Kind error in GHC-7.4.1, works in GHC-7.2.2
Roel van Dijk
vandijk.roel at gmail.com
Sun Feb 12 16:58:58 CET 2012
Thank you for the explanation. I now understand the problem. I have
rewritten the code using some parenthesis.
2012/2/10 Simon Peyton-Jones <simonpj at microsoft.com>:
> It should not have worked before. Consider
> I# $ 3#
> ($) is a polymorphic function and takes two *pointer* arguments. If we actually called it with I# and 3# as arguments we might seg-fault when we call the GC when allocating the box.
> Polymorphic type variables (in this case in the type of ($)) can only be instantiated with boxed types.
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