search

k0001 / pipes-network

Use network sockets together with the Haskell pipes library.
http://hackage.haskell.org/package/pipes-network
Other
24 stars 8 forks source link

`MonadSafe` fixes #12

Closed Gabriella439 closed 11 years ago

Gabriella439 commented 11 years ago

So I just merged in the type families stuff into pipes-safe this morning but that broke pipes-network. There are two ways to fix it:

The second approach is what I had in mind when I designed pipes-safe, but after seeing what you did I think I like your version better since it lets you use other monads (even ones that are not pipes-related) without lifting.

I already forked your library and added the necessary Base m ~ IO constraint everywhere, so if you want I can submit a pull request to add this in.

k0001 commented 11 years ago

Thanks Gabriel. I also prefer the first approach since it allows you to reuse the same code in different monads, I'd be happy to get your patch. However, would it make sense to embrace MonadIO as a base monad throughout pipes-network instead of IO? I confess that I don't completely understand the trade-offs of doing this, and that I haven't yet checked your new type-families code, so perhaps this idea doesn't even make sense.

k0001 commented 11 years ago

Oh, I see now. Base m should be the monad at the very bottom of the transformer stack, so it must be IO and not just any MonadIO instance.

Gabriella439 commented 11 years ago

Yes, I just changed the behavior of Base m as I was writing up this issue so that it now points directly to the true base monad and not the one directly below SafeT. So you don't need the MonadIO part any longer with that fix.

Gabriella439 commented 11 years ago

This was fixed by 1d16283d558b408e63b6286e95d50ddc9228c0bb