Ch. A. Herrmann wrote:
> [...] ghc-2.08 typechecker reports the following error message in the
> type definition of function "foo" which uses the instantiated "St":
>
> `St' should have no arguments, but has been given 1 .
> [...]
> type St = State TS
> [...]
It works if you change the above line to
type St a = State TS a
If I read the Haskell report correctly, your version should work, too,
and this is a bug in GHC. Section 4.2.2 says:
[...] The kind of the new type constructor T is of the form
k1->...->kk->k where the kinds ki of the arguments ui and k of the
right hand side t are determined by kind inference as described in
Section 4.6. For example, the following definition can be used to
provide an alternative way of writing the list type constructor:
type List = []
The following example fails in GHC, too:
module Foo where
type List = []
bar :: List Char
bar = "doesn't work in GHC"
GHC says:
kind.hs:3: `List' should have no arguments, but has been given 1 .
--
Sven Panne Tel.: +49/89/2178-2235
LMU, Institut fuer Informatik FAX : +49/89/2178-2211
LFE Programmier- und Modellierungssprachen Oettingenstr. 67
mailto:[EMAIL PROTECTED] D-80538 Muenchen
http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne
