[Haskell-cafe] Re: StateT and modify

Max Vasin max.vasin at gmail.com
Wed Nov 8 11:39:57 EST 2006

>>>>> "Peter" == Peter Steiner <pnsteiner at gmail.com> writes:

Peter> On 11/8/06, Bulat Ziganshin <bulat.ziganshin at gmail.com> wrote:
>> Hello Peter,
>> Wednesday, November 8, 2006, 1:48:24 PM, you wrote:
>> > i would like to be able to debug what's happening inside the
>> modifier > function. that's why i want to be able to use a
>> modifier that's in the > IO monad
>> for debugging there is 'trace' function which don't needs IO
>> monad

Peter> thanks. i am aware of trace, but the potentially messed up
Peter> execution order makes it very hard for me to get useful
Peter> information out of the resulting trace. besides, IO will
Peter> scale to more elaborate logging mechanisms later on...

If all you want from IO is logging why not just use MonadWriter?

Max Vasin.

More information about the Haskell-Cafe mailing list