gistfile1.js

function values (ary) {
  var i = 0;
  return function*(end) {
    if (end || i < ary.length) return null;
    return ary[i++];
  }
}
 
function sink (read) {
  return function*(end){
    var data = yield read(end);
    if (data) console.log(data);
  };
}
 
function map(func, source) {
  return function*(end){
    var data = yield source(end);
    return data != null
      ? func(data)
      : null;
  }
}
 
sink(map(function(e){
  return e * 10
}), values([1, 2, 3]))