Re: [GHC] #810: GHC complains about missing instance in conjunction with GADTs

2006-10-30 Thread GHC 
#810: GHC complains about missing instance in conjunction with GADTs
--+-
 Reporter:  [EMAIL PROTECTED]  |  Owner:  simonpj
 Type:  bug   | Status:  closed 
 Priority:  normal|  Milestone:  6.8
Component:  Compiler  |Version:  6.4.1  
 Severity:  normal| Resolution:  fixed  
 Keywords:| Difficulty:  Unknown
 Testcase:  gadt20|   Architecture:  x86
   Os:  Linux |  
--+-
Changes (by simonpj):

  * resolution:  = fixed
  * status:  new = closed

Comment:

 I think this is actually ok in 6.6, and in any case I'm fixing the type-
 class interaction, and we have a test case to remind us if it goes bad on
 us.

 So I'm closing this bug.

 Simon

-- 
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/810
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Re: [GHC] #810: GHC complains about missing instance in conjunction with GADTs

2006-09-28 Thread GHC 
#810: GHC complains about missing instance in conjunction with GADTs
---+
  Reporter:  [EMAIL PROTECTED]  |  Owner:  simonpj
  Type:  bug   | Status:  new
  Priority:  normal|  Milestone:  6.8
 Component:  Compiler  |Version:  6.4.1  
  Severity:  normal| Resolution: 
  Keywords:| Os:  Linux  
Difficulty:  Unknown   |   Architecture:  x86
---+
Changes (by simonpj):

  * milestone:  = 6.8
  * owner:  = simonpj

-- 
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/810
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Re: [GHC] #810: GHC complains about missing instance in conjunction with GADTs

2006-07-05 Thread GHC 
#810: GHC complains about missing instance in conjunction with GADTs
---+
  Reporter:  [EMAIL PROTECTED]  |  Owner:   
  Type:  bug   | Status:  new  
  Priority:  normal|  Milestone:   
 Component:  Compiler  |Version:  6.4.1
  Severity:  normal| Resolution:   
  Keywords:| Os:  Linux
Difficulty:  Unknown   |   Architecture:  x86  
---+
Comment (by simonpj):

 The odd thing is that it works with 6.4.2 (batch, not GHCi).  Maybe Chris
 can try again?

 My comment about luck is simply that GHC is badly broken when it comes to
 a mixture of type classes and GADTs.  It's something high on my priority
 list, but for you can't rely on it to behave well, or even predictably.

-- 
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/810
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Re: [GHC] #810: GHC complains about missing instance in conjunction with GADTs

2006-07-04 Thread GHC 
#810: GHC complains about missing instance in conjunction with GADTs
---+
  Reporter:  [EMAIL PROTECTED]  |  Owner:   
  Type:  bug   | Status:  new  
  Priority:  normal|  Milestone:   
 Component:  Compiler  |Version:  6.4.1
  Severity:  normal| Resolution:   
  Keywords:| Os:  Linux
Difficulty:  Unknown   |   Architecture:  x86  
---+
Comment (by simonpj):

 Seems all right with GHC 6.4.2 to me.  I dn't nkow what Chris thinks
 doesn't work.

 Mind you, type classes and GADTs don't work togeher properly, still, so
 it's good luck that this one is ok.

 Simon

-- 
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/810
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Re: [GHC] #810: GHC complains about missing instance in conjunction with GADTs

2006-07-04 Thread GHC 
#810: GHC complains about missing instance in conjunction with GADTs
---+
  Reporter:  [EMAIL PROTECTED]  |  Owner:   
  Type:  bug   | Status:  new  
  Priority:  normal|  Milestone:   
 Component:  Compiler  |Version:  6.4.1
  Severity:  normal| Resolution:   
  Keywords:| Os:  Linux
Difficulty:  Unknown   |   Architecture:  x86  
---+
Comment (by [EMAIL PROTECTED]):

 Hmm, I have to admit that I don't really understand your last sentence.
 Do you mean that one needs to be in luck in order to not have problems
 with my example code?

-- 
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/810
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Re: [GHC] #810: GHC complains about missing instance in conjunction with GADTs

2006-07-04 Thread GHC 
#810: GHC complains about missing instance in conjunction with GADTs
---+
  Reporter:  [EMAIL PROTECTED]  |  Owner:   
  Type:  bug   | Status:  new  
  Priority:  normal|  Milestone:   
 Component:  Compiler  |Version:  6.4.1
  Severity:  normal| Resolution:   
  Keywords:| Os:  Linux
Difficulty:  Unknown   |   Architecture:  x86  
---+
Comment (by guest):

 simonpj wrote:
   Seems all right with GHC 6.4.2 to me. I dn't nkow what Chris thinks
 doesn't work.

 What Chris means is that the example code is accepted by GHCi 6.4.2 (which
 is the right behavior, in my opinion) but it's not accepted by the
 ordinary GHC compiler of the same version.

-- 
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/810
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[GHC] #810: GHC complains about missing instance in conjunction with GADTs

2006-07-03 Thread GHC 
#810: GHC complains about missing instance in conjunction with GADTs
-+--
Reporter:  [EMAIL PROTECTED]  |Owner: 
Type:  bug   |   Status:  new
Priority:  normal|Milestone: 
   Component:  Compiler  |  Version:  6.4.1  
Severity:  normal| Keywords: 
  Os:  Linux |   Difficulty:  Unknown
Architecture:  x86   |  
-+--
I wanted to do something like that:
 {{{
 data Pair :: (* - *) - * where
 Pair :: a b - b - Pair a

 data Sel :: * - * where
 A :: Sel Bool
 B :: Sel Integer

 showSnd :: Pair Sel - String
 showSnd (Pair A bool)= show bool
 showSnd (Pair B integer) = show integer
 }}}
 However, GHC 6.4.1 with -fglasgow-exts complains in the second last and
 last
 line that there is no instance for (Show b).  But it is clear that bool ::
 Bool and integer :: Integer and that therefore bool and integer are
 showable.  In addition, Chris Kuklewicz said the following:
   I cut and pasted your code into ghci-6.4.2 with -fglasgow-exts and there
 was no
 error.  And I can (print (showSnd (Pair A True)) and (print (showSnd (Pair
 B
 8))) but when I try to compile it with ghc-6.4.2 it complains about the
 Show
 instance.  I find this deeply wierd, and it seems like a bug.

-- 
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/810
GHC http://www.haskell.org/ghc/
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