On Tue, Jun 26, 2012 at 9:36 PM, Robby Findler <ro...@eecs.northwestern.edu> wrote: > The safety in this case doesn't generalize to contracts like the one > Neil is suggesting when you go from an untyped value to a typed one, > tho, right?
Right, if we have an untyped value which we'd like to give the `case->` type that Neil described, we'd need to use a dependent contract, as you suggested. That's on the longer-term todo list. For the typed->untyped case, when the arguments and results are all first-order, the algorithm that Vincent uses for printing `case->` types will also work for generating appropriate simpler contracts, such as `(-> real? real?)`. Sam > Robby > > On Tue, Jun 26, 2012 at 8:32 PM, Sam Tobin-Hochstadt <sa...@ccs.neu.edu> > wrote: >> Certainly the dependent contract approach will work, but the 'Real -> Real' >> contract is also safe, so I'll see about generating that. >> >> Sam >> >> On Jun 26, 2012 8:37 PM, "Robby Findler" <ro...@eecs.northwestern.edu> >> wrote: >>> >>> In this case, the contract could turn into a dependent one with the >>> same semantics. Does it make sense for TR to allow a user to declare >>> the equivalent contract? >>> >>> Robby >>> >>> On Tue, Jun 26, 2012 at 7:17 PM, Neil Toronto <neil.toro...@gmail.com> >>> wrote: >>> > Ten minutes in, I've hit a snag. I'd like the stuff in math/functions to >>> > have precise types. For example, log1p could have the type >>> > >>> > (case-> (Zero -> Zero) >>> > (Float -> Float) >>> > (Real -> Real)) >>> > >>> > It was easy to get the implementation to typecheck, but when I tried to >>> > plot >>> > it in untyped Racket, I got this: >>> > >>> > Type Checker: The type of log1p cannot be converted to a contract in: >>> > log1p >>> > >>> > I really don't want to have two versions of the library. Could TR use >>> > the >>> > most general type (Real -> Real) as the contract? Or would that be >>> > unsound? >>> > >>> > Neil ⊥ >>> > _________________________ >>> > Racket Developers list: >>> > http://lists.racket-lang.org/dev >>> >>> _________________________ >>> Racket Developers list: >>> http://lists.racket-lang.org/dev _________________________ Racket Developers list: http://lists.racket-lang.org/dev
