# Latest **URL:** https://racket.discourse.group/latest.md?page=38 [Latest](https://racket.discourse.group/latest.md) · [Categories](https://racket.discourse.group/categories.md) · [Tags](https://racket.discourse.group/tags.md) **Page:** 39 --- ## [How to initialize a cstruct that has an array?](https://racket.discourse.group/t/how-to-initialize-a-cstruct-that-has-an-array/2414)
**Author:** [@db7](https://racket.discourse.group/u/db7)\ **Replies:** 2\ **Last updated:** [October 24, 2023, 7:13am UTC](https://racket.discourse.group/t/how-to-initialize-a-cstruct-that-has-an-array/2414 "2023-10-24T07:13:12Z")
Hi all, I'd like to create a cstruct which has an array as one of its fields. For the sake of the example, let's say the array is an array of integers. When I try create a new instance of the cstruct, I don't know how t… --- ## [Generating Conforming Programs with Xsmith \[SPLASH'23\]](https://racket.discourse.group/t/generating-conforming-programs-with-xsmith-splash23/2415)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [October 23, 2023, 3:11pm UTC](https://racket.discourse.group/t/generating-conforming-programs-with-xsmith-splash23/2415 "2023-10-23T15:11:52Z")
Generating Conforming Programs with Xsmith \[SPLASH'23\] Talk at SPLASH'23: https://www.youtube.com/watch?v=6zqOM4rez5M&t=10754s Paper: https://willghatch.net/publications/xsmith-gpce-2023-preprint.pdf from the abstract: … --- ## [Racket is now on Instagram](https://racket.discourse.group/t/racket-is-now-on-instagram/2413)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [October 23, 2023, 1:29pm UTC](https://racket.discourse.group/t/racket-is-now-on-instagram/2413 "2023-10-23T13:29:14Z")
Racket is now on Instagram at https://www.instagram.com/racketlang/ Racket has a presence on many social media platforms due to the diversity of the people who use Racket. Look here to find one that suits you: Racket on… --- ## [Set!: cannot mutate module-required identifier](https://racket.discourse.group/t/set-cannot-mutate-module-required-identifier/2411)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 1\ **Last updated:** [October 22, 2023, 7:57pm UTC](https://racket.discourse.group/t/set-cannot-mutate-module-required-identifier/2411 "2023-10-22T19:57:24Z")
i have a module that contains a single variable: (module infix-operators racket (provide infix-operators-lst) (include "exponential.scm") (include "modulo.scm") (include "bitwise.rkt") (include "not-equal.scm") … --- ## [Commit used for package in DrDr run](https://racket.discourse.group/t/commit-used-for-package-in-drdr-run/2409)
**Author:** [@Laurent.O](https://racket.discourse.group/u/Laurent.O)\ **Replies:** 2\ **Last updated:** [October 21, 2023, 7:47pm UTC](https://racket.discourse.group/t/commit-used-for-package-in-drdr-run/2409 "2023-10-21T19:47:24Z")
Is there a way to know which commit was used for a package for a particular DrDr test run? I can see the general commit for racket/racket but not for the rest. --- ## [The true meaning of recursion in the SICP book](https://racket.discourse.group/t/the-true-meaning-of-recursion-in-the-sicp-book/2388)
**Author:** [@syafiqfadillah](https://racket.discourse.group/u/syafiqfadillah)\ **Replies:** 8\ **Last updated:** [October 21, 2023, 12:47pm UTC](https://racket.discourse.group/t/the-true-meaning-of-recursion-in-the-sicp-book/2388 "2023-10-21T12:47:00Z")
In chapter 1 subchapter 1.1.3 there is the sentence "First, observe that the first step dictates that in order to accomplish the evaluation process for a combination we must first perform the evaluation process on each… --- ## [Racket v8.11 Release Thread](https://racket.discourse.group/t/racket-v8-11-release-thread/2361)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 10\ **Last updated:** [October 20, 2023, 11:39pm UTC](https://racket.discourse.group/t/racket-v8-11-release-thread/2361 "2023-10-20T23:39:35Z")
The release process for v8.11 will begin in about a week. 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: - 7th: Branch day, merg… --- ## [Yaml-exp - Write s-expressions in YAML](https://racket.discourse.group/t/yaml-exp-write-s-expressions-in-yaml/2398)
**Author:** [@Eutro](https://racket.discourse.group/u/Eutro)\ **Replies:** 2\ **Last updated:** [October 20, 2023, 2:22pm UTC](https://racket.discourse.group/t/yaml-exp-write-s-expressions-in-yaml/2398 "2023-10-20T14:22:13Z")
Have you ever thought, "I love lisp, but it's just got too many parentheses; it's too well delimited and too unambiguous to read"? Worry no longer, with yaml-exp you can have all the benefits of lisp, without having to w… --- ## [FFI Program not working on Mac](https://racket.discourse.group/t/ffi-program-not-working-on-mac/2400)
