# General **URL:** https://racket.discourse.group/c/general/12.md?page=13 [Latest](https://racket.discourse.group/latest.md) · [Categories](https://racket.discourse.group/categories.md) · [Tags](https://racket.discourse.group/tags.md) **Page:** 14 --- ## [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 … --- ## [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 … --- ## [Formatting negative numbers using \`~r\`](https://racket.discourse.group/t/formatting-negative-numbers-using-r/2354)
**Author:** [@alexh](https://racket.discourse.group/u/alexh)\ **Replies:** 1\ **Last updated:** [October 2, 2023, 9:30pm UTC](https://racket.discourse.group/t/formatting-negative-numbers-using-r/2354 "2023-10-02T21:30:05Z")
I was trying to format numbers using ~r to align them in a table, and noticed an unexpected, for me at least, result for negative numbers: the minus sign is put in front of the padding: \> (~r (- pi) #:precision 2 #:min-… --- ## [Debugging input port](https://racket.discourse.group/t/debugging-input-port/2357)
**Author:** [@sorawee](https://racket.discourse.group/u/sorawee)\ **Replies:** 2\ **Last updated:** [October 2, 2023, 9:57am UTC](https://racket.discourse.group/t/debugging-input-port/2357 "2023-10-02T09:57:43Z")
Frequently, I get an error from (read in), but it's difficult to see what goes wrong. I can try to use peek-... on in to help debugging, but that's also not convenient because I need to specify how many bytes I want to r… --- ## [Can I use Racket to install packages for Chez Scheme for Racket?](https://racket.discourse.group/t/can-i-use-racket-to-install-packages-for-chez-scheme-for-racket/2345)
**Author:** [@lewisl](https://racket.discourse.group/u/lewisl)\ **Replies:** 5\ **Last updated:** [September 28, 2023, 6:50pm UTC](https://racket.discourse.group/t/can-i-use-racket-to-install-packages-for-chez-scheme-for-racket/2345 "2023-09-28T18:50:41Z")
I followed some instructions to build the Chez Scheme underneath Racket to get a Chez Scheme that runs natively on M1 processors and OSX. That worked and completed quickly, but it created a very non-standard build which… --- ## [Macro optimisation in Racket](https://racket.discourse.group/t/macro-optimisation-in-racket/2342)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 2\ **Last updated:** [September 27, 2023, 9:24am UTC](https://racket.discourse.group/t/macro-optimisation-in-racket/2342 "2023-09-27T09:24:43Z")
hello, i need to optimise some scheme code i wrote. I can do that by "inlining macro expansion" and in other case by doing both and substituing procedure symbolic result instead of re-calculus all the numeric values at… --- ## [Rename-in with a generated identifier](https://racket.discourse.group/t/rename-in-with-a-generated-identifier/2340)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 0\ **Last updated:** [September 26, 2023, 10:49am UTC](https://racket.discourse.group/t/rename-in-with-a-generated-identifier/2340 "2023-09-26T10:49:59Z")
\#lang racket (require "overload-by-recursive-functions.rkt") (overload-existing-procedure length vector-length (vector?)) ;(overload-existing-procedure length string-length (string?)) ; ;(length #(1 2 3 4)) ;(length '(1… --- ## [How to use \`splicing-syntax-parameterize\`?](https://racket.discourse.group/t/how-to-use-splicing-syntax-parameterize/2319)
**Author:** [@soegaard](https://racket.discourse.group/u/soegaard)\ **Replies:** 9\ **Last updated:** [September 18, 2023, 11:47am UTC](https://racket.discourse.group/t/how-to-use-splicing-syntax-parameterize/2319 "2023-09-18T11:47:16Z")
The form (syntax-parameterize (\[id expr\] ...) body-expr ...+) binds the ids during the expansion of the body expressions. I am looking for something that allows be to do the same, but can be used in an internal definiti… --- ## [Tutorial for using frog on Windows?](https://racket.discourse.group/t/tutorial-for-using-frog-on-windows/2310)
**Author:** [@bremner](https://racket.discourse.group/u/bremner)\ **Replies:** 3\ **Last updated:** [September 16, 2023, 12:58pm UTC](https://racket.discourse.group/t/tutorial-for-using-frog-on-windows/2310 "2023-09-16T12:58:15Z")
One of my students asked me if it was possible to use frog on Windows. I guess the answer is "yes, with sufficient effort", and I see some hints in the source about "python.exe", but I was curious if someone has a nic… --- ## [Comparison of code between Scheme+ (an enhanced scheme language) and Python](https://racket.discourse.group/t/comparison-of-code-between-scheme-an-enhanced-scheme-language-and-python/2317)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 0\ **Last updated:** [September 16, 2023, 8:57am UTC](https://racket.discourse.group/t/comparison-of-code-between-scheme-an-enhanced-scheme-language-and-python/2317 "2023-09-16T08:57:10Z")
