Update - This is an automated commit

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diff --git a/school/node_modules/nwsapi/src/nwsapi.js b/school/node_modules/nwsapi/src/nwsapi.js
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+/*
+ * Copyright (C) 2007-2019 Diego Perini
+ * All rights reserved.
+ *
+ * nwsapi.js - Fast CSS Selectors API Engine
+ *
+ * Author: Diego Perini <diego.perini at gmail com>
+ * Version: 2.2.0
+ * Created: 20070722
+ * Release: 20220901
+ *
+ * License:
+ *  http://javascript.nwbox.com/nwsapi/MIT-LICENSE
+ * Download:
+ *  http://javascript.nwbox.com/nwsapi/nwsapi.js
+ */
+
+(function Export(global, factory) {
+
+  'use strict';
+
+  if (typeof module == 'object' && typeof exports == 'object') {
+    module.exports = factory;
+  } else if (typeof define == 'function' && define['amd']) {
+    define(factory);
+  } else {
+    global.NW || (global.NW = { });
+    global.NW.Dom = factory(global, Export);
+  }
+
+})(this, function Factory(global, Export) {
+
+  var version = 'nwsapi-2.2.2',
+
+  doc = global.document,
+  root = doc.documentElement,
+  slice = Array.prototype.slice,
+
+  WSP = '[\\x20\\t\\r\\n\\f]',
+
+  CFG = {
+    // extensions
+    operators: '[~*^$|]=|=',
+    combinators: '[\\x20\\t>+~](?=[^>+~])'
+  },
+
+  NOT = {
+    // not enclosed in double/single/parens/square
+    double_enc: '(?=(?:[^"]*["][^"]*["])*[^"]*$)',
+    single_enc: "(?=(?:[^']*['][^']*['])*[^']*$)",
+    parens_enc: '(?![^\\x28]*\\x29)',
+    square_enc: '(?![^\\x5b]*\\x5d)'
+  },
+
+  REX = {
+    // regular expressions
+    HasEscapes: RegExp('\\\\'),
+    HexNumbers: RegExp('^[0-9a-fA-F]'),
+    EscOrQuote: RegExp('^\\\\|[\\x22\\x27]'),
+    RegExpChar: RegExp('(?:(?!\\\\)[\\\\^$.*+?()[\\]{}|\\/])', 'g'),
+    TrimSpaces: RegExp('[\\r\\n\\f]|^' + WSP + '+|' + WSP + '+$', 'g'),
+    CommaGroup: RegExp('(\\s*,\\s*)' + NOT.square_enc + NOT.parens_enc, 'g'),
+    SplitGroup: RegExp('((?:\\x28[^\\x29]*\\x29|\\[[^\\]]*\\]|\\\\.|[^,])+)', 'g'),
+    FixEscapes: RegExp('\\\\([0-9a-fA-F]{1,6}' + WSP + '?|.)|([\\x22\\x27])', 'g'),
+    CombineWSP: RegExp('[\\n\\r\\f\\x20]+' + NOT.single_enc + NOT.double_enc, 'g'),
+    TabCharWSP: RegExp('(\\x20?\\t+\\x20?)' + NOT.single_enc + NOT.double_enc, 'g'),
+    PseudosWSP: RegExp('\\s+([-+])\\s+' + NOT.square_enc, 'g')
+  },
+
+  STD = {
+    combinator: RegExp('\\s?([>+~])\\s?', 'g'),
+    apimethods: RegExp('^(?:[a-z]+|\\*)\\|', 'i'),
+    namespaces: RegExp('(\\*|[a-z]+)\\|[-a-z]+', 'i')
+  },
+
+  GROUPS = {
+    // pseudo-classes requiring parameters
+    linguistic: '(dir|lang)\\x28\\s?([-\\w]{2,})\\s?(?:\\x29|$)',
+    logicalsel: '(is|where|matches|not)\\x28\\s?([^()]*|[^\\x28]*\\x28[^\\x29]*\\x29)\\s?(?:\\x29|$)',
+    treestruct: '(nth(?:-last)?(?:-child|-of-type))(?:\\x28\\s?(even|odd|(?:[-+]?\\d*)(?:n\\s?[-+]?\\s?\\d*)?)\\s?(?:\\x29|$))',
+    // pseudo-classes not requiring parameters
+    locationpc: '(any-link|link|visited|target)\\b',
+    useraction: '(hover|active|focus|focus-within)\\b',
+    structural: '(root|empty|(?:(?:first|last|only)(?:-child|-of-type)))\\b',
+    inputstate: '(enabled|disabled|read-only|read-write|placeholder-shown|default)\\b',
+    inputvalue: '(checked|indeterminate|required|optional|valid|invalid|in-range|out-of-range)\\b',
+    // pseudo-classes for parsing only selectors
+    pseudo_nop: '(autofill|-webkit-autofill)\\b',
+    // pseudo-elements starting with single colon (:)
+    pseudo_sng: '(after|before|first-letter|first-line)\\b',
+    // pseudo-elements starting with double colon (::)
+    pseudo_dbl: ':(after|before|first-letter|first-line|selection|placeholder|-webkit-[-a-zA-Z0-9]{2,})\\b'
+  },
+
+  Patterns = {
+    // pseudo-classes
+    treestruct: RegExp('^:(?:' + GROUPS.treestruct + ')(.*)', 'i'),
+    structural: RegExp('^:(?:' + GROUPS.structural + ')(.*)', 'i'),
+    linguistic: RegExp('^:(?:' + GROUPS.linguistic + ')(.*)', 'i'),
+    useraction: RegExp('^:(?:' + GROUPS.useraction + ')(.*)', 'i'),
+    inputstate: RegExp('^:(?:' + GROUPS.inputstate + ')(.*)', 'i'),
+    inputvalue: RegExp('^:(?:' + GROUPS.inputvalue + ')(.*)', 'i'),
+    locationpc: RegExp('^:(?:' + GROUPS.locationpc + ')(.*)', 'i'),
+    logicalsel: RegExp('^:(?:' + GROUPS.logicalsel + ')(.*)', 'i'),
+    pseudo_nop: RegExp('^:(?:' + GROUPS.pseudo_nop + ')(.*)', 'i'),
+    pseudo_sng: RegExp('^:(?:' + GROUPS.pseudo_sng + ')(.*)', 'i'),
+    pseudo_dbl: RegExp('^:(?:' + GROUPS.pseudo_dbl + ')(.*)', 'i'),
+    // combinator symbols
+    children: RegExp('^' + WSP + '?\\>' + WSP + '?(.*)'),
+    adjacent: RegExp('^' + WSP + '?\\+' + WSP + '?(.*)'),
+    relative: RegExp('^' + WSP + '?\\~' + WSP + '?(.*)'),
+    ancestor: RegExp('^' + WSP + '+(.*)'),
+   // universal & namespace
+   universal: RegExp('^\\*(.*)'),
+   namespace: RegExp('^(\\w+|\\*)?\\|(.*)')
+  },
+
+  // regexp to aproximate detection of RTL languages (Arabic)
+  RTL = RegExp('^[\\u0591-\\u08ff\\ufb1d-\\ufdfd\\ufe70-\\ufefc ]+$'),
+
+  // emulate firefox error strings
+  qsNotArgs = 'Not enough arguments',
+  qsInvalid = ' is not a valid selector',
+
+  // detect structural pseudo-classes in selectors
+  reNthElem = RegExp('(:nth(?:-last)?-child)', 'i'),
+  reNthType = RegExp('(:nth(?:-last)?-of-type)', 'i'),
+
+  // placeholder for global regexp
+  reOptimizer,
+  reValidator,
+
+  // special handling configuration flags
+  Config = {
+    IDS_DUPES: true,
+    MIXEDCASE: true,
+    LOGERRORS: true,
+    VERBOSITY: true
+  },
+
+  NAMESPACE,
+  QUIRKS_MODE,
+  HTML_DOCUMENT,
+
+  ATTR_STD_OPS = {
+    '=': 1, '^=': 1, '$=': 1, '|=': 1, '*=': 1, '~=': 1
+  },
+
+  HTML_TABLE = {
+    'accept': 1, 'accept-charset': 1, 'align': 1, 'alink': 1, 'axis': 1,
+    'bgcolor': 1, 'charset': 1, 'checked': 1, 'clear': 1, 'codetype': 1, 'color': 1,
+    'compact': 1, 'declare': 1, 'defer': 1, 'dir': 1, 'direction': 1, 'disabled': 1,
+    'enctype': 1, 'face': 1, 'frame': 1, 'hreflang': 1, 'http-equiv': 1, 'lang': 1,
+    'language': 1, 'link': 1, 'media': 1, 'method': 1, 'multiple': 1, 'nohref': 1,
+    'noresize': 1, 'noshade': 1, 'nowrap': 1, 'readonly': 1, 'rel': 1, 'rev': 1,
+    'rules': 1, 'scope': 1, 'scrolling': 1, 'selected': 1, 'shape': 1, 'target': 1,
+    'text': 1, 'type': 1, 'valign': 1, 'valuetype': 1, 'vlink': 1
+  },
+
+  Combinators = { },
+
+  Selectors = { },
+
+  Operators = {
+     '=': { p1: '^',
+            p2: '$',
+            p3: 'true' },
+    '^=': { p1: '^',
+            p2: '',
+            p3: 'true' },
+    '$=': { p1: '',
+            p2: '$',
+            p3: 'true' },
+    '*=': { p1: '',
+            p2: '',
+            p3: 'true' },
+    '|=': { p1: '^',
+            p2: '(-|$)',
+            p3: 'true' },
+    '~=': { p1: '(^|\\s)',
+            p2: '(\\s|$)',
+            p3: 'true' }
+  },
+
+  concatCall =
+    function(nodes, callback) {
+      var i = 0, l = nodes.length, list = Array(l);
+      while (l > i) {
+        if (false === callback(list[i] = nodes[i])) break;
+        ++i;
+      }
+      return list;
+    },
+
+  concatList =
+    function(list, nodes) {