**Author:** [@SamPhillips](https://racket.discourse.group/u/SamPhillips)\ **Replies:** 9\ **Last updated:** [October 19, 2023, 2:36pm UTC](https://racket.discourse.group/t/ffi-program-not-working-on-mac/2400 "2023-10-19T14:36:26Z")
Hi, This program works on Linux and fetches the web page, but on Mac it fails. Doing some small sleuthing it appears to not be able to parse the URL, but I do not understand how setting the URL is failing. Mac M1 Mont… --- ## [Literate Drag and Drop using the Racket GUI](https://racket.discourse.group/t/literate-drag-and-drop-using-the-racket-gui/2393)
**Author:** [@JustinZed](https://racket.discourse.group/u/JustinZed)\ **Replies:** 3\ **Last updated:** [October 18, 2023, 3:30am UTC](https://racket.discourse.group/t/literate-drag-and-drop-using-the-racket-gui/2393 "2023-10-18T03:30:09Z")
This is my entry for the 2023 Racket Summer Event. It is two examples in one: an example of implementing Drag and Drop using the Racket GUI as well as an example of literate programming in Racket. The code is at GitHub -… --- ## [The 2023 Racket Summer Event](https://racket.discourse.group/t/the-2023-racket-summer-event/2191)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 8\ **Last updated:** [October 18, 2023, 12:51am UTC](https://racket.discourse.group/t/the-2023-racket-summer-event/2191 "2023-10-18T00:51:37Z")
The 2023 Racket Summer Event This years theme is ‘racket examples’! The task is create an example - code and description - of a feature or algorithm. Entry Categories There will be two categories: Small to medium exam… --- ## [Greater than sign in javascript script in Racket](https://racket.discourse.group/t/greater-than-sign-in-javascript-script-in-racket/2385)
**Author:** [@hendrikboom3](https://racket.discourse.group/u/hendrikboom3)\ **Replies:** 3\ **Last updated:** [October 16, 2023, 2:52pm UTC](https://racket.discourse.group/t/greater-than-sign-in-javascript-script-in-racket/2385 "2023-10-16T14:52:39Z")
I have trouble with the xexpr conversion of a script. I run a very simple case extracted from a much larger program: #lang web-server (require xml net/url) (xexpr-\>string '(script "SetTimeOut(() =\> {let d = new Dat… --- ## [Douglas Crockford, author of ‘Javascript: the good parts’ and ‘How Javascript works’ will be giving the keynote presentation ‘From Here To Lambda And Back Again’ at the thirteenth RacketCon](https://racket.discourse.group/t/douglas-crockford-author-of-javascript-the-good-parts-and-how-javascript-works-will-be-giving-the-keynote-presentation-from-here-to-lambda-and-back-again-at-the-thirteenth-racketcon/2392)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [October 16, 2023, 9:26am UTC](https://racket.discourse.group/t/douglas-crockford-author-of-javascript-the-good-parts-and-how-javascript-works-will-be-giving-the-keynote-presentation-from-here-to-lambda-and-back-again-at-the-thirteenth-racketcon/2392 "2023-10-16T09:26:35Z")
:racket:​ Douglas Crockford, author of ‘Javascript: the good parts’ and ‘How Javascript works’ will be giving the keynote presentation From Here To Lambda And Back Again at the thirteenth RacketCon :racket:​ Come join u… --- ## [\[Quickscript\] Newline, but don't move the comments](https://racket.discourse.group/t/quickscript-newline-but-dont-move-the-comments/2384)
**Author:** [@Laurent.O](https://racket.discourse.group/u/Laurent.O)\ **Replies:** 0\ **Last updated:** [October 13, 2023, 1:30pm UTC](https://racket.discourse.group/t/quickscript-newline-but-dont-move-the-comments/2384 "2023-10-13T13:30:38Z")
Link to the quickscript. Suppose you have the following code: (define pairs '(\[a b\] \[c d\])) ; This pair is special and you want to add a new pair \[e f\]. You press Enter after the \[c d\] but you get: (define pair… --- ## [A micro-benchmark](https://racket.discourse.group/t/a-micro-benchmark/2347)
**Author:** [@lewisl](https://racket.discourse.group/u/lewisl)\ **Replies:** 68\ **Last updated:** [October 13, 2023, 9:59am UTC](https://racket.discourse.group/t/a-micro-benchmark/2347 "2023-10-13T09:59:53Z")
Micro-Benchmark of Summing a Floating Point Vector Take this with a grain of salt. All micro-benchmarks are fraught; it's easier to do wrong than to do correctly. Please correct anything I have done incorrectly or sugges… --- ## [How to match up macro-generated and user-defined identifiers?](https://racket.discourse.group/t/how-to-match-up-macro-generated-and-user-defined-identifiers/2379)
