#7516: GHC panic
-------------------------------+--------------------------------------------
Reporter: guest | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 7.4.2
Keywords: | Os: Unknown/Multiple
Architecture: x86_64 (amd64) | Failure: None/Unknown
Difficulty: Unknown | Testcase:
Blockedby: | Blocking:
Related: |
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Changes (by simonpj):
* difficulty: => Unknown
Old description:
> data RunLength = Single Char | Multiple (Char, Int) deriving(show)
> encode' :: String -> [RunLength]
> encode' [] = []
> encode' (x:xs) = if len == 1 then Single x : encode' xs else Multiple
> (x, len) : encode' rest
> where (first, rest) = span (==x) xs
> len = length first
>
> [1 of 1] Compiling Main ( 99_1.hs, interpreted )
> ghc: panic! (the 'impossible' happened)
> (GHC version 7.4.2 for x86_64-apple-darwin):
> nameModule show{tv abq4}
>
> Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
>
> I notice I mistyped Show as show, but I think it's better to report it
> since the compiler doesnt catch the error
New description:
{{{
data RunLength = Single Char | Multiple (Char, Int) deriving(show)
encode' :: String -> [RunLength]
encode' [] = []
encode' (x:xs) = if len == 1 then Single x : encode' xs else
Multiple (x, len) : encode' rest
where (first, rest) = span (==x) xs
len = length first
[1 of 1] Compiling Main ( 99_1.hs, interpreted )
ghc: panic! (the 'impossible' happened)
(GHC version 7.4.2 for x86_64-apple-darwin):
nameModule show{tv abq4}
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
}}}
I notice I mistyped `Show` as `show`, but I think it's better to report it
since the compiler doesnt catch the error
--
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7516#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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