IMHO, it is a bug that you can provide different fixities in different modules and we should fix that bug.

Manuel

Richard Eisenberg <rae@cs.brynmawr.edu>:

Unsurprisingly, I'm in favor of this proposal and do not wish to reject.

To me, the wart on the language is that we can use the same string for a term-level name and a potentially unrelated type-level name. Of course, this has served many people well, but it does create a certain awkwardness in places (and confusion for beginners!). As long as we have the possibility of one string representing two potentially unrelated names, it seems to be a weakness in expressiveness not to be able to assign different fixities to the names. (And indeed we *can* assign different fixities, as long as we do so in different modules.)

On the other hand, I am sensitive about all those other raw fish that need frying...

Richard

On Aug 28, 2017, at 5:05 AM, Simon Peyton Jones <simonpj@microsoft.com> wrote:

I don't have a strong opinion either way. The strongly reason in favour is encapsulated in Richard's comment
which points out that the two T's are entirely unrelated.
 
I had not fully realised this, but in fact it is /already/ possible to have different fixities for a single lexeme T; a concrete example is here
 
I added another comment
that tries to separate the AST issue from the source-code issue.  I do think we should make the internal change; but I’m unconvinced it’s worth the faff to solve the source-level issue.
 
Simon
 
 
 -----Original Message-----
 From: ghc-steering-committee [mailto:ghc-steering-committee-
 bounces@haskell.org] On Behalf Of Joachim Breitner
 Sent: 27 August 2017 19:16
 Subject: [ghc-steering-committee] Proposal: Type Fixity (#65),
 Recommendation: Reject
 
|  Dear Committee,
 
|  Ryan Scott’s proposal to allow fixity declaration to explicitly target
|  values or types has been brought before us:
 
|  I (the secretary) nominates myself as the shepherd, so I can right away
|  continue giving a recommendation.
 
|  I propose to reject this proposal. The main reasons are:
|   * it is not clear if there is a real use case for this. Has anyone
|     ever complained about the status quo?
|     The proposal does not motivate the need for a change well enough.
|     (There is a related bug in TH, but that bug can probably simply be
|     fixed.)
|   * The status quo can be sold as a feature, rather than a short-coming.
|     Namely that an operator has a fixed fixity, no matter what namespace
|     it lives in.
|     This matches morally what other languages do: In Gallina, fixity
|     is assigned to names independent of their definition, AFAIK.
|   * There is a non-trivial implementation and education overhead, a
|     weight that is not pulled by the gains.
 
|  If we’d design Haskell from scratch, my verdict might possibly be different
|  (but maybe we wouldn’t even allow types and values to share names then…)
 
 
|  Please contradict me or indicate consensus by staying silent.
 
 
|  Greetings,
|  Joachim
 
|  --
|  Joachim “nomeata” Breitner
 
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