	        descriptions.length = j;
	      }

	      switch (descriptions.length) {
	        case 1:
	          return descriptions[0];

	        case 2:
	          return descriptions[0] + " or " + descriptions[1];

	        default:
	          return descriptions.slice(0, -1).join(", ")
	            + ", or "
	            + descriptions[descriptions.length - 1];
	      }
	    }

	    function describeFound(found) {
	      return found ? "\"" + literalEscape(found) + "\"" : "end of input";
	    }

	    return "Expected " + describeExpected(expected) + " but " + describeFound(found) + " found.";
	  };

	  function peg$parse(input, options) {
	    options = options !== void 0 ? options : {};

	    var peg$FAILED = {},

	        peg$startRuleFunctions = { start: peg$parsestart },
	        peg$startRuleFunction  = peg$parsestart,

	        peg$c0 = function(ss) {
	            return ss.length === 1 ? ss[0] : { type: 'matches', selectors: ss };
	          },
	        peg$c1 = function() { return void 0; },
	        peg$c2 = " ",
	        peg$c3 = peg$literalExpectation(" ", false),
	        peg$c4 = /^[^ [\],():#!=><~+.]/,
	        peg$c5 = peg$classExpectation([" ", "[", "]", ",", "(", ")", ":", "#", "!", "=", ">", "<", "~", "+", "."], true, false),
	        peg$c6 = function(i) { return i.join(''); },
	        peg$c7 = ">",
	        peg$c8 = peg$literalExpectation(">", false),
	        peg$c9 = function() { return 'child'; },
	        peg$c10 = "~",
	        peg$c11 = peg$literalExpectation("~", false),
	        peg$c12 = function() { return 'sibling'; },
	        peg$c13 = "+",
	        peg$c14 = peg$literalExpectation("+", false),
	        peg$c15 = function() { return 'adjacent'; },
	        peg$c16 = function() { return 'descendant'; },
	        peg$c17 = ",",
	        peg$c18 = peg$literalExpectation(",", false),
	        peg$c19 = function(s, ss) {
	          return [s].concat(ss.map(function (s) { return s[3]; }));
	        },
	        peg$c20 = function(a, ops) {
	            return ops.reduce(function (memo, rhs) {
	              return { type: rhs[0], left: memo, right: rhs[1] };
	            }, a);
	          },
	        peg$c21 = "!",
	        peg$c22 = peg$literalExpectation("!", false),
	        peg$c23 = function(subject, as) {
	            const b = as.length === 1 ? as[0] : { type: 'compound', selectors: as };
	            if(subject) b.subject = true;
	            return b;
	          },
	        peg$c24 = "*",
	        peg$c25 = peg$literalExpectation("*", false),
	        peg$c26 = function(a) { return { type: 'wildcard', value: a }; },
	        peg$c27 = "#",
	        peg$c28 = peg$literalExpectation("#", false),
	        peg$c29 = function(i) { return { type: 'identifier', value: i }; },
	        peg$c30 = "[",
	        peg$c31 = peg$literalExpectation("[", false),
	        peg$c32 = "]",
	        peg$c33 = peg$literalExpectation("]", false),
	        peg$c34 = function(v) { return v; },
	        peg$c35 = /^[><!]/,
	        peg$c36 = peg$classExpectation([">", "<", "!"], false, false),
	        peg$c37 = "=",
	        peg$c38 = peg$literalExpectation("=", false),
	        peg$c39 = function(a) { return (a || '') + '='; },
	        peg$c40 = /^[><]/,
	        peg$c41 = peg$classExpectation([">", "<"], false, false),
	        peg$c42 = ".",
	        peg$c43 = peg$literalExpectation(".", false),
	        peg$c44 = function(name, op, value) {
	              return { type: 'attribute', name: name, operator: op, value: value };
	            },
	        peg$c45 = function(name) { return { type: 'attribute', name: name }; },
	        peg$c46 = "\"",
	        peg$c47 = peg$literalExpectation("\"", false),
	        peg$c48 = /^[^\\"]/,
	        peg$c49 = peg$classExpectation(["\\", "\""], true, false),
	        peg$c50 = "\\",
	        peg$c51 = peg$literalExpectation("\\", false),
	        peg$c52 = peg$anyExpectation(),
	        peg$c53 = function(a, b) { return a + b; },
	        peg$c54 = function(d) {
	                return { type: 'literal', value: strUnescape(d.join('')) };
	              },
	        peg$c55 = "'",
	        peg$c56 = peg$literalExpectation("'", false),
	        peg$c57 = /^[^\\']/,
	        peg$c58 = peg$classExpectation(["\\", "'"], true, false),
	        peg$c59 = /^[0-9]/,
	        peg$c60 = peg$classExpectation([["0", "9"]], false, false),
	        peg$c61 = function(a, b) {
	                // Can use `a.flat().join('')` once supported
	                const leadingDecimals = a ? [].concat.apply([], a).join('') : '';
	                return { type: 'literal', value: parseFloat(leadingDecimals + b.join('')) };
	              },
	        peg$c62 = function(i) { return { type: 'literal', value: i }; },
	        peg$c63 = "type(",
	        peg$c64 = peg$literalExpectation("type(", false),
	        peg$c65 = /^[^ )]/,
	        peg$c66 = peg$classExpectation([" ", ")"], true, false),
	        peg$c67 = ")",
	        peg$c68 = peg$literalExpectation(")", false),
	        peg$c69 = function(t) { return { type: 'type', value: t.join('') }; },
	        peg$c70 = /^[imsu]/,
	        peg$c71 = peg$classExpectation(["i", "m", "s", "u"], false, false),
	        peg$c72 = "/",
	        peg$c73 = peg$literalExpectation("/", false),
	        peg$c74 = /^[^\/]/,
	        peg$c75 = peg$classExpectation(["/"], true, false),
	        peg$c76 = function(d, flgs) { return {
	              type: 'regexp', value: new RegExp(d.join(''), flgs ? flgs.join('') : '') };
	            },
	        peg$c77 = function(i, is) {
	          return { type: 'field', name: is.reduce(function(memo, p){ return memo + p[0] + p[1]; }, i)};
	        },
	        peg$c78 = ":not(",
	        peg$c79 = peg$literalExpectation(":not(", false),
	        peg$c80 = function(ss) { return { type: 'not', selectors: ss }; },
	        peg$c81 = ":matches(",
	        peg$c82 = peg$literalExpectation(":matches(", false),
	        peg$c83 = function(ss) { return { type: 'matches', selectors: ss }; },
	        peg$c84 = ":has(",
	        peg$c85 = peg$literalExpectation(":has(", false),
	        peg$c86 = function(ss) { return { type: 'has', selectors: ss }; },
	        peg$c87 = ":first-child",
	        peg$c88 = peg$literalExpectation(":first-child", false),
	        peg$c89 = function() { return nth(1); },
	        peg$c90 = ":last-child",
	        peg$c91 = peg$literalExpectation(":last-child", false),
	        peg$c92 = function() { return nthLast(1); },
	        peg$c93 = ":nth-child(",
	        peg$c94 = peg$literalExpectation(":nth-child(", false),
	        peg$c95 = function(n) { return nth(parseInt(n.join(''), 10)); },
	        peg$c96 = ":nth-last-child(",
	        peg$c97 = peg$literalExpectation(":nth-last-child(", false),
	        peg$c98 = function(n) { return nthLast(parseInt(n.join(''), 10)); },
	        peg$c99 = ":",
	        peg$c100 = peg$literalExpectation(":", false),
	        peg$c101 = "statement",
	        peg$c102 = peg$literalExpectation("statement", true),
	        peg$c103 = "expression",
	        peg$c104 = peg$literalExpectation("expression", true),
	        peg$c105 = "declaration",
	        peg$c106 = peg$literalExpectation("declaration", true),
	        peg$c107 = "function",
	        peg$c108 = peg$literalExpectation("function", true),
	        peg$c109 = "pattern",
	        peg$c110 = peg$literalExpectation("pattern", true),
	        peg$c111 = function(c) {
	          return { type: 'class', name: c };
	        },

