[Haskell-cafe] SYB: queries using IO Monad

Andres Löh andres at well-typed.com
Fri Nov 1 09:00:05 UTC 2013


> However, the ext1Q, extQ and gmapQ functions have no monadic equivalent.
> There seems to be monadic transformation (from a to different a) but no
> monadic queries (from a to b).
> Do I have to rewrite these functions myself to work with monadic queries (it
> at all possible) or is there a better way? I've seen some functions that
> work with monads and MonadPlus, but I don't see anything that would work
> with IO.

I think the idea is that the Q functions don't need a monadic
counterpart because they can already be used at a monadic result type.


Andres Löh, Haskell Consultant
Well-Typed LLP, http://www.well-typed.com

More information about the Haskell-Cafe mailing list