# Latest **URL:** https://racket.discourse.group/latest.md?page=18 [Latest](https://racket.discourse.group/latest.md) · [Categories](https://racket.discourse.group/categories.md) · [Tags](https://racket.discourse.group/tags.md) **Page:** 19 --- ## [Don’t understand the behavior of this code](https://racket.discourse.group/t/don-t-understand-the-behavior-of-this-code/3538)
**Author:** [@munroec](https://racket.discourse.group/u/munroec)\ **Replies:** 3\ **Last updated:** [February 4, 2025, 12:16pm UTC](https://racket.discourse.group/t/don-t-understand-the-behavior-of-this-code/3538 "2025-02-04T12:16:04Z")
This is an. example from “Racket Programming the Fun Way “ #lang racket (define queue% (class object% (init \[queue-list '()\]) (define head '{}) (define tail '{}) (super-new) (define/public (enqueue val) (let (\[t… --- ## [Questions about what math/array does and how it works](https://racket.discourse.group/t/questions-about-what-math-array-does-and-how-it-works/3515)
**Author:** [@Gambiteer](https://racket.discourse.group/u/Gambiteer)\ **Replies:** 2\ **Last updated:** [February 3, 2025, 11:26pm UTC](https://racket.discourse.group/t/questions-about-what-math-array-does-and-how-it-works/3515 "2025-02-03T23:26:23Z")
I'm the author of SRFI 231 about arrays and I'm trying to figure out what Racket's math/array does and how it works internally. So I thought I'd ask my questions here. It appears at first reading that there is no way t… --- ## [Proper way(s) to write to the output port in a console application?](https://racket.discourse.group/t/proper-way-s-to-write-to-the-output-port-in-a-console-application/3537)
**Author:** [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\ **Replies:** 3\ **Last updated:** [February 3, 2025, 5:22pm UTC](https://racket.discourse.group/t/proper-way-s-to-write-to-the-output-port-in-a-console-application/3537 "2025-02-03T17:22:38Z")
Hi, Racket Discourse. I am busy fiddling around with a command-line script, and I am wondering what I am doing wrong with the "dynamic" display to the terminal's output. I am running on a kali linux instance, for what i… --- ## [Command for OS that calls racket etc](https://racket.discourse.group/t/command-for-os-that-calls-racket-etc/3533)
**Author:** [@Don](https://racket.discourse.group/u/Don)\ **Replies:** 2\ **Last updated:** [February 1, 2025, 9:01pm UTC](https://racket.discourse.group/t/command-for-os-that-calls-racket-etc/3533 "2025-02-01T21:01:32Z")
I can run a launcher that runs drracket and loads a file. Trying to setup a launcher that runs Racket, loads a file containing a module and calls the module. Something like following which does not work: drracket -l f… --- ## [A Little More On Powershell Scripting With Racket](https://racket.discourse.group/t/a-little-more-on-powershell-scripting-with-racket/3525)
**Author:** [@OldDutchCap](https://racket.discourse.group/u/OldDutchCap)\ **Replies:** 5\ **Last updated:** [January 31, 2025, 4:43pm UTC](https://racket.discourse.group/t/a-little-more-on-powershell-scripting-with-racket/3525 "2025-01-31T16:43:21Z")
Just thought others might find this somewhat interesting: https://onor.io/2025/01/more-scripting-with-racket.html --- ## [Racket meet-up: Saturday, 1 February 2025 at 18:00 UTC](https://racket.discourse.group/t/racket-meet-up-saturday-1-february-2025-at-18-00-utc/3529)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [January 31, 2025, 11:10am UTC](https://racket.discourse.group/t/racket-meet-up-saturday-1-february-2025-at-18-00-utc/3529 "2025-01-31T11:10:17Z")
Everyone is welcome to join us for the :racket: Racket meet-up: Saturday, 1 February 2025 at 18:00 UTC In your timezone: 2025-02-01T18:00:00Z (UTC). (converter) At this meet-up: Book Club Reading/Discussing "How To D… --- ## [\`match\` for parsing into hash](https://racket.discourse.group/t/match-for-parsing-into-hash/3523)
**Author:** [@dstorrs](https://racket.discourse.group/u/dstorrs)\ **Replies:** 2\ **Last updated:** [January 30, 2025, 5:35am UTC](https://racket.discourse.group/t/match-for-parsing-into-hash/3523 "2025-01-30T05:35:33Z")
\#lang racket (match (list 7 2 3 7) ; displays: 7 \[(list row b c row) row\]) (match (list 7 2 3 (hash 7 'ok )) ; displays: (list 7 'ok) … --- ## [Uncommenting does not work on any Linux distro with Gnome 3+](https://racket.discourse.group/t/uncommenting-does-not-work-on-any-linux-distro-with-gnome-3/1299)
