text: /*! Picturefill - v3.0.1
   * http://scottjehl.github.io/picturefill
   * Copyright (c) 2015 https://github.com/scottjehl/picturefill/blob/master/Authors.txt;
   *  License: MIT
   */
  
  (function( window, document, undefined ) {
  	// Enable strict mode
  	"use strict";
  
  	// HTML shim|v it for old IE (IE9 will still need the HTML video tag workaround)
  	document.createElement( "picture" );
  
  	var warn, eminpx, alwaysCheckWDescriptor, evalId;
  	// local object for method references and testing exposure
  	var pf = {};
  	var noop = function() {};
  	var image = document.createElement( "img" );
  	var getImgAttr = image.getAttribute;
  	var setImgAttr = image.setAttribute;
  	var removeImgAttr = image.removeAttribute;
  	var docElem = document.documentElement;
  	var types = {};
  	var cfg = {
  		//resource selection:
  		algorithm: ""
  	};
  	var srcAttr = "data-pfsrc";
  	var srcsetAttr = srcAttr + "set";
  	// ua sniffing is done for undetectable img loading features,
  	// to do some non crucial perf optimizations
  	var ua = navigator.userAgent;
  	var supportAbort = (/rident/).test(ua) || ((/ecko/).test(ua) && ua.match(/rv\:(\d+)/) && RegExp.$1 > 35 );
  	var curSrcProp = "currentSrc";
  	var regWDesc = /\s+\+?\d+(e\d+)?w/;
  	var regSize = /(\([^)]+\))?\s*(.+)/;
  	var setOptions = window.picturefillCFG;
  	/**
  	 * Shortcut property for https://w3c.github.io/webappsec/specs/mixedcontent/#restricts-mixed-content ( for easy overriding in tests )
  	 */
  	// baseStyle also used by getEmValue (i.e.: width: 1em is important)
  	var baseStyle = "position:absolute;left:0;visibility:hidden;display:block;padding:0;border:none;font-size:1em;width:1em;overflow:hidden;clip:rect(0px, 0px, 0px, 0px)";
  	var fsCss = "font-size:100%!important;";
  	var isVwDirty = true;
  
  	var cssCache = {};
  	var sizeLengthCache = {};
  	var DPR = window.devicePixelRatio;
  	var units = {
  		px: 1,
  		"in": 96
  	};
  	var anchor = document.createElement( "a" );
  	/**
  	 * alreadyRun flag used for setOptions. is it true setOptions will reevaluate
  	 * @type {boolean}
  	 */
  	var alreadyRun = false;
  
  	// Reusable, non-"g" Regexes
  
  	// (Don't use \s, to avoid matching non-breaking space.)
  	var regexLeadingSpaces = /^[ \t\n\r\u000c]+/,
  	    regexLeadingCommasOrSpaces = /^[, \t\n\r\u000c]+/,
  	    regexLeadingNotSpaces = /^[^ \t\n\r\u000c]+/,
  	    regexTrailingCommas = /[,]+$/,
  	    regexNonNegativeInteger = /^\d+$/,
  
  	    // ( Positive or negative or unsigned integers or decimals, without or without exponents.
  	    // Must include at least one digit.
  	    // According to spec tests any decimal point must be followed by a digit.
  	    // No leading plus sign is allowed.)
  	    // https://html.spec.whatwg.org/multipage/infrastructure.html#valid-floating-point-number
  	    regexFloatingPoint = /^-?(?:[0-9]+|[0-9]*\.[0-9]+)(?:[eE][+-]?[0-9]+)?$/;
  
  	var on = function(obj, evt, fn, capture) {
  		if ( obj.addEventListener ) {
  			obj.addEventListener(evt, fn, capture || false);
  		} else if ( obj.attachEvent ) {
  			obj.attachEvent( "on" + evt, fn);
  		}
  	};
  
  	/**
  	 * simple memoize function:
  	 */
  
  	var memoize = function(fn) {
  		var cache = {};
  		return function(input) {
  			if ( !(input in cache) ) {
  				cache[ input ] = fn(input);
  			}
  			return cache[ input ];
  		};
  	};
  
  	// UTILITY FUNCTIONS
  
  	// Manual is faster than RegEx
  	// http://jsperf.com/whitespace-character/5
  	function isSpace(c) {
  		return (c === "\u0020" || // space
  		        c === "\u0009" || // horizontal tab
  		        c === "\u000A" || // new line
  		        c === "\u000C" || // form feed
  		        c === "\u000D");  // carriage return
  	}
  
  	/**
  	 * gets a mediaquery and returns a boolean or gets a css length and returns a number
  	 * @param css mediaqueries or css length
  	 * @returns {boolean|number}
  	 *
  	 * based on: https://gist.github.com/jonathantneal/db4f77009b155f083738
  	 */
  	var evalCSS = (function() {
  
  		var regLength = /^([\d\.]+)(em|vw|px)$/;
  		var replace = function() {
  			var args = arguments, index = 0, string = args[0];
  			while (++index in args) {
  				string = string.replace(args[index], args[++index]);
  			}
  			return string;
  		};
  
  		var buildStr = memoize(function(css) {
  
  			return "return " + replace((css || "").toLowerCase(),
  				// interpret `and`
  				/\band\b/g, "&&",
  
  				// interpret `,`
  				/,/g, "||",
  
  				// interpret `min-` as >=
  				/min-([a-z-\s]+):/g, "e.$1>=",
  
  				// interpret `max-` as <=
  				/max-([a-z-\s]+):/g, "e.$1<=",
  
  				//calc value
  				/calc([^)]+)/g, "($1)",
  
  				// interpret css values
  				/(\d+[\.]*[\d]*)([a-z]+)/g, "($1 * e.$2)",
  				//make eval less evil
  				/^(?!(e.[a-z]|[0-9\.&=|><\+\-\*\(\)\/])).*/ig, ""
  			) + ";";
  		});
  
  		return function(css, length) {
  			var parsedLength;
  			if (!(css in cssCache)) {
  				cssCache[css] = false;
  				if (length && (parsedLength = css.match( regLength ))) {
  					cssCache[css] = parsedLength[ 1 ] * units[parsedLength[ 2 ]];
  				} else {
  					/*jshint evil:true */
  					try{
  						cssCache[css] = new Function("e", buildStr(css))(units);
  					} catch(e) {}
  					/*jshint evil:false */
  				}
  			}
  			return cssCache[css];
  		};
  	})();
  
  	var setResolution = function( candidate, sizesattr ) {
  		if ( candidate.w ) { // h = means height: || descriptor.type === 'h' do not handle yet...
  			candidate.cWidth = pf.calcListLength( sizesattr || "100vw" );
  			candidate.res = candidate.w / candidate.cWidth ;
  		} else {
  			candidate.res = candidate.d;
  		}
  		return candidate;
  	};
  
