Is this a known bug?

Duncan Coutts duncan.coutts at worcester.oxford.ac.uk
Tue Feb 3 15:56:23 EST 2004


Is this a known TH bug?

import Language.Haskell.THSyntax

foo e = $( [| e |] )

$ ghc -fglasgow-exts AlternateTH.hs 
ghc-6.2: panic! (the `impossible' happened, GHC version 6.2):
	nameModule e {- v a8 -}

Please report it as a compiler bug to glasgow-haskell-bugs at haskell.org,
or http://sourceforge.net/projects/ghc/.

If don't splice the expression in, there's no problem and there's no
problem if I write it like so:

foo e = $( [| Nothing |] )

ie putting something simple in there rather than a lambda variable bound
outside the quasi-quotes.

You see, what I'm trying to do is something like:
foo e = $( [| \m -> case m of
                      Nothing -> False
                      (Just _) -> True
            |] `appE` [| e |] )

which is part of my investigations into the feasibility of using TH to
implement partial evaluation.

Duncan



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