transducers.js
function toArray(coll, xform) {
  if(!xform) {
    return reduce(coll, arrayReducer, []);
  }
  return transduce(coll, xform, arrayReducer, []);
}
function toArray(coll, xform) {
  if(!xform) {
    return reduce(coll, arrayReducer, []);
  }
  return transduce(coll, xform, arrayReducer, []);
}
function toArray ( coll , xform ) { if ( ! xform ) { return reduce ( coll , arrayReducer , [ ] ) ; } return transduce ( coll , xform , arrayReducer , [ ] ) ; }
building new collections
building new collections