On Sun, 30 Nov 2014 15:26:09 -0500 Thanks, Vincent. Vincent St-Amour <stamo...@ccs.neu.edu> wrote:
> At Sun, 30 Nov 2014 16:38:02 +0100, > Manfred Lotz wrote: > > 1. You offered assert? as an alternative. Is this preferable in > > comparison to cast? > > Yes. Assertions are simple first order checks, and are quite > inexpensive. Casts, on the other hand, use contracts and may require > wrapping for mutable data or higher-order types. > Aaah, good to know. > > 2. My solution seems to be bad because the decision about the type > > happens at runtime. > > I wouldn't be too worried about the cost of assertions, they're > usually quite cheap. If you want to know whether assertions are > slowing your program down, try using the `feature-profile` package. > It reports the cost of various language features, including > assertions. > I accept it when it is cheap although I would prefer to be able to work out the type thing at compile time. -- Manfred ____________________ Racket Users list: http://lists.racket-lang.org/users