	        peg$currPos          = 0,
	        peg$posDetailsCache  = [{ line: 1, column: 1 }],
	        peg$maxFailPos       = 0,
	        peg$maxFailExpected  = [],
	        peg$resultsCache = {},

	        peg$result;

	    if ("startRule" in options) {
	      if (!(options.startRule in peg$startRuleFunctions)) {
	        throw new Error("Can't start parsing from rule \"" + options.startRule + "\".");
	      }

	      peg$startRuleFunction = peg$startRuleFunctions[options.startRule];
	    }

	    function peg$literalExpectation(text, ignoreCase) {
	      return { type: "literal", text: text, ignoreCase: ignoreCase };
	    }

	    function peg$classExpectation(parts, inverted, ignoreCase) {
	      return { type: "class", parts: parts, inverted: inverted, ignoreCase: ignoreCase };
	    }

	    function peg$anyExpectation() {
	      return { type: "any" };
	    }

	    function peg$endExpectation() {
	      return { type: "end" };
	    }

	    function peg$computePosDetails(pos) {
	      var details = peg$posDetailsCache[pos], p;

	      if (details) {
	        return details;
	      } else {
	        p = pos - 1;
	        while (!peg$posDetailsCache[p]) {
	          p--;
	        }

	        details = peg$posDetailsCache[p];
	        details = {
	          line:   details.line,
	          column: details.column
	        };

	        while (p < pos) {
	          if (input.charCodeAt(p) === 10) {
	            details.line++;
	            details.column = 1;
	          } else {
	            details.column++;
	          }

	          p++;
	        }

	        peg$posDetailsCache[pos] = details;
	        return details;
	      }
	    }

	    function peg$computeLocation(startPos, endPos) {
	      var startPosDetails = peg$computePosDetails(startPos),
	          endPosDetails   = peg$computePosDetails(endPos);

	      return {
	        start: {
	          offset: startPos,
	          line:   startPosDetails.line,
	          column: startPosDetails.column
	        },
	        end: {
	          offset: endPos,
	          line:   endPosDetails.line,
	          column: endPosDetails.column
	        }
	      };
	    }

	    function peg$fail(expected) {
	      if (peg$currPos < peg$maxFailPos) { return; }

	      if (peg$currPos > peg$maxFailPos) {
	        peg$maxFailPos = peg$currPos;
	        peg$maxFailExpected = [];
	      }

	      peg$maxFailExpected.push(expected);
	    }

	    function peg$buildStructuredError(expected, found, location) {
	      return new peg$SyntaxError(
	        peg$SyntaxError.buildMessage(expected, found),
	        expected,
	        found,
	        location
	      );
	    }

	    function peg$parsestart() {
	      var s0, s1, s2, s3;

	      var key    = peg$currPos * 30 + 0,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      s1 = peg$parse_();
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parseselectors();
	        if (s2 !== peg$FAILED) {
	          s3 = peg$parse_();
	          if (s3 !== peg$FAILED) {
	            s1 = peg$c0(s2);
	            s0 = s1;
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }
	      if (s0 === peg$FAILED) {
	        s0 = peg$currPos;
	        s1 = peg$parse_();
	        if (s1 !== peg$FAILED) {
	          s1 = peg$c1();
	        }
	        s0 = s1;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parse_() {
	      var s0, s1;

	      var key    = peg$currPos * 30 + 1,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = [];
	      if (input.charCodeAt(peg$currPos) === 32) {
	        s1 = peg$c2;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c3); }
	      }
	      while (s1 !== peg$FAILED) {
	        s0.push(s1);
	        if (input.charCodeAt(peg$currPos) === 32) {
	          s1 = peg$c2;
	          peg$currPos++;
	        } else {
	          s1 = peg$FAILED;
	          { peg$fail(peg$c3); }
	        }
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseidentifierName() {
	      var s0, s1, s2;

	      var key    = peg$currPos * 30 + 2,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      s1 = [];
	      if (peg$c4.test(input.charAt(peg$currPos))) {
	        s2 = input.charAt(peg$currPos);
	        peg$currPos++;
	      } else {
	        s2 = peg$FAILED;
	        { peg$fail(peg$c5); }
	      }
	      if (s2 !== peg$FAILED) {
	        while (s2 !== peg$FAILED) {
	          s1.push(s2);
	          if (peg$c4.test(input.charAt(peg$currPos))) {
	            s2 = input.charAt(peg$currPos);
	            peg$currPos++;
	          } else {
	            s2 = peg$FAILED;
	            { peg$fail(peg$c5); }
	          }
	        }
	      } else {
	        s1 = peg$FAILED;
	      }
	      if (s1 !== peg$FAILED) {
	        s1 = peg$c6(s1);
	      }
	      s0 = s1;

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsebinaryOp() {
	      var s0, s1, s2, s3;

	      var key    = peg$currPos * 30 + 3,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      s1 = peg$parse_();
	      if (s1 !== peg$FAILED) {
	        if (input.charCodeAt(peg$currPos) === 62) {
	          s2 = peg$c7;
	          peg$currPos++;
	        } else {
	          s2 = peg$FAILED;
	          { peg$fail(peg$c8); }
	        }
	        if (s2 !== peg$FAILED) {
	          s3 = peg$parse_();
	          if (s3 !== peg$FAILED) {
	            s1 = peg$c9();
	            s0 = s1;
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }
	      if (s0 === peg$FAILED) {
	        s0 = peg$currPos;
	        s1 = peg$parse_();
	        if (s1 !== peg$FAILED) {
	          if (input.charCodeAt(peg$currPos) === 126) {
	            s2 = peg$c10;
	            peg$currPos++;
	          } else {
	            s2 = peg$FAILED;
	            { peg$fail(peg$c11); }
	          }
	          if (s2 !== peg$FAILED) {
	            s3 = peg$parse_();
	            if (s3 !== peg$FAILED) {
	              s1 = peg$c12();
	              s0 = s1;
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	        if (s0 === peg$FAILED) {
	          s0 = peg$currPos;
	          s1 = peg$parse_();
	          if (s1 !== peg$FAILED) {
	            if (input.charCodeAt(peg$currPos) === 43) {
	              s2 = peg$c13;
	              peg$currPos++;
	            } else {
	              s2 = peg$FAILED;
	              { peg$fail(peg$c14); }
	            }
	            if (s2 !== peg$FAILED) {
	              s3 = peg$parse_();
	              if (s3 !== peg$FAILED) {
	                s1 = peg$c15();
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	          if (s0 === peg$FAILED) {
	            s0 = peg$currPos;
	            if (input.charCodeAt(peg$currPos) === 32) {
	              s1 = peg$c2;
	              peg$currPos++;
	            } else {
	              s1 = peg$FAILED;
	              { peg$fail(peg$c3); }
	            }
	            if (s1 !== peg$FAILED) {
	              s2 = peg$parse_();
	              if (s2 !== peg$FAILED) {
	                s1 = peg$c16();
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          }
	        }
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseselectors() {
	      var s0, s1, s2, s3, s4, s5, s6, s7;

