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  • Glasgow Haskell Compiler
  • GHCGHC
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  • #11336

Closed
Open
Created Jan 02, 2016 by baramoglo@trac-baramoglo

GHC craches on this combination of ViewPatterns and PatternSynonyms

The attached file crashes:

$ ghc Bug.hs 
[1 of 1] Compiling Bug              ( Bug.hs, Bug.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 7.10.2 for x86_64-unknown-linux):
	Prelude.last: empty list

I wasn't able to shrink the example further despite many attepts.

Tested on GHC 7.8.3 and 7.10.2.

Trac metadata
Trac field Value
Version 7.10.2
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component Compiler
Test case
Differential revisions
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