I present a comparison of the same algorithm between two languages: Python versus Scheme+, a language based and written in Scheme. The algorithm is based on fundamental deep learning : a multi-layer neural network simul… --- ## [RacketCon should have a live stream](https://racket.discourse.group/t/racketcon-should-have-a-live-stream/2307)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 1\ **Last updated:** [September 15, 2023, 4:19pm UTC](https://racket.discourse.group/t/racketcon-should-have-a-live-stream/2307 "2023-09-15T16:19:00Z")
I feel strongly about this. RacketCon should have a live stream. We are a global community and participation should not be restricted by geography. I know it’s expensive to arrange. I’m willing to put money where my mo… --- ## [What is the Racket roadmap?](https://racket.discourse.group/t/what-is-the-racket-roadmap/2204)
**Author:** [@joeld](https://racket.discourse.group/u/joeld)\ **Replies:** 28\ **Last updated:** [September 11, 2023, 9:31pm UTC](https://racket.discourse.group/t/what-is-the-racket-roadmap/2204 "2023-09-11T21:31:32Z")
I’ve been saving this question for the RacketCon town hall, but the more I think about it, it’s probably worth asking ahead of time. Hopefully I can ask it in a way that generates productive discussion. What improvement… --- ## [\[ANN\] A pretty expressive printer](https://racket.discourse.group/t/ann-a-pretty-expressive-printer/2094)
**Author:** [@sorawee](https://racket.discourse.group/u/sorawee)\ **Replies:** 3\ **Last updated:** [September 11, 2023, 11:03pm UTC](https://racket.discourse.group/t/ann-a-pretty-expressive-printer/2094 "2023-09-11T23:03:05Z")
Announcing pretty-expressive, a pretty printer based on our paper, A pretty expressive printer\[1\], which is to appear in the upcoming OOPSLA'23. The precursor of this pretty printer, pprint-compact, will be deprecated, … --- ## [Relative path for require does not works as i expect](https://racket.discourse.group/t/relative-path-for-require-does-not-works-as-i-expect/2299)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 4\ **Last updated:** [September 10, 2023, 9:43pm UTC](https://racket.discourse.group/t/relative-path-for-require-does-not-works-as-i-expect/2299 "2023-09-10T21:43:01Z")
i have a file path1/file.rkt where i have this: (include "../Scheme-PLUS-for-Racket/main/Scheme-PLUS-for-Racket/Scheme+.rkt") in path2/Scheme+.rkt file i a have: (require "overload.scm"). ;; i also tried "./overload.s… --- ## [Macros expanding to definitions](https://racket.discourse.group/t/macros-expanding-to-definitions/2301)
**Author:** [@soegaard](https://racket.discourse.group/u/soegaard)\ **Replies:** 0\ **Last updated:** [September 10, 2023, 3:23pm UTC](https://racket.discourse.group/t/macros-expanding-to-definitions/2301 "2023-09-10T15:23:30Z")
Macros expanding to definitions This post is about macros that expand into definitions. The examples will use syntax/parse, so all snippets work if they are preceded with: #lang racket (require (for-syntax racket/synt… --- ## [Question about macro order expansion](https://racket.discourse.group/t/question-about-macro-order-expansion/2259)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 4\ **Last updated:** [August 30, 2023, 7:49pm UTC](https://racket.discourse.group/t/question-about-macro-order-expansion/2259 "2023-08-30T19:49:37Z")
i have this macro i just modified: ;; "abcdefgh" ;; \> {s\[2 \* 3 - 4 $ 2 \* 3 + 1 $ 2 \* 4 - 6\] \<- "0000"} ;; "ab0d0f0h" ;; $bracket-apply$ is from SRFI 105 bracket-apply is an argument of the macro (define-syntax \<- … --- ## [Do we have a RFC \*process\* for the core Racket language(s)? Do we need one?](https://racket.discourse.group/t/do-we-have-a-rfc-process-for-the-core-racket-language-s-do-we-need-one/2233)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 5\ **Last updated:** [August 30, 2023, 7:45am UTC](https://racket.discourse.group/t/do-we-have-a-rfc-process-for-the-core-racket-language-s-do-we-need-one/2233 "2023-08-30T07:45:36Z")
Do we have a community-led RFC process for the core Racket language(s)? Do we need one? I'll give an example where a community-led RFC process may be valuable: I've noticed the issue below has bitten another experienc… --- ## [By default read-line leaves the \\r character at the end of a line entered on the command line on Windows](https://racket.discourse.group/t/by-default-read-line-leaves-the-r-character-at-the-end-of-a-line-entered-on-the-command-line-on-windows/2235)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 3\ **Last updated:** [August 30, 2023, 5:14am UTC](https://racket.discourse.group/t/by-default-read-line-leaves-the-r-character-at-the-end-of-a-line-entered-on-the-command-line-on-windows/2235 "2023-08-30T05:14:41Z")