	      var key    = peg$currPos * 30 + 4,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      s1 = peg$parseselector();
	      if (s1 !== peg$FAILED) {
	        s2 = [];
	        s3 = peg$currPos;
	        s4 = peg$parse_();
	        if (s4 !== peg$FAILED) {
	          if (input.charCodeAt(peg$currPos) === 44) {
	            s5 = peg$c17;
	            peg$currPos++;
	          } else {
	            s5 = peg$FAILED;
	            { peg$fail(peg$c18); }
	          }
	          if (s5 !== peg$FAILED) {
	            s6 = peg$parse_();
	            if (s6 !== peg$FAILED) {
	              s7 = peg$parseselector();
	              if (s7 !== peg$FAILED) {
	                s4 = [s4, s5, s6, s7];
	                s3 = s4;
	              } else {
	                peg$currPos = s3;
	                s3 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s3;
	              s3 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s3;
	            s3 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s3;
	          s3 = peg$FAILED;
	        }
	        while (s3 !== peg$FAILED) {
	          s2.push(s3);
	          s3 = peg$currPos;
	          s4 = peg$parse_();
	          if (s4 !== peg$FAILED) {
	            if (input.charCodeAt(peg$currPos) === 44) {
	              s5 = peg$c17;
	              peg$currPos++;
	            } else {
	              s5 = peg$FAILED;
	              { peg$fail(peg$c18); }
	            }
	            if (s5 !== peg$FAILED) {
	              s6 = peg$parse_();
	              if (s6 !== peg$FAILED) {
	                s7 = peg$parseselector();
	                if (s7 !== peg$FAILED) {
	                  s4 = [s4, s5, s6, s7];
	                  s3 = s4;
	                } else {
	                  peg$currPos = s3;
	                  s3 = peg$FAILED;
	                }
	              } else {
	                peg$currPos = s3;
	                s3 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s3;
	              s3 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s3;
	            s3 = peg$FAILED;
	          }
	        }
	        if (s2 !== peg$FAILED) {
	          s1 = peg$c19(s1, s2);
	          s0 = s1;
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseselector() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 5,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      s1 = peg$parsesequence();
	      if (s1 !== peg$FAILED) {
	        s2 = [];
	        s3 = peg$currPos;
	        s4 = peg$parsebinaryOp();
	        if (s4 !== peg$FAILED) {
	          s5 = peg$parsesequence();
	          if (s5 !== peg$FAILED) {
	            s4 = [s4, s5];
	            s3 = s4;
	          } else {
	            peg$currPos = s3;
	            s3 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s3;
	          s3 = peg$FAILED;
	        }
	        while (s3 !== peg$FAILED) {
	          s2.push(s3);
	          s3 = peg$currPos;
	          s4 = peg$parsebinaryOp();
	          if (s4 !== peg$FAILED) {
	            s5 = peg$parsesequence();
	            if (s5 !== peg$FAILED) {
	              s4 = [s4, s5];
	              s3 = s4;
	            } else {
	              peg$currPos = s3;
	              s3 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s3;
	            s3 = peg$FAILED;
	          }
	        }
	        if (s2 !== peg$FAILED) {
	          s1 = peg$c20(s1, s2);
	          s0 = s1;
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsesequence() {
	      var s0, s1, s2, s3;

	      var key    = peg$currPos * 30 + 6,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.charCodeAt(peg$currPos) === 33) {
	        s1 = peg$c21;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c22); }
	      }
	      if (s1 === peg$FAILED) {
	        s1 = null;
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = [];
	        s3 = peg$parseatom();
	        if (s3 !== peg$FAILED) {
	          while (s3 !== peg$FAILED) {
	            s2.push(s3);
	            s3 = peg$parseatom();
	          }
	        } else {
	          s2 = peg$FAILED;
	        }
	        if (s2 !== peg$FAILED) {
	          s1 = peg$c23(s1, s2);
	          s0 = s1;
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseatom() {
	      var s0;

	      var key    = peg$currPos * 30 + 7,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$parsewildcard();
	      if (s0 === peg$FAILED) {
	        s0 = peg$parseidentifier();
	        if (s0 === peg$FAILED) {
	          s0 = peg$parseattr();
	          if (s0 === peg$FAILED) {
	            s0 = peg$parsefield();
	            if (s0 === peg$FAILED) {
	              s0 = peg$parsenegation();
	              if (s0 === peg$FAILED) {
	                s0 = peg$parsematches();
	                if (s0 === peg$FAILED) {
	                  s0 = peg$parsehas();
	                  if (s0 === peg$FAILED) {
	                    s0 = peg$parsefirstChild();
	                    if (s0 === peg$FAILED) {
	                      s0 = peg$parselastChild();
	                      if (s0 === peg$FAILED) {
	                        s0 = peg$parsenthChild();
	                        if (s0 === peg$FAILED) {
	                          s0 = peg$parsenthLastChild();
	                          if (s0 === peg$FAILED) {
	                            s0 = peg$parseclass();
	                          }
	                        }
	                      }
	                    }
	                  }
	                }
	              }
	            }
	          }
	        }
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsewildcard() {
	      var s0, s1;

	      var key    = peg$currPos * 30 + 8,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.charCodeAt(peg$currPos) === 42) {
	        s1 = peg$c24;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c25); }
	      }
	      if (s1 !== peg$FAILED) {
	        s1 = peg$c26(s1);
	      }
	      s0 = s1;

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseidentifier() {
	      var s0, s1, s2;

	      var key    = peg$currPos * 30 + 9,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.charCodeAt(peg$currPos) === 35) {
	        s1 = peg$c27;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c28); }
	      }
	      if (s1 === peg$FAILED) {
	        s1 = null;
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parseidentifierName();
	        if (s2 !== peg$FAILED) {
	          s1 = peg$c29(s2);
	          s0 = s1;
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseattr() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 10,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.charCodeAt(peg$currPos) === 91) {
	        s1 = peg$c30;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c31); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parse_();
	        if (s2 !== peg$FAILED) {
	          s3 = peg$parseattrValue();
	          if (s3 !== peg$FAILED) {
	            s4 = peg$parse_();
	            if (s4 !== peg$FAILED) {
	              if (input.charCodeAt(peg$currPos) === 93) {
	                s5 = peg$c32;
	                peg$currPos++;
	              } else {
	                s5 = peg$FAILED;
	                { peg$fail(peg$c33); }
	              }
	              if (s5 !== peg$FAILED) {
	                s1 = peg$c34(s3);
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseattrOps() {
	      var s0, s1, s2;

	      var key    = peg$currPos * 30 + 11,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (peg$c35.test(input.charAt(peg$currPos))) {
	        s1 = input.charAt(peg$currPos);
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c36); }
	      }
	      if (s1 === peg$FAILED) {
	        s1 = null;
	      }
	      if (s1 !== peg$FAILED) {
	        if (input.charCodeAt(peg$currPos) === 61) {
	          s2 = peg$c37;
	          peg$currPos++;
	        } else {
	          s2 = peg$FAILED;
	          { peg$fail(peg$c38); }
	        }
	        if (s2 !== peg$FAILED) {
	          s1 = peg$c39(s1);
	          s0 = s1;
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }
	      if (s0 === peg$FAILED) {
	        if (peg$c40.test(input.charAt(peg$currPos))) {
	          s0 = input.charAt(peg$currPos);
	          peg$currPos++;
	        } else {
	          s0 = peg$FAILED;
	          { peg$fail(peg$c41); }
	        }
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseattrEqOps() {
	      var s0, s1, s2;

	      var key    = peg$currPos * 30 + 12,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.charCodeAt(peg$currPos) === 33) {
	        s1 = peg$c21;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c22); }
	      }
	      if (s1 === peg$FAILED) {
	        s1 = null;
	      }
	      if (s1 !== peg$FAILED) {
	        if (input.charCodeAt(peg$currPos) === 61) {
	          s2 = peg$c37;
	          peg$currPos++;
	        } else {
	          s2 = peg$FAILED;
	          { peg$fail(peg$c38); }
	        }
	        if (s2 !== peg$FAILED) {
	          s1 = peg$c39(s1);
	          s0 = s1;
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseattrName() {
	      var s0, s1, s2;

	      var key    = peg$currPos * 30 + 13,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      s1 = [];
	      s2 = peg$parseidentifierName();
	      if (s2 === peg$FAILED) {
	        if (input.charCodeAt(peg$currPos) === 46) {
	          s2 = peg$c42;
	          peg$currPos++;
	        } else {
	          s2 = peg$FAILED;
	          { peg$fail(peg$c43); }
	        }
	      }
	      if (s2 !== peg$FAILED) {
	        while (s2 !== peg$FAILED) {
	          s1.push(s2);
	          s2 = peg$parseidentifierName();
	          if (s2 === peg$FAILED) {
	            if (input.charCodeAt(peg$currPos) === 46) {
	              s2 = peg$c42;
	              peg$currPos++;
	            } else {
	              s2 = peg$FAILED;
	              { peg$fail(peg$c43); }
	            }
	          }
	        }
	      } else {
	        s1 = peg$FAILED;
	      }
	      if (s1 !== peg$FAILED) {
	        s1 = peg$c6(s1);
	      }
	      s0 = s1;

