Matching on pattern synonym succeeds compiled with ghc, fails with ghci
A file /tmp/test.hs
{-# Language PatternSynonyms, ViewPatterns #-}
pattern Parsed x = [(x, "")]
pattern Read a <- (reads -> Parsed a)
main = do
let Read x = "420"
print (x::Int)
$ ghc -ignore-dot-ghci /tmp/test.hs && /tmp/test
420
fails with ghci
$ ghci -ignore-dot-ghci /tmp/test.hs
GHCi, version 8.0.0.20160511: http://www.haskell.org/ghc/ :? for help
[1 of 1] Compiling Main ( /tmp/test.hs, interpreted )
ghc: panic! (the 'impossible' happened)
(GHC version 8.0.0.20160511 for x86_64-unknown-linux):
kindPrimRep.go rep_a1XC
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
>
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | mpickering |
Operating system | |
Architecture |