On Sat, Jul 7, 2012 at 10:14 AM, Matthias Felleisen <matth...@ccs.neu.edu> wrote:
> p.s. Sam's version forces too early because strict functions should > force not variable lookups. This is a common misconception among programmers. > I suspect it goes back to Abelson and Sussman getting it wrong (see what > happens if you don't understand the foundations). I still don't think my version forces too early -- your alternative contains no calls to `force` at all. Are you suggesting that I should `force` around the recursive calls to `sum`? In that case, clients are exposed to promises, and the result type is (U Integer (Promise Integer)). I can't tell from your description if you think that's an acceptable result. -- sam th sa...@ccs.neu.edu _________________________ Racket Developers list: http://lists.racket-lang.org/dev
