[Haskell-cafe] operating on nested monads

ajb at spamcop.net ajb at spamcop.net
Sun Mar 28 23:41:33 EST 2004

G'day Marco.

Quoting Marco Righele <marco_righele at yahoo.it>:

> How can I achieve the same effect (if it is ever possible)?
> I feel like it should be something almost trivial, but I really can't get it.

One approach is to use a monad which works like Maybe, but as a monad
transformer over IO.

You might want to try NegateT, which does pretty much precisely this:


Andrew Bromage

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