es3 array comprehensions.js

var a = [x*2 for each (x in [1,2,3])];
var a = [1,2,3].map(_("x -> 2*x"));

var b = [x*2 for each (x in [1,2,3]) if (x>1)];
var a = [1,2,3].filter(_("x -> x > 1")).map(_("x -> 2*x"));

var c = [x+y 
  for each (x in [1,2,3])
  for each (y in [10,20,30])
  if (x>1)
];
var c = Array._zip({
    x: [1,2,3].filter(_("x -> x > 1"), 
    y: [10,20,30]
  }).map(_("v -> v.x + v.y")
;