pvdz.ee - 8.10.5 ToPropertyDescriptor

PropertyDescriptor ToPropertyDescriptor(Obj)

Create a new PropertyDescriptor based on the attributes of the properties of given object.

Code: (Abstract Ecma)

function ToPropertyDescriptor(Obj){
  if (Type(Obj) != 'Object') throw TypeError;
  var desc = new PropertyDescriptor(); // a new uninitialized property descriptor
  if (Obj.[[HasProperty]]("enumerable")) {
    var enum = Obj.[[Get]]("enumerable");
    desc.[[Enumerable]] = ToBoolean(enum);
  }
  if (Obj.[[HasProperty]]("value")) {
    var value = Obj.[[Get]]("value");
    desc.[[Value]] = ToBoolean(value);
  }
  if (Obj.[[HasProperty]]("writable")) {
    var write = Obj.[[Get]]("writable");
    desc.[[Writable]] = ToBoolean(write);
  }
  if (Obj.[[HasProperty]]("get")) {
    var get = Obj.[[Get]]("get");
    desc.[[Get]] = ToBoolean(get);
  }
  if (Obj.[[HasProperty]]("set")) {
    var set = Obj.[[Get]]("set");
    desc.[[Set]] = ToBoolean(set);
  }
  if ([[Get]] in desc || [[Set]] in desc) {
    if ([[Value]] in desc || [[Writable]] in desc) {
      throw TypeError;
    }
  }
  return desc;
}