docs: update call-with-espace-continuation

The performance notes there applied to BC, not CS.

Closes #3373
This commit is contained in:
Matthew Flatt 2020-08-28 14:08:53 -06:00
parent 0ae3ef7b42
commit 7382f5d7e4

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@ -182,15 +182,15 @@ called in tail position, and the continuation procedure supplied to
@racket[proc] can only be called during the dynamic extent of the
@racket[call-with-escape-continuation] call.
Due to the limited applicability of its continuation,
@racket[call-with-escape-continuation] can be implemented more efficiently
than @racket[call-with-current-continuation].
A continuation obtained from @racket[call-with-escape-continuation] is
actually a kind of prompt. Escape continuations are provided mainly
for backwards compatibility, since they pre-date general prompts in
Racket, and because @racket[call/ec] is often an easy replacement
for @racket[call/cc] to improve performance.}
Racket. In the 3m and CGC variants of Racket,
@racket[call-with-escape-continuation] is implemented more efficiently
than @racket[call-with-current-continuation], so
@racket[call-with-escape-continuation] can sometimes replace
@racket[call-with-current-continuation] to improve performance in
those older Racket variants.}
@defproc[(call/ec
[proc (continuation? . -> . any)])