gistfile1.js

function convert(cards) {
  cache = {}
  each(cards, function(card) {
    cache[card.format(card.formatters.ref)] = card
  }
  function lookup(cardReference) {
    return cache[cardReference];
  }
  return function(card) {
    return {
      depender: lookup(card.properties.Depender),
      dependee: lookup(card.properties.Dependee)
    };
  };
}