**Author:** [@pcn](https://racket.discourse.group/u/pcn)\ **Replies:** 2\ **Last updated:** [October 13, 2023, 4:11am UTC](https://racket.discourse.group/t/how-to-match-up-macro-generated-and-user-defined-identifiers/2379 "2023-10-13T04:11:19Z")
The question is likely very basic. I'm just rusty :grin: I'm trying to implement poor man's module that can be parameterized by types, using structs. An example is I can do something like: (define-signature (expr E) … --- ## [Release for v8.11 has begun](https://racket.discourse.group/t/release-for-v8-11-has-begun/2383)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 0\ **Last updated:** [October 12, 2023, 10:48pm UTC](https://racket.discourse.group/t/release-for-v8-11-has-begun/2383 "2023-10-12T22:48:43Z")
The release process for v8.11 has begun: release checkpoints have been created for all packages in the main distribution, and release branches have been created when necessary. You can go on using \`master\` branches as us… --- ## [Check-syntax occasional confusion](https://racket.discourse.group/t/check-syntax-occasional-confusion/2376)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 2\ **Last updated:** [October 11, 2023, 3:33am UTC](https://racket.discourse.group/t/check-syntax-occasional-confusion/2376 "2023-10-11T03:33:33Z")
In this screenshot, the green oval is highlighting something that is clearly not an identifier. Things like this are much more common for me recently (maybe just this latest version?). Are any of y'all seeing things like… --- ## [Parsack: cannot reference an identifier before its definition](https://racket.discourse.group/t/parsack-cannot-reference-an-identifier-before-its-definition/2349)
**Author:** [@indrjo](https://racket.discourse.group/u/indrjo)\ **Replies:** 2\ **Last updated:** [October 10, 2023, 12:08pm UTC](https://racket.discourse.group/t/parsack-cannot-reference-an-identifier-before-its-definition/2349 "2023-10-10T12:08:36Z")
I wrote some code in Haskell that I'd like to translate in Racket. It's about Parsec and Parsack. #lang racket (require parsack) (define quote-marks "'\\"\`") (define quoted-name (between (oneOf quote-marks) … --- ## [Call for Contributions: BOB 2024, Berlin \[March 15, Deadline Nov 17\]](https://racket.discourse.group/t/call-for-contributions-bob-2024-berlin-march-15-deadline-nov-17/2375)
**Author:** [@mike](https://racket.discourse.group/u/mike)\ **Replies:** 0\ **Last updated:** [October 10, 2023, 6:37am UTC](https://racket.discourse.group/t/call-for-contributions-bob-2024-berlin-march-15-deadline-nov-17/2375 "2023-10-10T06:37:44Z")
Racket material is very welcome at BOB! Web version of call is here: https://bobkonf.de/2024/cfc.html ================================================================================ BOB Confe… --- ## [Best practices for testing compiler optimizations?](https://racket.discourse.group/t/best-practices-for-testing-compiler-optimizations/2369)
**Author:** [@countvajhula](https://racket.discourse.group/u/countvajhula)\ **Replies:** 5\ **Last updated:** [October 9, 2023, 7:32pm UTC](https://racket.discourse.group/t/best-practices-for-testing-compiler-optimizations/2369 "2023-10-09T19:32:00Z")
Hello, we're building an optimizing compiler for Qi, and we (cc @benknoble @dominik.pantucek ) are trying to figure out the best way to validate that compiler rewrite rules are carried out as expected. So far, there are… --- ## [Call for Participation: RacketCon 2023](https://racket.discourse.group/t/call-for-participation-racketcon-2023/2351)
**Author:** [@jesse](https://racket.discourse.group/u/jesse)\ **Replies:** 0\ **Last updated:** [September 29, 2023, 5:08pm UTC](https://racket.discourse.group/t/call-for-participation-racketcon-2023/2351 "2023-09-29T17:08:02Z")
We are heading into October, with just under a month to go until RacketCon 2023. This means that we can confidently and proudly Call For Your Participation at the event. We have lined up a great list of speakers; … --- ## [Gtk: gtk\_notebook\_get\_tab\_label: assertion 'list != NULL' failed](https://racket.discourse.group/t/gtk-gtk-notebook-get-tab-label-assertion-list-null-failed/2373)
