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. > 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. Vincent ____________________ Racket Users list: http://lists.racket-lang.org/users