**Author:** [@hrvoje064](https://racket.discourse.group/u/hrvoje064)\ **Replies:** 13\ **Last updated:** [January 28, 2025, 4:00am UTC](https://racket.discourse.group/t/uncommenting-does-not-work-on-any-linux-distro-with-gnome-3/1299 "2025-01-28T04:00:24Z")
This is a long running issue, even before 8.5. I reported it (not here) maybe 2 or so years ago, when I switched to latest Fedora that came with Gnome 3. At that time both comment/uncomment did not work. By the way, both… --- ## [EoPL Exercise 1.36](https://racket.discourse.group/t/eopl-exercise-1-36/3520)
**Author:** [@matteo-daddio](https://racket.discourse.group/u/matteo-daddio)\ **Replies:** 4\ **Last updated:** [January 27, 2025, 8:27pm UTC](https://racket.discourse.group/t/eopl-exercise-1-36/3520 "2025-01-27T20:27:02Z")
Hello, I’m reading EoPL and I’m stuck in the 1.36 exercise. Write a procedure g such that number-elements from page 23 could be defined as: (define number-elements (lambda (lst) (if (null? lst) ’() (g (lis… --- ## [Racket/gui list-box% vs choice% append](https://racket.discourse.group/t/racket-gui-list-box-vs-choice-append/3516)
**Author:** [@gekkonier](https://racket.discourse.group/u/gekkonier)\ **Replies:** 3\ **Last updated:** [January 26, 2025, 7:00pm UTC](https://racket.discourse.group/t/racket-gui-list-box-vs-choice-append/3516 "2025-01-26T19:00:44Z")
Hi! This is my first post, so I hope I don't violate something here. If this does not fit here I hope you tell me so I can adapt. I enjoy programming small tools with Racket, and I really like the easy to use gui Racke… --- ## [Racket tutorials](https://racket.discourse.group/t/racket-tutorials/3511)
**Author:** [@Eeb](https://racket.discourse.group/u/Eeb)\ **Replies:** 2\ **Last updated:** [January 26, 2025, 6:40pm UTC](https://racket.discourse.group/t/racket-tutorials/3511 "2025-01-26T18:40:20Z")
Hi everyone! I've recently started creating educational content on YouTube in my free time, and I started a series about everyone’s favorite programming language—Racket! There isn’t much content on racket so I thought it… --- ## [The use of #: in the program listing below](https://racket.discourse.group/t/the-use-of-in-the-program-listing-below/3505)
**Author:** [@munroec](https://racket.discourse.group/u/munroec)\ **Replies:** 12\ **Last updated:** [January 24, 2025, 3:02pm UTC](https://racket.discourse.group/t/the-use-of-in-the-program-listing-below/3505 "2025-01-24T15:02:25Z")
I'm less than a week into learning DrRacket and one of my books on Racket had a brief routine to plot 2 cycles of a sine wave. It didn't run as written in the book but it was fairly easy to get it to run in DrRacket how… --- ## [Audio support in Racket for music player](https://racket.discourse.group/t/audio-support-in-racket-for-music-player/3373)
**Author:** [@Robert](https://racket.discourse.group/u/Robert)\ **Replies:** 8\ **Last updated:** [January 23, 2025, 2:17am UTC](https://racket.discourse.group/t/audio-support-in-racket-for-music-player/3373 "2025-01-23T02:17:49Z")
I'm researching languages and libraries to make a music player. I'm considering Racket, but wonder if Racket has support for playing common audio files, or if there's an agreeable method to achieve the desired functional… --- ## [Imported syntax class works different from syntax class copy-pasted into file](https://racket.discourse.group/t/imported-syntax-class-works-different-from-syntax-class-copy-pasted-into-file/3507)
**Author:** [@sora22](https://racket.discourse.group/u/sora22)\ **Replies:** 4\ **Last updated:** [January 21, 2025, 9:21pm UTC](https://racket.discourse.group/t/imported-syntax-class-works-different-from-syntax-class-copy-pasted-into-file/3507 "2025-01-21T21:21:37Z")
I'm currently trying to reuse some syntax classes that I've made, and want to match certain identifiers within them. These syntax classes produce an error if I attempt to import them rather than defining them directly wi… --- ## [Testing for the v8.16 release](https://racket.discourse.group/t/testing-for-the-v8-16-release/3503)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 0\ **Last updated:** [January 20, 2025, 11:34pm UTC](https://racket.discourse.group/t/testing-for-the-v8-16-release/3503 "2025-01-20T23:34:23Z")
