#10216: Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance -------------------------------------+------------------------------------- Reporter: strake888 | Owner: ekmett Type: bug | Status: new Priority: normal | Milestone: Component: Core Libraries | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by ekmett): This would also necessitate a change to the MINIMAL pragma, I suppose. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10216#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10216: Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance -------------------------------------+------------------------------------- Reporter: strake888 | Owner: ekmett Type: bug | Status: new Priority: normal | Milestone: Component: Core Libraries | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Comment (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 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10216#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10216: Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance -------------------------------------+------------------------------------- Reporter: strake888 | Owner: ekmett Type: bug | Status: patch Priority: normal | Milestone: 7.12.1 Component: Core Libraries | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Description changed by strake888: Old description: New description: 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. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10216#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10216: Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance -------------------------------------+------------------------------------- Reporter: strake888 | Owner: ekmett Type: bug | Status: infoneeded Priority: normal | Milestone: 7.12.1 Component: Core Libraries | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Changes (by bgamari): * status: patch => infoneeded Comment: 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. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10216#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10216: Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance -------------------------------------+------------------------------------- Reporter: strake888 | Owner: ekmett Type: bug | Status: infoneeded Priority: normal | Milestone: 7.12.1 Component: Core Libraries | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by strake888): Replying to [comment:7 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.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10216#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10216: Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance -------------------------------------+------------------------------------- Reporter: strake888 | Owner: ekmett Type: bug | Status: patch Priority: normal | Milestone: 8.0.1 Component: Core Libraries | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by simonpj): Edward, can we have your ok? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10216#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10216: Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance -------------------------------------+------------------------------------- Reporter: strake888 | Owner: Type: bug | Status: patch Priority: normal | Milestone: 8.0.1 Component: Core Libraries | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): -------------------------------------+------------------------------------- Comment (by Austin Seipp ): In [changeset:"e8c8173923302268ef950c3b21e276779e45ac83/ghc" e8c81739/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="e8c8173923302268ef950c3b21e276779e45ac83" Allow arr ∧ (first ∨ (***)) as minimal definition of Arrow instance See #10216. Signed-off-by: Austin Seipp }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10216#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler