[Haskell-cafe] Re: Need help from a newby

[ChrisK]

karle wrote:
> My declaration is as followed:-
> 
> type Address = Int 
> data Port = C | D deriving(Eq,Show) 
> data Payload = UP[Char] | RTDP(Address,Port) deriving(Eq,Show) 
> data Pkgtype = RTD | U deriving(Eq,Show)
> type Pkg = (Pkgtype,Address,Payload) 
> type Table = [(Address,Port)] 
> 
> 
> findport::[Pkg]->[Table]->[([Pkg],[Pkg])]
> findport [(pt,ad,pa)]  [(a,p)] 
>       | ( p == C) = ([pt,ad,a],[])
>       | otherwise = ([],[pt,ad,a])
> 
> Error received:-
> 
> Type error in explicitly typed binding
> *** Term           : [(a,p)]
> *** Type           : [(a,b)]
> *** Does not match : [Table]
> 
> Can anyone please help?

There seems to be several things that look wrong.

Could you explain what findport is supposed to be doing?