From bada20a57f04626a9596a1249267d22f71453288 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Wed, 16 Jul 2014 13:08:05 +0100
Subject: [PATCH] fix documented contract for `guard-evt` et al.

The `(or/c evt? any/c)` result contract is, of course, equivalent to
`any/c`, but the verbose variant hopefully helps explain that `evt?`
is really expected.

Yes, it would be better if the result contract actually was `evt?`
(and I implemented `replace-evt` that way before re-reading the
`guard-evt` docs).
---
 .../scribblings/reference/evts.scrbl          | 23 +++++++++----------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/pkgs/racket-pkgs/racket-doc/scribblings/reference/evts.scrbl b/pkgs/racket-pkgs/racket-doc/scribblings/reference/evts.scrbl
index 34402f127f..e2dfefff49 100644
--- a/pkgs/racket-pkgs/racket-doc/scribblings/reference/evts.scrbl
+++ b/pkgs/racket-pkgs/racket-doc/scribblings/reference/evts.scrbl
@@ -188,7 +188,7 @@ breaks explicitly disabled---when it is not wrapped by @racket[wrap-evt],
 ]}
 
 
-@defproc[(guard-evt [maker (-> evt?)]) evt?]{
+@defproc[(guard-evt [maker (-> (or/c evt? any/c))]) evt?]{
 
 Creates a value that behaves as an event, but that is actually an
 event maker.
@@ -208,7 +208,7 @@ synchronization} and whose @tech{synchronization result} is
 @racket[_guard].}
 
 
-@defproc[(nack-guard-evt [maker (evt? . -> . evt?)]) evt?]{
+@defproc[(nack-guard-evt [maker (evt? . -> . (or/c evt? any/c))]) evt?]{
 
 Like @racket[guard-evt], but when @racket[maker] is called, it is
 given a NACK (``negative acknowledgment'') event. After starting the
@@ -225,7 +225,7 @@ value). If the event returned by @racket[maker] is chosen, then the
 NACK event never becomes @tech{ready for synchronization}.}
 
 
-@defproc[(poll-guard-evt [maker (boolean? . -> . evt?)]) evt?]{
+@defproc[(poll-guard-evt [maker (boolean? . -> . (or/c evt? any/c))]) evt?]{
 
 Like @racket[guard-evt], but when @racket[maker] is called, it is
 provided a boolean value that indicates whether the event will be used
@@ -238,15 +238,7 @@ resulting event produces a @tech{synchronization result}, then the event
 will certainly be chosen for its result.}
 
 
-@defthing[always-evt evt?]{A constant event that is always @tech{ready
-for synchronization}, with itself as its @tech{synchronization result}.
-
-@examples[#:eval evt-eval
-  (sync always-evt)
-]}
-
-
-@defproc[(replace-evt [evt evt?] [maker (any/c ... . -> . evt?)]) evt?]{
+@defproc[(replace-evt [evt evt?] [maker (any/c ... . -> . (or/c evt? any/c))]) evt?]{
 
 Like @racket[guard-evt], but @racket[maker] is called only after
 @racket[evt] becomes @tech{ready for synchronization}, and the
@@ -269,6 +261,13 @@ synchronization} and whose @tech{synchronization result} is
 @history[#:added "6.1.0.3"]}
 
 
+@defthing[always-evt evt?]{A constant event that is always @tech{ready
+for synchronization}, with itself as its @tech{synchronization result}.
+
+@examples[#:eval evt-eval
+  (sync always-evt)
+]}
+
 
 @defthing[never-evt evt?]{A constant event that is never @tech{ready
 for synchronization}.