-module(iarray).
-export([new/1,   % new imperative array of given size
	 get/2,   % element at given index
	 set/3    % set element at given index
	]).

-export([element/1]).  % internal

element(Val) ->
    receive
        {get, Pid} ->
            Pid ! {self(), Val},
            element(Val);
        {set, Val1} ->
            element(Val1)
    end.
eget(E) ->
    E ! {get, self()},
    receive
        {E, none} ->
            not_initialized;
        {E, Val} ->
            Val
    end.
eset(Val, E) ->
    E ! {set, Val},
    ok.

elements(N) ->
    elements(N, []).
elements(0, Buffer) ->
    Buffer;
elements(N, Buffer) when N > 0 ->
    elements(N-1, [spawn(iarray, element, [none]) | Buffer]).

new(N) ->
    array:from_list(elements(N)).

get(Index, A) ->
    eget(array:get(Index, A)).
set(Index, Val, A) ->
    eset(Val, array:get(Index, A)).