Testing for the v8.16 release (using the v8.15.900 release candidate build) Search for your name on the checklist page to find relevant items, either reply when you finish an item (please indicate which item/s is/are … --- ## [Racket Events Calendar](https://racket.discourse.group/t/racket-events-calendar/2173)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 4\ **Last updated:** [January 20, 2025, 12:00pm UTC](https://racket.discourse.group/t/racket-events-calendar/2173 "2025-01-20T12:00:27Z")
Hi Racket has many events, both virtual and in-person. You can now subscribe to the Racket meet-ups calendar to see upcoming events including Rhombus, Qi, Racket, RacketCon and RacketFest. https://calendar.google.com/… --- ## [Dealing with multiple values](https://racket.discourse.group/t/dealing-with-multiple-values/3500)
**Author:** [@matteo-daddio](https://racket.discourse.group/u/matteo-daddio)\ **Replies:** 3\ **Last updated:** [January 19, 2025, 11:20pm UTC](https://racket.discourse.group/t/dealing-with-multiple-values/3500 "2025-01-19T23:20:33Z")
Hello, some months ago, when I started working with streams, I developed a procedure that takes some single valued streams and return a multi valued stream. Then I thought if the opposite was possible: create a procedur… --- ## [Am I "hallucinating" again ;) (aka - My Topics)](https://racket.discourse.group/t/am-i-hallucinating-again-aka-my-topics/3497)
**Author:** [@AlexG](https://racket.discourse.group/u/AlexG)\ **Replies:** 2\ **Last updated:** [January 18, 2025, 11:53am UTC](https://racket.discourse.group/t/am-i-hallucinating-again-aka-my-topics/3497 "2025-01-18T11:53:37Z")
Was there not previously a menu selection for "My Topics"? Can't seem to see it. --- ## [3d dataset visualization using the plot package](https://racket.discourse.group/t/3d-dataset-visualization-using-the-plot-package/1563)
**Author:** [@alexh](https://racket.discourse.group/u/alexh)\ **Replies:** 2\ **Last updated:** [January 17, 2025, 11:20am UTC](https://racket.discourse.group/t/3d-dataset-visualization-using-the-plot-package/1563 "2025-01-17T11:20:52Z")
I needed a way to visualize a 3D dataset and I used the racket plot package for it, and, while the dataset is not Racket related, I thought I share the end result here: The racket plot package uses paralle… --- ## [Qi 5 Release Party](https://racket.discourse.group/t/qi-5-release-party/3461)
**Author:** [@countvajhula](https://racket.discourse.group/u/countvajhula)\ **Replies:** 4\ **Last updated:** [January 16, 2025, 5:01pm UTC](https://racket.discourse.group/t/qi-5-release-party/3461 "2025-01-16T17:01:20Z")
Hey all, After a year of work, Qi is nearing a new release. Please join us for the release party on 2025-01-17T18:00:00Z (UTC) (i.e. Friday two weeks from today)! Read on for more details. Qi allows you to embed expres… --- ## [What does #:track-literals do?](https://racket.discourse.group/t/what-does-track-literals-do/3496)
**Author:** [@acarrico](https://racket.discourse.group/u/acarrico)\ **Replies:** 2\ **Last updated:** [January 16, 2025, 1:02pm UTC](https://racket.discourse.group/t/what-does-track-literals-do/3496 "2025-01-16T13:02:39Z")
What does #:track-literals do in syntax-parse? Why doesn't define-syntax-class also have #:track-literals? --- ## [Something Like Pipe Forward In Racket?](https://racket.discourse.group/t/something-like-pipe-forward-in-racket/3492)
**Author:** [@OldDutchCap](https://racket.discourse.group/u/OldDutchCap)\ **Replies:** 14\ **Last updated:** [January 16, 2025, 3:58am UTC](https://racket.discourse.group/t/something-like-pipe-forward-in-racket/3492 "2025-01-16T03:58:22Z")
Is there anything in Racket like the pipe forward operator (|\>) that I've seen in Haskell, F# and Elixir? For those unfamiliar with this operator it simply passes the output of one function as the input to the next. So… --- ## [A real code example in infix/prefix Scheme+ for Racket](https://racket.discourse.group/t/a-real-code-example-in-infix-prefix-scheme-for-racket/3491)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 0\ **Last updated:** [January 14, 2025, 1:05pm UTC](https://racket.discourse.group/t/a-real-code-example-in-infix-prefix-scheme-for-racket/3491 "2025-01-14T13:05:04Z")
