From 3dd17c73ed59730d5f188f8e93e5e833d19d067c Mon Sep 17 00:00:00 2001 From: Sam Tobin-Hochstadt Date: Wed, 23 Aug 2017 16:58:52 -0400 Subject: [PATCH] Clarify current-future. (#1780) --- pkgs/racket-doc/scribblings/reference/futures.scrbl | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/pkgs/racket-doc/scribblings/reference/futures.scrbl b/pkgs/racket-doc/scribblings/reference/futures.scrbl index e8015a1685..4275a4f3c0 100644 --- a/pkgs/racket-doc/scribblings/reference/futures.scrbl +++ b/pkgs/racket-doc/scribblings/reference/futures.scrbl @@ -81,10 +81,12 @@ execute through a call to @racket[touch], however. @defproc[(current-future) (or/c #f future?)]{ Returns the descriptor of the future whose thunk execution is the - current continuation. If a future thunk itself uses @racket[touch], + current continuation; that is, if a future descriptor @racket[f] is returned, + @racket[(touch f)] will produce the result of the current continuation. + If a future thunk itself uses @racket[touch], future-thunk executions can be nested, in which case the descriptor of the most immediately executing future is returned. If the current - continuation is not a future-thunk execution, the result is + continuation does not return to the @racket[touch] of any future, the result is @racket[#f]. }