Counter process

counter.erl

-module('counter').
-export([incr/2, get_count/1, loop/1]).

loop(Count) ->
    receive
        { incr, Add } ->
            loop(Count + Add);
        { report, To } ->
            To ! { count, Count },
            loop(Count)
    end.

incr(Counter, Add) ->
    Counter ! { incr, Add }.

get_count(Counter) ->
    Counter ! { report, self() },
    receive
        { count, Count } -> Count
    end.