},

"selected": function( elem ) {
// Accessing this property makes selected-by-default
// options in Safari work properly
if ( elem.parentNode ) {
elem.parentNode.selectedIndex;
}

return elem.selected === true;
},

// Contents
"empty": function( elem ) {
// http://www.w3.org/TR/selectors/#empty-pseudo
// :empty is negated by element (1) or content nodes (text: 3; cdata: 4; entity ref: 5),
// but not by others (comment: 8; processing instruction: 7; etc.)
// nodeType < 6 works because attributes (2) do not appear as children
for ( elem = elem.firstChild; elem; elem = elem.nextSibling ) {
if ( elem.nodeType < 6 ) {
return false;
}
}
return true;
},

"parent": function( elem ) {
return !Expr.pseudos["empty"]( elem );
},

// Element/input types
"header": function( elem ) {
return rheader.test( elem.nodeName );
},

"input": function( elem ) {
return rinputs.test( elem.nodeName );
},

"button": function( elem ) {
var name = elem.nodeName.toLowerCase();
return name === "input" && elem.type === "button" || name === "button";
},

"text": function( elem ) {
var attr;
return elem.nodeName.toLowerCase() === "input" &&
elem.type === "text" &&

// Support: IE<8
// New HTML5 attribute values (e.g., "search") appear with elem.type === "text"
( (attr = elem.getAttribute("type")) == null || attr.toLowerCase() === "text" );
},

// Position-in-collection
"first": createPositionalPseudo(function() {
return [ 0 ];
}),

"last": createPositionalPseudo(function( matchIndexes, length ) {
return [ length - 1 ];
}),

"eq": createPositionalPseudo(function( matchIndexes, length, argument ) {
return [ argument < 0 ? argument + length : argument ];
}),

"even": createPositionalPseudo(function( matchIndexes, length ) {
var i = 0;
for ( ; i < length; i += 2 ) {
matchIndexes.push( i );
}
return matchIndexes;
}),

"odd": createPositionalPseudo(function( matchIndexes, length ) {
var i = 1;
for ( ; i < length; i += 2 ) {
matchIndexes.push( i );
}
return matchIndexes;
}),

"lt": createPositionalPseudo(function( matchIndexes, length, argument ) {
var i = argument < 0 ? argument + length : argument;
for ( ; --i >= 0; ) {
matchIndexes.push( i );
}
return matchIndexes;
}),

"gt": createPositionalPseudo(function( matchIndexes, length, argument ) {
var i = argument < 0 ? argument + length : argument;
for ( ; ++i < length; ) {
matchIndexes.push( i );
}
return matchIndexes;
})
}
};

Expr.pseudos["nth"] = Expr.pseudos["eq"];

// Add button/input type pseudos
for ( i in { radio: true, checkbox: true, file: true, password: true, image: true } ) {
Expr.pseudos[ i ] = createInputPseudo( i );
}
for ( i in { submit: true, reset: true } ) {
Expr.pseudos[ i ] = createButtonPseudo( i );
}

// Easy API for creating new setFilters
function setFilters() {}
setFilters.prototype = Expr.filters = Expr.pseudos;
Expr.setFilters = new setFilters();

tokenize = Sizzle.tokenize = function( selector, parseOnly ) {
var matched, match, tokens, type,
soFar, groups, preFilters,
cached = tokenCache[ selector + " " ];

if ( cached ) {
return parseOnly ? 0 : cached.slice( 0 );
}

soFar = selector;
groups = [];
preFilters = Expr.preFilter;

while ( soFar ) {

// Comma and first run
if ( !matched || (match = rcomma.exec( soFar )) ) {
if ( match ) {
// Don't consume trailing commas as valid
soFar = soFar.slice( match[0].length ) || soFar;
}
groups.push( (tokens = []) );
}

matched = false;

// Combinators
if ( (match = rcombinators.exec( soFar )) ) {
matched = match.shift();
tokens.push({
value: matched,
// Cast descendant combinators to space
type: match[0].replace( rtrim, " " )
});
soFar = soFar.slice( matched.length );
}

// Filters
for ( type in Expr.filter ) {
if ( (match = matchExpr[ type ].exec( soFar )) && (!preFilters[ type ] ||
(match = preFilters[ type ]( match ))) ) {
matched = match.shift();
tokens.push({
value: matched,
type: type,
matches: match
});
soFar = soFar.slice( matched.length );
}
}

if ( !matched ) {
break;
}
}

// Return the length of the invalid excess
// if we're just parsing
// Otherwise, throw an error or return tokens
return parseOnly ?
soFar.length :
soFar ?
Sizzle.error( selector ) :
// Cache the tokens
tokenCache( selector, groups ).slice( 0 );
};

function toSelector( tokens ) {
var i = 0,
len = tokens.length,
selector = "";
for ( ; i < len; i++ ) {
selector += tokens[i].value;
}
return selector;
}

function addCombinator( matcher, combinator, base ) {
var dir = combinator.dir,
checkNonElements = base && dir === "parentNode",
doneName = done++;

return combinator.first ?
// Check against closest ancestor/preceding element
function( elem, context, xml ) {
while ( (elem = elem[ dir ]) ) {
if ( elem.nodeType === 1 || checkNonElements ) {
return matcher( elem, context, xml );
}
}
} :

// Check against all ancestor/preceding elements
function( elem, context, xml ) {
var oldCache, outerCache,
newCache = [ dirruns, doneName ];

// We can't set arbitrary data on XML nodes, so they don't benefit from dir caching
if ( xml ) {
while ( (elem = elem[ dir ]) ) {
if ( elem.nodeType === 1 || checkNonElements ) {
if ( matcher( elem, context, xml ) ) {
return true;
}
}
}
} else {
while ( (elem = elem[ dir ]) ) {
if ( elem.nodeType === 1 || checkNonElements ) {
outerCache = elem[ expando ] || (elem[ expando ] = {});
if ( (oldCache = outerCache[ dir ]) &&
oldCache[ 0 ] === dirruns && oldCache[ 1 ] === doneName ) {

// Assign to newCache so results back-propagate to previous elements