  	/**
  	 *
  	 * @param opt
  	 */
  	var picturefill = function( opt ) {
  		var elements, i, plen;
  
  		var options = opt || {};
  
  		if ( options.elements && options.elements.nodeType === 1 ) {
  			if ( options.elements.nodeName.toUpperCase() === "IMG" ) {
  				options.elements =  [ options.elements ];
  			} else {
  				options.context = options.elements;
  				options.elements =  null;
  			}
  		}
  
  		elements = options.elements || pf.qsa( (options.context || document), ( options.reevaluate || options.reselect ) ? pf.sel : pf.selShort );
  
  		if ( (plen = elements.length) ) {
  
  			pf.setupRun( options );
  			alreadyRun = true;
  
  			// Loop through all elements
  			for ( i = 0; i < plen; i++ ) {
  				pf.fillImg(elements[ i ], options);
  			}
  
  			pf.teardownRun( options );
  		}
  	};
  
  	/**
  	 * outputs a warning for the developer
  	 * @param {message}
  	 * @type {Function}
  	 */
  	warn = ( window.console && console.warn ) ?
  		function( message ) {
  			console.warn( message );
  		} :
  		noop
  	;
  
  	if ( !(curSrcProp in image) ) {
  		curSrcProp = "src";
  	}
  
  	// Add support for standard mime types.
  	types[ "image/jpeg" ] = true;
  	types[ "image/gif" ] = true;
  	types[ "image/png" ] = true;
  
  	function detectTypeSupport( type, typeUri ) {
  		// based on Modernizr's lossless img-webp test
  		// note: asynchronous
  		var image = new window.Image();
  		image.onerror = function() {
  			types[ type ] = false;
  			picturefill();
  		};
  		image.onload = function() {
  			types[ type ] = image.width === 1;
  			picturefill();
  		};
  		image.src = typeUri;
  		return "pending";
  	}
  
  	// test svg support
  	types[ "image/svg+xml" ] = document.implementation.hasFeature( "http://wwwindow.w3.org/TR/SVG11/feature#Image", "1.1" );
  
  	/**
  	 * updates the internal vW property with the current viewport width in px
  	 */
  	function updateMetrics() {
  
  		isVwDirty = false;
  		DPR = window.devicePixelRatio;
  		cssCache = {};
  		sizeLengthCache = {};
  
  		pf.DPR = DPR || 1;
  
  		units.width = Math.max(window.innerWidth || 0, docElem.clientWidth);
  		units.height = Math.max(window.innerHeight || 0, docElem.clientHeight);
  
  		units.vw = units.width / 100;
  		units.vh = units.height / 100;
  
  		evalId = [ units.height, units.width, DPR ].join("-");
  
  		units.em = pf.getEmValue();
  		units.rem = units.em;
  	}
  
  	function chooseLowRes( lowerValue, higherValue, dprValue, isCached ) {
  		var bonusFactor, tooMuch, bonus, meanDensity;
  
  		//experimental
  		if (cfg.algorithm === "saveData" ){
  			if ( lowerValue > 2.7 ) {
  				meanDensity = dprValue + 1;
  			} else {
  				tooMuch = higherValue - dprValue;
  				bonusFactor = Math.pow(lowerValue - 0.6, 1.5);
  
  				bonus = tooMuch * bonusFactor;
  
  				if (isCached) {
  					bonus += 0.1 * bonusFactor;
  				}
  
  				meanDensity = lowerValue + bonus;
  			}
  		} else {
  			meanDensity = (dprValue > 1) ?
  				Math.sqrt(lowerValue * higherValue) :
  				lowerValue;
  		}
  
  		return meanDensity > dprValue;
  	}
  
  	function applyBestCandidate( img ) {
  		var srcSetCandidates;
  		var matchingSet = pf.getSet( img );
  		var evaluated = false;
  		if ( matchingSet !== "pending" ) {
  			evaluated = evalId;
  			if ( matchingSet ) {
  				srcSetCandidates = pf.setRes( matchingSet );
  				pf.applySetCandidate( srcSetCandidates, img );
  			}
  		}
  		img[ pf.ns ].evaled = evaluated;
  	}
  
  	function ascendingSort( a, b ) {
  		return a.res - b.res;
  	}
  
  	function setSrcToCur( img, src, set ) {
  		var candidate;
  		if ( !set && src ) {
  			set = img[ pf.ns ].sets;
  			set = set && set[set.length - 1];
  		}
  
  		candidate = getCandidateForSrc(src, set);
  
  		if ( candidate ) {
  			src = pf.makeUrl(src);
  			img[ pf.ns ].curSrc = src;
  			img[ pf.ns ].curCan = candidate;
  
  			if ( !candidate.res ) {
  				setResolution( candidate, candidate.set.sizes );
  			}
  		}
  		return candidate;
  	}
  
  	function getCandidateForSrc( src, set ) {
  		var i, candidate, candidates;
  		if ( src && set ) {
  			candidates = pf.parseSet( set );
  			src = pf.makeUrl(src);
  			for ( i = 0; i < candidates.length; i++ ) {
  				if ( src === pf.makeUrl(candidates[ i ].url) ) {
  					candidate = candidates[ i ];
  					break;
  				}
  			}
  		}
  		return candidate;
  	}
  
  	function getAllSourceElements( picture, candidates ) {
  		var i, len, source, srcset;
  
