From aa8e895f3226bad1d8305af0f11690868e60240b Mon Sep 17 00:00:00 2001 From: Chris Vine Date: Mon, 25 Apr 2016 10:20:36 +0100 Subject: [PATCH] Don't encourage escape continuations with await-geteveryline! --- a-sync/event-loop.scm | 9 ++++----- docs/event-loop.texi | 30 +++++++++++++----------------- docs/guile-a-sync.info | 37 +++++++++++++++++-------------------- docs/html/event-loop.html | 30 +++++++++++++----------------- 4 files changed, 47 insertions(+), 59 deletions(-) diff --git a/a-sync/event-loop.scm b/a-sync/event-loop.scm index c38670c..2079a0c 100644 --- a/a-sync/event-loop.scm +++ b/a-sync/event-loop.scm @@ -898,11 +898,10 @@ ;; This procedure is implemented using a-sync-read-watch!. Unlike the ;; await-getline! procedure, the watch will continue after a line of ;; text has been received in order to receive further lines. The -;; watch will not end until end-of-file or an exceptional condition is -;; reached. In the event of that happening, this procedure will end -;; and return an end-of-file object or #f respectively. To finish -;; before end-of-file or an exceptional condition, 'proc' can invoke a -;; call/ec escape continuation. +;; watch will not end until end-of-file or an exceptional condition +;; ('excpt) is reached. In the event of that happening, this +;; procedure will end and return an end-of-file object or #f +;; respectively. ;; ;; The 'loop' argument is optional: this procedure operates on the ;; event loop passed in as an argument, or if none is passed (or #f is diff --git a/docs/event-loop.texi b/docs/event-loop.texi index 093d886..7652da0 100644 --- a/docs/event-loop.texi +++ b/docs/event-loop.texi @@ -455,11 +455,9 @@ to be called in a waitable procedure invoked by a-sync, and this procedure is implemented using a-sync-read-watch!. Unlike the await-getline! procedure, the watch will continue after a line of text has been received in order to receive further lines. The watch will -not end until end-of-file or an exceptional condition is reached. In -the event of that happening, this procedure will end and return an -end-of-file object or #f respectively. To finish before end-of-file -or an exceptional condition, 'proc' can invoke a call/ec escape -continuation. +not end until end-of-file or an exceptional condition ('excpt) is +reached. In the event of that happening, this procedure will end and +return an end-of-file object or #f respectively. The 'loop' argument is optional: this procedure operates on the event loop passed in as an argument, or if none is passed (or #f is passed), @@ -473,21 +471,19 @@ setting up (that is, before the first call to 'await' is made), which shouldn't happen unless memory is exhausted. Subsequent exceptions (say, because of port errors) will propagate out of event-loop-run!. -Here is an example of the use of await-geteveryline!: +Here is an example of the use of await-geteveryline! (because the +keyboard has no end-of-file, use Ctrl-C to exit this code snippet): @example (set-default-event-loop!) ;; if none has yet been set (a-sync (lambda (await resume) - (display "Enter lines of text at the keyboard, enter empty line to finish\n") - (call/ec (lambda (k) - (await-geteveryline! await resume - (open "/dev/tty" O_RDONLY) - (lambda (line) - (when (string=? line "") - (k #f)) - (simple-format #t - "The line was: ~A\n" - line))))) - (event-loop-quit!))) + (display "Enter lines of text at the keyboard, ^C to finish\n") + (let ((port (open "/dev/tty" O_RDONLY))) + (await-geteveryline! await resume + port + (lambda (line) + (simple-format #t + "The line was: ~A\n" + line)))))) (event-loop-run!) @end example @end deffn diff --git a/docs/guile-a-sync.info b/docs/guile-a-sync.info index a33f023..2f8b0ca 100644 --- a/docs/guile-a-sync.info +++ b/docs/guile-a-sync.info @@ -735,11 +735,10 @@ thread. and this procedure is implemented using a-sync-read-watch!. Unlike the await-getline! procedure, the watch will continue after a line of text has been received in order to receive further lines. The - watch will not end until end-of-file or an exceptional condition is - reached. In the event of that happening, this procedure will end - and return an end-of-file object or #f respectively. To finish - before end-of-file or an exceptional condition, 'proc' can invoke a - call/ec escape continuation. + watch will not end until end-of-file or an exceptional condition + ('excpt) is reached. In the event of that happening, this + procedure will end and return an end-of-file object or #f + respectively. The 'loop' argument is optional: this procedure operates on the event loop passed in as an argument, or if none is passed (or #f is @@ -754,20 +753,18 @@ thread. exceptions (say, because of port errors) will propagate out of event-loop-run!. - Here is an example of the use of await-geteveryline!: + Here is an example of the use of await-geteveryline! (because the + keyboard has no end-of-file, use Ctrl-C to exit this code snippet): (set-default-event-loop!) ;; if none has yet been set (a-sync (lambda (await resume) - (display "Enter lines of text at the keyboard, enter empty line to finish\n") - (call/ec (lambda (k) - (await-geteveryline! await resume - (open "/dev/tty" O_RDONLY) - (lambda (line) - (when (string=? line "") - (k #f)) - (simple-format #t - "The line was: ~A\n" - line))))) - (event-loop-quit!))) + (display "Enter lines of text at the keyboard, ^C to finish\n") + (let ((port (open "/dev/tty" O_RDONLY))) + (await-geteveryline! await resume + port + (lambda (line) + (simple-format #t + "The line was: ~A\n" + line)))))) (event-loop-run!) -- Scheme Procedure: a-sync-write-watch! resume file proc [loop] @@ -1222,8 +1219,8 @@ Tag Table: Node: Top85 Node: coroutines1099 Node: event loop14941 -Node: monotonic time42148 -Node: gnome glib43582 -Node: compose57361 +Node: monotonic time41996 +Node: gnome glib43430 +Node: compose57209  End Tag Table diff --git a/docs/html/event-loop.html b/docs/html/event-loop.html index 7e81f6e..a37f736 100644 --- a/docs/html/event-loop.html +++ b/docs/html/event-loop.html @@ -529,11 +529,9 @@

