Re: Overlapping and incoherent instances

2014-08-11 Thread Twan van Laarhoven
To me, perhaps naively, IncoherentInstances is way more scary than OverlappingInstances. What behavior do these new pragmas have? In particular, will it be an error if there is no single most specific instance? And can the user decide whether it is an error? Twan On 29/07/14 11:11, Simon

Re: Overlapping and incoherent instances

2014-08-11 Thread Dan Doel
On Mon, Aug 11, 2014 at 11:36 AM, Twan van Laarhoven twa...@gmail.com wrote: To me, perhaps naively, IncoherentInstances is way more scary than OverlappingInstances. ​It might be a bit naive. Most things that incoherent instances would allow are allowed with overlapping instances so long as

Re: Overlapping and incoherent instances

2014-08-11 Thread Iavor Diatchki
Hello, this is clearly a bug in GHC: where `B` and `C` are imported, there should have been an error, saying that there is a duplicate instance of `Foo Int`. If there is no ticket for this already, could you please add one? -Iavor On Mon, Aug 11, 2014 at 12:35 PM, Dan Doel

Re: Overlapping and incoherent instances

2014-08-11 Thread Richard Eisenberg
This has been reported: https://ghc.haskell.org/trac/ghc/ticket/8338 But it's really not clear what the solution is! Richard On Aug 11, 2014, at 9:27 PM, Iavor Diatchki iavor.diatc...@gmail.com wrote: Hello, this is clearly a bug in GHC: where `B` and `C` are imported, there should have

[Haskell] WLP/WFLP - Call for Participation - September 15-17

2014-08-11 Thread Janis Voigtlaender
Call for Participation 28th Workshop on (Constraint) Logic Programming (WLP 2014) co-located with 23rd International Workshop on Functional and (Constraint) Logic Programming (WFLP 2014) Lutherstadt Wittenberg, Germany, September 15 - 17 Early registration deadline: August 26 The