+      var i = -1, l = nodes.length;
+      while (l--) { list[list.length] = nodes[++i]; }
+      return list;
+    },
+
+  documentOrder =
+    function(a, b) {
+      if (!hasDupes && a === b) {
+        hasDupes = true;
+        return 0;
+      }
+      return a.compareDocumentPosition(b) & 4 ? -1 : 1;
+    },
+
+  hasDupes = false,
+
+  unique =
+    function(nodes) {
+      var i = 0, j = -1, l = nodes.length + 1, list = [ ];
+      while (--l) {
+        if (nodes[i++] === nodes[i]) continue;
+        list[++j] = nodes[i - 1];
+      }
+      hasDupes = false;
+      return list;
+    },
+
+  // check context for mixed content
+  hasMixedCaseTagNames =
+    function(context) {
+      var ns, api = 'getElementsByTagNameNS';
+
+      // current host context (ownerDocument)
+      context = context.ownerDocument || context;
+
+      // documentElement (root) element namespace or default html/xhtml namespace
+      ns = context.documentElement.namespaceURI || 'http://www.w3.org/1999/xhtml';
+
+      // checking the number of non HTML nodes in the document
+      return (context[api]('*', '*').length - context[api](ns, '*').length) > 0;
+    },
+
+  switchContext =
+    function(context, force) {
+      var oldDoc = doc;
+      doc = context.ownerDocument || context;
+      if (force || oldDoc !== doc) {
+        // force a new check for each document change
+        // performed before the next select operation
+        root = doc.documentElement;
+        HTML_DOCUMENT = isHTML(doc);
+        QUIRKS_MODE = HTML_DOCUMENT &&
+          doc.compatMode.indexOf('CSS') < 0;
+        NAMESPACE = root && root.namespaceURI;
+        Snapshot.doc = doc;
+        Snapshot.root = root;
+      }
+      return (Snapshot.from = context);
+    },
+
+  // convert single codepoint to UTF-16 encoding
+  codePointToUTF16 =
+    function(codePoint) {
+      // out of range, use replacement character
+      if (codePoint < 1 || codePoint > 0x10ffff ||
+        (codePoint > 0xd7ff && codePoint < 0xe000)) {
+        return '\\ufffd';
+      }
+      // javascript strings are UTF-16 encoded
+      if (codePoint < 0x10000) {
+        var lowHex = '000' + codePoint.toString(16);
+        return '\\u' + lowHex.substr(lowHex.length - 4);
+      }
+      // supplementary high + low surrogates
+      return '\\u' + (((codePoint - 0x10000) >> 0x0a) + 0xd800).toString(16) +
+             '\\u' + (((codePoint - 0x10000) % 0x400) + 0xdc00).toString(16);
+    },
+
+  // convert single codepoint to string
+  stringFromCodePoint =
+    function(codePoint) {
+      // out of range, use replacement character
+      if (codePoint < 1 || codePoint > 0x10ffff ||
+        (codePoint > 0xd7ff && codePoint < 0xe000)) {
+        return '\ufffd';
+      }
+      if (codePoint < 0x10000) {
+        return String.fromCharCode(codePoint);
+      }
+      return String.fromCodePoint ?
+        String.fromCodePoint(codePoint) :
+        String.fromCharCode(
+          ((codePoint - 0x10000) >> 0x0a) + 0xd800,
+          ((codePoint - 0x10000) % 0x400) + 0xdc00);
+    },
+
+  // convert escape sequence in a CSS string or identifier
+  // to javascript string with javascript escape sequences
+  convertEscapes =
+    function(str) {
+      return REX.HasEscapes.test(str) ?
+        str.replace(REX.FixEscapes,
+          function(substring, p1, p2) {
+            // unescaped " or '
+            return p2 ? '\\' + p2 :
+              // javascript strings are UTF-16 encoded
+              REX.HexNumbers.test(p1) ? codePointToUTF16(parseInt(p1, 16)) :
+              // \' \"
+              REX.EscOrQuote.test(p1) ? substring :
+              // \g \h \. \# etc
+              p1;
+          }
+        ) : str;
+    },
+
+  // convert escape sequence in a CSS string or identifier
+  // to javascript string with characters representations
+  unescapeIdentifier =
+    function(str) {
+      return REX.HasEscapes.test(str) ?
+        str.replace(REX.FixEscapes,
+          function(substring, p1, p2) {
+            // unescaped " or '
+            return p2 ? p2 :
+              // javascript strings are UTF-16 encoded
+              REX.HexNumbers.test(p1) ? stringFromCodePoint(parseInt(p1, 16)) :
+              // \' \"
+              REX.EscOrQuote.test(p1) ? substring :
+              // \g \h \. \# etc
+              p1;
+          }
+        ) : str;
+    },
+
+  method = {
+    '#': 'getElementById',
+    '*': 'getElementsByTagName',
+    '|': 'getElementsByTagNameNS',
+    '.': 'getElementsByClassName'
+    },
+
+  compat = {
+    '#': function(c, n) { REX.HasEscapes.test(n) && (n = unescapeIdentifier(n)); return function(e, f) { return byId(n, c); }; },
+    '*': function(c, n) { REX.HasEscapes.test(n) && (n = unescapeIdentifier(n)); return function(e, f) { return byTag(n, c); }; },
+    '|': function(c, n) { REX.HasEscapes.test(n) && (n = unescapeIdentifier(n)); return function(e, f) { return byTag(n, c); }; },
+    '.': function(c, n) { REX.HasEscapes.test(n) && (n = unescapeIdentifier(n)); return function(e, f) { return byClass(n, c); }; }
+    },
+
+  // find duplicate ids using iterative walk
+  byIdRaw =
+    function(id, context) {
+      var node = context, nodes = [ ], next = node.firstElementChild;
+      while ((node = next)) {
+        node.id == id && (nodes[nodes.length] = node);
+        if ((next = node.firstElementChild || node.nextElementSibling)) continue;
+        while (!next && (node = node.parentElement) && node !== context) {
+          next = node.nextElementSibling;
+        }
+      }
+      return nodes;
+    },
+
+  // context agnostic getElementById
+  byId =
+    function(id, context) {
+      var e, nodes, api = method['#'];
+
+      // duplicates id allowed
+      if (Config.IDS_DUPES === false) {
+        if (api in context) {
+          return (e = context[api](id)) ? [ e ] : none;
+        }
+      } else {
+        if ('all' in context) {
+          if ((e = context.all[id])) {
+            if (e.nodeType == 1) return e.getAttribute('id') != id ? [ ] : [ e ];
+            else if (id == 'length') return (e = context[api](id)) ? [ e ] : none;
+            for (i = 0, l = e.length, nodes = [ ]; l > i; ++i) {
+              if (e[i].id == id) nodes[nodes.length] = e[i];
+            }
+            return nodes && nodes.length ? nodes : [ nodes ];
+          } else return none;
+        }
+      }
+
+      return byIdRaw(id, context);
+    },
+
+  // context agnostic getElementsByTagName
+  byTag =
+    function(tag, context) {
+      var e, nodes, api = method['*'];
+      // DOCUMENT_NODE (9) & ELEMENT_NODE (1)
+      if (api in context) {
+        return slice.call(context[api](tag));
+      } else {
+        tag = tag.toLowerCase();
+        // DOCUMENT_FRAGMENT_NODE (11)
+        if ((e = context.firstElementChild)) {
+          if (!(e.nextElementSibling || tag == '*' || e.localName == tag)) {
+            return slice.call(e[api](tag));
+          } else {
+            nodes = [ ];
+            do {
+              if (tag == '*' || e.localName == tag) nodes[nodes.length] = e;
