Dynamic object key interpolation

_.js

var formatObj = function(data, obj) {
  return Object.keys(obj).reduce(function(acc, k) {
    acc[data[k.match(/#\{(\w+)\}/)[1]]] = obj[k]
    return acc
  },{})
}

formatObj({a:'foo', b:'baz'}, {'#{a}': 'this is foo'
                              ,'#{b}': 'this is baz'})
//^
// {foo: "this is foo"
// ,baz: "this is baz"}