Re: [ghc-steering-committee] Recommendation: reject #367 (was: Re: Please review #367: Clarify primops using unboxed sums, Shepherd: Simon Marlow)

Hi, your points sounds reasonable, and the author got a heads up on the Github thread (so unlikely that there was a misunderstanding or oversight), so I’ll concur with the shepherd. Cheers, Joachim Am Montag, den 08.03.2021, 15:51 +0000 schrieb Simon Marlow:

Committee,

Proposal #367 suggests using unboxed sums for the results of 7 (seven) primops that use sum types but currently have to encode those explicitly using `Int#`.

https://github.com/treeowl/ghc-proposals/blob/unboxed-sum-primops/proposals/...

The proposal is arguably the right thing, however I'm suggesting we reject it for the following reasons: The implementations of the primops would bake in the translation of unboxed sums. Right now our unboxed sum translation is defined in one place - CorePrep - but this proposal would leak it into the implementations of a few primops. Migration would entail adding a backwards-compatibility layer, with the associated complexity and risk of performance regressions. While the current situation is perhaps inelegant, it's not broken and it's easy to understand. Thoughts?

Simon

On Sun, 4 Oct 2020 at 22:14, Joachim Breitner wrote:

...

Dear Committee,

this is your secretary speaking:

Clarify primops using unboxed sum has been proposed by David Feuer https://github.com/ghc-proposals/ghc-proposals/pull/367 https://github.com/treeowl/ghc-proposals/blob/unboxed-sum-primops/proposals/...

I’ll propose Simon Marlow as the shepherd.

Please guide us to a conclusion as outlined in https://github.com/ghc-proposals/ghc-proposals#committee-process

Thanks, Joachim _______________________________________________ ghc-steering-committee mailing list ghc-steering-committee@haskell.org https://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-steering-committee -- Joachim Breitner mail@joachim-breitner.de http://www.joachim-breitner.de/