+              concatList(nodes, e[api](tag));
+            } while ((e = e.nextElementSibling));
+          }
+        } else nodes = none;
+      }
+      return nodes;
+    },
+
+  // context agnostic getElementsByClassName
+  byClass =
+    function(cls, context) {
+      var e, nodes, api = method['.'], reCls;
+      // DOCUMENT_NODE (9) & ELEMENT_NODE (1)
+      if (api in context) {
+        return slice.call(context[api](cls));
+      } else {
+        // DOCUMENT_FRAGMENT_NODE (11)
+        if ((e = context.firstElementChild)) {
+          reCls = RegExp('(^|\\s)' + cls + '(\\s|$)', QUIRKS_MODE ? 'i' : '');
+          if (!(e.nextElementSibling || reCls.test(e.className))) {
+            return slice.call(e[api](cls));
+          } else {
+            nodes = [ ];
+            do {
+              if (reCls.test(e.className)) nodes[nodes.length] = e;
+              concatList(nodes, e[api](cls));
+            } while ((e = e.nextElementSibling));
+          }
+        } else nodes = none;
+      }
+      return nodes;
+    },
+
+  // namespace aware hasAttribute
+  // helper for XML/XHTML documents
+  hasAttributeNS =
+    function(e, name) {
+      var i, l, attr = e.getAttributeNames();
+      name = RegExp(':?' + name + '$', HTML_DOCUMENT ? 'i' : '');
+      for (i = 0, l = attr.length; l > i; ++i) {
+        if (name.test(attr[i])) return true;
+      }
+      return false;
+    },
+
+  // fast resolver for the :nth-child() and :nth-last-child() pseudo-classes
+  nthElement = (function() {
+    var idx = 0, len = 0, set = 0, parent = undefined, parents = Array(), nodes = Array();
+    return function(element, dir) {
+      // ensure caches are emptied after each run, invoking with dir = 2
+      if (dir == 2) {
+        idx = 0; len = 0; set = 0; nodes.length = 0;
+        parents.length = 0; parent = undefined;
+        return -1;
+      }
+      var e, i, j, k, l;
+      if (parent === element.parentElement) {
+        i = set; j = idx; l = len;
+      } else {
+        l = parents.length;
+        parent = element.parentElement;
+        for (i = -1, j = 0, k = l - 1; l > j; ++j, --k) {
+          if (parents[j] === parent) { i = j; break; }
+          if (parents[k] === parent) { i = k; break; }
+        }
+        if (i < 0) {
+          parents[i = l] = parent;
+          l = 0; nodes[i] = Array();
+          e = parent && parent.firstElementChild || element;
+          while (e) { nodes[i][l] = e; if (e === element) j = l; e = e.nextElementSibling; ++l; }
+          set = i; idx = 0; len = l;
+          if (l < 2) return l;
+        } else {
+          l = nodes[i].length;
+          set = i;
+        }
+      }
+      if (element !== nodes[i][j] && element !== nodes[i][j = 0]) {
+        for (j = 0, e = nodes[i], k = l - 1; l > j; ++j, --k) {
+          if (e[j] === element) { break; }
+          if (e[k] === element) { j = k; break; }
+        }
+      }
+      idx = j + 1; len = l;
+      return dir ? l - j : idx;
+    };
+  })(),
+
+  // fast resolver for the :nth-of-type() and :nth-last-of-type() pseudo-classes
+  nthOfType = (function() {
+    var idx = 0, len = 0, set = 0, parent = undefined, parents = Array(), nodes = Array();
+    return function(element, dir) {
+      // ensure caches are emptied after each run, invoking with dir = 2
+      if (dir == 2) {
+        idx = 0; len = 0; set = 0; nodes.length = 0;
+        parents.length = 0; parent = undefined;
+        return -1;
+      }
+      var e, i, j, k, l, name = element.localName;
+      if (nodes[set] && nodes[set][name] && parent === element.parentElement) {
+        i = set; j = idx; l = len;
+      } else {
+        l = parents.length;
+        parent = element.parentElement;
+        for (i = -1, j = 0, k = l - 1; l > j; ++j, --k) {
+          if (parents[j] === parent) { i = j; break; }
+          if (parents[k] === parent) { i = k; break; }
+        }
+        if (i < 0 || !nodes[i][name]) {
+          parents[i = l] = parent;
+          nodes[i] || (nodes[i] = Object());
+          l = 0; nodes[i][name] = Array();
+          e = parent && parent.firstElementChild || element;
+          while (e) { if (e === element) j = l; if (e.localName == name) { nodes[i][name][l] = e; ++l; } e = e.nextElementSibling; }
+          set = i; idx = j; len = l;
+          if (l < 2) return l;
+        } else {
+          l = nodes[i][name].length;
+          set = i;
+        }
+      }
+      if (element !== nodes[i][name][j] && element !== nodes[i][name][j = 0]) {
+        for (j = 0, e = nodes[i][name], k = l - 1; l > j; ++j, --k) {
+          if (e[j] === element) { break; }
+          if (e[k] === element) { j = k; break; }
+        }
+      }
+      idx = j + 1; len = l;
+      return dir ? l - j : idx;
+    };
+  })(),
+
+  // check if the document type is HTML
+  isHTML =
+    function(node) {
+      var doc = node.ownerDocument || node;
+      return doc.nodeType == 9 &&
+        // contentType not in IE <= 11
+        'contentType' in doc ?
+          doc.contentType.indexOf('/html') > 0 :
+          doc.createElement('DiV').localName == 'div';
+    },
+
+  // configure the engine to use special handling
+  configure =
+    function(option, clear) {
+      if (typeof option == 'string') { return !!Config[option]; }
+      if (typeof option != 'object') { return Config; }
+      for (var i in option) {
+        Config[i] = !!option[i];
+      }
+      // clear lambda cache
+      if (clear) {
+        matchResolvers = { };
+        selectResolvers = { };
+      }
+      setIdentifierSyntax();
+      return true;
+    },
+
+  // centralized error and exceptions handling
+  emit =
+    function(message, proto) {
+      var err;
+      if (Config.VERBOSITY) {
+        if (proto) {
+          err = new proto(message);
+        } else {
+          err = new global.DOMException(message, 'SyntaxError');
+        }
+        throw err;
+      }
+      if (Config.LOGERRORS && console && console.log) {
+        console.log(message);
+      }
+    },
+
+  // execute the engine initialization code
+  initialize =
+    function(doc) {
+      setIdentifierSyntax();
+      lastContext = switchContext(doc, true);
+    },
+
+  // build validation regexps used by the engine
+  setIdentifierSyntax =
+    function() {
+
+      //
+      // NOTE: SPECIAL CASES IN CSS SYNTAX PARSING RULES
+      //
+      // The <EOF-token> https://drafts.csswg.org/css-syntax/#typedef-eof-token
+      // allow mangled|unclosed selector syntax at the end of selectors strings
+      //
+      // Literal equivalent hex representations of the characters: " ' ` ] )
+      //
+      //     \\x22 = " - double quotes    \\x5b = [ - open square bracket
+      //     \\x27 = ' - single quote     \\x5d = ] - closed square bracket
+      //     \\x60 = ` - back tick        \\x28 = ( - open round parens
+      //     \\x5c = \ - back slash       \\x29 = ) - closed round parens
+      //
+      // using hex format prevents false matches of opened/closed instances
+      // pairs, coloring breakage and other editors highlightning problems.