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseattrValue() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 14,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      s1 = peg$parseattrName();
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parse_();
	        if (s2 !== peg$FAILED) {
	          s3 = peg$parseattrEqOps();
	          if (s3 !== peg$FAILED) {
	            s4 = peg$parse_();
	            if (s4 !== peg$FAILED) {
	              s5 = peg$parsetype();
	              if (s5 === peg$FAILED) {
	                s5 = peg$parseregex();
	              }
	              if (s5 !== peg$FAILED) {
	                s1 = peg$c44(s1, s3, s5);
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }
	      if (s0 === peg$FAILED) {
	        s0 = peg$currPos;
	        s1 = peg$parseattrName();
	        if (s1 !== peg$FAILED) {
	          s2 = peg$parse_();
	          if (s2 !== peg$FAILED) {
	            s3 = peg$parseattrOps();
	            if (s3 !== peg$FAILED) {
	              s4 = peg$parse_();
	              if (s4 !== peg$FAILED) {
	                s5 = peg$parsestring();
	                if (s5 === peg$FAILED) {
	                  s5 = peg$parsenumber();
	                  if (s5 === peg$FAILED) {
	                    s5 = peg$parsepath();
	                  }
	                }
	                if (s5 !== peg$FAILED) {
	                  s1 = peg$c44(s1, s3, s5);
	                  s0 = s1;
	                } else {
	                  peg$currPos = s0;
	                  s0 = peg$FAILED;
	                }
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	        if (s0 === peg$FAILED) {
	          s0 = peg$currPos;
	          s1 = peg$parseattrName();
	          if (s1 !== peg$FAILED) {
	            s1 = peg$c45(s1);
	          }
	          s0 = s1;
	        }
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsestring() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 15,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.charCodeAt(peg$currPos) === 34) {
	        s1 = peg$c46;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c47); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = [];
	        if (peg$c48.test(input.charAt(peg$currPos))) {
	          s3 = input.charAt(peg$currPos);
	          peg$currPos++;
	        } else {
	          s3 = peg$FAILED;
	          { peg$fail(peg$c49); }
	        }
	        if (s3 === peg$FAILED) {
	          s3 = peg$currPos;
	          if (input.charCodeAt(peg$currPos) === 92) {
	            s4 = peg$c50;
	            peg$currPos++;
	          } else {
	            s4 = peg$FAILED;
	            { peg$fail(peg$c51); }
	          }
	          if (s4 !== peg$FAILED) {
	            if (input.length > peg$currPos) {
	              s5 = input.charAt(peg$currPos);
	              peg$currPos++;
	            } else {
	              s5 = peg$FAILED;
	              { peg$fail(peg$c52); }
	            }
	            if (s5 !== peg$FAILED) {
	              s4 = peg$c53(s4, s5);
	              s3 = s4;
	            } else {
	              peg$currPos = s3;
	              s3 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s3;
	            s3 = peg$FAILED;
	          }
	        }
	        while (s3 !== peg$FAILED) {
	          s2.push(s3);
	          if (peg$c48.test(input.charAt(peg$currPos))) {
	            s3 = input.charAt(peg$currPos);
	            peg$currPos++;
	          } else {
	            s3 = peg$FAILED;
	            { peg$fail(peg$c49); }
	          }
	          if (s3 === peg$FAILED) {
	            s3 = peg$currPos;
	            if (input.charCodeAt(peg$currPos) === 92) {
	              s4 = peg$c50;
	              peg$currPos++;
	            } else {
	              s4 = peg$FAILED;
	              { peg$fail(peg$c51); }
	            }
	            if (s4 !== peg$FAILED) {
	              if (input.length > peg$currPos) {
	                s5 = input.charAt(peg$currPos);
	                peg$currPos++;
	              } else {
	                s5 = peg$FAILED;
	                { peg$fail(peg$c52); }
	              }
	              if (s5 !== peg$FAILED) {
	                s4 = peg$c53(s4, s5);
	                s3 = s4;
	              } else {
	                peg$currPos = s3;
	                s3 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s3;
	              s3 = peg$FAILED;
	            }
	          }
	        }
	        if (s2 !== peg$FAILED) {
	          if (input.charCodeAt(peg$currPos) === 34) {
	            s3 = peg$c46;
	            peg$currPos++;
	          } else {
	            s3 = peg$FAILED;
	            { peg$fail(peg$c47); }
	          }
	          if (s3 !== peg$FAILED) {
	            s1 = peg$c54(s2);
	            s0 = s1;
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }
	      if (s0 === peg$FAILED) {
	        s0 = peg$currPos;
	        if (input.charCodeAt(peg$currPos) === 39) {
	          s1 = peg$c55;
	          peg$currPos++;
	        } else {
	          s1 = peg$FAILED;
	          { peg$fail(peg$c56); }
	        }
	        if (s1 !== peg$FAILED) {
	          s2 = [];
	          if (peg$c57.test(input.charAt(peg$currPos))) {
	            s3 = input.charAt(peg$currPos);
	            peg$currPos++;
	          } else {
	            s3 = peg$FAILED;
	            { peg$fail(peg$c58); }
	          }
	          if (s3 === peg$FAILED) {
	            s3 = peg$currPos;
	            if (input.charCodeAt(peg$currPos) === 92) {
	              s4 = peg$c50;
	              peg$currPos++;
	            } else {
	              s4 = peg$FAILED;
	              { peg$fail(peg$c51); }
	            }
	            if (s4 !== peg$FAILED) {
	              if (input.length > peg$currPos) {
	                s5 = input.charAt(peg$currPos);
	                peg$currPos++;
	              } else {
	                s5 = peg$FAILED;
	                { peg$fail(peg$c52); }
	              }
	              if (s5 !== peg$FAILED) {
	                s4 = peg$c53(s4, s5);
	                s3 = s4;
	              } else {
	                peg$currPos = s3;
	                s3 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s3;
	              s3 = peg$FAILED;
	            }
	          }
	          while (s3 !== peg$FAILED) {
	            s2.push(s3);
	            if (peg$c57.test(input.charAt(peg$currPos))) {
	              s3 = input.charAt(peg$currPos);
	              peg$currPos++;
	            } else {
	              s3 = peg$FAILED;
	              { peg$fail(peg$c58); }
	            }
	            if (s3 === peg$FAILED) {
	              s3 = peg$currPos;
	              if (input.charCodeAt(peg$currPos) === 92) {
	                s4 = peg$c50;
	                peg$currPos++;
	              } else {
	                s4 = peg$FAILED;
	                { peg$fail(peg$c51); }
	              }
	              if (s4 !== peg$FAILED) {
	                if (input.length > peg$currPos) {
	                  s5 = input.charAt(peg$currPos);
	                  peg$currPos++;
	                } else {
	                  s5 = peg$FAILED;
	                  { peg$fail(peg$c52); }
	                }
	                if (s5 !== peg$FAILED) {
	                  s4 = peg$c53(s4, s5);
	                  s3 = s4;
	                } else {
	                  peg$currPos = s3;
	                  s3 = peg$FAILED;
	                }
	              } else {
	                peg$currPos = s3;
	                s3 = peg$FAILED;
	              }
	            }
	          }
	          if (s2 !== peg$FAILED) {
	            if (input.charCodeAt(peg$currPos) === 39) {
	              s3 = peg$c55;
	              peg$currPos++;
	            } else {
	              s3 = peg$FAILED;
	              { peg$fail(peg$c56); }
	            }
	            if (s3 !== peg$FAILED) {
	              s1 = peg$c54(s2);
	              s0 = s1;
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsenumber() {
	      var s0, s1, s2, s3;

