Re: sequence causing stack overflow on pretty small lists

On Mon, Aug 26, 2013 at 1:46 AM, Niklas Hambüchen wrote:

This is because sequence is implemented as

sequence (m:ms) = do x <- m xs <- sequence ms return (x:xs)

and uses stack space when used on some [IO a].

This problem is not due to sequence, which doesn't need to add any strictness here. It occurs because the functions in System.Random are excessively lazy. In particular, randomIO returns an unevaluated thunk.