[Haskell-beginners] Question regarding the ListT Monad Transformer

Tim Cowlishaw tim at timcowlishaw.co.uk
Wed Aug 4 14:47:41 EDT 2010

On 04/08/10 18:42, Edward Z. Yang wrote:
> ListT IO a = IO [a], so you're looking for a function [IO a] ->  IO [a].
> This function is called sequence :: Monad m =>  [m a] ->  m [a]

Aha, yep, that's exactly what I was after! Thanks very much...

> My best advice for you is to get rid of the newtype wrapping and unwrapping
> when you're trying to an understand a monad transformer.
Aah I see - that makes sense, Will try and have another crack at them 



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