	      var key    = peg$currPos * 30 + 16,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      s1 = peg$currPos;
	      s2 = [];
	      if (peg$c59.test(input.charAt(peg$currPos))) {
	        s3 = input.charAt(peg$currPos);
	        peg$currPos++;
	      } else {
	        s3 = peg$FAILED;
	        { peg$fail(peg$c60); }
	      }
	      while (s3 !== peg$FAILED) {
	        s2.push(s3);
	        if (peg$c59.test(input.charAt(peg$currPos))) {
	          s3 = input.charAt(peg$currPos);
	          peg$currPos++;
	        } else {
	          s3 = peg$FAILED;
	          { peg$fail(peg$c60); }
	        }
	      }
	      if (s2 !== peg$FAILED) {
	        if (input.charCodeAt(peg$currPos) === 46) {
	          s3 = peg$c42;
	          peg$currPos++;
	        } else {
	          s3 = peg$FAILED;
	          { peg$fail(peg$c43); }
	        }
	        if (s3 !== peg$FAILED) {
	          s2 = [s2, s3];
	          s1 = s2;
	        } else {
	          peg$currPos = s1;
	          s1 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s1;
	        s1 = peg$FAILED;
	      }
	      if (s1 === peg$FAILED) {
	        s1 = null;
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = [];
	        if (peg$c59.test(input.charAt(peg$currPos))) {
	          s3 = input.charAt(peg$currPos);
	          peg$currPos++;
	        } else {
	          s3 = peg$FAILED;
	          { peg$fail(peg$c60); }
	        }
	        if (s3 !== peg$FAILED) {
	          while (s3 !== peg$FAILED) {
	            s2.push(s3);
	            if (peg$c59.test(input.charAt(peg$currPos))) {
	              s3 = input.charAt(peg$currPos);
	              peg$currPos++;
	            } else {
	              s3 = peg$FAILED;
	              { peg$fail(peg$c60); }
	            }
	          }
	        } else {
	          s2 = peg$FAILED;
	        }
	        if (s2 !== peg$FAILED) {
	          s1 = peg$c61(s1, s2);
	          s0 = s1;
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsepath() {
	      var s0, s1;

	      var key    = peg$currPos * 30 + 17,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      s1 = peg$parseidentifierName();
	      if (s1 !== peg$FAILED) {
	        s1 = peg$c62(s1);
	      }
	      s0 = s1;

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsetype() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 18,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.substr(peg$currPos, 5) === peg$c63) {
	        s1 = peg$c63;
	        peg$currPos += 5;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c64); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parse_();
	        if (s2 !== peg$FAILED) {
	          s3 = [];
	          if (peg$c65.test(input.charAt(peg$currPos))) {
	            s4 = input.charAt(peg$currPos);
	            peg$currPos++;
	          } else {
	            s4 = peg$FAILED;
	            { peg$fail(peg$c66); }
	          }
	          if (s4 !== peg$FAILED) {
	            while (s4 !== peg$FAILED) {
	              s3.push(s4);
	              if (peg$c65.test(input.charAt(peg$currPos))) {
	                s4 = input.charAt(peg$currPos);
	                peg$currPos++;
	              } else {
	                s4 = peg$FAILED;
	                { peg$fail(peg$c66); }
	              }
	            }
	          } else {
	            s3 = peg$FAILED;
	          }
	          if (s3 !== peg$FAILED) {
	            s4 = peg$parse_();
	            if (s4 !== peg$FAILED) {
	              if (input.charCodeAt(peg$currPos) === 41) {
	                s5 = peg$c67;
	                peg$currPos++;
	              } else {
	                s5 = peg$FAILED;
	                { peg$fail(peg$c68); }
	              }
	              if (s5 !== peg$FAILED) {
	                s1 = peg$c69(s3);
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseflags() {
	      var s0, s1;

	      var key    = peg$currPos * 30 + 19,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = [];
	      if (peg$c70.test(input.charAt(peg$currPos))) {
	        s1 = input.charAt(peg$currPos);
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c71); }
	      }
	      if (s1 !== peg$FAILED) {
	        while (s1 !== peg$FAILED) {
	          s0.push(s1);
	          if (peg$c70.test(input.charAt(peg$currPos))) {
	            s1 = input.charAt(peg$currPos);
	            peg$currPos++;
	          } else {
	            s1 = peg$FAILED;
	            { peg$fail(peg$c71); }
	          }
	        }
	      } else {
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseregex() {
	      var s0, s1, s2, s3, s4;

	      var key    = peg$currPos * 30 + 20,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.charCodeAt(peg$currPos) === 47) {
	        s1 = peg$c72;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c73); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = [];
	        if (peg$c74.test(input.charAt(peg$currPos))) {
	          s3 = input.charAt(peg$currPos);
	          peg$currPos++;
	        } else {
	          s3 = peg$FAILED;
	          { peg$fail(peg$c75); }
	        }
	        if (s3 !== peg$FAILED) {
	          while (s3 !== peg$FAILED) {
	            s2.push(s3);
	            if (peg$c74.test(input.charAt(peg$currPos))) {
	              s3 = input.charAt(peg$currPos);
	              peg$currPos++;
	            } else {
	              s3 = peg$FAILED;
	              { peg$fail(peg$c75); }
	            }
	          }
	        } else {
	          s2 = peg$FAILED;
	        }
	        if (s2 !== peg$FAILED) {
	          if (input.charCodeAt(peg$currPos) === 47) {
	            s3 = peg$c72;
	            peg$currPos++;
	          } else {
	            s3 = peg$FAILED;
	            { peg$fail(peg$c73); }
	          }
	          if (s3 !== peg$FAILED) {
	            s4 = peg$parseflags();
	            if (s4 === peg$FAILED) {
	              s4 = null;
	            }
	            if (s4 !== peg$FAILED) {
	              s1 = peg$c76(s2, s4);
	              s0 = s1;
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsefield() {
	      var s0, s1, s2, s3, s4, s5, s6;