+      //
+
+      var identifier =
+        // doesn't start with a digit
+        '(?=[^0-9])' +
+        // can start with double dash
+        '(?:-{2}' +
+          // may include ascii chars
+          '|[a-zA-Z0-9-_]' +
+          // non-ascii chars
+          '|[^\\x00-\\x9f]' +
+          // escaped chars
+          '|\\\\[^\\r\\n\\f0-9a-fA-F]' +
+          // unicode chars
+          '|\\\\[0-9a-fA-F]{1,6}(?:\\r\\n|\\s)?' +
+          // any escaped chars
+          '|\\\\.' +
+        ')+',
+
+      pseudonames = '[-\\w]+',
+      pseudoparms = '(?:[-+]?\\d*)(?:n\\s?[-+]?\\s?\\d*)',
+      doublequote = '"[^"\\\\]*(?:\\\\.[^"\\\\]*)*(?:"|$)',
+      singlequote = "'[^'\\\\]*(?:\\\\.[^'\\\\]*)*(?:'|$)",
+
+      attrparser = identifier + '|' + doublequote + '|' + singlequote,
+
+      attrvalues = '([\\x22\\x27]?)((?!\\3)*|(?:\\\\?.)*?)(?:\\3|$)',
+
+      attributes =
+        '\\[' +
+          // attribute presence
+          '(?:\\*\\|)?' +
+          WSP + '?' +
+          '(' + identifier + '(?::' + identifier + ')?)' +
+          WSP + '?' +
+          '(?:' +
+            '(' + CFG.operators + ')' + WSP + '?' +
+            '(?:' + attrparser + ')' +
+          ')?' +
+          // attribute case sensitivity
+          '(?:' + WSP + '?\\b(i))?' + WSP + '?' +
+        '(?:\\]|$)',
+
+      attrmatcher = attributes.replace(attrparser, attrvalues),
+
+      pseudoclass =
+        '(?:\\x28' + WSP + '*' +
+          '(?:' + pseudoparms + '?)?|' +
+          // universal * &
+          // namespace *|*
+          '(?:\\*|\\|)|' +
+          '(?:' +
+            '(?::' + pseudonames +
+            '(?:\\x28' + pseudoparms + '?(?:\\x29|$))?|' +
+          ')|' +
+          '(?:[.#]?' + identifier + ')|' +
+          '(?:' + attributes + ')' +
+          ')+|' +
+          '(?:' + WSP + '?,' + WSP + '?)|' +
+          '(?:' + WSP + '?)|' +
+          '(?:\\x29|$))*',
+
+      standardValidator =
+        '(?=' + WSP + '?[^>+~(){}<>])' +
+        '(?:' +
+          // universal * &
+          // namespace *|*
+          '(?:\\*|\\|)|' +
+          '(?:[.#]?' + identifier + ')+|' +
+          '(?:' + attributes + ')+|' +
+          '(?:::?' + pseudonames + pseudoclass + ')|' +
+          '(?:' + WSP + '?' + CFG.combinators + WSP + '?)|' +
+          '(?:' + WSP + '?,' + WSP + '?)|' +
+          '(?:' + WSP + '?)' +
+        ')+';
+
+      // the following global RE is used to return the
+      // deepest localName in selector strings and then
+      // use it to retrieve all possible matching nodes
+      // that will be filtered by compiled resolvers
+      reOptimizer = RegExp(
+        '(?:([.:#*]?)' +
+        '(' + identifier + ')' +
+        '(?:' +
+          ':[-\\w]+|' +
+          '\\[[^\\]]+(?:\\]|$)|' +
+          '\\x28[^\\x29]+(?:\\x29|$)' +
+        ')*)$');
+
+      // global
+      reValidator = RegExp(standardValidator, 'g');
+
+      Patterns.id = RegExp('^#(' + identifier + ')(.*)');
+      Patterns.tagName = RegExp('^(' + identifier + ')(.*)');
+      Patterns.className = RegExp('^\\.(' + identifier + ')(.*)');
+      Patterns.attribute = RegExp('^(?:' + attrmatcher + ')(.*)');
+    },
+
+  F_INIT = '"use strict";return function Resolver(c,f,x,r)',
+
+  S_HEAD = 'var e,n,o,j=r.length-1,k=-1',
+  M_HEAD = 'var e,n,o',
+
+  S_LOOP = 'main:while((e=c[++k]))',
+  N_LOOP = 'main:while((e=c.item(++k)))',
+  M_LOOP = 'e=c;',
+
+  S_BODY = 'r[++j]=c[k];',
+  N_BODY = 'r[++j]=c.item(k);',
+  M_BODY = '',
+
+  S_TAIL = 'continue main;',
+  M_TAIL = 'r=true;',
+
+  S_TEST = 'if(f(c[k])){break main;}',
+  N_TEST = 'if(f(c.item(k))){break main;}',
+  M_TEST = 'f(c);',
+
+  S_VARS = [ ],
+  M_VARS = [ ],
+
+  // compile groups or single selector strings into
+  // executable functions for matching or selecting
+  compile =
+    function(selector, mode, callback) {
+      var factory, token, head = '', loop = '', macro = '', source = '', vars = '';
+
+      // 'mode' can be boolean or null
+      // true = select / false = match
+      // null to use collection.item()
+      switch (mode) {
+        case true:
+          if (selectLambdas[selector]) { return selectLambdas[selector]; }
+          macro = S_BODY + (callback ? S_TEST : '') + S_TAIL;
+          head = S_HEAD;
+          loop = S_LOOP;
+          break;
+        case false:
+          if (matchLambdas[selector]) { return matchLambdas[selector]; }
+          macro = M_BODY + (callback ? M_TEST : '') + M_TAIL;
+          head = M_HEAD;
+          loop = M_LOOP;
+          break;
+        case null:
+          if (selectLambdas[selector]) { return selectLambdas[selector]; }
+          macro = N_BODY + (callback ? N_TEST : '') + S_TAIL;
+          head = S_HEAD;
+          loop = N_LOOP;
+          break;
+        default:
+          break;
+      }
+
+      source = compileSelector(selector, macro, mode, callback);
+
+      loop += mode || mode === null ? '{' + source + '}' : source;
+
+      if (mode || mode === null && selector.includes(':nth')) {
+        loop += reNthElem.test(selector) ? 's.nthElement(null, 2);' : '';
+        loop += reNthType.test(selector) ? 's.nthOfType(null, 2);' : '';
+      }
+
+      if (S_VARS[0] || M_VARS[0]) {
+        vars = ',' + (S_VARS.join(',') || M_VARS.join(','));
+        S_VARS.length = 0;
+        M_VARS.length = 0;
+      }
+
+      factory = Function('s', F_INIT + '{' + head + vars + ';' + loop + 'return r;}')(Snapshot);
+
+      return mode || mode === null ? (selectLambdas[selector] = factory) : (matchLambdas[selector] = factory);
+    },
+
+  // build conditional code to check components of selector strings
+  compileSelector =
+    function(expression, source, mode, callback) {
+
+      // N is the negation pseudo-class flag
+      // D is the default inverted negation flag
+      var a, b, n, f, i, l, name, NS, N = '', D = '!',
+      compat, expr, match, result, status, symbol, test,
+      type, selector = expression, selector_string, vars;
+
+      // original 'select' or 'match' selector string before normalization
+      selector_string = mode ? lastSelected : lastMatched;
+
+      // isolate selector combinators/components and normalize whitespace
+      selector = selector.replace(STD.combinator, '$1');//.replace(STD.whitespace, ' ');
+
+      // javascript needs a label to break
+      // out of the while loops processing
+      selector_recursion_label:
+
+      while (selector) {
+
+        // get namespace prefix if present or get first char of selector
+        symbol = STD.apimethods.test(selector) ? '|' : selector[0];
+
+        switch (symbol) {
+
+          // universal resolver
+          case '*':
+            match = selector.match(Patterns.universal);
+            if (N == '!') {
+              source = 'if(' + N + 'true' +
+                '){' + source + '}';
+            }
+            break;
+
+          // id resolver
+          case '#':
+            match = selector.match(Patterns.id);
+            source = 'if(' + N + '(/^' + match[1] + '$/.test(e.getAttribute("id"))' +
+              ')){' + source + '}';
+            break;
+
+          // class name resolver
+          case '.':
+            match = selector.match(Patterns.className);
+            compat = (QUIRKS_MODE ? 'i' : '') + '.test(e.getAttribute("class"))';
+            source = 'if(' + N + '(/(^|\\s)' + match[1] + '(\\s|$)/' + compat +
+              ')){' + source + '}';
+            break;
+
+          // tag name resolver
+          case (/[_a-z]/i.test(symbol) ? symbol : undefined):
+            match = selector.match(Patterns.tagName);
+            source = 'if(' + N + '(e.localName' +
+              (Config.MIXEDCASE || hasMixedCaseTagNames(doc) ?
+                '=="' + match[1].toLowerCase() + '"' :
+                '=="' + match[1].toUpperCase() + '"') +
+              ')){' + source + '}';
+            break;
+
+          // namespace resolver
+          case '|':
+            match = selector.match(Patterns.namespace);
+            if (match[1] == '*') {
+              source = 'if(' + N + 'true){' + source + '}';
+            } else if (!match[1]) {
+              source = 'if(' + N + '(!e.namespaceURI)){' + source + '}';
+            } else if (typeof match[1] == 'string' && root.prefix == match[1]) {
+              source = 'if(' + N + '(e.namespaceURI=="' + NAMESPACE + '")){' + source + '}';
+            } else {
+              emit('\'' + selector_string + '\'' + qsInvalid);
+            }
+            break;
+
+          // attributes resolver
+          case '[':
+            match = selector.match(Patterns.attribute);
+            NS = match[0].match(STD.namespaces);
+            name = match[1];
+            expr = name.split(':');
+            expr = expr.length == 2 ? expr[1] : expr[0];
+            if (match[2] && !(test = Operators[match[2]])) {
+              emit('\'' + selector_string + '\'' + qsInvalid);
+              return '';
+            }
+            if (match[4] === '') {
+              test = match[2] == '~=' ?
+                { p1: '^\\s', p2: '+$', p3: 'true' } :
+                  match[2] in ATTR_STD_OPS && match[2] != '~=' ?