  		// SPEC mismatch intended for size and perf:
  		// actually only source elements preceding the img should be used
  		// also note: don't use qsa here, because IE8 sometimes doesn't like source as the key part in a selector
  		var sources = picture.getElementsByTagName( "source" );
  
  		for ( i = 0, len = sources.length; i < len; i++ ) {
  			source = sources[ i ];
  			source[ pf.ns ] = true;
  			srcset = source.getAttribute( "srcset" );
  
  			// if source does not have a srcset attribute, skip
  			if ( srcset ) {
  				candidates.push( {
  					srcset: srcset,
  					media: source.getAttribute( "media" ),
  					type: source.getAttribute( "type" ),
  					sizes: source.getAttribute( "sizes" )
  				} );
  			}
  		}
  	}
  
  	/**
  	 * Srcset Parser
  	 * By Alex Bell |  MIT License
  	 *
  	 * @returns Array [{url: _, d: _, w: _, h:_, set:_(????)}, ...]
  	 *
  	 * Based super duper closely on the reference algorithm at:
  	 * https://html.spec.whatwg.org/multipage/embedded-content.html#parse-a-srcset-attribute
  	 */
  
  	// 1. Let input be the value passed to this algorithm.
  	// (TO-DO : Explain what "set" argument is here. Maybe choose a more
  	// descriptive & more searchable name.  Since passing the "set" in really has
  	// nothing to do with parsing proper, I would prefer this assignment eventually
  	// go in an external fn.)
  	function parseSrcset(input, set) {
  
  		function collectCharacters(regEx) {
  			var chars,
  			    match = regEx.exec(input.substring(pos));
  			if (match) {
  				chars = match[ 0 ];
  				pos += chars.length;
  				return chars;
  			}
  		}
  
  		var inputLength = input.length,
  		    url,
  		    descriptors,
  		    currentDescriptor,
  		    state,
  		    c,
  
  		    // 2. Let position be a pointer into input, initially pointing at the start
  		    //    of the string.
  		    pos = 0,
  
  		    // 3. Let candidates be an initially empty source set.
  		    candidates = [];
  
  		/**
  		* Adds descriptor properties to a candidate, pushes to the candidates array
  		* @return undefined
  		*/
  		// (Declared outside of the while loop so that it's only created once.
  		// (This fn is defined before it is used, in order to pass JSHINT.
  		// Unfortunately this breaks the sequencing of the spec comments. :/ )
  		function parseDescriptors() {
  
  			// 9. Descriptor parser: Let error be no.
  			var pError = false,
  
  			// 10. Let width be absent.
  			// 11. Let density be absent.
  			// 12. Let future-compat-h be absent. (We're implementing it now as h)
  			    w, d, h, i,
  			    candidate = {},
  			    desc, lastChar, value, intVal, floatVal;
  
  			// 13. For each descriptor in descriptors, run the appropriate set of steps
  			// from the following list:
  			for (i = 0 ; i < descriptors.length; i++) {
  				desc = descriptors[ i ];
  
  				lastChar = desc[ desc.length - 1 ];
  				value = desc.substring(0, desc.length - 1);
  				intVal = parseInt(value, 10);
  				floatVal = parseFloat(value);
  
  				// If the descriptor consists of a valid non-negative integer followed by
  				// a U+0077 LATIN SMALL LETTER W character
  				if (regexNonNegativeInteger.test(value) && (lastChar === "w")) {
  
  					// If width and density are not both absent, then let error be yes.
  					if (w || d) {pError = true;}
  
  					// Apply the rules for parsing non-negative integers to the descriptor.
  					// If the result is zero, let error be yes.
  					// Otherwise, let width be the result.
  					if (intVal === 0) {pError = true;} else {w = intVal;}
  
  				// If the descriptor consists of a valid floating-point number followed by
  				// a U+0078 LATIN SMALL LETTER X character
  				} else if (regexFloatingPoint.test(value) && (lastChar === "x")) {
  
  					// If width, density and future-compat-h are not all absent, then let error
  					// be yes.
  					if (w || d || h) {pError = true;}
  
  					// Apply the rules for parsing floating-point number values to the descriptor.
  					// If the result is less than zero, let error be yes. Otherwise, let density
  					// be the result.
  					if (floatVal < 0) {pError = true;} else {d = floatVal;}
  
  				// If the descriptor consists of a valid non-negative integer followed by
  				// a U+0068 LATIN SMALL LETTER H character
  				} else if (regexNonNegativeInteger.test(value) && (lastChar === "h")) {
  
  					// If height and density are not both absent, then let error be yes.
  					if (h || d) {pError = true;}
  
  					// Apply the rules for parsing non-negative integers to the descriptor.
  					// If the result is zero, let error be yes. Otherwise, let future-compat-h
  					// be the result.
  					if (intVal === 0) {pError = true;} else {h = intVal;}
  
  				// Anything else, Let error be yes.
  				} else {pError = true;}
  			} // (close step 13 for loop)
  
  			// 15. If error is still no, then append a new image source to candidates whose
  			// URL is url, associated with a width width if not absent and a pixel
  			// density density if not absent. Otherwise, there is a parse error.
  			if (!pError) {
  				candidate.url = url;
  
  				if (w) { candidate.w = w;}
  				if (d) { candidate.d = d;}
  				if (h) { candidate.h = h;}
  				if (!h && !d && !w) {candidate.d = 1;}
  				if (candidate.d === 1) {set.has1x = true;}
  				candidate.set = set;
  
  				candidates.push(candidate);
  			}
  		} // (close parseDescriptors fn)
  
  		/**
  		* Tokenizes descriptor properties prior to parsing
  		* Returns undefined.
  		* (Again, this fn is defined before it is used, in order to pass JSHINT.
  		* Unfortunately this breaks the logical sequencing of the spec comments. :/ )
  		*/
  		function tokenize() {
  
  			// 8.1. Descriptor tokeniser: Skip whitespace
  			collectCharacters(regexLeadingSpaces);
  
  			// 8.2. Let current descriptor be the empty string.
  			currentDescriptor = "";
  
  			// 8.3. Let state be in descriptor.
  			state = "in descriptor";
  
  			while (true) {
  
  				// 8.4. Let c be the character at position.
  				c = input.charAt(pos);
  
  				//  Do the following depending on the value of state.
  				//  For the purpose of this step, "EOF" is a special character representing
  				//  that position is past the end of input.
  
  				// In descriptor
  				if (state === "in descriptor") {
  					// Do the following, depending on the value of c:
  
  				  // Space character
  				  // If current descriptor is not empty, append current descriptor to
  				  // descriptors and let current descriptor be the empty string.
  				  // Set state to after descriptor.
  					if (isSpace(c)) {
  						if (currentDescriptor) {
  							descriptors.push(currentDescriptor);
  							currentDescriptor = "";
  							state = "after descriptor";
  						}
  
  					// U+002C COMMA (,)
  					// Advance position to the next character in input. If current descriptor
  					// is not empty, append current descriptor to descriptors. Jump to the step
  					// labeled descriptor parser.
  					} else if (c === ",") {
  						pos += 1;
  						if (currentDescriptor) {
  							descriptors.push(currentDescriptor);
  						}
  						parseDescriptors();
  						return;
  
  					// U+0028 LEFT PARENTHESIS (()
  					// Append c to current descriptor. Set state to in parens.
  					} else if (c === "\u0028") {
  						currentDescriptor = currentDescriptor + c;
  						state = "in parens";
  
  					// EOF
  					// If current descriptor is not empty, append current descriptor to
  					// descriptors. Jump to the step labeled descriptor parser.
  					} else if (c === "") {
  						if (currentDescriptor) {
  							descriptors.push(currentDescriptor);
  						}
  						parseDescriptors();
  						return;
  
  					// Anything else
  					// Append c to current descriptor.
  					} else {
  						currentDescriptor = currentDescriptor + c;
  					}
  				// (end "in descriptor"
  
  				// In parens
  				} else if (state === "in parens") {
  
  					// U+0029 RIGHT PARENTHESIS ())
  					// Append c to current descriptor. Set state to in descriptor.
  					if (c === ")") {
  						currentDescriptor = currentDescriptor + c;
  						state = "in descriptor";
  
  					// EOF
  					// Append current descriptor to descriptors. Jump to the step labeled
  					// descriptor parser.
  					} else if (c === "") {
  						descriptors.push(currentDescriptor);
  						parseDescriptors();
  						return;
  
  					// Anything else
  					// Append c to current descriptor.
  					} else {
  						currentDescriptor = currentDescriptor + c;
  					}
  
  				// After descriptor
  				} else if (state === "after descriptor") {
  
  					// Do the following, depending on the value of c:
  					// Space character: Stay in this state.
  					if (isSpace(c)) {
  
  					// EOF: Jump to the step labeled descriptor parser.
  					} else if (c === "") {
  						parseDescriptors();
  						return;
  
  					// Anything else
  					// Set state to in descriptor. Set position to the previous character in input.
  					} else {
  						state = "in descriptor";
  						pos -= 1;
  
  					}
  				}
  
  				// Advance position to the next character in input.
  				pos += 1;
  
  			// Repeat this step.
  			} // (close while true loop)
  		}
  
  		// 4. Splitting loop: Collect a sequence of characters that are space
  		//    characters or U+002C COMMA characters. If any U+002C COMMA characters
  		//    were collected, that is a parse error.
  		while (true) {
  			collectCharacters(regexLeadingCommasOrSpaces);
  
  			// 5. If position is past the end of input, return candidates and abort these steps.
  			if (pos >= inputLength) {
  				return candidates; // (we're done, this is the sole return path)
  			}
  
  			// 6. Collect a sequence of characters that are not space characters,
  			//    and let that be url.
  			url = collectCharacters(regexLeadingNotSpaces);
  
  			// 7. Let descriptors be a new empty list.
  			descriptors = [];
  
  			// 8. If url ends with a U+002C COMMA character (,), follow these substeps:
  			//		(1). Remove all trailing U+002C COMMA characters from url. If this removed
  			//         more than one character, that is a parse error.
  			if (url.slice(-1) === ",") {
  				url = url.replace(regexTrailingCommas, "");
  				// (Jump ahead to step 9 to skip tokenization and just push the candidate).
  				parseDescriptors();
  
  			//	Otherwise, follow these substeps:
  			} else {
  				tokenize();
  			} // (close else of step 8)
  
  		// 16. Return to the step labeled splitting loop.
  		} // (Close of big while loop.)
  	}
  
  	/*
  	 * Sizes Parser
  	 *
  	 * By Alex Bell |  MIT License
  	 *
  	 * Non-strict but accurate and lightweight JS Parser for the string value <img sizes="here">
  	 *
  	 * Reference algorithm at:
  	 * https://html.spec.whatwg.org/multipage/embedded-content.html#parse-a-sizes-attribute
  	 *
  	 * Most comments are copied in directly from the spec
  	 * (except for comments in parens).
  	 *
  	 * Grammar is:
  	 * <source-size-list> = <source-size># [ , <source-size-value> ]? | <source-size-value>
  	 * <source-size> = <media-condition> <source-size-value>
  	 * <source-size-value> = <length>
  	 * http://www.w3.org/html/wg/drafts/html/master/embedded-content.html#attr-img-sizes
  	 *
  	 * E.g. "(max-width: 30em) 100vw, (max-width: 50em) 70vw, 100vw"
  	 * or "(min-width: 30em), calc(30vw - 15px)" or just "30vw"
  	 *
  	 * Returns the first valid <css-length> with a media condition that evaluates to true,
  	 * or "100vw" if all valid media conditions evaluate to false.
  	 *
  	 */
  
  	function parseSizes(strValue) {
  
  		// (Percentage CSS lengths are not allowed in this case, to avoid confusion:
  		// https://html.spec.whatwg.org/multipage/embedded-content.html#valid-source-size-list
  		// CSS allows a single optional plus or minus sign:
  		// http://www.w3.org/TR/CSS2/syndata.html#numbers
  		// CSS is ASCII case-insensitive:
  		// http://www.w3.org/TR/CSS2/syndata.html#characters )
  		// Spec allows exponential notation for <number> type:
  		// http://dev.w3.org/csswg/css-values/#numbers
  		var regexCssLengthWithUnits = /^(?:[+-]?[0-9]+|[0-9]*\.[0-9]+)(?:[eE][+-]?[0-9]+)?(?:ch|cm|em|ex|in|mm|pc|pt|px|rem|vh|vmin|vmax|vw)$/i;
  
