Re: [ghc-steering-committee] Proposal #638: Prefix form for MkSolo# (Recommend Accept)

Well this proposal deepens the commitment to an exception for Solo and Solo#. But I'm not really objecting, just asking. Simon On Tue, 12 Mar 2024 at 09:34, Arnaud Spiwack wrote:

In favour.

Simon: I don't think your objection pertains to this particular proposal amendment, does it? Rather it's a further change to the original proposal that you'd like to see.

On Mon, 11 Mar 2024 at 11:48, Simon Peyton Jones < simon.peytonjones@gmail.com> wrote:

...

Thanks Matthias

I'm generally supportive, but please see my comment exploring a minor alternative https://github.com/ghc-proposals/ghc-proposals/pull/638#issuecomment-1988147... .

Simon

On Sat, 9 Mar 2024 at 00:12, Matthías Páll Gissurarson wrote:

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Greetings committee!

In [proposal #638]( https://github.com/ghc-proposals/ghc-proposals/pull/638), @int-index proposes that we introduce a prefix form of MkSolo#, and apparent oversight in proposal #475 [Non-punning list and tuple syntax]( https://github.com/ghc-proposals/ghc-proposals/pull/475).

Previously, you would write `(# a #)` to construct a `Solo# a`. But the question is: what would be the prefix form of this constructor? It can't be `(# #)`, because this is already defined as a constructor of `Unit#`!

This amendment proposes the `MkSolo#` constructor, having us write `MkSolo# a` for the prefix form. The discussion seems unanimous, after care was taken to clarify that a fully applied `MkSolo# a` would still be pretty printed as `(# a #)`, avoiding programmer confusion.

It seems quite straightforward to me, so:

I recommend accepting this amendment to #475.

-- -- Matthías Páll Gissurarson http://mpg.is/ _______________________________________________ ghc-steering-committee mailing list ghc-steering-committee@haskell.org https://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-steering-committee

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-- Arnaud Spiwack Director, Research at https://moduscreate.com and https://tweag.io.