On Thu, Feb 13, 2014 at 2:45 PM, Bloch Stephen <bl...@adelphi.edu> wrote: > I've removed a lot of possibly-irrelevant stuff and boiled my current > obstacle down to the following: > > In #lang racket, the following works fine: > > (for/sum [[ii 300]] > pi) > > > > In #lang typed/racket, I try to do the same thing: > > (for/sum: : Flonum [[ii : Index 300]] > pi) > > and I get the type error "Expected Flonum, but got Zero". Where is there a > zero anywhere in this code? And even if there were a zero, shouldn't Zero > be a subtype of Flonum? > > Don't tell me the Zero I'm running into is the initial value of for/sum's > hidden accumulator....
Unfortunately, that's exactly what I'm going to tell you. Typed Racket isn't smart enough to know that the initial value is never used, and so 0 is thought to be a possibility. I recommend using `for/fold` for this case as a workaround. Sam ____________________ Racket Users list: http://lists.racket-lang.org/users
