jQuery plugin to sort a list of measurements

measureSort.js

(function($){  
  
$.fn.sortByMeasurement = function(child_type){  

  var element = this;
	if(!child_type) child_type = "li";

	  
	var SINGLE_REGEX = /\s*(\d*)?([\.\/])?(\d*)\s*([a-zA-z]*)/;


	function normalizeMeasurmentString( str ){

		str = stripBadCharacters(str);

		if( isSingleDim(str) )
			return normalizeOneDim( str );
		else 
			return normalizeTwoDim( str );

	}

	function normalizeOneDim( str ){
		var match = str.match(SINGLE_REGEX);

		var value, unit;

		value = parseInt( match[1] );
		if(!value) value = 0;

		unit  = match[4];

		if( match[2] ){ // a / or . seperator

			if(match[2] === "/") // convert to decimal
				value = value / parseInt( match[3] );

			else if(match[2] === ".") // append decimal
				value += parseInt(match[3]) / Math.pow( 10, match[3].length );

			else
				error("Separator not a / or . ---- ["+match[2]+"]")
		}

		if(unit !== "in"){

			value = convertUnits(unit, value);

		}

		return value;
	}

	function normalizeTwoDim(str){
		var str1 = str.split("×")[0].trim();
		var str2 = str.split("×")[1].trim();

		return normalizeOneDim(str1) * normalizeOneDim(str2);
	}

	function isSingleDim(str){
		return str.indexOf("×") === -1;
	}

	function error(msg){
		console.log("ERROR: "+msg);
	}

	function convertUnits(unit, value){

		error("conversion not implemented for: "+unit);

		return value;
	}

	function stripBadCharacters(str){

		var plus_minus_regex = /±\s*[\d\.\/]*/

		var plus_minus = str.match( plus_minus_regex );

		if(plus_minus)
			return str.replace(plus_minus[0], "");
		
		return str;
	}

	function sortElements(parent_el){

		parent_el.children(child_type).sort( function(a, b){

			var a_str = $(a).text().trim()
			var b_str = $(b).text().trim()

			return normalizeMeasurmentString(a_str) - normalizeMeasurmentString(b_str);

		}).each( function(){

			parent_el.append( $(this) );

		});

	}

	sortElements(this, child_type);

};  
  
})(jQuery);