	      var key    = peg$currPos * 30 + 21,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.charCodeAt(peg$currPos) === 46) {
	        s1 = peg$c42;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c43); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parseidentifierName();
	        if (s2 !== peg$FAILED) {
	          s3 = [];
	          s4 = peg$currPos;
	          if (input.charCodeAt(peg$currPos) === 46) {
	            s5 = peg$c42;
	            peg$currPos++;
	          } else {
	            s5 = peg$FAILED;
	            { peg$fail(peg$c43); }
	          }
	          if (s5 !== peg$FAILED) {
	            s6 = peg$parseidentifierName();
	            if (s6 !== peg$FAILED) {
	              s5 = [s5, s6];
	              s4 = s5;
	            } else {
	              peg$currPos = s4;
	              s4 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s4;
	            s4 = peg$FAILED;
	          }
	          while (s4 !== peg$FAILED) {
	            s3.push(s4);
	            s4 = peg$currPos;
	            if (input.charCodeAt(peg$currPos) === 46) {
	              s5 = peg$c42;
	              peg$currPos++;
	            } else {
	              s5 = peg$FAILED;
	              { peg$fail(peg$c43); }
	            }
	            if (s5 !== peg$FAILED) {
	              s6 = peg$parseidentifierName();
	              if (s6 !== peg$FAILED) {
	                s5 = [s5, s6];
	                s4 = s5;
	              } else {
	                peg$currPos = s4;
	                s4 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s4;
	              s4 = peg$FAILED;
	            }
	          }
	          if (s3 !== peg$FAILED) {
	            s1 = peg$c77(s2, s3);
	            s0 = s1;
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsenegation() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 22,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.substr(peg$currPos, 5) === peg$c78) {
	        s1 = peg$c78;
	        peg$currPos += 5;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c79); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parse_();
	        if (s2 !== peg$FAILED) {
	          s3 = peg$parseselectors();
	          if (s3 !== peg$FAILED) {
	            s4 = peg$parse_();
	            if (s4 !== peg$FAILED) {
	              if (input.charCodeAt(peg$currPos) === 41) {
	                s5 = peg$c67;
	                peg$currPos++;
	              } else {
	                s5 = peg$FAILED;
	                { peg$fail(peg$c68); }
	              }
	              if (s5 !== peg$FAILED) {
	                s1 = peg$c80(s3);
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsematches() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 23,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.substr(peg$currPos, 9) === peg$c81) {
	        s1 = peg$c81;
	        peg$currPos += 9;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c82); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parse_();
	        if (s2 !== peg$FAILED) {
	          s3 = peg$parseselectors();
	          if (s3 !== peg$FAILED) {
	            s4 = peg$parse_();
	            if (s4 !== peg$FAILED) {
	              if (input.charCodeAt(peg$currPos) === 41) {
	                s5 = peg$c67;
	                peg$currPos++;
	              } else {
	                s5 = peg$FAILED;
	                { peg$fail(peg$c68); }
	              }
	              if (s5 !== peg$FAILED) {
	                s1 = peg$c83(s3);
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsehas() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 24,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.substr(peg$currPos, 5) === peg$c84) {
	        s1 = peg$c84;
	        peg$currPos += 5;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c85); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parse_();
	        if (s2 !== peg$FAILED) {
	          s3 = peg$parseselectors();
	          if (s3 !== peg$FAILED) {
	            s4 = peg$parse_();
	            if (s4 !== peg$FAILED) {
	              if (input.charCodeAt(peg$currPos) === 41) {
	                s5 = peg$c67;
	                peg$currPos++;
	              } else {
	                s5 = peg$FAILED;
	                { peg$fail(peg$c68); }
	              }
	              if (s5 !== peg$FAILED) {
	                s1 = peg$c86(s3);
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsefirstChild() {
	      var s0, s1;

	      var key    = peg$currPos * 30 + 25,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.substr(peg$currPos, 12) === peg$c87) {
	        s1 = peg$c87;
	        peg$currPos += 12;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c88); }
	      }
	      if (s1 !== peg$FAILED) {
	        s1 = peg$c89();
	      }
	      s0 = s1;

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parselastChild() {
	      var s0, s1;

	      var key    = peg$currPos * 30 + 26,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.substr(peg$currPos, 11) === peg$c90) {
	        s1 = peg$c90;
	        peg$currPos += 11;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c91); }
	      }
	      if (s1 !== peg$FAILED) {
	        s1 = peg$c92();
	      }
	      s0 = s1;

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsenthChild() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 27,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.substr(peg$currPos, 11) === peg$c93) {
	        s1 = peg$c93;
	        peg$currPos += 11;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c94); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parse_();
	        if (s2 !== peg$FAILED) {
	          s3 = [];
	          if (peg$c59.test(input.charAt(peg$currPos))) {
	            s4 = input.charAt(peg$currPos);
	            peg$currPos++;
	          } else {
	            s4 = peg$FAILED;
	            { peg$fail(peg$c60); }
	          }
	          if (s4 !== peg$FAILED) {
	            while (s4 !== peg$FAILED) {
	              s3.push(s4);
	              if (peg$c59.test(input.charAt(peg$currPos))) {
	                s4 = input.charAt(peg$currPos);
	                peg$currPos++;
	              } else {
	                s4 = peg$FAILED;
	                { peg$fail(peg$c60); }
	              }
	            }
	          } else {
	            s3 = peg$FAILED;
	          }
	          if (s3 !== peg$FAILED) {
	            s4 = peg$parse_();
	            if (s4 !== peg$FAILED) {
	              if (input.charCodeAt(peg$currPos) === 41) {
	                s5 = peg$c67;
	                peg$currPos++;
	              } else {
	                s5 = peg$FAILED;
	                { peg$fail(peg$c68); }
	              }
	              if (s5 !== peg$FAILED) {
	                s1 = peg$c95(s3);
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parsenthLastChild() {
	      var s0, s1, s2, s3, s4, s5;

	      var key    = peg$currPos * 30 + 28,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.substr(peg$currPos, 16) === peg$c96) {
	        s1 = peg$c96;
	        peg$currPos += 16;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c97); }
	      }
	      if (s1 !== peg$FAILED) {
	        s2 = peg$parse_();
	        if (s2 !== peg$FAILED) {
	          s3 = [];
	          if (peg$c59.test(input.charAt(peg$currPos))) {
	            s4 = input.charAt(peg$currPos);
	            peg$currPos++;
	          } else {
	            s4 = peg$FAILED;
	            { peg$fail(peg$c60); }
	          }
	          if (s4 !== peg$FAILED) {
	            while (s4 !== peg$FAILED) {
	              s3.push(s4);
	              if (peg$c59.test(input.charAt(peg$currPos))) {
	                s4 = input.charAt(peg$currPos);
	                peg$currPos++;
	              } else {
	                s4 = peg$FAILED;
	                { peg$fail(peg$c60); }
	              }
	            }
	          } else {
	            s3 = peg$FAILED;
	          }
	          if (s3 !== peg$FAILED) {
	            s4 = peg$parse_();
	            if (s4 !== peg$FAILED) {
	              if (input.charCodeAt(peg$currPos) === 41) {
	                s5 = peg$c67;
	                peg$currPos++;
	              } else {
	                s5 = peg$FAILED;
	                { peg$fail(peg$c68); }
	              }
	              if (s5 !== peg$FAILED) {
	                s1 = peg$c98(s3);
	                s0 = s1;
	              } else {
	                peg$currPos = s0;
	                s0 = peg$FAILED;
	              }
	            } else {
	              peg$currPos = s0;
	              s0 = peg$FAILED;
	            }
	          } else {
	            peg$currPos = s0;
	            s0 = peg$FAILED;
	          }
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }

	    function peg$parseclass() {
	      var s0, s1, s2;

	      var key    = peg$currPos * 30 + 29,
	          cached = peg$resultsCache[key];

	      if (cached) {
	        peg$currPos = cached.nextPos;