+                { p1: '^',    p2: '$',  p3: 'true' } : test;
+            } else if (match[2] == '~=' && match[4].includes(' ')) {
+              // whitespace separated list but value contains space
+              source = 'if(' + N + 'false){' + source + '}';
+              break;
+            } else if (match[4]) {
+              match[4] = convertEscapes(match[4]).replace(REX.RegExpChar, '\\$&');
+            }
+            type = match[5] == 'i' || (HTML_DOCUMENT && HTML_TABLE[expr.toLowerCase()]) ? 'i' : '';
+            source = 'if(' + N + '(' +
+              (!match[2] ? (NS ? 's.hasAttributeNS(e,"' + name + '")' : 'e.hasAttribute&&e.hasAttribute("' + name + '")') :
+              !match[4] && ATTR_STD_OPS[match[2]] && match[2] != '~=' ? 'e.getAttribute&&e.getAttribute("' + name + '")==""' :
+              '(/' + test.p1 + match[4] + test.p2 + '/' + type + ').test(e.getAttribute&&e.getAttribute("' + name + '"))==' + test.p3) +
+              ')){' + source + '}';
+            break;
+
+          // *** General sibling combinator
+          // E ~ F (F relative sibling of E)
+          case '~':
+            match = selector.match(Patterns.relative);
+            source = 'n=e;while((e=e.previousElementSibling)){' + source + '}e=n;';
+            break;
+          // *** Adjacent sibling combinator
+          // E + F (F adiacent sibling of E)
+          case '+':
+            match = selector.match(Patterns.adjacent);
+            source = 'n=e;if((e=e.previousElementSibling)){' + source + '}e=n;';
+            break;
+          // *** Descendant combinator
+          // E F (E ancestor of F)
+          case '\x09':
+          case '\x20':
+            match = selector.match(Patterns.ancestor);
+            source = 'n=e;while((e=e.parentElement)){' + source + '}e=n;';
+            break;
+          // *** Child combinator
+          // E > F (F children of E)
+          case '>':
+            match = selector.match(Patterns.children);
+            source = 'n=e;if((e=e.parentElement)){' + source + '}e=n;';
+            break;
+
+          // *** user supplied combinators extensions
+          case (symbol in Combinators ? symbol : undefined):
+            // for other registered combinators extensions
+            match[match.length - 1] = '*';
+            source = Combinators[symbol](match) + source;
+            break;
+
+          // *** tree-structural pseudo-classes
+          // :root, :empty, :first-child, :last-child, :only-child, :first-of-type, :last-of-type, :only-of-type
+          case ':':
+            if ((match = selector.match(Patterns.structural))) {
+              match[1] = match[1].toLowerCase();
+              switch (match[1]) {
+                case 'root':
+                  // there can only be one :root element, so exit the loop once found
+                  source = 'if(' + N + '(e===s.root)){' + source + (mode ? 'break main;' : '') + '}';
+                  break;
+                case 'empty':
+                  // matches elements that don't contain elements or text nodes
+                  source = 'n=e.firstChild;while(n&&!(/1|3/).test(n.nodeType)){n=n.nextSibling}if(' + D + 'n){' + source + '}';
+                  break;
+
+                // *** child-indexed pseudo-classes
+                // :first-child, :last-child, :only-child
+                case 'only-child':
+                  source = 'if(' + N + '(!e.nextElementSibling&&!e.previousElementSibling)){' + source + '}';
+                  break;
+                case 'last-child':
+                  source = 'if(' + N + '(!e.nextElementSibling)){' + source + '}';
+                  break;
+                case 'first-child':
+                  source = 'if(' + N + '(!e.previousElementSibling)){' + source + '}';
+                  break;
+
+                // *** typed child-indexed pseudo-classes
+                // :only-of-type, :last-of-type, :first-of-type
+                case 'only-of-type':
+                  source = 'o=e.localName;' +
+                    'n=e;while((n=n.nextElementSibling)&&n.localName!=o);if(!n){' +
+                    'n=e;while((n=n.previousElementSibling)&&n.localName!=o);}if(' + D + 'n){' + source + '}';
+                  break;
+                case 'last-of-type':
+                  source = 'n=e;o=e.localName;while((n=n.nextElementSibling)&&n.localName!=o);if(' + D + 'n){' + source + '}';
+                  break;
+                case 'first-of-type':
+                  source = 'n=e;o=e.localName;while((n=n.previousElementSibling)&&n.localName!=o);if(' + D + 'n){' + source + '}';
+                  break;
+                default:
+                  emit('\'' + selector_string + '\'' + qsInvalid);
+                  break;
+              }
+            }
+
+            // *** child-indexed & typed child-indexed pseudo-classes
+            // :nth-child, :nth-of-type, :nth-last-child, :nth-last-of-type
+            else if ((match = selector.match(Patterns.treestruct))) {
+              match[1] = match[1].toLowerCase();
+              switch (match[1]) {
+                case 'nth-child':
+                case 'nth-of-type':
+                case 'nth-last-child':
+                case 'nth-last-of-type':
+                  expr = /-of-type/i.test(match[1]);
+                  if (match[1] && match[2]) {
+                    type = /last/i.test(match[1]);
+                    if (match[2] == 'n') {
+                      source = 'if(' + N + 'true){' + source + '}';
+                      break;
+                    } else if (match[2] == '1') {
+                      test = type ? 'next' : 'previous';
+                      source = expr ? 'n=e;o=e.localName;' +
+                        'while((n=n.' + test + 'ElementSibling)&&n.localName!=o);if(' + D + 'n){' + source + '}' :
+                        'if(' + N + '!e.' + test + 'ElementSibling){' + source + '}';
+                      break;
+                    } else if (match[2] == 'even' || match[2] == '2n0' || match[2] == '2n+0' || match[2] == '2n') {
+                      test = 'n%2==0';
+                    } else if (match[2] == 'odd'  || match[2] == '2n1' || match[2] == '2n+1') {
+                      test = 'n%2==1';
+                    } else {
+                      f = /n/i.test(match[2]);
+                      n = match[2].split('n');
+                      a = parseInt(n[0], 10) || 0;
+                      b = parseInt(n[1], 10) || 0;
+                      if (n[0] == '-') { a = -1; }
+                      if (n[0] == '+') { a = +1; }
+                      test = (b ? '(n' + (b > 0 ? '-' : '+') + Math.abs(b) + ')' : 'n') + '%' + a + '==0' ;
+                      test =
+                        a >= +1 ? (f ? 'n>' + (b - 1) + (Math.abs(a) != 1 ? '&&' + test : '') : 'n==' + a) :
+                        a <= -1 ? (f ? 'n<' + (b + 1) + (Math.abs(a) != 1 ? '&&' + test : '') : 'n==' + a) :
+                        a === 0 ? (n[0] ? 'n==' + b : 'n>' + (b - 1)) : 'false';
+                    }
+                    expr = expr ? 'OfType' : 'Element';
+                    type = type ? 'true' : 'false';
+                    source = 'n=s.nth' + expr + '(e,' + type + ');if(' + N + '(' + test + ')){' + source + '}';
+                  } else {
+                    emit('\'' + selector_string + '\'' + qsInvalid);
+                  }
+                  break;
+                default:
+                  emit('\'' + selector_string + '\'' + qsInvalid);
+                  break;
+              }
+            }
+
+            // *** logical combination pseudo-classes
+            // :is( s1, [ s2, ... ]), :not( s1, [ s2, ... ])
+            else if ((match = selector.match(Patterns.logicalsel))) {
+              match[1] = match[1].toLowerCase();
+              switch (match[1]) {
+                case 'is':
+                case 'where':
+                case 'matches':
+                  expr = match[2].replace(REX.CommaGroup, ',').replace(REX.TrimSpaces, '');
+                  source = 'if(s.match("' + expr.replace(/\x22/g, '\\"') + '",e)){' + source + '}';
+                  break;
+                case 'not':
+                  expr = match[2].replace(REX.CommaGroup, ',').replace(REX.TrimSpaces, '');
+                  source = 'if(!s.match("' + expr.replace(/\x22/g, '\\"') + '",e)){' + source + '}';
+                  break;
+                default:
+                  emit('\'' + selector_string + '\'' + qsInvalid);
+                  break;
+              }
+            }
+
+            // *** linguistic pseudo-classes
+            // :dir( ltr / rtl ), :lang( en )
+            else if ((match = selector.match(Patterns.linguistic))) {
+              match[1] = match[1].toLowerCase();
+              switch (match[1]) {
+                case 'dir':
+                  source = 'var p;if(' + N + '(' +
+                    '(/' + match[2] + '/i.test(e.dir))||(p=s.ancestor("[dir]", e))&&' +
+                    '(/' + match[2] + '/i.test(p.dir))||(e.dir==""||e.dir=="auto")&&' +
+                    '(' + (match[2] == 'ltr' ? '!':'')+ RTL +'.test(e.textContent)))' +
+                    '){' + source + '};';
+                  break;
+                case 'lang':
+                  expr = '(?:^|-)' + match[2] + '(?:-|$)';
+                  source = 'var p;if(' + N + '(' +
+                    '(e.isConnected&&(e.lang==""&&(p=s.ancestor("[lang]",e)))&&' +
+                    '(p.lang=="' + match[2] + '")||/'+ expr +'/i.test(e.lang)))' +
+                    '){' + source + '};';
+                  break;
+                default:
+                  emit('\'' + selector_string + '\'' + qsInvalid);
+                  break;
+              }
+            }
+
+            // *** location pseudo-classes
+            // :any-link, :link, :visited, :target
+            else if ((match = selector.match(Patterns.locationpc))) {
+              match[1] = match[1].toLowerCase();
+              switch (match[1]) {
+                case 'any-link':
+                  source = 'if(' + N + '(/^a|area$/i.test(e.localName)&&e.hasAttribute("href")||e.visited)){' + source + '}';
+                  break;
+                case 'link':
+                  source = 'if(' + N + '(/^a|area$/i.test(e.localName)&&e.hasAttribute("href"))){' + source + '}';
+                  break;
+                case 'visited':
+                  source = 'if(' + N + '(/^a|area$/i.test(e.localName)&&e.hasAttribute("href")&&e.visited)){' + source + '}';
+                  break;
+                case 'target':
+                  source = 'if(' + N + '((s.doc.compareDocumentPosition(e)&16)&&s.doc.location.hash&&e.id==s.doc.location.hash.slice(1))){' + source + '}';
+                  break;
+                default:
+                  emit('\'' + selector_string + '\'' + qsInvalid);
+                  break;
+              }
+            }
+
+            // *** user actions pseudo-classes
+            // :hover, :active, :focus
+            else if ((match = selector.match(Patterns.useraction))) {
+              match[1] = match[1].toLowerCase();
+              switch (match[1]) {
+                case 'hover':
+                  source = 'hasFocus' in doc && doc.hasFocus() ?
