On Tue, 28 Nov 2006 07:43 pm, Daniel McAllansmith wrote: > On Tuesday 28 November 2006 20:50, Alexis Hazell wrote: > > i don't understand why i need to specify type signatures when they should > > already be in scope? > > Is this a result of the monomorphism restriction?
Er . . . . i hadn't heard of this until just now. So i'll have to do some reading on the matter. :-) > You need to add a type signature that specifies a specific arrow data type > 'a' that is an instance of ArrowXml. Ah! i see - thanks. > By the way, once you have the declaration of contact in a source file, and > it is being used by a function in which the ArrowXml instance is not > ambiguous eg: > > foo = runX contact > > the type checker will be able to infer the type and you don't have to > include the type signature. *nod* Thanks again for your help. :-) Alexis. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe