[ghc-steering-committee] #216: Qualified Do again, recommendation: accept the alternative
Joachim Breitner
mail at joachim-breitner.de
Thu Apr 16 15:11:12 UTC 2020
Hi,
Am Donnerstag, den 16.04.2020, 15:01 +0000 schrieb Simon Peyton Jones
via ghc-steering-committee:
> > And you are sure that the complexity of this is more than that of
> > “fully settled” types?
>
> I didn't say that. But I am sure that it's more complicated than 6.1
> without 6.1.2! If I understand aright, the *only* gain is that one
> can omit three words:
>
> import qualified MyMonad
that’s fair… I guess with 6.1 we would imply
To use qualified do, the recommended idiom is to import the module
(1) qualified and
(2) without an explicit import list.
Put like this, I think I can live it with it.
I still find it odd that those people who like to list all imports
explicitly would be forced to write
import qualified MyMonad ((>>))
foo = MyMonad.do { a; b }
and then even have to adjust the import list when they write
foo = MyMonad.do { _ <- a; b }
instead. But yeah, saying “just don’t list your imports when you
qualify your module import” works indeed.
With that, I am happy to support 6.1 as well (but still prefer 6.1.2)
Cheers,
Joachim
--
Joachim Breitner
mail at joachim-breitner.de
http://www.joachim-breitner.de/
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