+                    'if(' + N + '(e===s.doc.hoverElement)){' + source + '}' :
+                    'if(' + D + 'true){' + source + '}';
+                  break;
+                case 'active':
+                  source = 'hasFocus' in doc && doc.hasFocus() ?
+                    'if(' + N + '(e===s.doc.activeElement)){' + source + '}' :
+                    'if(' + D + 'true){' + source + '}';
+                  break;
+                case 'focus':
+                  source = 'hasFocus' in doc ?
+                    'if(' + N + '(e===s.doc.activeElement&&s.doc.hasFocus()&&(e.type||e.href||typeof e.tabIndex=="number"))){' + source + '}' :
+                    'if(' + N + '(e===s.doc.activeElement&&(e.type||e.href))){' + source + '}';
+                  break;
+                case 'focus-within':
+                  source = 'hasFocus' in doc ?
+                    'n=s.doc.activeElement;while(e){if(e===n||e.parentNode===n)break;}' +
+                    'if(' + N + '(e===n&&s.doc.hasFocus()&&(e.type||e.href||typeof e.tabIndex=="number"))){' + source + '}' : source;
+                  break;
+                default:
+                  emit('\'' + selector_string + '\'' + qsInvalid);
+                  break;
+              }
+            }
+
+            // *** user interface and form pseudo-classes
+            // :enabled, :disabled, :read-only, :read-write, :placeholder-shown, :default
+            else if ((match = selector.match(Patterns.inputstate))) {
+              match[1] = match[1].toLowerCase();
+              switch (match[1]) {
+                case 'enabled':
+                  source = 'if(' + N + '(("form" in e||/^optgroup$/i.test(e.localName))&&"disabled" in e &&e.disabled===false' +
+                    ')){' + source + '}';
+                  break;
+                case 'disabled':
+                  // https://www.w3.org/TR/html5/forms.html#enabling-and-disabling-form-controls:-the-disabled-attribute
+                  source = 'if(' + N + '(("form" in e||/^optgroup$/i.test(e.localName))&&"disabled" in e&&' +
+                    '(e.disabled===true||(n=s.ancestor("fieldset",e))&&(n=s.first("legend",n))&&!n.contains(e))' +
+                    ')){' + source + '}';
+                  break;
+                case 'read-only':
+                  source =
+                    'if(' + N + '(' +
+                      '(/^textarea$/i.test(e.localName)&&(e.readOnly||e.disabled))||' +
+                      '("|password|text|".includes("|"+e.type+"|")&&e.readOnly)' +
+                    ')){' + source + '}';
+                  break;
+                case 'read-write':
+                  source =
+                    'if(' + N + '(' +
+                      '((/^textarea$/i.test(e.localName)&&!e.readOnly&&!e.disabled)||' +
+                      '("|password|text|".includes("|"+e.type+"|")&&!e.readOnly&&!e.disabled))||' +
+                      '(e.hasAttribute("contenteditable")||(s.doc.designMode=="on"))' +
+                    ')){' + source + '}';
+                  break;
+                case 'placeholder-shown':
+                  source =
+                    'if(' + N + '(' +
+                      '(/^input|textarea$/i.test(e.localName))&&e.hasAttribute("placeholder")&&' +
+                      '("|textarea|password|number|search|email|text|tel|url|".includes("|"+e.type+"|"))&&' +
+                      '(!s.match(":focus",e))' +
+                    ')){' + source + '}';
+                  break;
+                case 'default':
+                  source =
+                    'if(' + N + '("form" in e && e.form)){' +
+                      'var x=0;n=[];' +
+                      'if(e.type=="image")n=e.form.getElementsByTagName("input");' +
+                      'if(e.type=="submit")n=e.form.elements;' +
+                      'while(n[x]&&e!==n[x]){' +
+                        'if(n[x].type=="image")break;' +
+                        'if(n[x].type=="submit")break;' +
+                        'x++;' +
+                      '}' +
+                    '}' +
+                    'if(' + N + '(e.form&&(e===n[x]&&"|image|submit|".includes("|"+e.type+"|"))||' +
+                      '((/^option$/i.test(e.localName))&&e.defaultSelected)||' +
+                      '(("|radio|checkbox|".includes("|"+e.type+"|"))&&e.defaultChecked)' +
+                    ')){' + source + '}';
+                  break;
+                default:
+                  emit('\'' + selector_string + '\'' + qsInvalid);
+                  break;
+              }
+            }
+
+            // *** input pseudo-classes (for form validation)
+            // :checked, :indeterminate, :valid, :invalid, :in-range, :out-of-range, :required, :optional
+            else if ((match = selector.match(Patterns.inputvalue))) {
+              match[1] = match[1].toLowerCase();
+              switch (match[1]) {
+                case 'checked':
+                  source = 'if(' + N + '(/^input$/i.test(e.localName)&&' +
+                    '("|radio|checkbox|".includes("|"+e.type+"|")&&e.checked)||' +
+                    '(/^option$/i.test(e.localName)&&(e.selected||e.checked))' +
+                    ')){' + source + '}';
+                  break;
+                case 'indeterminate':
+                  source =
+                    'if(' + N + '(/^progress$/i.test(e.localName)&&!e.hasAttribute("value"))||' +
+                      '(/^input$/i.test(e.localName)&&("checkbox"==e.type&&e.indeterminate)||' +
+                      '("radio"==e.type&&e.name&&!s.first("input[name="+e.name+"]:checked",e.form))' +
+                    ')){' + source + '}';
+                  break;
+                case 'required':
+                  source =
+                    'if(' + N +
+                      '(/^input|select|textarea$/i.test(e.localName)&&e.required)' +
+                    '){' + source + '}';
+                  break;
+                case 'optional':
+                  source =
+                    'if(' + N +
+                      '(/^input|select|textarea$/i.test(e.localName)&&!e.required)' +
+                    '){' + source + '}';
+                  break;
+                case 'invalid':
+                  source =
+                    'if(' + N + '((' +
+                      '(/^form$/i.test(e.localName)&&!e.noValidate)||' +
+                      '(e.willValidate&&!e.formNoValidate))&&!e.checkValidity())||' +
+                      '(/^fieldset$/i.test(e.localName)&&s.first(":invalid",e))' +
+                    '){' + source + '}';
+                  break;
+                case 'valid':
+                  source =
+                    'if(' + N + '((' +
+                      '(/^form$/i.test(e.localName)&&!e.noValidate)||' +
+                      '(e.willValidate&&!e.formNoValidate))&&e.checkValidity())||' +
+                      '(/^fieldset$/i.test(e.localName)&&s.first(":valid",e))' +
+                    '){' + source + '}';
+                  break;
+                case 'in-range':
+                  source =
+                    'if(' + N +
+                      '(/^input$/i.test(e.localName))&&' +
+                      '(e.willValidate&&!e.formNoValidate)&&' +
+                      '(!e.validity.rangeUnderflow&&!e.validity.rangeOverflow)&&' +
+                      '("|date|datetime-local|month|number|range|time|week|".includes("|"+e.type+"|"))&&' +
+                      '("range"==e.type||e.getAttribute("min")||e.getAttribute("max"))' +
+                    '){' + source + '}';
+                  break;
+                case 'out-of-range':
+                  source =
+                    'if(' + N +
+                      '(/^input$/i.test(e.localName))&&' +
+                      '(e.willValidate&&!e.formNoValidate)&&' +
+                      '(e.validity.rangeUnderflow||e.validity.rangeOverflow)&&' +
+                      '("|date|datetime-local|month|number|range|time|week|".includes("|"+e.type+"|"))&&' +
+                      '("range"==e.type||e.getAttribute("min")||e.getAttribute("max"))' +
+                    '){' + source + '}';
+                  break;
+                default:
+                  emit('\'' + selector_string + '\'' + qsInvalid);
+                  break;
+              }
+            }
+
+            // allow pseudo-elements starting with single colon (:)
+            // :after, :before, :first-letter, :first-line
+            // assert: e.type is in double-colon format, like ::after
+            else if ((match = selector.match(Patterns.pseudo_sng))) {
+              source = 'if(e.element&&e.type.toLowerCase()=="' +
+                ':' + match[0].toLowerCase() + '"){e=e.element;' + source + '}';
+            }
+
+            // allow pseudo-elements starting with double colon (::)
+            // ::after, ::before, ::marker, ::placeholder, ::inactive-selection, ::selection, ::-webkit-<foo-bar>
+            // assert: e.type is in double-colon format, like ::after
+            else if ((match = selector.match(Patterns.pseudo_dbl))) {
