old_contents: var inverseXML = getInverseObj(require("../maps/xml.json")),
      xmlReplacer = getInverseReplacer(inverseXML);
  
  exports.XML = getInverse(inverseXML, xmlReplacer);
  
  var inverseHTML = getInverseObj(require("../maps/entities.json")),
      htmlReplacer = getInverseReplacer(inverseHTML);
  
  exports.HTML = getInverse(inverseHTML, htmlReplacer);
  
  function getInverseObj(obj){
  	return Object.keys(obj).sort().reduce(function(inverse, name){
  		inverse[obj[name]] = "&" + name + ";";
  		return inverse;
  	}, {});
  }
  
  function getInverseReplacer(inverse){
  	return new RegExp("\\" + Object.keys(inverse).sort().join("|\\"), "g");
  }
  
  var re_nonASCII = /[^\0-\x7F]/g,
      re_astralSymbols = /[\uD800-\uDBFF][\uDC00-\uDFFF]/g;
  
  function nonUTF8Replacer(c){
  	return "&#x" + c.charCodeAt(0).toString(16).toUpperCase() + ";";
  }
  
  function astralReplacer(c){
  	// http://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
  	var high = c.charCodeAt(0);
  	var low  = c.charCodeAt(1);
  	var codePoint = (high - 0xD800) * 0x400 + low - 0xDC00 + 0x10000;
  	return "&#x" + codePoint.toString(16).toUpperCase() + ";";
  }
  
  function getInverse(inverse, re){
  	function func(name){
  		return inverse[name];
  	}
  
  	return function(data){
  		return data
  				.replace(re, func)
  				.replace(re_astralSymbols, astralReplacer)
  				.replace(re_nonASCII, nonUTF8Replacer);
  	};
  }
new_contents: var inverseXML = getInverseObj(require("../maps/xml.json")),
      xmlReplacer = getInverseReplacer(inverseXML);
  
  exports.XML = getInverse(inverseXML, xmlReplacer);
  
  var inverseHTML = getInverseObj(require("../maps/entities.json")),
      htmlReplacer = getInverseReplacer(inverseHTML);
  
  exports.HTML = getInverse(inverseHTML, htmlReplacer);
  
  function getInverseObj(obj){
  	return Object.keys(obj).sort().reduce(function(inverse, name){
  		inverse[obj[name]] = "&" + name + ";";
  		return inverse;
  	}, {});
  }
  
  function getInverseReplacer(inverse){
  	return new RegExp("\\" + Object.keys(inverse).sort().join("|\\"), "g");
  }
  
  var re_nonASCII = /[^\0-\x7F]/g,
      re_astralSymbols = /[\uD800-\uDBFF][\uDC00-\uDFFF]/g;
  
  function singleCharReplacer(c){
  	return "&#x" + c.charCodeAt(0).toString(16).toUpperCase() + ";";
  }
  
  function astralReplacer(c){
  	// http://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
  	var high = c.charCodeAt(0);
  	var low  = c.charCodeAt(1);
  	var codePoint = (high - 0xD800) * 0x400 + low - 0xDC00 + 0x10000;
  	return "&#x" + codePoint.toString(16).toUpperCase() + ";";
  }
  
  function getInverse(inverse, re){
  	function func(name){
  		return inverse[name];
  	}
  
  	return function(data){
  		return data
  				.replace(re, func)
  				.replace(re_astralSymbols, astralReplacer)
  				.replace(re_nonASCII, singleCharReplacer);
  	};
  }
subject: rename nonUTF8Replacer