Karle, The expression (t,d,y) must have type Pkg, by your type annotation for update_table1, so [ (t,d,y) ] has type [Pkg]. Also by your type annotation, the result of update_table1 should by of type Table. Is the type [Pkg] compatible with type Table? In other words, is the type [ (Pkgtype,Address,Payload) ] the same as the type [ (Address,Port) ]?
Judging from your questions yesterday and today, I suspect that you have not worked carefully through a Haskell language tutorial. I would not discourage you from asking questions on the mailing list, but I would strongly encourage you to consider referring to some of the resources at http://haskell.org/haskellwiki/Books_and_tutorials before trying to proceed with whatever programming project you are working on. Regards, Chris On 11/2/07, karle <[EMAIL PROTECTED]> wrote: > > The same declaration.- > > > 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)] > > update_table1::Table -> Pkg -> Table > update_table1 [] (t,d,y) = [(t,d,y)] > > Error is > > Type error in explicitly typed binding > *** Term : update_table1 > *** Type : Table -> Pkg -> [(Pkgtype,Int,Payload)] > *** Does not match : Table -> Pkg -> Table > > Please kindly suggest, thanks in advance. > > > > > > -- > View this message in context: > http://www.nabble.com/Please-help-from-a-newby-tf4740192.html#a13555338 > Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. > > _______________________________________________ > Haskell-Cafe mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-cafe > > _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
