[racket-users] does handin-server really need racket/gui/base?
I tried the handin-server on a Windows computer and it worked just fine. Now I'm trying it on a headless UNIX system and, upon first run, I got: $ racket -l handin-server Unable to init server: Could not connect: Connection refused Gtk initialization failed for display ":0" context...: "/usr/share/racket/pkgs/gui-lib/mred/private/wx/gtk/queue.rkt": [running body] temp37_0 for-loop run-module-instance!125 for-loop [repeats 1 more time] run-module-instance!125 for-loop [repeats 1 more time] run-module-instance!125 do-dynamic-require5 "/usr/share/racket/pkgs/gui-lib/mred/private/wx/platform.rkt": [running body] temp37_0 for-loop run-module-instance!125 for-loop ... Then taking a peek at ~/.racket/7.2/pkgs/handin/handin-server/main.rkt I saw (require ... ;; workaround for a confusing problem: without this, the gui ;; gets initialized in a handler (since checks use it, and ;; they're being required dynamically), and further handlers ;; will fail with "queue-callback: eventspace is shutdown", ;; requiring it here makes it avoids killing the eventspace racket/gui/base) Just to see what happens, I commented out the racket/gui/base requirement and the server ran, but the comment says there'll be a confusing problem. $ racket -l handin-server [-|2019-08-17T01:52:22] *** embedded web server started [-|2019-08-17T01:52:22] Cleaning up all submission directories [-|2019-08-17T01:52:22] *** handin server started on port 7979 Why does the server need anything GUI-related? How do you run this server in production? -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/RxyC6B4i7HgNSuVjlatCo9H-fgEEC2x2L38zkodCjrx8FqWGGkkBEIhW-ndhGc-ieeByffOnG81S9kvYd-PHt1J5wfO1cTvZko8OgqCdXL8%3D%40protonmail.com.
[racket-users] Re: Improved synchronous concurrency example for rosettacode.org ?
On Friday, August 16, 2019 at 6:46:14 PM UTC-4, Brian Adkins wrote: > > I went ahead and added my version to the Racket section w/ some subtle > changes from my original post. I'm happy to edit it if necessary. > > https://rosettacode.org/wiki/Synchronous_concurrency#Racket > > I added a note above my entry re: using thread mailboxes, and I added a > note above the existing entry re: using channels. > > Brian Adkins > >> >> Thanks to Matthew Butterick, the printer function is much nicer now :) https://rosettacode.org/wiki/Synchronous_concurrency#Racket This latest version compares very favorably with a lot of other languages now. Racket continues to pleasantly surprise me - just keep those beautiful parens coming :) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/808f7243-7bbc-4f18-9e8b-e88b90e1dda2%40googlegroups.com.
[racket-users] Re: Improved synchronous concurrency example for rosettacode.org ?
I went ahead and added my version to the Racket section w/ some subtle changes from my original post. I'm happy to edit it if necessary. https://rosettacode.org/wiki/Synchronous_concurrency#Racket I added a note above my entry re: using thread mailboxes, and I added a note above the existing entry re: using channels. Brian Adkins > > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/1733f179-bd48-46ae-87d1-8263cfd8c177%40googlegroups.com.
[racket-users] Improved synchronous concurrency example for rosettacode.org ?
The current Racket example for Synchronous Concurrency seems a little verbose and overly complicated: https://rosettacode.org/wiki/Synchronous_concurrency#Racket What do you think of the following example instead? Brian Adkins --- snip --- (define (reader) (for ([line (in-lines (open-input-file "input.txt"))]) (thread-send printer-thread line)) (thread-send printer-thread eof) (printf "Number of lines: ~a\n" (thread-receive))) (define (printer) (let loop ([line (thread-receive)][count 0]) (if (eof-object? line) (thread-send reader-thread count) (begin (printf "~a\n" line) (loop (thread-receive) (add1 count)) (define printer-thread (thread printer)) (define reader-thread (thread reader)) (thread-wait printer-thread) --- snip --- or the following (using a macro probably just muddies the waters, but I didn't like the (thread (thunk ... nesting ) :) --- snip --- (require syntax/parse/define) (define-simple-macro (thread-start thread-name:id rhs:expr ...) (define thread-name (thread (thunk rhs ... (thread-start printer-thread (let loop ([line (thread-receive)][count 0]) (if (eof-object? line) (thread-send reader-thread count) (begin (printf "~a\n" line) (loop (thread-receive) (add1 count)) (thread-start reader-thread (for ([line (in-lines (open-input-file "input.txt"))]) (thread-send printer-thread line)) (thread-send printer-thread eof) (printf "Number of lines: ~a\n" (thread-receive))) (thread-wait printer-thread) --- snip --- -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/cb2751e8-f0cb-492d-bffb-d2b0f994210a%40googlegroups.com.
Re: [racket-users] See expanded code?
One nice interactive way is with the Macro Stepper feature in DrRacket, which is easy to use once you know the button to start it. Sometimes it helps to copy&paste, into a new file, the minimal usage of a macro you're interested in, and just expand that. Also: https://docs.racket-lang.org/macro-debugger/index.html https://docs.racket-lang.org/reference/Expanding_Top-Level_Forms.html -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/5133ad54-6c26-5aa8-44e7-53b69bb96342%40neilvandyke.org.
[racket-users] See expanded code?
I always try to understand things from the bottom up. How can I see the expansion of things like (match ...)? More generally, how do Racket developers look at the internal forms of programs? -- Josh Rubin jlru...@gmail.com -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/b86a875a-51e6-3855-1f10-12d63c1451fb%40gmail.com.
[racket-users] Racket News - Issue 14
Racket News issue 14 is here. https://racket-news.com/2019/08/racket-news-issue-14.html Enjoy! -- Paulo Matos -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/05377b52-dc75-09ce-97b6-5c9734bbaec3%40linki.tools.
