Why is Erlang crashing on large sequences?

Question

I have just started learning Erlang and am trying out some Project Euler problems to get started. However, I seem to be able to do any operations on large sequences without cra

Answer 1

Your OS may have a default limit on the size of a user process. On Linux you can change this with ulimit.

You probably want to iterate over these 64000000 numbers without needing them all in memory at once. Lazy lists let you write code similar in style to the list-all-at-once code:

-module(lazy).
-export([seq/2]).

seq(M, N) when M =< N ->
    fun() -> [M | seq(M+1, N)] end;
seq(_, _) ->
    fun () -> [] end.

1> Ns = lazy:seq(1, 64000000).
#Fun
2> hd(Ns()).
1
3> Ns2 = tl(Ns()).
#Fun
4> hd(Ns2()).
2