patch applied (haskell-prime-status): add ""Make $ left associative, like application"

Manuel M T Chakravarty chak at cse.unsw.edu.au
Sun Apr 27 22:27:20 EDT 2008


Sittampalam, Ganesh:
> Manuel Chakravarty wrote:
>> We should be careful about where we break existing code, and
>> we should try to support automatic translation of H98 to H' code,
>> but any changes that we do not make now will become even more
>> difficult in the future when there is even more Haskell code.
>> Look at what is happening now already, industrial users applying
>> pressure on the committee to not change the language too much
>> for the sake of legacy code.  A clear indication that anything
>> we don't change now, we will have to live with forever.
>
> I wasn't arguing for special treatment as an "industrial" user,
> just listing one datapoint that I have to counter any impression
> that the only or main cost to the community as a whole is fixing
> what's on hackage.

I agree with that.  However, maybe somewhat paradoxically, I think,  
given the resistance that changes to the language already invoke now,  
we should actually be fairly aggressive with changes this one time  
(ie, in Haskell').

>> Hence, anything that is *important* to change, we should change now.
>
> Agreed. It's just in this case the pain of changing will be huge and
> the benefits marginal at best.

Yes, I was not arguing for that particular change, my comment was of a  
general nature.

>> We should mitigate the pain by having a H98 to H' translator
>
> Such a translator would have to maintain existing layout etc, and
> produce reasonably nice looking code in places where it makes changes.
> Do we have any infrastructure that would make writing one easy?

For H98, simple[1] changes might be possible with haskell-src if it  
would be modified to be able to preserve comments and layout.

Manuel

[1] For example, purely syntactic ones.


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