  		// (This is a quick and lenient test. Because of optional unlimited-depth internal
  		// grouping parens and strict spacing rules, this could get very complicated.)
  		var regexCssCalc = /^calc\((?:[0-9a-z \.\+\-\*\/\(\)]+)\)$/i;
  
  		var i;
  		var unparsedSizesList;
  		var unparsedSizesListLength;
  		var unparsedSize;
  		var lastComponentValue;
  		var size;
  
  		// UTILITY FUNCTIONS
  
  		//  (Toy CSS parser. The goals here are:
  		//  1) expansive test coverage without the weight of a full CSS parser.
  		//  2) Avoiding regex wherever convenient.
  		//  Quick tests: http://jsfiddle.net/gtntL4gr/3/
  		//  Returns an array of arrays.)
  		function parseComponentValues(str) {
  			var chrctr;
  			var component = "";
  			var componentArray = [];
  			var listArray = [];
  			var parenDepth = 0;
  			var pos = 0;
  			var inComment = false;
  
  			function pushComponent() {
  				if (component) {
  					componentArray.push(component);
  					component = "";
  				}
  			}
  
  			function pushComponentArray() {
  				if (componentArray[0]) {
  					listArray.push(componentArray);
  					componentArray = [];
  				}
  			}
  
  			// (Loop forwards from the beginning of the string.)
  			while (true) {
  				chrctr = str.charAt(pos);
  
  				if (chrctr === "") { // ( End of string reached.)
  					pushComponent();
  					pushComponentArray();
  					return listArray;
  				} else if (inComment) {
  					if ((chrctr === "*") && (str[pos + 1] === "/")) { // (At end of a comment.)
  						inComment = false;
  						pos += 2;
  						pushComponent();
  						continue;
  					} else {
  						pos += 1; // (Skip all characters inside comments.)
  						continue;
  					}
  				} else if (isSpace(chrctr)) {
  					// (If previous character in loop was also a space, or if
  					// at the beginning of the string, do not add space char to
  					// component.)
  					if ( (str.charAt(pos - 1) && isSpace( str.charAt(pos - 1) ) ) || !component ) {
  						pos += 1;
  						continue;
  					} else if (parenDepth === 0) {
  						pushComponent();
  						pos +=1;
  						continue;
  					} else {
  						// (Replace any space character with a plain space for legibility.)
  						chrctr = " ";
  					}
  				} else if (chrctr === "(") {
  					parenDepth += 1;
  				} else if (chrctr === ")") {
  					parenDepth -= 1;
  				} else if (chrctr === ",") {
  					pushComponent();
  					pushComponentArray();
  					pos += 1;
  					continue;
  				} else if ( (chrctr === "/") && (str.charAt(pos + 1) === "*") ) {
  					inComment = true;
  					pos += 2;
  					continue;
  				}
  
  				component = component + chrctr;
  				pos += 1;
  			}
  		}
  
  		function isValidNonNegativeSourceSizeValue(s) {
  			if (regexCssLengthWithUnits.test(s) && (parseFloat(s) >= 0)) {return true;}
  			if (regexCssCalc.test(s)) {return true;}
  			// ( http://www.w3.org/TR/CSS2/syndata.html#numbers says:
  			// "-0 is equivalent to 0 and is not a negative number." which means that
  			// unitless zero and unitless negative zero must be accepted as special cases.)
  			if ((s === "0") || (s === "-0") || (s === "+0")) {return true;}
  			return false;
  		}
  
  		// When asked to parse a sizes attribute from an element, parse a
  		// comma-separated list of component values from the value of the element's
  		// sizes attribute (or the empty string, if the attribute is absent), and let
  		// unparsed sizes list be the result.
  		// http://dev.w3.org/csswg/css-syntax/#parse-comma-separated-list-of-component-values
  
  		unparsedSizesList = parseComponentValues(strValue);
  		unparsedSizesListLength = unparsedSizesList.length;
  
  		// For each unparsed size in unparsed sizes list:
  		for (i = 0; i < unparsedSizesListLength; i++) {
  			unparsedSize = unparsedSizesList[i];
  
  			// 1. Remove all consecutive <whitespace-token>s from the end of unparsed size.
  			// ( parseComponentValues() already omits spaces outside of parens. )
  
  			// If unparsed size is now empty, that is a parse error; continue to the next
  			// iteration of this algorithm.
  			// ( parseComponentValues() won't push an empty array. )
  
  			// 2. If the last component value in unparsed size is a valid non-negative
  			// <source-size-value>, let size be its value and remove the component value
  			// from unparsed size. Any CSS function other than the calc() function is
  			// invalid. Otherwise, there is a parse error; continue to the next iteration
  			// of this algorithm.
  			// http://dev.w3.org/csswg/css-syntax/#parse-component-value
  			lastComponentValue = unparsedSize[unparsedSize.length - 1];
  
  			if (isValidNonNegativeSourceSizeValue(lastComponentValue)) {
  				size = lastComponentValue;
  				unparsedSize.pop();
  			} else {
  				continue;
  			}
  
  			// 3. Remove all consecutive <whitespace-token>s from the end of unparsed
  			// size. If unparsed size is now empty, return size and exit this algorithm.
  			// If this was not the last item in unparsed sizes list, that is a parse error.
  			if (unparsedSize.length === 0) {
  				return size;
  			}
  
  			// 4. Parse the remaining component values in unparsed size as a
  			// <media-condition>. If it does not parse correctly, or it does parse
  			// correctly but the <media-condition> evaluates to false, continue to the
  			// next iteration of this algorithm.
  			// (Parsing all possible compound media conditions in JS is heavy, complicated,
  			// and the payoff is unclear. Is there ever an situation where the
  			// media condition parses incorrectly but still somehow evaluates to true?
  			// Can we just rely on the browser/polyfill to do it?)
  			unparsedSize = unparsedSize.join(" ");
  			if (!(pf.matchesMedia( unparsedSize ) ) ) {
  				continue;
  			}
  
