Bugs item #1178851, was opened at 2005-04-07 13:39
Message generated for change (Comment added) made by nobody
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Category: Compiler (Type checker)
Group: 6.4
Status: Open
Resolution: None
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Nobody/Anonymous (nobody)
Summary: double-panic with GADTs
Initial Comment:
ghc-6.4: panic! (the `impossible' happened, GHC version
6.4):
cgPanic
deref{v a1yz}
static binds for:
local binds for:
SRT labelghc-6.4: panic! (the `impossible'
happened, GHC version 6.4):
initC: srt
Please report it as a compiler bug to
glasgow-haskell-bugs@haskell.org,
or http://sourceforge.net/projects/ghc/.
I've attached a test driver that can reproduce the problem.
-- Esa Pulkkinen <[EMAIL PROTECTED]>
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Comment By: Nobody/Anonymous (nobody)
Date: 2005-04-12 09:22
Message:
Logged In: NO
Thank you, this information allowed me to find a workaround.
I need to just use -<< instead of -< for this, and the
problem disappears.
-- Esa Pulkkinen <[EMAIL PROTECTED]>
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Comment By: Nobody/Anonymous (nobody)
Date: 2005-04-12 03:39
Message:
Logged In: NO
The short version is a great help.
I think this program should yield a type error. The value of foo
here is a component of the local variable x, and therefore
should
be unavailable to the left of -<. I've no idea how to
implement it,
though -- presumably a constraint on the free type vars on the
left of -<.
-- Ross
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Comment By: Nobody/Anonymous (nobody)
Date: 2005-04-07 16:00
Message:
Logged In: NO
Fwiw, here's a trimmed-down version of the above program.
{-# OPTIONS -farrows -fglasgow-exts #-}
class Foo a where foo :: a -> ()
data Bar = forall a. Foo a => Bar a
get :: Bar -> ()
get = proc x -> case x of Bar a -> do foo -< a
-- Thomas Jäger <[EMAIL PROTECTED]>
----------------------------------------------------------------------
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