+              source = 'if(e.element&&e.type.toLowerCase()=="' +
+                match[0].toLowerCase() + '"){e=e.element;' + source + '}';
+            }
+
+            // placeholder for parsed only no-op selectors
+            else if ((match = selector.match(Patterns.pseudo_nop))) {
+              source = 'if(' + N + 'false' + '){' + source + '}';
+            }
+
+            else {
+
+              // reset
+              expr = false;
+              status = false;
+
+              // process registered selector extensions
+              for (expr in Selectors) {
+                if ((match = selector.match(Selectors[expr].Expression))) {
+                  result = Selectors[expr].Callback(match, source, mode, callback);
+                  if ('match' in result) { match = result.match; }
+                  vars = result.modvar;
+                  if (mode) {
+                     // add extra select() vars
+                     vars && S_VARS.indexOf(vars) < 0 && (S_VARS[S_VARS.length] = vars);
+                  } else {
+                     // add extra match() vars
+                     vars && M_VARS.indexOf(vars) < 0 && (M_VARS[M_VARS.length] = vars);
+                  }
+                  // extension source code
+                  source = result.source;
+                  // extension status code
+                  status = result.status;
+                  // break on status error
+                  if (status) { break; }
+                }
+              }
+
+              if (!status) {
+                emit('unknown pseudo-class selector \'' + selector + '\'');
+                return '';
+              }
+
+              if (!expr) {
+                emit('unknown token in selector \'' + selector + '\'');
+                return '';
+              }
+
+            }
+            break;
+
+        default:
+          emit('\'' + selector_string + '\'' + qsInvalid);
+          break selector_recursion_label;
+
+        }
+        // end of switch symbol
+
+        if (!match) {
+          emit('\'' + selector_string + '\'' + qsInvalid);
+          return '';
+        }
+
+        // pop last component
+        selector = match.pop();
+      }
+      // end of while selector
+
+      return source;
+    },
+
+  // replace ':scope' pseudo-class with element references
+  makeref =
+    function(selectors, element) {
+      return selectors.replace(/:scope/ig,
+        element.localName +
+        (element.id ? '#' + element.id : '') +
+        (element.className ? '.' + element.classList[0] : ''));
+    },
+
+  // equivalent of w3c 'closest' method
+  ancestor =
+    function _closest(selectors, element, callback) {
+
+      if ((/:scope/i).test(selectors)) {
+        selectors = makeref(selectors, element);
+      }
+
+      while (element) {
+        if (match(selectors, element, callback)) break;
+        element = element.parentElement;
+      }
+      return element;
+    },
+
+  match_assert =
+    function(f, element, callback) {
+      for (var i = 0, l = f.length, r = false; l > i; ++i)
+        f[i](element, callback, null, false) && (r = true);
+      return r;
+    },
+
+  match_collect =
+    function(selectors, callback) {
+      for (var i = 0, l = selectors.length, f = [ ]; l > i; ++i)
+        f[i] = compile(selectors[i], false, callback);
+      return { factory: f };
+    },
+
+  // equivalent of w3c 'matches' method
+  match =
+    function _matches(selectors, element, callback) {
+
+      var expressions, parsed;
+
+      if (element && matchResolvers[selectors]) {
+        return match_assert(matchResolvers[selectors].factory, element, callback);
+      }
+
+      lastMatched = selectors;
+
+      // arguments validation
+      if (arguments.length === 0) {
+        emit(qsNotArgs, TypeError);
+        return Config.VERBOSITY ? undefined : false;
+      } else if (arguments[0] === '') {
+        emit('\'\'' + qsInvalid);
+        return Config.VERBOSITY ? undefined : false;
+      }
+
+      // input NULL or UNDEFINED
+      if (typeof selectors != 'string') {
+        selectors = '' + selectors;
+      }
+
+      if ((/:scope/i).test(selectors)) {
+        selectors = makeref(selectors, element);
+      }
+
+      // normalize input string
+      parsed = selectors.
+        replace(/\x00|\\$/g, '\ufffd').
+        replace(REX.CombineWSP, '\x20').
+        replace(REX.PseudosWSP, '$1').
+        replace(REX.TabCharWSP, '\t').
+        replace(REX.CommaGroup, ',').
+        replace(REX.TrimSpaces, '');
+
+      // parse, validate and split possible compound selectors
+      if ((expressions = parsed.match(reValidator)) && expressions.join('') == parsed) {
+        expressions = parsed.match(REX.SplitGroup);
+        if (parsed[parsed.length - 1] == ',') {
+          emit(qsInvalid);
+          return Config.VERBOSITY ? undefined : false;
+        }
+      } else {
+        emit('\'' + selectors + '\'' + qsInvalid);
+        return Config.VERBOSITY ? undefined : false;
+      }
+
+      matchResolvers[selectors] = match_collect(expressions, callback);
+
+      return match_assert(matchResolvers[selectors].factory, element, callback);
+    },
+
+  // equivalent of w3c 'querySelector' method
+  first =
+    function _querySelector(selectors, context, callback) {
+      if (arguments.length === 0) {
+        emit(qsNotArgs, TypeError);
+      }
+      return select(selectors, context,
+        typeof callback == 'function' ?
+        function firstMatch(element) {
+          callback(element);
+          return false;
+        } :
+        function firstMatch() {
+          return false;
+        }
+      )[0] || null;
+    },
+
+  // equivalent of w3c 'querySelectorAll' method
+  select =
+    function _querySelectorAll(selectors, context, callback) {
+
+      var expressions, nodes = [ ], parsed, resolver;
+
+      context || (context = doc);
+
+      if (selectors) {
+        if ((resolver = selectResolvers[selectors])) {
+          if (resolver.context === context && resolver.callback === callback) {
+            var f = resolver.factory, h = resolver.htmlset, n = resolver.nodeset;
+            if (n.length > 1) {
+              for (var i = 0, l = n.length, list; l > i; ++i) {
+                list = compat[n[i][0]](context, n[i].slice(1))();
+                if (f[i] !== null) {
+                  f[i](list, callback, context, nodes);
+                } else {
+                  nodes = nodes.concat(list);
+                }
+              }
+              if (l > 1 && nodes.length > 1) {
+                nodes.sort(documentOrder);
+                hasDupes && (nodes = unique(nodes));
+              }
+            } else {
+              if (f[0]) {
+                nodes = f[0](h[0](), callback, context, nodes);
+              } else {
+                nodes = h[0]();
+              }
+            }
+            return typeof callback == 'function' ?
+              concatCall(nodes, callback) : nodes;
+          }
+        }
+      }
+
+      lastSelected = selectors;
+
+      // arguments validation
+      if (arguments.length === 0) {
+        emit(qsNotArgs, TypeError);
+        return Config.VERBOSITY ? undefined : none;
+      } else if (arguments[0] === '') {
+        emit('\'\'' + qsInvalid);
+        return Config.VERBOSITY ? undefined : none;
+      } else if (lastContext !== context) {
+        lastContext = switchContext(context);
+      }
+
+      // input NULL or UNDEFINED
+      if (typeof selectors != 'string') {
+        selectors = '' + selectors;
+      }
+
+      if ((/:scope/i).test(selectors)) {
+        selectors = makeref(selectors, context);
+      }
+
+      // normalize input string
+      parsed = selectors.
+        replace(/\x00|\\$/g, '\ufffd').
+        replace(REX.CombineWSP, '\x20').
+        replace(REX.PseudosWSP, '$1').
+        replace(REX.TabCharWSP, '\t').
+        replace(REX.CommaGroup, ',').
+        replace(REX.TrimSpaces, '');
+
+      // parse, validate and split possible compound selectors
+      if ((expressions = parsed.match(reValidator)) && expressions.join('') == parsed) {
+        expressions = parsed.match(REX.SplitGroup);
+        if (parsed[parsed.length - 1] == ',') {
+          emit(qsInvalid);
+          return Config.VERBOSITY ? undefined : false;
+        }
+      } else {
+        emit('\'' + selectors + '\'' + qsInvalid);
+        return Config.VERBOSITY ? undefined : false;
+      }
+
+      // save/reuse factory and closure collection
+      selectResolvers[selectors] = collect(expressions, context, callback);
+
+      nodes = selectResolvers[selectors].results;
+
+      return typeof callback == 'function' ?
+        concatCall(nodes, callback) : nodes;
+    },
+
+  // optimize selectors avoiding duplicated checks
+  optimize =
+    function(selector, token) {
+      var index = token.index,
+      length = token[1].length + token[2].length;
+      return selector.slice(0, index) +
+        (' >+~'.indexOf(selector.charAt(index - 1)) > -1 ?