  			// 5. Return size and exit this algorithm.
  			return size;
  		}
  
  		// If the above algorithm exhausts unparsed sizes list without returning a
  		// size value, return 100vw.
  		return "100vw";
  	}
  
  	// namespace
  	pf.ns = ("pf" + new Date().getTime()).substr(0, 9);
  
  	// srcset support test
  	pf.supSrcset = "srcset" in image;
  	pf.supSizes = "sizes" in image;
  	pf.supPicture = !!window.HTMLPictureElement;
  
  	if (pf.supSrcset && pf.supPicture && !pf.supSizes) {
  		(function(image2) {
  			image.srcset = "data:,a";
  			image2.src = "data:,a";
  			pf.supSrcset = image.complete === image2.complete;
  			pf.supPicture = pf.supSrcset && pf.supPicture;
  		})(document.createElement("img"));
  	}
  
  	// using pf.qsa instead of dom traversing does scale much better,
  	// especially on sites mixing responsive and non-responsive images
  	pf.selShort = "picture>img,img[srcset]";
  	pf.sel = pf.selShort;
  	pf.cfg = cfg;
  
  	if ( pf.supSrcset ) {
  		pf.sel += ",img[" + srcsetAttr + "]";
  	}
  
  	/**
  	 * Shortcut property for `devicePixelRatio` ( for easy overriding in tests )
  	 */
  	pf.DPR = (DPR  || 1 );
  	pf.u = units;
  
  	// container of supported mime types that one might need to qualify before using
  	pf.types =  types;
  
  	alwaysCheckWDescriptor = pf.supSrcset && !pf.supSizes;
  
  	pf.setSize = noop;
  
  	/**
  	 * Gets a string and returns the absolute URL
  	 * @param src
  	 * @returns {String} absolute URL
  	 */
  
  	pf.makeUrl = memoize(function(src) {
  		anchor.href = src;
  		return anchor.href;
  	});
  
  	/**
  	 * Gets a DOM element or document and a selctor and returns the found matches
  	 * Can be extended with jQuery/Sizzle for IE7 support
  	 * @param context
  	 * @param sel
  	 * @returns {NodeList}
  	 */
  	pf.qsa = function(context, sel) {
  		return context.querySelectorAll(sel);
  	};
  
  	/**
  	 * Shortcut method for matchMedia ( for easy overriding in tests )
  	 * wether native or pf.mMQ is used will be decided lazy on first call
  	 * @returns {boolean}
  	 */
  	pf.matchesMedia = function() {
  		if ( window.matchMedia && (matchMedia( "(min-width: 0.1em)" ) || {}).matches ) {
  			pf.matchesMedia = function( media ) {
  				return !media || ( matchMedia( media ).matches );
  			};
  		} else {
  			pf.matchesMedia = pf.mMQ;
  		}
  
  		return pf.matchesMedia.apply( this, arguments );
  	};
  
  	/**
  	 * A simplified matchMedia implementation for IE8 and IE9
  	 * handles only min-width/max-width with px or em values
  	 * @param media
  	 * @returns {boolean}
  	 */
  	pf.mMQ = function( media ) {
  		return media ? evalCSS(media) : true;
  	};
  
  	/**
  	 * Returns the calculated length in css pixel from the given sourceSizeValue
  	 * http://dev.w3.org/csswg/css-values-3/#length-value
  	 * intended Spec mismatches:
  	 * * Does not check for invalid use of CSS functions
  	 * * Does handle a computed length of 0 the same as a negative and therefore invalid value
  	 * @param sourceSizeValue
  	 * @returns {Number}
  	 */
  	pf.calcLength = function( sourceSizeValue ) {
  
  		var value = evalCSS(sourceSizeValue, true) || false;
  		if (value < 0) {
  			value = false;
  		}
  
  		return value;
  	};
  
  	/**
  	 * Takes a type string and checks if its supported
  	 */
  
  	pf.supportsType = function( type ) {
  		return ( type ) ? types[ type ] : true;
  	};
  
  	/**
  	 * Parses a sourceSize into mediaCondition (media) and sourceSizeValue (length)
  	 * @param sourceSizeStr
  	 * @returns {*}
  	 */
  	pf.parseSize = memoize(function( sourceSizeStr ) {
  		var match = ( sourceSizeStr || "" ).match(regSize);
  		return {
  			media: match && match[1],
  			length: match && match[2]
  		};
  	});
  
  	pf.parseSet = function( set ) {
  		if ( !set.cands ) {
  			set.cands = parseSrcset(set.srcset, set);
  		}
  		return set.cands;
  	};
  
  	/**
  	 * returns 1em in css px for html/body default size
  	 * function taken from respondjs
  	 * @returns {*|number}
  	 */
  	pf.getEmValue = function() {
  		var body;
  		if ( !eminpx && (body = document.body) ) {
  			var div = document.createElement( "div" ),
  				originalHTMLCSS = docElem.style.cssText,
  				originalBodyCSS = body.style.cssText;
  
  			div.style.cssText = baseStyle;
  
  			// 1em in a media query is the value of the default font size of the browser
  			// reset docElem and body to ensure the correct value is returned
  			docElem.style.cssText = fsCss;
  			body.style.cssText = fsCss;
  
  			body.appendChild( div );
  			eminpx = div.offsetWidth;
  			body.removeChild( div );
  
  			//also update eminpx before returning
  			eminpx = parseFloat( eminpx, 10 );
  
  			// restore the original values
  			docElem.style.cssText = originalHTMLCSS;
  			body.style.cssText = originalBodyCSS;
  
  		}
  		return eminpx || 16;
  	};
  
  	/**
  	 * Takes a string of sizes and returns the width in pixels as a number
  	 */
  	pf.calcListLength = function( sourceSizeListStr ) {
  		// Split up source size list, ie ( max-width: 30em ) 100%, ( max-width: 50em ) 50%, 33%
  		//
  		//                           or (min-width:30em) calc(30% - 15px)
  		if ( !(sourceSizeListStr in sizeLengthCache) || cfg.uT ) {
  			var winningLength = pf.calcLength( parseSizes( sourceSizeListStr ) );
  
  			sizeLengthCache[ sourceSizeListStr ] = !winningLength ? units.width : winningLength;
  		}
  
  		return sizeLengthCache[ sourceSizeListStr ];
  	};
  
