February 2022 - ghc-steering-committee

Please review: #454 Custom type warnings
by Tom Harding 25 Jun '22

25 Jun '22

Hi all, As Joachim noted, #454 <https://github.com/ghc-proposals/ghc-proposals/pull/454> is extracted from Adam’s previous efforts with the Unsatisfiable constraint <https://github.com/ghc-proposals/ghc-proposals/pull/433> proposal (which has since been accepted). In short, it covers an interface for custom warnings, and I can already think of plenty of ways I’d use it. I’d therefore like to recommend acceptance, and discuss any issues or changes. Thanks, Tom

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Please review #451: Sized literals proposal; Shepherd: Simon M
by Richard Eisenberg 23 Apr '22

23 Apr '22

Dear Committee, This is your interim secretary speaking: Sized literals proposal, proposing syntax for literals for the new sized primitive numeric types, has been proposed by Sylvain Henry. https://github.com/ghc-proposals/ghc-proposals/pull/451 https://github.com/hsyl20/ghc-proposals/blob/sized-literals/proposals/0000-… I propose Simon M as the shepherd. Please guide us to a conclusion as outlined in https://github.com/ghc-proposals/ghc-proposals#committee-process Thanks, Richard

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#425: invisible binders in type declarations; rec: accept
by Richard Eisenberg 07 Apr '22

07 Apr '22

Hi all, I am the shepherd for proposal #425, https://github.com/ghc-proposals/ghc-proposals/pull/425, proposing to add invisible binders in type declarations. The main payload of the proposal is to allow definitions like > data Proxy @k (a :: k) = Proxy instead of today's > data Proxy (a :: k) = Proxy which has no explicit binding site for k. This new syntax solves a number of smallish syntax conundra, as very well outlined in the proposal. In addition, the proposal includes two small unrelated tweaks to the syntax of type family instances; these are points (6) and (7) in the proposal. Both changes will break some obscure (but still realistic, knowing Haskell) programs, but both fixes are backward compatible. --- I recommend acceptance. The proposal is motivated nicely (do check out the examples) and solves a real problem. The new syntax fits in with other similar features. The small cleanups to existing syntax will lead to better error messages. The one drawback, as I see it, is that this proposal includes point (5), which is a breaking change to the way type synonyms work. Right now, we can say > type P = (Proxy :: k -> Type) and GHC will infer P :: forall k. k -> Type. Under this proposal, you would have to write > type P @k = (Proxy :: k -> Type) bringing k into scope explicitly. The fix is not backward compatible, and so I think this proposal should come with a migration strategy, where we warn about the former version for some releases before banning it. (Continuing to support it is possible, but it's very awkward to have a variable mentioned only in a synonym's right-hand side.) Sorry for the delay in producing this recommendation! Richard

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#477: Unicode ellipsis, recommendation: accept
by Joachim Breitner 30 Mar '22

30 Mar '22

Dear Committee, Proposal #277 “Unicode ellipsis” has been submitted by Ignat Insarov, and I’m shepherding it myself. https://github.com/ghc-proposals/ghc-proposals/pull/477 https://github.com/kindaro/ghc-proposals/blob/unicode-ellipsis/proposals/47… This is a very small proposal that lets GHC understand the nice Unicode syntax `…` in places where in ASCII world we have .., under -XUnicodeSyntax. I am fond of Unicode in general, and I expect that users of - XUnicodeSyntax expect this to work, and therefore recommend acceptance of this proposal. Cheers, Joachim -- Joachim Breitner mail(a)joachim-breitner.de http://www.joachim-breitner.de/

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Please review #475: New tuple and list syntax, Shepherd: Vlad
by Joachim Breitner 24 Mar '22

24 Mar '22

Dear Committee, New syntax for tuples and lists to remove punning has been resubmitted by Richard https://github.com/ghc-proposals/ghc-proposals/pull/475 https://github.com/goldfirere/ghc-proposals/blob/tuple-syntax/proposals/000… Please guide us to a conclusion as outlined in https://github.com/ghc-proposals/ghc-proposals#committee-process Thanks, Joachim -- Joachim Breitner mail(a)joachim-breitner.de http://www.joachim-breitner.de/

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#270: Support pun-free code, recommendation: accept
by Vitaly Bragilevsky 14 Feb '22

14 Feb '22

Dear Committee, Proposal #270 "Support pun-free code" has been resubmitted by Artyom Kuznetsov. https://github.com/ghc-proposals/ghc-proposals/pull/270 https://github.com/hithroc/ghc-proposals/blob/master/proposals/0000-support… This proposal was heavily revised since Iavor recommended rejection. As of now, it is quite thin suggesting just a couple of things: - warnings for the code with panning (understood as using same names for both types and values) - a syntax change for import declarations to reflect which names (types or values) are actually imported when importing from libraries relied on punning. The first change promotes a new style of writing Haskell code without distinguishing types and values and having a single unified namespace. We are already on that road anyway and I don't see any reason not to support this. The second change allows using an old style with punning. It could lead to doubling import declarations, but I don't think that this is really a problem. I think the proposal is mature enough so I recommend acceptance. We can also decide on the actual word used in import declarations (data, value, or pattern). I personally prefer value, but I don't see this issue as something important. Vitaly

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Unimplemented proposals for GSoC
by Joachim Breitner 11 Feb '22

11 Feb '22

Hallo allerseits, Gershom suggests that maybe some of the unimplemented accepted GHC proposals might make good material for a GSoC project. You can find the (imprecise) list of such proposals at https://github.com/ghc-proposals/ghc-proposals/pulls?q=is%3Apr+-label%3A%22… There are ~50 of them! Surely, a fair number of them _have_ been implemented and the tag is missing. But still… so maybe this is a good idea. Although not every proposal might have the right size and depth for a GSoC project… Is there anyone on this commmittee with a bit of experience with GSoC who might go through the list and highlight possible candidates? Cheers, Joachim -- Joachim Breitner mail(a)joachim-breitner.de http://www.joachim-breitner.de/

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