#7529: Crash when using (->) instead of (=>) in a typeclass instance
-------------------------------+--------------------------------------------
Reporter: Helkafen | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler (Parser)
Version: 7.4.1 | Keywords:
Os: Linux | Architecture: x86
Failure: Compile-time crash | Blockedby:
Blocking: | Related:
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import qualified Data.Vector as V
import Test.QuickCheck
import Control.Monad (liftM)
instance (Arbitrary a) -> Arbitrary (V.Vector a) where
arbitrary = fmap V.fromList arbitrary
main = do
print "bla"
The arrow is obviously incorrect.
runghc <thisfile> tells me:
*** Exception: compiler/rename/RnSource.lhs:429:14-81: Irrefutable pattern
failed for pattern Data.Maybe.Just (inst_tyvars,
_,
SrcLoc.L _ cls,
_)
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7529>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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