**Author:** [@Laurent.O](https://racket.discourse.group/u/Laurent.O)\ **Replies:** 1\ **Last updated:** [October 8, 2023, 5:03pm UTC](https://racket.discourse.group/t/gtk-gtk-notebook-get-tab-label-assertion-list-null-failed/2373 "2023-10-08T17:03:35Z")
When testing quickscript-test, I have some GTK errors that I didn't use to have: Gtk: gtk\_notebook\_get\_tab\_label: assertion 'list != NULL' failed This appears to be a non-Racket-specific bug, e.g. linux mint. There se… --- ## [Racket meet-up: Saturday, October 7, 2023 at 18:00 UTC :Racket:](https://racket.discourse.group/t/racket-meet-up-saturday-october-7-2023-at-18-00-utc/2367)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 2\ **Last updated:** [October 7, 2023, 10:49pm UTC](https://racket.discourse.group/t/racket-meet-up-saturday-october-7-2023-at-18-00-utc/2367 "2023-10-07T22:49:47Z")
Racket meet-up: Saturday, October 7, 2023 at 18:00 UTC In your timezone: 2023-10-07T18:00:00Z (UTC) At this meet-up: (thirteenth RacketCon) 28&29 October with remote+onsite participation … --- ## [Passing command line arguments at compile-time?](https://racket.discourse.group/t/passing-command-line-arguments-at-compile-time/2368)
**Author:** [@rscho](https://racket.discourse.group/u/rscho)\ **Replies:** 2\ **Last updated:** [October 7, 2023, 1:48pm UTC](https://racket.discourse.group/t/passing-command-line-arguments-at-compile-time/2368 "2023-10-07T13:48:02Z")
Hi, I am writing a kind of constraint solver for a combinatorics problem involving bignums. The single best optimization I can perform is of course pruning the solution space as early as possible. So, I thought about i… --- ## [Testing changes to a plugin](https://racket.discourse.group/t/testing-changes-to-a-plugin/2364)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 2\ **Last updated:** [October 7, 2023, 12:13pm UTC](https://racket.discourse.group/t/testing-changes-to-a-plugin/2364 "2023-10-07T12:13:16Z")
I'm finally getting round to submitting changes to the quickscript plugin that is included in Dr Racket. My guide to doing this is usually Tutorial: Contributing to Racket on the Racket Blog I used raco pkg update --de… --- ## [Minor DrRacket question](https://racket.discourse.group/t/minor-drracket-question/2363)
**Author:** [@lewisl](https://racket.discourse.group/u/lewisl)\ **Replies:** 14\ **Last updated:** [October 7, 2023, 12:09am UTC](https://racket.discourse.group/t/minor-drracket-question/2363 "2023-10-07T00:09:26Z")
Why doesn't DrRacket use xrepl for the interactions pane? xrepl is really brilliant and the repl in DrRacket is, politely, less brilliant. Nothing wrong with just using VS Code (or other) with xrepl in the integrated… --- ## [Trying to treat flvector as a collection: violates contract](https://racket.discourse.group/t/trying-to-treat-flvector-as-a-collection-violates-contract/2362)
**Author:** [@lewisl](https://racket.discourse.group/u/lewisl)\ **Replies:** 3\ **Last updated:** [October 6, 2023, 1:41pm UTC](https://racket.discourse.group/t/trying-to-treat-flvector-as-a-collection-violates-contract/2362 "2023-10-06T13:41:37Z")
I thought that data/collection was meant to allow a set of functions to be collection type agnostic. There must be some syntactic trick that is not documented for doing so. #lang racket/base (require racket/flonum) (re… --- ## [Racket Guide Module Basics typo](https://racket.discourse.group/t/racket-guide-module-basics-typo/2358)
**Author:** [@matteo-daddio](https://racket.discourse.group/u/matteo-daddio)\ **Replies:** 2\ **Last updated:** [October 5, 2023, 7:58am UTC](https://racket.discourse.group/t/racket-guide-module-basics-typo/2358 "2023-10-05T07:58:08Z")
Hello, I think I’ve found a typo in the racket guide. It’s at the bottom of the 6.1 Module Basics page: The text says raco exec instead of raco exe. Matteo --- ## [Adding inset and margings to plots (new feature in the plot package)](https://racket.discourse.group/t/adding-inset-and-margings-to-plots-new-feature-in-the-plot-package/2360)
**Author:** [@alexh](https://racket.discourse.group/u/alexh)\ **Replies:** 0\ **Last updated:** [October 2, 2023, 11:00pm UTC](https://racket.discourse.group/t/adding-inset-and-margings-to-plots-new-feature-in-the-plot-package/2360 "2023-10-02T23:00:05Z")
I put up a pull request to the racket plot package to allow controlling the margin left around a plot picture. The motivation for this is that, when using thicker lines for the drawing, the end caps for these lines are … [Previous page](https://racket.discourse.group/latest.md?page=37) [Next page](https://racket.discourse.group/latest.md?page=39)