// Build QSA regex
// Regex strategy adopted from Diego Perini
assert(function( div ) {
// Select is set to empty string on purpose
// This is to test IE's treatment of not explictly
// setting a boolean content attribute,
// since its presence should be enough
// http://bugs.jquery.com/ticket/12359
div.innerHTML = "<select><option selected=''></option></select>";

// IE8 - Some boolean attributes are not treated correctly
if ( !div.querySelectorAll("[selected]").length ) {
rbuggyQSA.push( "\\[" + whitespace + "*(?:checked|disabled|ismap|multiple|readonly|selected|value)" );
}

// Webkit/Opera - :checked should return selected option elements
// http://www.w3.org/TR/2011/REC-css3-selectors-20110929/#checked
// IE8 throws error here and will not see later tests
if ( !div.querySelectorAll(":checked").length ) {
rbuggyQSA.push(":checked");
}
});

assert(function( div ) {

// Opera 10-12/IE8 - ^= $= *= and empty values
// Should not select anything
div.innerHTML = "<input type='hidden' i=''/>";
if ( div.querySelectorAll("[i^='']").length ) {
rbuggyQSA.push( "[*^$]=" + whitespace + "*(?:\"\"|'')" );
}

// FF 3.5 - :enabled/:disabled and hidden elements (hidden elements are still enabled)
// IE8 throws error here and will not see later tests
if ( !div.querySelectorAll(":enabled").length ) {
rbuggyQSA.push( ":enabled", ":disabled" );
}

// Opera 10-11 does not throw on post-comma invalid pseudos
div.querySelectorAll("*,:x");
rbuggyQSA.push(",.*:");
});
}

if ( (support.matchesSelector = isNative( (matches = docElem.matchesSelector ||
docElem.mozMatchesSelector ||
docElem.webkitMatchesSelector ||
docElem.oMatchesSelector ||
docElem.msMatchesSelector) )) ) {

assert(function( div ) {
// Check to see if it's possible to do matchesSelector
// on a disconnected node (IE 9)
support.disconnectedMatch = matches.call( div, "div" );

// This should fail with an exception
// Gecko does not error, returns false instead
matches.call( div, "[s!='']:x" );
rbuggyMatches.push( "!=", pseudos );
});
}

rbuggyQSA = new RegExp( rbuggyQSA.join("|") );
rbuggyMatches = new RegExp( rbuggyMatches.join("|") );

// Element contains another
// Purposefully does not implement inclusive descendent
// As in, an element does not contain itself
contains = isNative(docElem.contains) || docElem.compareDocumentPosition ?
function( a, b ) {
var adown = a.nodeType === 9 ? a.documentElement : a,
bup = b && b.parentNode;
return a === bup || !!( bup && bup.nodeType === 1 && (
adown.contains ?
adown.contains( bup ) :
a.compareDocumentPosition && a.compareDocumentPosition( bup ) & 16
));
} :
function( a, b ) {
if ( b ) {
while ( (b = b.parentNode) ) {
if ( b === a ) {
return true;
}
}
}
return false;
};

// Document order sorting
sortOrder = docElem.compareDocumentPosition ?
function( a, b ) {
var compare;

if ( a === b ) {
hasDuplicate = true;
return 0;
}

if ( (compare = b.compareDocumentPosition && a.compareDocumentPosition && a.compareDocumentPosition( b )) ) {
if ( compare & 1 || a.parentNode && a.parentNode.nodeType === 11 ) {
if ( a === doc || contains( preferredDoc, a ) ) {
return -1;
}
if ( b === doc || contains( preferredDoc, b ) ) {
return 1;
}
return 0;
}
return compare & 4 ? -1 : 1;
}

return a.compareDocumentPosition ? -1 : 1;
} :
function( a, b ) {
var cur,
i = 0,
aup = a.parentNode,
bup = b.parentNode,
ap = [ a ],
bp = [ b ];

// Exit early if the nodes are identical
if ( a === b ) {
hasDuplicate = true;
return 0;

// Parentless nodes are either documents or disconnected
} else if ( !aup || !bup ) {
return a === doc ? -1 :
b === doc ? 1 :
aup ? -1 :
bup ? 1 :
0;

// If the nodes are siblings, we can do a quick check
} else if ( aup === bup ) {
return siblingCheck( a, b );
}

// Otherwise we need full lists of their ancestors for comparison
cur = a;
while ( (cur = cur.parentNode) ) {
ap.unshift( cur );
}
cur = b;
while ( (cur = cur.parentNode) ) {
bp.unshift( cur );
}

// Walk down the tree looking for a discrepancy
while ( ap[i] === bp[i] ) {
i++;
}

return i ?
// Do a sibling check if the nodes have a common ancestor
siblingCheck( ap[i], bp[i] ) :

// Otherwise nodes in our document sort first
ap[i] === preferredDoc ? -1 :
bp[i] === preferredDoc ? 1 :
0;
};

// Always assume the presence of duplicates if sort doesn't
// pass them to our comparison function (as in Google Chrome).
hasDuplicate = false;
[0, 0].sort( sortOrder );
support.detectDuplicates = hasDuplicate;

return document;
};

Sizzle.matches = function( expr, elements ) {
return Sizzle( expr, null, null, elements );
};

Sizzle.matchesSelector = function( elem, expr ) {
// Set document vars if needed
if ( ( elem.ownerDocument || elem ) !== document ) {
setDocument( elem );
}

// Make sure that attribute selectors are quoted
expr = expr.replace( rattributeQuotes, "='$1']" );

// rbuggyQSA always contains :focus, so no need for an existence check
if ( support.matchesSelector && !documentIsXML && (!rbuggyMatches || !rbuggyMatches.test(expr)) && !rbuggyQSA.test(expr) ) {
try {
var ret = matches.call( elem, expr );

// IE 9's matchesSelector returns false on disconnected nodes
if ( ret || support.disconnectedMatch ||
// As well, disconnected nodes are said to be in a document
// fragment in IE 9
elem.document && elem.document.nodeType !== 11 ) {
return ret;
}
} catch(e) {}
}

return Sizzle( expr, document, null, [elem] ).length > 0;
};

Sizzle.contains = function( context, elem ) {
// Set document vars if needed
if ( ( context.ownerDocument || context ) !== document ) {
setDocument( context );
}
return contains( context, elem );
};

Sizzle.attr = function( elem, name ) {
var val;

// Set document vars if needed
if ( ( elem.ownerDocument || elem ) !== document ) {
setDocument( elem );