	        return cached.result;
	      }

	      s0 = peg$currPos;
	      if (input.charCodeAt(peg$currPos) === 58) {
	        s1 = peg$c99;
	        peg$currPos++;
	      } else {
	        s1 = peg$FAILED;
	        { peg$fail(peg$c100); }
	      }
	      if (s1 !== peg$FAILED) {
	        if (input.substr(peg$currPos, 9).toLowerCase() === peg$c101) {
	          s2 = input.substr(peg$currPos, 9);
	          peg$currPos += 9;
	        } else {
	          s2 = peg$FAILED;
	          { peg$fail(peg$c102); }
	        }
	        if (s2 === peg$FAILED) {
	          if (input.substr(peg$currPos, 10).toLowerCase() === peg$c103) {
	            s2 = input.substr(peg$currPos, 10);
	            peg$currPos += 10;
	          } else {
	            s2 = peg$FAILED;
	            { peg$fail(peg$c104); }
	          }
	          if (s2 === peg$FAILED) {
	            if (input.substr(peg$currPos, 11).toLowerCase() === peg$c105) {
	              s2 = input.substr(peg$currPos, 11);
	              peg$currPos += 11;
	            } else {
	              s2 = peg$FAILED;
	              { peg$fail(peg$c106); }
	            }
	            if (s2 === peg$FAILED) {
	              if (input.substr(peg$currPos, 8).toLowerCase() === peg$c107) {
	                s2 = input.substr(peg$currPos, 8);
	                peg$currPos += 8;
	              } else {
	                s2 = peg$FAILED;
	                { peg$fail(peg$c108); }
	              }
	              if (s2 === peg$FAILED) {
	                if (input.substr(peg$currPos, 7).toLowerCase() === peg$c109) {
	                  s2 = input.substr(peg$currPos, 7);
	                  peg$currPos += 7;
	                } else {
	                  s2 = peg$FAILED;
	                  { peg$fail(peg$c110); }
	                }
	              }
	            }
	          }
	        }
	        if (s2 !== peg$FAILED) {
	          s1 = peg$c111(s2);
	          s0 = s1;
	        } else {
	          peg$currPos = s0;
	          s0 = peg$FAILED;
	        }
	      } else {
	        peg$currPos = s0;
	        s0 = peg$FAILED;
	      }

	      peg$resultsCache[key] = { nextPos: peg$currPos, result: s0 };

	      return s0;
	    }


	      function nth(n) { return { type: 'nth-child', index: { type: 'literal', value: n } }; }
	      function nthLast(n) { return { type: 'nth-last-child', index: { type: 'literal', value: n } }; }
	      function strUnescape(s) {
	        return s.replace(/\\(.)/g, function(match, ch) {
	          switch(ch) {
	            case 'b': return '\b';
	            case 'f': return '\f';
	            case 'n': return '\n';
	            case 'r': return '\r';
	            case 't': return '\t';
	            case 'v': return '\v';
	            default: return ch;
	          }
	        });
	      }


	    peg$result = peg$startRuleFunction();

	    if (peg$result !== peg$FAILED && peg$currPos === input.length) {
	      return peg$result;
	    } else {
	      if (peg$result !== peg$FAILED && peg$currPos < input.length) {
	        peg$fail(peg$endExpectation());
	      }

	      throw peg$buildStructuredError(
	        peg$maxFailExpected,
	        peg$maxFailPos < input.length ? input.charAt(peg$maxFailPos) : null,
	        peg$maxFailPos < input.length
	          ? peg$computeLocation(peg$maxFailPos, peg$maxFailPos + 1)
	          : peg$computeLocation(peg$maxFailPos, peg$maxFailPos)
	      );
	    }
	  }

	  return {
	    SyntaxError: peg$SyntaxError,
	    parse:       peg$parse
	  };
	});
	});

	/* vim: set sw=4 sts=4 : */

	/**
	* @typedef {"LEFT_SIDE"|"RIGHT_SIDE"} Side
	*/

	const LEFT_SIDE = 'LEFT_SIDE';
	const RIGHT_SIDE = 'RIGHT_SIDE';

	/**
	 * @external AST
	 * @see https://esprima.readthedocs.io/en/latest/syntax-tree-format.html
	 */

	/**
	 * One of the rules of `grammar.pegjs`
	 * @typedef {PlainObject} SelectorAST
	 * @see grammar.pegjs
	*/

	/**
	 * The `sequence` production of `grammar.pegjs`
	 * @typedef {PlainObject} SelectorSequenceAST
	*/

	/**
	 * Get the value of a property which may be multiple levels down
	 * in the object.
	 * @param {?PlainObject} obj
	 * @param {string} key
	 * @returns {undefined|boolean|string|number|external:AST}
	 */
	function getPath(obj, key) {
	    const keys = key.split('.');
	    for (let i = 0; i < keys.length; i++) {
	        if (obj == null) { return obj; }
	        obj = obj[keys[i]];
	    }
	    return obj;
	}

	/**
	 * Determine whether `node` can be reached by following `path`,
	 * starting at `ancestor`.
	 * @param {?external:AST} node
	 * @param {?external:AST} ancestor
	 * @param {string[]} path
	 * @returns {boolean}
	 */
	function inPath(node, ancestor, path) {
	    if (path.length === 0) { return node === ancestor; }
	    if (ancestor == null) { return false; }
	    const field = ancestor[path[0]];
	    const remainingPath = path.slice(1);
	    if (Array.isArray(field)) {
	        for (let i = 0, l = field.length; i < l; ++i) {
	            if (inPath(node, field[i], remainingPath)) { return true; }
	        }
	        return false;
	    } else {
	        return inPath(node, field, remainingPath);
	    }
	}

	/**
	 * Given a `node` and its ancestors, determine if `node` is matched
	 * by `selector`.
	 * @param {?external:AST} node
	 * @param {?SelectorAST} selector
	 * @param {external:AST[]} [ancestry=[]]
	 * @throws {Error} Unknowns (operator, class name, selector type, or
	 * selector value type)
	 * @returns {boolean}
	 */
	function matches(node, selector, ancestry) {
	    if (!selector) { return true; }
	    if (!node) { return false; }
	    if (!ancestry) { ancestry = []; }

	    switch(selector.type) {
	        case 'wildcard':
	            return true;

	        case 'identifier':
	            return selector.value.toLowerCase() === node.type.toLowerCase();

	        case 'field': {
	            const path = selector.name.split('.');
	            const ancestor = ancestry[path.length - 1];
	            return inPath(node, ancestor, path);

	        }
	        case 'matches':
	            for (let i = 0, l = selector.selectors.length; i < l; ++i) {
	                if (matches(node, selector.selectors[i], ancestry)) { return true; }
	            }
	            return false;

	        case 'compound':
	            for (let i = 0, l = selector.selectors.length; i < l; ++i) {
	                if (!matches(node, selector.selectors[i], ancestry)) { return false; }
	            }
	            return true;

	        case 'not':
	            for (let i = 0, l = selector.selectors.length; i < l; ++i) {
	                if (matches(node, selector.selectors[i], ancestry)) { return false; }
	            }
	            return true;

	        case 'has': {
	            const collector = [];
	            for (let i = 0, l = selector.selectors.length; i < l; ++i) {
	                const a = [];
	                estraverse.traverse(node, {
	                    enter (node, parent) {
	                        if (parent != null) { a.unshift(parent); }
	                        if (matches(node, selector.selectors[i], a)) {
	                            collector.push(node);
	                        }
	                    },
	                    leave () { a.shift(); },
	                    fallback: 'iteration'
	                });
	            }
	            return collector.length !== 0;

	        }
	        case 'child':
	            if (matches(node, selector.right, ancestry)) {
	                return matches(ancestry[0], selector.left, ancestry.slice(1));
	            }
	            return false;

	        case 'descendant':
	            if (matches(node, selector.right, ancestry)) {
	                for (let i = 0, l = ancestry.length; i < l; ++i) {
	                    if (matches(ancestry[i], selector.left, ancestry.slice(i + 1))) {
	                        return true;
	                    }
	                }
	            }
	            return false;