Topic for discussion of by default read-line leaves the \\r character at the end of a line entered on the command line on Windows Related GitHub items https://github.com/racket/racket/pull/4074#issuecomment-16858618… --- ## [Fixed size list signatures in htdp/isl+](https://racket.discourse.group/t/fixed-size-list-signatures-in-htdp-isl/2247)
**Author:** [@bremner](https://racket.discourse.group/u/bremner)\ **Replies:** 3\ **Last updated:** [August 26, 2023, 12:57pm UTC](https://racket.discourse.group/t/fixed-size-list-signatures-in-htdp-isl/2247 "2023-08-26T12:57:08Z")
I wanted to try one of the exercises from 6 Functional Abstraction using signatures instead of contracts, but I hit what seems to be a limitation of the signatures in ISL+. In particular there seems to be no way to e… --- ## [How can i use 'map' with a procedure on a list of lists](https://racket.discourse.group/t/how-can-i-use-map-with-a-procedure-on-a-list-of-lists/2251)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 3\ **Last updated:** [August 26, 2023, 12:01pm UTC](https://racket.discourse.group/t/how-can-i-use-map-with-a-procedure-on-a-list-of-lists/2251 "2023-08-26T12:01:56Z")
example : (map + (list 1 2) (list 3 4) (list 5 6)) (9 12) suppose now i have a list : (list (list 1 2) (list 3 4) (list 5 6)) and i want to do the same with the elements of the list, how can i do? note here i have … --- ## [Rationale for per-version user scope packages?](https://racket.discourse.group/t/rationale-for-per-version-user-scope-packages/543)
**Author:** [@Laurent.O](https://racket.discourse.group/u/Laurent.O)\ **Replies:** 38\ **Last updated:** [August 23, 2023, 1:50pm UTC](https://racket.discourse.group/t/rationale-for-per-version-user-scope-packages/543 "2023-08-23T13:50:58Z")
Currently user-scope packages for releases are installed in version-specific directories. The main advantage I see is that if someone has several versions of racket installed, there is no need to recompile when switchin… --- ## [How to rename a procedure and use it](https://racket.discourse.group/t/how-to-rename-a-procedure-and-use-it/2232)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 2\ **Last updated:** [August 21, 2023, 6:56am UTC](https://racket.discourse.group/t/how-to-rename-a-procedure-and-use-it/2232 "2023-08-21T06:56:27Z")
i have this file containing: (require srfi/31) ;; for 'rec in def.scm (require srfi/69) ;; Basic hash tables (require srfi/25) ;; Multi-dimensional Array Primitives (require srfi/8) ;; Values , receive (require (renam… --- ## [I can not find a real subject for this problem : (display +) (define + 7) : error](https://racket.discourse.group/t/i-can-not-find-a-real-subject-for-this-problem-display-define-7-error/2229)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 8\ **Last updated:** [August 19, 2023, 10:55pm UTC](https://racket.discourse.group/t/i-can-not-find-a-real-subject-for-this-problem-display-define-7-error/2229 "2023-08-19T22:55:37Z")
\#lang racket (display +) (define + 3) Welcome to DrRacket, version 8.9 \[cs\]. Language: racket, with debugging; memory limit: 8192 MB. . . +: undefined; cannot reference an identifier before its definition does anyone k… --- ## [Racket meet-up: Saturday, 2 September 2023 at 18:00 UTC :Racket:](https://racket.discourse.group/t/racket-meet-up-saturday-2-september-2023-at-18-00-utc/2172)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [August 7, 2023, 7:00am UTC](https://racket.discourse.group/t/racket-meet-up-saturday-2-september-2023-at-18-00-utc/2172 "2023-08-07T07:00:31Z")
:racket: Racket meet-up: Saturday, 2 September 2023 at 18:00 UTC :racket: 2023-09-02T18:00:00Z (UTC) At this meet-up: RacketCon!! Racket Examples Summer Event Show and tell News & rumours AOB This meet-up will be h… --- ## [Why is the official org website down?](https://racket.discourse.group/t/why-is-the-official-org-website-down/2216)
**Author:** [@axdxhxdx](https://racket.discourse.group/u/axdxhxdx)\ **Replies:** 2\ **Last updated:** [August 14, 2023, 11:23am UTC](https://racket.discourse.group/t/why-is-the-official-org-website-down/2216 "2023-08-14T11:23:42Z")
I'm stuck in a project and I can't read the docs because the website is down! --- ## [Do you know the history of Racket and LeetCode?](https://racket.discourse.group/t/do-you-know-the-history-of-racket-and-leetcode/2211)
**Author:** [@david-christiansen](https://racket.discourse.group/u/david-christiansen)\ **Replies:** 0\ **Last updated:** [August 11, 2023, 10:44am UTC](https://racket.discourse.group/t/do-you-know-the-history-of-racket-and-leetcode/2211 "2023-08-11T10:44:44Z")
Was anyone here involved in getting Racket onto LeetCode who would be willing to share some experiences? Over at the Haskell Foundation, we've been asked to try to figure out what it would take to get Haskell on there, … [Previous page](https://racket.discourse.group/c/general/12.md?page=12) [Next page](https://racket.discourse.group/c/general/12.md?page=14)