Crash: strange interaction of ScopedTypeVariables extension with type class name resolution
I saw a compiler crash ("the 'impossible' happened..."), seemingly caused by a strange interaction of the ScopedTypeVariables GHC extension with type class name resolution. I am attaching a cut-down example showing the crash. I hope this helps to find the bug. I have only tested with GHC 7.0.4; I am not sure if it is still present in later versions of the compiler. The crash occurs when I load the file in GHCi and evaluate the code
parseRD (pure_ 'a') "a"
or when I simply try to compile the file from the command line.
Trac metadata
Trac field | Value |
---|---|
Version | 7.0.4 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
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