  	/**
  	 * Takes a candidate object with a srcset property in the form of url/
  	 * ex. "images/pic-medium.png 1x, images/pic-medium-2x.png 2x" or
  	 *     "images/pic-medium.png 400w, images/pic-medium-2x.png 800w" or
  	 *     "images/pic-small.png"
  	 * Get an array of image candidates in the form of
  	 *      {url: "/foo/bar.png", resolution: 1}
  	 * where resolution is http://dev.w3.org/csswg/css-values-3/#resolution-value
  	 * If sizes is specified, res is calculated
  	 */
  	pf.setRes = function( set ) {
  		var candidates;
  		if ( set ) {
  
  			candidates = pf.parseSet( set );
  
  			for ( var i = 0, len = candidates.length; i < len; i++ ) {
  				setResolution( candidates[ i ], set.sizes );
  			}
  		}
  		return candidates;
  	};
  
  	pf.setRes.res = setResolution;
  
  	pf.applySetCandidate = function( candidates, img ) {
  		if ( !candidates.length ) {return;}
  		var candidate,
  			i,
  			j,
  			length,
  			bestCandidate,
  			curSrc,
  			curCan,
  			candidateSrc,
  			abortCurSrc;
  
  		var imageData = img[ pf.ns ];
  		var dpr = pf.DPR;
  
  		curSrc = imageData.curSrc || img[curSrcProp];
  
  		curCan = imageData.curCan || setSrcToCur(img, curSrc, candidates[0].set);
  
  		// if we have a current source, we might either become lazy or give this source some advantage
  		if ( curCan && curCan.set === candidates[ 0 ].set ) {
  
  			// if browser can abort image request and the image has a higher pixel density than needed
  			// and this image isn't downloaded yet, we skip next part and try to save bandwidth
  			abortCurSrc = (supportAbort && !img.complete && curCan.res - 0.1 > dpr);
  
  			if ( !abortCurSrc ) {
  				curCan.cached = true;
  
  				// if current candidate is "best", "better" or "okay",
  				// set it to bestCandidate
  				if ( curCan.res >= dpr ) {
  					bestCandidate = curCan;
  				}
  			}
  		}
  
  		if ( !bestCandidate ) {
  
  			candidates.sort( ascendingSort );
  
  			length = candidates.length;
  			bestCandidate = candidates[ length - 1 ];
  
  			for ( i = 0; i < length; i++ ) {
  				candidate = candidates[ i ];
  				if ( candidate.res >= dpr ) {
  					j = i - 1;
  
  					// we have found the perfect candidate,
  					// but let's improve this a little bit with some assumptions ;-)
  					if (candidates[ j ] &&
  						(abortCurSrc || curSrc !== pf.makeUrl( candidate.url )) &&
  						chooseLowRes(candidates[ j ].res, candidate.res, dpr, candidates[ j ].cached)) {
  
  						bestCandidate = candidates[ j ];
  
  					} else {
  						bestCandidate = candidate;
  					}
  					break;
  				}
  			}
  		}
  
  		if ( bestCandidate ) {
  
  			candidateSrc = pf.makeUrl( bestCandidate.url );
  
  			imageData.curSrc = candidateSrc;
  			imageData.curCan = bestCandidate;
  
  			if ( candidateSrc !== curSrc ) {
  				pf.setSrc( img, bestCandidate );
  			}
  			pf.setSize( img );
  		}
  	};
  
  	pf.setSrc = function( img, bestCandidate ) {
  		var origWidth;
  		img.src = bestCandidate.url;
  
  		// although this is a specific Safari issue, we don't want to take too much different code paths
  		if ( bestCandidate.set.type === "image/svg+xml" ) {
  			origWidth = img.style.width;
  			img.style.width = (img.offsetWidth + 1) + "px";
  
  			// next line only should trigger a repaint
  			// if... is only done to trick dead code removal
  			if ( img.offsetWidth + 1 ) {
  				img.style.width = origWidth;
  			}
  		}
  	};
  
  	pf.getSet = function( img ) {
  		var i, set, supportsType;
  		var match = false;
  		var sets = img [ pf.ns ].sets;
  
  		for ( i = 0; i < sets.length && !match; i++ ) {
  			set = sets[i];
  
  			if ( !set.srcset || !pf.matchesMedia( set.media ) || !(supportsType = pf.supportsType( set.type )) ) {
  				continue;
  			}
  
  			if ( supportsType === "pending" ) {
  				set = supportsType;
  			}
  
  			match = set;
  			break;
  		}
  
  		return match;
  	};
  
  	pf.parseSets = function( element, parent, options ) {
  		var srcsetAttribute, imageSet, isWDescripor, srcsetParsed;
  
  		var hasPicture = parent && parent.nodeName.toUpperCase() === "PICTURE";
  		var imageData = element[ pf.ns ];
  
  		if ( imageData.src === undefined || options.src ) {
  			imageData.src = getImgAttr.call( element, "src" );
  			if ( imageData.src ) {
  				setImgAttr.call( element, srcAttr, imageData.src );
  			} else {
  				removeImgAttr.call( element, srcAttr );
  			}
  		}
  
  		if ( imageData.srcset === undefined || options.srcset || !pf.supSrcset || element.srcset ) {
  			srcsetAttribute = getImgAttr.call( element, "srcset" );
  			imageData.srcset = srcsetAttribute;
  			srcsetParsed = true;
  		}
  
  		imageData.sets = [];
  
  		if ( hasPicture ) {
  			imageData.pic = true;
  			getAllSourceElements( parent, imageData.sets );
  		}
  
  		if ( imageData.srcset ) {
  			imageSet = {
  				srcset: imageData.srcset,
  				sizes: getImgAttr.call( element, "sizes" )
  			};
  
  			imageData.sets.push( imageSet );
  
  			isWDescripor = (alwaysCheckWDescriptor || imageData.src) && regWDesc.test(imageData.srcset || "");
  
  			// add normal src as candidate, if source has no w descriptor
  			if ( !isWDescripor && imageData.src && !getCandidateForSrc(imageData.src, imageSet) && !imageSet.has1x ) {
  				imageSet.srcset += ", " + imageData.src;
  				imageSet.cands.push({
  					url: imageData.src,
  					d: 1,
  					set: imageSet
  				});
  			}
  
  		} else if ( imageData.src ) {
  			imageData.sets.push( {
  				srcset: imageData.src,
  				sizes: null
  			} );
  		}
  
  		imageData.curCan = null;
  		imageData.curSrc = undefined;
  
  		// if img has picture or the srcset was removed or has a srcset and does not support srcset at all
  		// or has a w descriptor (and does not support sizes) set support to false to evaluate
  		imageData.supported = !( hasPicture || ( imageSet && !pf.supSrcset ) || isWDescripor );
  
  		if ( srcsetParsed && pf.supSrcset && !imageData.supported ) {
  			if ( srcsetAttribute ) {
  				setImgAttr.call( element, srcsetAttr, srcsetAttribute );
  				element.srcset = "";
  			} else {
  				removeImgAttr.call( element, srcsetAttr );
  			}
  		}
  
  		if (imageData.supported && !imageData.srcset && ((!imageData.src && element.src) ||  element.src !== pf.makeUrl(imageData.src))) {
  			if (imageData.src === null) {
  				element.removeAttribute("src");
  			} else {
  				element.src = imageData.src;
  			}
  		}
  
  		imageData.parsed = true;
  	};
  
  	pf.fillImg = function(element, options) {
  		var imageData;
  		var extreme = options.reselect || options.reevaluate;
  
  		// expando for caching data on the img
  		if ( !element[ pf.ns ] ) {
  			element[ pf.ns ] = {};
  		}
  
  		imageData = element[ pf.ns ];
  
  		// if the element has already been evaluated, skip it
  		// unless `options.reevaluate` is set to true ( this, for example,
  		// is set to true when running `picturefill` on `resize` ).
  		if ( !extreme && imageData.evaled === evalId ) {
  			return;
  		}
  
  		if ( !imageData.parsed || options.reevaluate ) {
  			pf.parseSets( element, element.parentNode, options );
  		}
  
  		if ( !imageData.supported ) {
  			applyBestCandidate( element );
  		} else {
  			imageData.evaled = evalId;
  		}
  	};
  
  	pf.setupRun = function() {
  		if ( !alreadyRun || isVwDirty || (DPR !== window.devicePixelRatio) ) {
  			updateMetrics();
  		}
  	};
  
  	// If picture is supported, well, that's awesome.
  	if ( pf.supPicture ) {
  		picturefill = noop;
  		pf.fillImg = noop;
  	} else {
  
  		 // Set up picture polyfill by polling the document
  		(function() {
  			var isDomReady;
  			var regReady = window.attachEvent ? /d$|^c/ : /d$|^c|^i/;
  
  			var run = function() {
  				var readyState = document.readyState || "";
  
  				timerId = setTimeout(run, readyState === "loading" ? 200 :  999);
  				if ( document.body ) {
  					pf.fillImgs();
  					isDomReady = isDomReady || regReady.test(readyState);
  					if ( isDomReady ) {
  						clearTimeout( timerId );
  					}
  
  				}
  			};
  
  			var timerId = setTimeout(run, document.body ? 9 : 99);
  
  			// Also attach picturefill on resize and readystatechange
  			// http://modernjavascript.blogspot.com/2013/08/building-better-debounce.html
  			var debounce = function(func, wait) {
  				var timeout, timestamp;
  				var later = function() {
  					var last = (new Date()) - timestamp;
  
  					if (last < wait) {
  						timeout = setTimeout(later, wait - last);
  					} else {
  						timeout = null;
  						func();
  					}
  				};
  
  				return function() {
  					timestamp = new Date();
  
  					if (!timeout) {
  						timeout = setTimeout(later, wait);
  					}
  				};
  			};
  			var lastClientWidth = docElem.clientHeight;
  			var onResize = function() {
  				isVwDirty = Math.max(window.innerWidth || 0, docElem.clientWidth) !== units.width || docElem.clientHeight !== lastClientWidth;
  				lastClientWidth = docElem.clientHeight;
  				if ( isVwDirty ) {
  					pf.fillImgs();
  				}
  			};
  
  			on( window, "resize", debounce(onResize, 99 ) );
  			on( document, "readystatechange", run );
  		})();
  	}
  
  	pf.picturefill = picturefill;
  	//use this internally for easy monkey patching/performance testing
  	pf.fillImgs = picturefill;
  	pf.teardownRun = noop;
  
  	/* expose methods for testing */
  	picturefill._ = pf;
  
  	window.picturefillCFG = {
  		pf: pf,
  		push: function(args) {
  			var name = args.shift();
  			if (typeof pf[name] === "function") {
  				pf[name].apply(pf, args);
  			} else {
  				cfg[name] = args[0];
  				if (alreadyRun) {
  					pf.fillImgs( { reselect: true } );
  				}
  			}
  		}
  	};
  
  	while (setOptions && setOptions.length) {
  		window.picturefillCFG.push(setOptions.shift());
  	}
  
  	/* expose picturefill */
  	window.picturefill = picturefill;
  
  	/* expose picturefill */
  	if ( typeof module === "object" && typeof module.exports === "object" ) {
  		// CommonJS, just export
  		module.exports = picturefill;
  	} else if ( typeof define === "function" && define.amd ) {
  		// AMD support
  		define( "picturefill", function() { return picturefill; } );
  	}
  
  	// IE8 evals this sync, so it must be the last thing we do
  	if ( !pf.supPicture ) {
  		types[ "image/webp" ] = detectTypeSupport("image/webp", "data:image/webp;base64,UklGRkoAAABXRUJQVlA4WAoAAAAQAAAAAAAAAAAAQUxQSAwAAAABBxAR/Q9ERP8DAABWUDggGAAAADABAJ0BKgEAAQADADQlpAADcAD++/1QAA==" );
  	}
  
  } )( window, document );
  