GHC-problem with parsing infix type synonyms - bug?
glimming at kth.se
Wed Feb 16 09:41:28 EST 2005
I read from the type-extensions.html part of the GHC 6.2 manual:
"After expanding type synonyms, GHC does validity checking on types,
looking for the following mal-formedness which isn't detected simply by
kind checking: ... Partially-applied type synonym."
However, when entering:
> infix 9 :-+-:
> type (f :-+-: g) t o1 o2 = Either (f t o1 o2) (g t o1 o2)
or simpler variations e.g. without brackets, except where no arguments
are present after (f :-+-: g), I get parse errors (yes, _parse_) on
this very line.
Also, the above works for data, and the "lexical syntax is the same as
that for data constructors" [someone had read this somewhere].
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