Hugs version: 1.3c Configuration options: nothing special OS: Sun 5 & Windows NT Compiler: gcc & N/A respectively Expected behavior: Expected the type class to be accepted. This example was posted to comp.lang.functional by Sigbjorn Finne on March 30, as an example of how Haskell multi-parameter type classes would be used. I had tried something similar earlier the same day, without success. So I tried the posted example, and got the same kind of failure. Observed behavior: Hugs reported error. Session transcript: Reading script file "\hugs\prelude.hs": Hugs session for: \hugs\prelude.hs Type :? for help ? :l bug1.hs Reading script file "bug1.hs": ERROR "bug1.hs" (line 5): Ambiguous type signature in class declaration *** ambiguous type : Stream a b => a c -> c -> IO () *** assigned to : write Related programs: bug1.hs: data Priority = Pri class Stream source sink where makeStream :: Priority -> (source a, sink a) write :: source a -> a -> IO () read :: sink a -> IO a pipe :: source a -> sink a -> IO () -- never returns -- Scott Turner [EMAIL PROTECTED] http://www.ma.ultranet.com/~pkturner
