siso dagbovie wrote: > Hi, > > I've defined the datatype: > > data Graph a b = Empty | Context a b :& Graph a b > > and the function > > isEmpty :: Graph a b -> Bool > isEmpty Empty = True > isEmpty _ = False > > and when I do a test run with the graph, > ( [ ],2,'c',[("down",3)]) :& Empty > > Haskell is bringing the message " Not in scope: data constructor `:&' " > Why is that so?
This works for me. Are the definitions in the same file? Otherwise, you will need to import your definition. All the best, -- Jochem Berndsen | joc...@functor.nl GPG: 0xE6FABFAB _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe