[Haskell-cafe] SYB: queries using IO Monad

[JP Moresmau]

Well, I'm stupid, I only need to combine sequence with gmapQ and it works!
Thanks Andres!

JP


On Fri, Nov 1, 2013 at 11:07 AM, JP Moresmau <jpmoresmau at gmail.com> wrote:

> You're perfectly right Andres. ext1Q and extQ work well with monadic
> result type. I can't get gmapQ to work though, but I seem to in fact not
> need it, so I've removed its usage totally.
>
> Thanks a million!
>
> JP
>
>
> On Fri, Nov 1, 2013 at 10:00 AM, Andres Löh <andres at well-typed.com> wrote:
>
>> Hi.
>>
>> > 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.
>>
>> Cheers,
>>   Andres
>>
>> --
>> Andres Löh, Haskell Consultant
>> Well-Typed LLP, http://www.well-typed.com
>>
>
>
>
> --
> JP Moresmau
> http://jpmoresmau.blogspot.com/
>



-- 
JP Moresmau
http://jpmoresmau.blogspot.com/
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