event loop

procedure is implemented using a-sync-read-watch!. Unlike the await-getline! procedure, the watch will continue after a line of text has been received in order to receive further lines. The watch will -not end until end-of-file or an exceptional condition is reached. In -the event of that happening, this procedure will end and return an -end-of-file object or #f respectively. To finish before end-of-file -or an exceptional condition, ’proc’ can invoke a call/ec escape -continuation. +not end until end-of-file or an exceptional condition (’excpt) is +reached. In the event of that happening, this procedure will end and +return an end-of-file object or #f respectively.

The ’loop’ argument is optional: this procedure operates on the event loop passed in as an argument, or if none is passed (or #f is passed), @@ -547,21 +545,19 @@

event loop

shouldn’t happen unless memory is exhausted. Subsequent exceptions (say, because of port errors) will propagate out of event-loop-run!.

-

Here is an example of the use of await-geteveryline!: +

Here is an example of the use of await-geteveryline! (because the +keyboard has no end-of-file, use Ctrl-C to exit this code snippet): 

(set-default-event-loop!) ;; if none has yet been set
 (a-sync (lambda (await resume)
-	  (display "Enter lines of text at the keyboard, enter empty line to finish\n")
-	  (call/ec (lambda (k)
-		     (await-geteveryline! await resume
-					  (open "/dev/tty" O_RDONLY)
-					  (lambda (line)
-					    (when (string=? line "")
-					      (k #f))
-					    (simple-format #t
-							   "The line was: ~A\n"
-							   line)))))
-	  (event-loop-quit!)))
+	  (display "Enter lines of text at the keyboard, ^C to finish\n")
+	  (let ((port (open "/dev/tty" O_RDONLY)))
+	    (await-geteveryline! await resume
+				 port
+				 (lambda (line)
+				   (simple-format #t
+						  "The line was: ~A\n"
+						  line))))))
 (event-loop-run!)