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 listI 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 | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |