The following hugs module is rejected under Hugs 1.3c.
module Oops where
class Foo t s where
foo :: t -> s
class (Foo t s) => Bar t s where
bar :: t -> s
instance (Foo t s) => Bar t s where
bar = foo
with the message:
ERROR "Oops.hs" (line 9): Cannot build superclass instance
*** Instance : Bar a b
*** Context supplied : Foo a b (bad type)
*** Required superclass : Foo a b
Is this a bug, implementation restriction or user error?
Lex
--
Name: dr.ir. Lex Augusteijn
Address: WL 1.1.13
Philips Research Laboratories
Prof. Holstlaan 4
5656 AA Eindhoven
The Netherlands
Phone: (+31 40 27)43938
Fax: (+31 40 27)44004
E-Mail: [EMAIL PROTECTED]
