Comment by natefaubion

It meshes pretty well as is. If only I could get rid of the strings and redundant arguments.

  mymap = pattern {
    '_, []' : -> []
    'f, [x, xs...]' : (f, x, xs) -> 
      [f x].concat mymap(f, xs)
  }

It shares a lot of the same splat/rest/destructuring syntax.