On 16 February 2005 14:41, Johan Glimming wrote:

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].

I think the syntax used in your type synonym declaration isn't supported at the moment. For consistency it probably should be. Cheers, Simon