[ghc-steering-committee] #216: Qualified Do again, recommendation: accept the alternative

[Joachim Breitner]

Dear Committee,

it seems discussion has ebbed down. Are there any new arguments that
can be brought forward? Did anyone have a change of mind which would
bring us closer to (or farther away from) consensus? Or should we vote?

Simon Marlow, Chris, Cale, Tom:
You have not stated an opinion. Do you have one?

Cheers,
Joachim

Am Mittwoch, den 22.04.2020, 12:26 +0200 schrieb Joachim Breitner:
> Dear Committe,
> 
> trying to summarize the discussion here.
> 
> The main decision seems to be: Record based or module based.
> 
>    Record based is preferred by:
>    Arnaud (one of the authors), SPJ
> 
>    Module based is preferred by:
>    Richard (after changing his mind), Eric, Iavor, Vitaly, Alejandro,
>    me
> 
> This is not a vote, merely a summary of sentimenss. But it seems that
> maybe the onus to make stronger arguments for the record-based approach
> is on Simon and Arnaud?
> 
> 
> Related to the  module based variant, there was some discussion about
> whether the
>  * desugaring should go to a “qualified name”, that is then resolved 
>    like any manually written name
>    (i.e. could conceptually be done in the parser)
>  * or if it should go directly a suitable “original name” of a suitable
>    function, even if not explicitly imported
>    (i.e. could conceptually be done in the renamer, but not the parser)
> 
> I initially advocated for the latter, arguing with a “you shall not
> have to import stuff you do not write explicitly” rule.
> But Simon’s recent argument that   
> 
>     import qualified Monad as M
> 
> (i.e. _with_ qualification, but _without_ an import list) will give the
> developer a good user experience, and if they try to do things like 
> 
>     import Monad as M (runMonad)
>     … M.do …
> 
> then, well, they shouldn’t. So I am happy to advocate for the module
> based approach with the “must be in scope” rule. But maybe we should
> keep the focus more on the fundamental question above.
> 
> 
> 
> We could keep in mind that eventually, people will ask for M.if; M.[
> and other “qualified syntax”. But it seems that that will work equally
> well with either choice here.
> 
> Cheers,
> Joachim
> 
> 
-- 
Joachim Breitner
  mail at joachim-breitner.de
  http://www.joachim-breitner.de/