+          (':['.indexOf(selector.charAt(index + length + 1)) > -1 ?
+          '*' : '') : '') + selector.slice(index + length - (token[1] == '*' ? 1 : 0));
+    },
+
+  // prepare factory resolvers and closure collections
+  collect =
+    function(selectors, context, callback) {
+
+      var i, l, seen = { }, token = ['', '*', '*'], optimized = selectors,
+      factory = [ ], htmlset = [ ], nodeset = [ ], results = [ ], type;
+
+      for (i = 0, l = selectors.length; l > i; ++i) {
+
+        if (!seen[selectors[i]] && (seen[selectors[i]] = true)) {
+          type = selectors[i].match(reOptimizer);
+          if (type && type[1] != ':' && (token = type)) {
+            token[1] || (token[1] = '*');
+            optimized[i] = optimize(optimized[i], token);
+          } else {
+            token = ['', '*', '*'];
+          }
+        }
+
+        nodeset[i] = token[1] + token[2];
+        htmlset[i] = compat[token[1]](context, token[2]);
+        factory[i] = compile(optimized[i], true, null);
+
+        factory[i] ?
+          factory[i](htmlset[i](), callback, context, results) :
+          result.concat(htmlset[i]());
+      }
+
+      if (l > 1) {
+        results.sort(documentOrder);
+        hasDupes && (results = unique(results));
+      }
+
+      return {
+        callback: callback,
+        context: context,
+        factory: factory,
+        htmlset: htmlset,
+        nodeset: nodeset,
+        results: results
+      };
+
+    },
+
+  // QSA placeholders to native references
+  _closest, _matches, _querySelector, _querySelectorAll,
+
+  // overrides QSA methods (only for browsers)
+  install =
+    function(all) {
+
+      // save native QSA references
+      _closest = Element.prototype.closest;
+      _matches = Element.prototype.matches;
+      _querySelector = Document.prototype.querySelector;
+      _querySelectorAll = Document.prototype.querySelectorAll;
+
+      Element.prototype.closest =
+        function closest() {
+          var ctor = Object.getPrototypeOf(this).__proto__.__proto__.constructor.name;
+          if (!('nodeType' in this)) { emit('\'closest\' called on an object that does not implement interface ' + ctor + '.', TypeError); }
+          return arguments.length < 1 ? ancestor.apply(this, [ ]) :
+                 arguments.length < 2 ? ancestor.apply(this, [ arguments[0], this ]) :
+                                        ancestor.apply(this, [ arguments[0], this, typeof arguments[1] == 'function' ? arguments[1] : undefined ]);
+        };
+
+      Element.prototype.matches =
+        function matches() {
+          var ctor = Object.getPrototypeOf(this).__proto__.__proto__.constructor.name;
+          if (!('nodeType' in this)) { emit('\'matches\' called on an object that does not implement interface ' + ctor + '.', TypeError); }
+          return arguments.length < 1 ? match.apply(this, [ ]) :
+                 arguments.length < 2 ? match.apply(this, [ arguments[0], this ]) :
+                                        match.apply(this, [ arguments[0], this, typeof arguments[1] == 'function' ? arguments[1] : undefined ]);
+        };
+
+      Element.prototype.querySelector =
+      Document.prototype.querySelector =
+      DocumentFragment.prototype.querySelector =
+        function querySelector() {
+          var ctor = Object.getPrototypeOf(this).__proto__.__proto__.constructor.name;
+          if (!('nodeType' in this)) { emit('\'querySelector\' called on an object that does not implement interface ' + ctor + '.', TypeError); }
+          return arguments.length < 1 ? first.apply(this, [ ]) :
+                 arguments.length < 2 ? first.apply(this, [ arguments[0], this ]) :
+                                        first.apply(this, [ arguments[0], this, typeof arguments[1] == 'function' ? arguments[1] : undefined ]);
+        };
+
+      Element.prototype.querySelectorAll =
+      Document.prototype.querySelectorAll =
+      DocumentFragment.prototype.querySelectorAll =
+        function querySelectorAll() {
+          var ctor = Object.getPrototypeOf(this).__proto__.__proto__.constructor.name;
+          if (!('nodeType' in this)) { emit('\'querySelectorAll\' called on an object that does not implement interface ' + ctor + '.', TypeError); }
+          return arguments.length < 1 ? select.apply(this, [ ]) :
+                 arguments.length < 2 ? select.apply(this, [ arguments[0], this ]) :
+                                        select.apply(this, [ arguments[0], this, typeof arguments[1] == 'function' ? arguments[1] : undefined ]);
+        };
+
+      if (all) {
+        document.addEventListener('load', function(e) {
+          var c, d, r, s, t = e.target;
+          if (/iframe/i.test(t.localName)) {
+            c = '(' + Export + ')(this, ' + Factory + ');'; d = t.contentDocument;
+            s = d.createElement('script'); s.textContent = c + 'NW.Dom.install()';
+            r = d.documentElement; r.removeChild(r.insertBefore(s, r.firstChild));
+          }
+        }, true);
+      }
+
+    },
+
+  // restore QSA methods (only for browsers)
+  uninstall =
+    function() {
+      // reinstates QSA native references
+      Element.prototype.closest = _closest;
+      Element.prototype.matches = _matches;
+      Element.prototype.querySelector =
+      Document.prototype.querySelector =
+      DocumentFragment.prototype.querySelector = _querySelector;
+      Element.prototype.querySelectorAll =
+      Document.prototype.querySelectorAll =
+      DocumentFragment.prototype.querySelectorAll = _querySelectorAll;
+    },
+
+  // empty set
+  none = Array(),
+
+  // context
+  lastContext,
+
+  // selector
+  lastMatched,
+  lastSelected,
+
+  // cached lambdas
+  matchLambdas = { },
+  selectLambdas = { },
+
+  // cached resolvers
+  matchResolvers = { },
+  selectResolvers = { },
+
+  // passed to resolvers
+  Snapshot = {
+
+    doc: doc,
+    from: doc,
+    root: root,
+
+    byTag: byTag,
+
+    first: first,
+    match: match,
+
+    ancestor: ancestor,
+
+    nthOfType: nthOfType,
+    nthElement: nthElement,
+
+    hasAttributeNS: hasAttributeNS
+  },
+
+  // public exported methods/objects
+  Dom = {
+
+    // exported cache objects
+
+    lastMatched: lastMatched,
+    lastSelected: lastSelected,
+
+    matchLambdas: matchLambdas,
+    selectLambdas: selectLambdas,
+
+    matchResolvers: matchResolvers,
+    selectResolvers: selectResolvers,
+
+    // exported compiler macros
+
+    CFG: CFG,
+
+    M_BODY: M_BODY,
+    S_BODY: S_BODY,
+    M_TEST: M_TEST,
+    S_TEST: S_TEST,
+
+    // exported engine methods
+
+    byId: byId,
+    byTag: byTag,
+    byClass: byClass,
+
+    match: match,
+    first: first,
+    select: select,
+    closest: ancestor,
+
+    compile: compile,
+    configure: configure,
+
+    emit: emit,
+    Config: Config,
+    Snapshot: Snapshot,
+
+    Version: version,
+
+    install: install,
+    uninstall: uninstall,
+
+    Operators: Operators,
+    Selectors: Selectors,
+
+    // register a new selector combinator symbol and its related function resolver
+    registerCombinator:
+      function(combinator, resolver) {
+        var i = 0, l = combinator.length, symbol;
+        for (; l > i; ++i) {
+          if (combinator[i] != '=') {
+            symbol = combinator[i];
+            break;
+          }
+        }
+        if (CFG.combinators.indexOf(symbol) < 0) {
+          CFG.combinators = CFG.combinators.replace('](', symbol + '](');
+          CFG.combinators = CFG.combinators.replace('])', symbol + '])');
+          Combinators[combinator] = resolver;
+          setIdentifierSyntax();
+        } else {
+          console.warn('Warning: the \'' + combinator + '\' combinator is already registered.');
+        }
+      },
+
+    // register a new attribute operator symbol and its related function resolver
+    registerOperator:
+      function(operator, resolver) {
+        var i = 0, l = operator.length, symbol;
+        for (; l > i; ++i) {
+          if (operator[i] != '=') {
+            symbol = operator[i];
+            break;
+          }
+        }
+        if (CFG.operators.indexOf(symbol) < 0 && !Operators[operator]) {
+          CFG.operators = CFG.operators.replace(']=', symbol + ']=');
+          Operators[operator] = resolver;
+          setIdentifierSyntax();
+        } else {
+          console.warn('Warning: the \'' + operator + '\' operator is already registered.');
+        }
+      },
+
+    // register a new selector symbol and its related function resolver
+    registerSelector:
+      function(name, rexp, func) {
+        Selectors[name] || (Selectors[name] = {
+          Expression: rexp,
+          Callback: func
+        });
+      }
+
+  };
+
+  initialize(doc);
+
+  return Dom;
+
+});