Hello and Happy new year, i think interesting to post an example of code with Scheme+ for Racket used in real in a web application. (that also use PHP,Python...) Here the Racket Scheme+ code is only used as a glue betw… --- ## [Where is the "Check Syntax" button in DrRacket?](https://racket.discourse.group/t/where-is-the-check-syntax-button-in-drracket/3489)
**Author:** [@jsampson45](https://racket.discourse.group/u/jsampson45)\ **Replies:** 2\ **Last updated:** [January 14, 2025, 12:14pm UTC](https://racket.discourse.group/t/where-is-the-check-syntax-button-in-drracket/3489 "2025-01-14T12:14:10Z")
I cannot find the "Check Syntax" button mentioned in the docs. The interface to DrRacket that I see is: --- ## [Specifying other repos for packages to be included in \`make installers\`](https://racket.discourse.group/t/specifying-other-repos-for-packages-to-be-included-in-make-installers/3486)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 1\ **Last updated:** [January 13, 2025, 1:16pm UTC](https://racket.discourse.group/t/specifying-other-repos-for-packages-to-be-included-in-make-installers/3486 "2025-01-13T13:16:06Z")
Hi, I'm having fun making my own Racket, but I've come across a situation where I want to build against different repos to those in the package catalog. Is it possible to specify repos for the make installers sites.rkt… --- ## [Racket v8.16 Release Thread](https://racket.discourse.group/t/racket-v8-16-release-thread/3468)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 5\ **Last updated:** [January 13, 2025, 10:03am UTC](https://racket.discourse.group/t/racket-v8-16-release-thread/3468 "2025-01-13T10:03:58Z")
The release process for v8.16 will begin in about four days. If you have any new features that you want in and are relatively close to to being done, now is a good time to do that. Upcoming dates: - 10th: Branch day, … --- ## [Question on eval and modules](https://racket.discourse.group/t/question-on-eval-and-modules/3482)
**Author:** [@ndykman](https://racket.discourse.group/u/ndykman)\ **Replies:** 5\ **Last updated:** [January 13, 2025, 3:49am UTC](https://racket.discourse.group/t/question-on-eval-and-modules/3482 "2025-01-13T03:49:48Z")
I was trying to make a simple video showing how it was easy to take a list of numbers '(1 2 3 4 5) and create a list like the following ( (define (plus-1 n) (+ 1 n)) (define (plus-2 n) (+ 2 n)) ) in the context of a… --- ## [Lifetime of sessions in \`net/http-easy\`](https://racket.discourse.group/t/lifetime-of-sessions-in-net-http-easy/3483)
**Author:** [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\ **Replies:** 8\ **Last updated:** [January 12, 2025, 4:49pm UTC](https://racket.discourse.group/t/lifetime-of-sessions-in-net-http-easy/3483 "2025-01-12T16:49:37Z")
Hi, Racket Discourse. I encountered an API (specifically ThreatFox), which requires an SSL context for the session when making requests; I am using net/http-easy. Easy enough, after I figured that part out, but now I a… --- ## [URL-builder macro](https://racket.discourse.group/t/url-builder-macro/3476)
**Author:** [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\ **Replies:** 7\ **Last updated:** [January 11, 2025, 10:38pm UTC](https://racket.discourse.group/t/url-builder-macro/3476 "2025-01-11T22:38:44Z")
Hi, Racket Discourse. I have been tinkering with this idea for the past couple of weeks, because I realized I was abstracting the URLs of API endpoints at the wrong level in my HTTP requests library, which made it hard … --- ## [Problem accessing docs](https://racket.discourse.group/t/problem-accessing-docs/3308)
**Author:** [@AlexG](https://racket.discourse.group/u/AlexG)\ **Replies:** 17\ **Last updated:** [January 11, 2025, 7:49pm UTC](https://racket.discourse.group/t/problem-accessing-docs/3308 "2025-01-11T19:49:55Z")
I've had this problem for a while, since about two updates ago, but I've just worked around it. I thought maybe now, with the latest version 8.15 out, might be a good time to fix it. I am also using Racket a lot more t… [Previous page](https://racket.discourse.group/latest.md?page=17) [Next page](https://racket.discourse.group/latest.md?page=19)