Bug or feature?

[Iavor Diatchki]

OK, I made #16684 to track the issue:
https://gitlab.haskell.org/ghc/ghc/issues/16684

Perhaps we should continue the discussion over there.

-Iavor

On Tue, May 21, 2019 at 10:18 PM Nicolas Frisby
<nicolas.frisby at gmail.com> wrote:
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> I'd be happy to raise a ticket, but it might take a few days -- work trip.
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> On Tue, May 21, 2019, 01:55 Simon Peyton Jones <simonpj at microsoft.com> wrote:
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>> We have to be careful in how we define "equality" in the above sentence, including class constraints that (may) have superclass equality constraints.
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>> Indeed. That’s what happens now.
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>> I do think this would work.
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>> Cool.  Nick or Iavor: would you like to turn this conversation into a ticket?
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>> (Although it is technically user-facing, it is a very small corner and I’m not sure it would need a GHC proposal – others may want to comment.)
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>> Simon
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>> From: Richard Eisenberg <rae at cs.brynmawr.edu>
>> Sent: 21 May 2019 09:43
>> To: Simon Peyton Jones <simonpj at microsoft.com>
>> Cc: Nicolas Frisby <nicolas.frisby at gmail.com>; Iavor Diatchki <iavor.diatchki at gmail.com>; ghc-devs at haskell.org; Ryan Scott <ryan.gl.scott at gmail.com>
>> Subject: Re: Bug or feature?
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>> On May 21, 2019, at 10:23 AM, Simon Peyton Jones via ghc-devs <ghc-devs at haskell.org> wrote:
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>> But (A) looks sound to me.
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>> I like (A). (B) makes me nervous, too.
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>> > A. An implication is considered to “bind local equalities” iff it has at least one given equality whose free variables are not all bound by the same implication.
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>> We have to be careful in how we define "equality" in the above sentence, including class constraints that (may) have superclass equality constraints. I do think this would work.
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>> Richard