	        case 'attribute': {
	            const p = getPath(node, selector.name);
	            switch (selector.operator) {
	                case void 0:
	                    return p != null;
	                case '=':
	                    switch (selector.value.type) {
	                        case 'regexp': return typeof p === 'string' && selector.value.value.test(p);
	                        case 'literal': return `${selector.value.value}` === `${p}`;
	                        case 'type': return selector.value.value === typeof p;
	                    }
	                    throw new Error(`Unknown selector value type: ${selector.value.type}`);
	                case '!=':
	                    switch (selector.value.type) {
	                        case 'regexp': return !selector.value.value.test(p);
	                        case 'literal': return `${selector.value.value}` !== `${p}`;
	                        case 'type': return selector.value.value !== typeof p;
	                    }
	                    throw new Error(`Unknown selector value type: ${selector.value.type}`);
	                case '<=': return p <= selector.value.value;
	                case '<': return p < selector.value.value;
	                case '>': return p > selector.value.value;
	                case '>=': return p >= selector.value.value;
	            }
	            throw new Error(`Unknown operator: ${selector.operator}`);
	        }
	        case 'sibling':
	            return matches(node, selector.right, ancestry) &&
	                sibling(node, selector.left, ancestry, LEFT_SIDE) ||
	                selector.left.subject &&
	                matches(node, selector.left, ancestry) &&
	                sibling(node, selector.right, ancestry, RIGHT_SIDE);
	        case 'adjacent':
	            return matches(node, selector.right, ancestry) &&
	                adjacent(node, selector.left, ancestry, LEFT_SIDE) ||
	                selector.right.subject &&
	                matches(node, selector.left, ancestry) &&
	                adjacent(node, selector.right, ancestry, RIGHT_SIDE);

	        case 'nth-child':
	            return matches(node, selector.right, ancestry) &&
	                nthChild(node, ancestry, function () {
	                    return selector.index.value - 1;
	                });

	        case 'nth-last-child':
	            return matches(node, selector.right, ancestry) &&
	                nthChild(node, ancestry, function (length) {
	                    return length - selector.index.value;
	                });

	        case 'class':
	            switch(selector.name.toLowerCase()){
	                case 'statement':
	                    if(node.type.slice(-9) === 'Statement') return true;
	                    // fallthrough: interface Declaration <: Statement { }
	                case 'declaration':
	                    return node.type.slice(-11) === 'Declaration';
	                case 'pattern':
	                    if(node.type.slice(-7) === 'Pattern') return true;
	                    // fallthrough: interface Expression <: Node, Pattern { }
	                case 'expression':
	                    return node.type.slice(-10) === 'Expression' ||
	                        node.type.slice(-7) === 'Literal' ||
	                        (
	                            node.type === 'Identifier' &&
	                            (ancestry.length === 0 || ancestry[0].type !== 'MetaProperty')
	                        ) ||
	                        node.type === 'MetaProperty';
	                case 'function':
	                    return node.type === 'FunctionDeclaration' ||
	                        node.type === 'FunctionExpression' ||
	                        node.type === 'ArrowFunctionExpression';
	            }
	            throw new Error(`Unknown class name: ${selector.name}`);
	    }

	    throw new Error(`Unknown selector type: ${selector.type}`);
	}

	/**
	 * Determines if the given node has a sibling that matches the
	 * given selector.
	 * @param {external:AST} node
	 * @param {SelectorSequenceAST} selector
	 * @param {external:AST[]} ancestry
	 * @param {Side} side
	 * @returns {boolean}
	 */
	function sibling(node, selector, ancestry, side) {
	    const [parent] = ancestry;
	    if (!parent) { return false; }
	    const keys = estraverse.VisitorKeys[parent.type];
	    for (let i = 0, l = keys.length; i < l; ++i) {
	        const listProp = parent[keys[i]];
	        if (Array.isArray(listProp)) {
	            const startIndex = listProp.indexOf(node);
	            if (startIndex < 0) { continue; }
	            let lowerBound, upperBound;
	            if (side === LEFT_SIDE) {
	                lowerBound = 0;
	                upperBound = startIndex;
	            } else {
	                lowerBound = startIndex + 1;
	                upperBound = listProp.length;
	            }
	            for (let k = lowerBound; k < upperBound; ++k) {
	                if (matches(listProp[k], selector, ancestry)) {
	                    return true;
	                }
	            }
	        }
	    }
	    return false;
	}

	/**
	 * Determines if the given node has an adjacent sibling that matches
	 * the given selector.
	 * @param {external:AST} node
	 * @param {SelectorSequenceAST} selector
	 * @param {external:AST[]} ancestry
	 * @param {Side} side
	 * @returns {boolean}
	 */
	function adjacent(node, selector, ancestry, side) {
	    const [parent] = ancestry;
	    if (!parent) { return false; }
	    const keys = estraverse.VisitorKeys[parent.type];
	    for (let i = 0, l = keys.length; i < l; ++i) {
	        const listProp = parent[keys[i]];
	        if (Array.isArray(listProp)) {
	            const idx = listProp.indexOf(node);
	            if (idx < 0) { continue; }
	            if (side === LEFT_SIDE && idx > 0 && matches(listProp[idx - 1], selector, ancestry)) {
	                return true;
	            }
	            if (side === RIGHT_SIDE && idx < listProp.length - 1 && matches(listProp[idx + 1], selector, ancestry)) {
	                return true;
	            }
	        }
	    }
	    return false;
	}

	/**
	* @callback IndexFunction
	* @param {Integer} len Containing list's length
	* @returns {Integer}
	*/

	/**
	 * Determines if the given node is the nth child, determined by
	 * `idxFn`, which is given the containing list's length.
	 * @param {external:AST} node
	 * @param {external:AST[]} ancestry
	 * @param {IndexFunction} idxFn
	 * @returns {boolean}
	 */
	function nthChild(node, ancestry, idxFn) {
	    const [parent] = ancestry;
	    if (!parent) { return false; }
	    const keys = estraverse.VisitorKeys[parent.type];
	    for (let i = 0, l = keys.length; i < l; ++i) {
	        const listProp = parent[keys[i]];
	        if (Array.isArray(listProp)) {
	            const idx = listProp.indexOf(node);
	            if (idx >= 0 && idx === idxFn(listProp.length)) { return true; }
	        }
	    }
	    return false;
	}

	/**
	 * For each selector node marked as a subject, find the portion of the
	 * selector that the subject must match.
	 * @param {SelectorAST} selector
	 * @param {SelectorAST} [ancestor] Defaults to `selector`
	 * @returns {SelectorAST[]}
	 */
	function subjects(selector, ancestor) {
	    if (selector == null || typeof selector != 'object') { return []; }
	    if (ancestor == null) { ancestor = selector; }
	    const results = selector.subject ? [ancestor] : [];
	    for (const [p, sel] of Object.entries(selector)) {
	        results.push(...subjects(sel, p === 'left' ? sel : ancestor));
	    }
	    return results;
	}

	/**
	 * From a JS AST and a selector AST, collect all JS AST nodes that
	 * match the selector.
	 * @param {external:AST} ast
	 * @param {?SelectorAST} selector
	 * @returns {external:AST[]}
	 */
	function match(ast, selector) {
	    const ancestry = [], results = [];
	    if (!selector) { return results; }
	    const altSubjects = subjects(selector);
	    estraverse.traverse(ast, {
	        enter (node, parent) {
	            if (parent != null) { ancestry.unshift(parent); }
	            if (matches(node, selector, ancestry)) {
	                if (altSubjects.length) {
	                    for (let i = 0, l = altSubjects.length; i < l; ++i) {
	                        if (matches(node, altSubjects[i], ancestry)) { results.push(node); }
	                        for (let k = 0, m = ancestry.length; k < m; ++k) {
	                            if (matches(ancestry[k], altSubjects[i], ancestry.slice(k + 1))) {
	                                results.push(ancestry[k]);
	                            }
	                        }
	                    }
	                } else {
	                    results.push(node);
	                }
	            }
	        },
	        leave () { ancestry.shift(); },
	        fallback: 'iteration'
	    });
	    return results;
	}

	/**
	 * Parse a selector string and return its AST.
	 * @param {string} selector
	 * @returns {SelectorAST}
	 */
	function parse(selector) {
	    return parser.parse(selector);
	}

	/**
	 * Query the code AST using the selector string.
	 * @param {external:AST} ast
	 * @param {string} selector
	 * @returns {external:AST[]}
	 */
	function query(ast, selector) {
	    return match(ast, parse(selector));
	}

	query.parse = parse;
	query.match = match;
	query.matches = matches;
	query.query = query;

	return query;

})));