Opened 3 years ago

Closed 2 years ago

#10216 closed bug (fixed)

Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance

Reported by: strake888 Owned by:
Priority: normal Milestone: 8.0.1
Component: Core Libraries Version: 7.10.1
Keywords: Cc: core-libraries-committee@…, ekmett
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: None/Unknown Test Case:
Blocked By: Blocking:
Related Tickets: Differential Rev(s):
Wiki Page:

Description (last modified by strake888)

Add default definitions of first, second in terms of (***) to let one define an Arrow instance in terms of (***) rather than first, which is sometimes more elegant or convenient.

Attachments (1)

0001-Allow-arr-first-as-minimal-definition-of-Arrow-insta.patch (2.1 KB) - added by strake888 3 years ago.

Download all attachments as: .zip

Change History (17)

comment:1 Changed 3 years ago by ekmett

This would also necessitate a change to the MINIMAL pragma, I suppose.

comment:2 Changed 3 years ago by ekmett

No objection here, BTW. This makes Arrow's internals far more symmetrical.

comment:3 Changed 3 years ago by simonpj

I suggest that

  • You add a description to the ticket that explains what you are doing, and why it is a good thing. Perhaps add comments in the code to explain subtleties?
  • Pursue it through the core libraries committee (Edward clearly has it on his radar, which is good).

Simon

comment:4 Changed 3 years ago by thomie

Milestone: 7.12.1
Status: newpatch

comment:5 Changed 3 years ago by strake888

Description: modified (diff)

comment:6 in reply to:  3 Changed 3 years ago by strake888

Replying to simonpj:

Perhaps add comments in the code to explain subtleties?

I'm not sure what is subtle here; you mean any subtleties in particular?

Pursue it through the core libraries committee (Edward clearly has it on his radar, which is good).

Any action required from me until further notice? Should I notify core-libraries-committee@?

Last edited 3 years ago by strake888 (previous) (diff)

comment:7 Changed 2 years ago by bgamari

Status: patchinfoneeded

Yes, I think it would be best to put together a formal proposal and send it through the core libraries committee. It needn't be much effort and it sounds like it shouldn't be terribly controversial but I would like to make sure that this goes through the correct channels.

comment:8 Changed 2 years ago by strake888

Description: modified (diff)

comment:9 in reply to:  7 Changed 2 years ago by strake888

Replying to bgamari:

Yes, I think it would be best to put together a formal proposal and send it through the core libraries committee.

Done. (I wasn't sure earlier whether to do so as the core-libraries-committee chair had already seen this ticket.)

comment:10 Changed 2 years ago by thoughtpolice

Milestone: 7.12.18.0.1

Milestone renamed

comment:11 Changed 2 years ago by strake888

Status: infoneededpatch

I sent a proposal to libraries@… and no one complained so I'm setting the status back to patch ☺

comment:12 Changed 2 years ago by simonpj

Edward, can we have your ok?

comment:13 Changed 2 years ago by thomie

Owner: ekmett deleted

comment:14 Changed 2 years ago by ekmett

Cc: ekmett added

Granted.

comment:15 Changed 2 years ago by Austin Seipp <austin@…>

In e8c81739/ghc:

Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance

See #10216.

Signed-off-by: Austin Seipp <austin@well-typed.com>

comment:16 Changed 2 years ago by thoughtpolice

Resolution: fixed
Status: patchclosed

Thanks, merged!

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