On Dec 2, 2012, at 1:42 AM, Galler wrote: > Racket also provides operations for inspecting continuations, for example > (continuation-marks k) returns the set of marks associated with k. (see Ref. > s9.5).
Those are somewhat orthogonal to the opaqueness of continuations but yes, I wrote "Imagine we lied." > Is the answer 'Racket can't provide mutable continuations b/c continuations > are implemented like procedures' You are confusing mutation with synthesizing new kinds of continuations. I carefully wrote set-frame : Continuation Nat Any -> Continuation This is functional but yes, one could also imagine an imperative version. No matter what it would demand a change in the set of operations on continuations (and possibly their representation). > And, to be clear, I don't have a single reason for why it should provide > mutable continuations. As mentioned, I know only one such use. > On Dec 2, 2012, at 5:18 AM, Jan Burse wrote: > >> Galler schrieb: >>> 'Racket could implement mutable continuations, but has not' >> >> I was just thinking whether mutable continuations can >> be used for some JIT-ing. Sure this would affect compilation strategies but no worse than using eval. -- Matthias ____________________ Racket Users list: http://lists.racket-lang.org/users
