On Tue, Jul 03, 2007 at 07:57:02PM -0400, Isaac Dupree wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Lennart Augustsson wrote: > > And ghci gives the only sensible answer. Once you start trying to be > > clever > > you're on the slippery slope to undecidability. How would one know > > where to > > stop? > > I would be most perturbed if Haskell were to try and ignore "unused" > > variables. > > >> Since deciding whether a certain variable is used is very easy in this > >> setting(for example CPP macros that expand into "if debugging", where > >> debugging will have a constant value. (I don't expect you to solve the > >> Halting Problem). > > Does this make CPP-usage put you on the slippery slope to > undecidability? just a thought...
It only would if we tried to type check code with CPP in, rather than type checking it after CPP has been run. Although CPP should be avoided where possible precisely because the typechecker can't check that you haven't made a mistake, e.g. broken the code for a different platform. Thanks Ian _______________________________________________ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
