[EMAIL PROTECTED] wrote: > we might attempt to write > >> testr = either (error) (ev) (typecheck env0 te3) >> where ev (TypedTerm t e) = sin (eval e) > > We know that it should work.
If we know it has to be a Double, we can express that: > testr = either (error) (ev) (typecheck env0 te3) > where ev (TypedTerm TDouble e) = sin (eval e) and this compiles. Of course, we can consider the other types as well: > testr = either (error) (ev) (typecheck env0 te3) > where ev (TypedTerm TDouble e) = Right $ sin (eval e) > ev _ = Left "not a Double" Zun. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
