Hello,

What are the intended invariants of Unique values?

So far I thought that it is always gives a unique identity to things during a whole GHC invocation. However this is not true. I.e. eta expansion breaks this assumption.

Here is a snippet from the STG IR of GHC.PrimopWrappers:

extendInt8# [InlPrag=NOINLINE] :: Int8# -> Int#
[GblId, Arity=1, Unf=OtherCon []] =
\r [eta_B1] extendInt8# [eta_B1];

ord# [InlPrag=NOINLINE] :: Char# -> Int#
[GblId, Arity=1, Unf=OtherCon []] =
\r [eta_B1] ord# [eta_B1];

Where eta_B1 is redefined, so it is only unique in the scope.

Is this intentional?

Thanks,

Csaba Hruska