pragmatic.ex

defmodule C do

    def map([], _), do: []
    def map([ head | tail ], func) do:
        [ func.(head), map(tail, func) ]
    end

    def child(element, func, parent) do:
        parent <- { self, func.(element) }
    end

    def spawn_children(collection, func) do
        map collection, fn element -> spawn(__MODULE__, :child, [ element, func, self ]) end
    end

    def collect_results(pids) do
        map pids, fn pid -> receive do: ( {^pid, value} -> value ) end
    end

    def pmap(collection, func) do
        collection |> spawn_children(func) |> collect_results
    end

end

IO.inspect C.map [1,2,3,4,5], &1*&1