Re: [GHC] #9209: Template haskell panic

15 Jun 2014

      #9209: Template haskell panic
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        Reporter:  tulcod            |            Owner:
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.8.2
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Description changed by tulcod:

Old description:
...
I was trying to get some template haskell thing to work and was messing
around and ran into this bug.
Prelude> let $([d||])
ghc: panic! (the 'impossible' happened)
  (GHC version 7.8.2 for x86_64-unknown-linux):
        cvBindsAndSigs $[splice{v}]([d| |])
Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
Prelude>

...
The following file:
{-# LANGUAGE TemplateHaskell #-}
let $([d||])
main = do
   return ()
gives the following error message:
test.hs:3:1:
    parse error (possibly incorrect indentation or mismatched brackets)
but doesn't crash. So it seems to be ghci-specific...?

...
the other oxford brackets work fine (or don't suffer from exactly the
same bug, anyway)
New description:

 I was trying to get some template haskell thing to work and was messing
 around and ran into this bug.
 {{{
 Prelude> let $([d||])
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.8.2 for x86_64-unknown-linux):
         cvBindsAndSigs $[splice{v}]([d| |])

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

 Prelude>
 }}}

 The following file:
 {{{
 {-# LANGUAGE TemplateHaskell #-}
 let $([d||])
 main = do
    return ()
 }}}
 gives the following error message:
 {{{
 test.hs:3:1:
     parse error (possibly incorrect indentation or mismatched brackets)
 }}}
 but doesn't crash. So it seems to be ghci-specific...?

 the other oxford brackets work fine (or don't suffer from exactly the same
 bug, anyway)

--

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9209#comment:1
GHC http://www.haskell.org/ghc/
The Glasgow Haskell Compiler