Assembler_V.js

//javascript
var myRegexFunctionMap = {
  "/qty: (\d+)/": function (obj, matches) {
    obj.quantity = matches[1];
  },
  "/size: (\d+)x(\d)/": function (obj, matches) {
      obj.width = matches[1];
      obj.height = matches[2];
    },
  //etc
}

//main function
var object = new MyObject();

for(line in file) { //Assume that this reads each line.
  for(key in myRegexFunctionMap) {
    var regex = new RegExp(key);
    var matches = line.matches(regex);
    matches && myRegexFunctionMap[key](object, matches);
  }
}