# Latest **URL:** https://racket.discourse.group/latest.md?page=19 [Latest](https://racket.discourse.group/latest.md) · [Categories](https://racket.discourse.group/categories.md) · [Tags](https://racket.discourse.group/tags.md) **Page:** 20 --- ## [\`for/treelist\` vs \`vector-\>treelist\`](https://racket.discourse.group/t/for-treelist-vs-vector-treelist/3441)
**Author:** [@NoahStoryM](https://racket.discourse.group/u/NoahStoryM)\ **Replies:** 5\ **Last updated:** [January 10, 2025, 3:41pm UTC](https://racket.discourse.group/t/for-treelist-vs-vector-treelist/3441 "2025-01-10T15:41:56Z")
While working on a package, I encountered a performance issue that I'd like to illustrate with the following example code: (time (define mtl (mutable-treelist 'x)) (define d\* (build-list 10000000 values)) (define f … --- ## [\[json\] Provide Better Support for Modifying JSON Files](https://racket.discourse.group/t/json-provide-better-support-for-modifying-json-files/3473)
**Author:** [@NoahStoryM](https://racket.discourse.group/u/NoahStoryM)\ **Replies:** 3\ **Last updated:** [January 9, 2025, 8:48pm UTC](https://racket.discourse.group/t/json-provide-better-support-for-modifying-json-files/3473 "2025-01-09T20:48:31Z")
I'd like to explore how the json library could provide a more convenient way to modify JSON files. My previous approach was to read JSON data using read-json, convert it into mutable hashtables for objects, and then modi… --- ## [Cadence Of Regenerating Documentation](https://racket.discourse.group/t/cadence-of-regenerating-documentation/3474)
**Author:** [@OldDutchCap](https://racket.discourse.group/u/OldDutchCap)\ **Replies:** 3\ **Last updated:** [January 9, 2025, 8:31pm UTC](https://racket.discourse.group/t/cadence-of-regenerating-documentation/3474 "2025-01-09T20:31:01Z")
I was able to submit a change to the Racket Documentation in this section of it: https://docs.racket-lang.org/guide/scripts.html The change was accepted several days ago but I don't see the changed text on the site. I… --- ## [Book Club Reading/Discussing "How To Design Programs"](https://racket.discourse.group/t/book-club-reading-discussing-how-to-design-programs/3435)
**Author:** [@OldDutchCap](https://racket.discourse.group/u/OldDutchCap)\ **Replies:** 16\ **Last updated:** [January 7, 2025, 12:04am UTC](https://racket.discourse.group/t/book-club-reading-discussing-how-to-design-programs/3435 "2025-01-07T00:04:46Z")
I am going to be reading "How To Design Programs" and I thought others might like to read and discuss it so I set up a book club via the Fable - Detroit Tech Watch Book Club Feel free to forward the invite. Of course t… --- ## [Threads and modules; how do they interact?](https://racket.discourse.group/t/threads-and-modules-how-do-they-interact/3286)
**Author:** [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\ **Replies:** 12\ **Last updated:** [January 6, 2025, 5:59pm UTC](https://racket.discourse.group/t/threads-and-modules-how-do-they-interact/3286 "2025-01-06T17:59:05Z")
Hi, Racket Discourse. I have a very simple application, with a small set of log-sources (services and schedule), so I have only two loggers provided to the rest of the application, along with the starting-of and shuttin… --- ## [Drracket won't run on NetBSD 10.1 with racket-minimal](https://racket.discourse.group/t/drracket-wont-run-on-netbsd-10-1-with-racket-minimal/3463)
**Author:** [@Roc](https://racket.discourse.group/u/Roc)\ **Replies:** 10\ **Last updated:** [January 6, 2025, 2:25am UTC](https://racket.discourse.group/t/drracket-wont-run-on-netbsd-10-1-with-racket-minimal/3463 "2025-01-06T02:25:26Z")
Is there a way to get drracket going on NetBSD 10.1? Having racket-mini-8.15 installed and then performing $ raco pkg install --auto drracket there are ffi-lib issues, see as follows racket-minimal-8.15 drracket inst… --- ## [Rackunit: test-case makes testing higher-order functions with exception handlers behave oddly](https://racket.discourse.group/t/rackunit-test-case-makes-testing-higher-order-functions-with-exception-handlers-behave-oddly/3467)
**Author:** [@benknoble](https://racket.discourse.group/u/benknoble)\ **Replies:** 0\ **Last updated:** [January 5, 2025, 4:08pm UTC](https://racket.discourse.group/t/rackunit-test-case-makes-testing-higher-order-functions-with-exception-handlers-behave-oddly/3467 "2025-01-05T16:08:13Z")
There's a good chance I'm "holding it wrong," so someone please point out where I've missed things. I have a test that looks like this: (define (f g) (with-handlers (\[exn:fail? (lambda (e) … --- ## [Racket meet-up: Saturday, 4 January 2025 at 18:00 UTC](https://racket.discourse.group/t/racket-meet-up-saturday-4-january-2025-at-18-00-utc/3458)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [January 3, 2025, 2:20pm UTC](https://racket.discourse.group/t/racket-meet-up-saturday-4-january-2025-at-18-00-utc/3458 "2025-01-03T14:20:53Z")
Everyone is welcome to join us for the :racket: Racket meet-up: Saturday, 4 January 2025 at 18:00 UTC In your timezone: 2025-01-04T18:00:00Z (UTC). (converter) At this meet-up: Book Club Reading/Discussing "How To De… --- ## [How to write a simple TCP server](https://racket.discourse.group/t/how-to-write-a-simple-tcp-server/3457)
**Author:** [@tinkererthinker](https://racket.discourse.group/u/tinkererthinker)\ **Replies:** 2\ **Last updated:** [January 2, 2025, 2:09pm UTC](https://racket.discourse.group/t/how-to-write-a-simple-tcp-server/3457 "2025-01-02T14:09:57Z")
I'm interested in network programming. In order to test my understanding of the TCP/IP protocol, I wanted to write a simple TCP client and server. I read the docs but I don't know which procedures I would need to make i… --- ## [Understanding vectorof: Q's on flatness, eager, immutable](https://racket.discourse.group/t/understanding-vectorof-qs-on-flatness-eager-immutable/3455)
**Author:** [@maueroats](https://racket.discourse.group/u/maueroats)\ **Replies:** 2\ **Last updated:** [January 1, 2025, 2:50am UTC](https://racket.discourse.group/t/understanding-vectorof-qs-on-flatness-eager-immutable/3455 "2025-01-01T02:50:47Z")
When should vectorof be #:flat? There is an option to declare a vectorof contract as flat. I believe this is because a vector might be mutated, but if your code is not supposed to be mutating the vector you can declare t… --- ## [MacOS shell-\>Drr open file? (quality-of-life improvement yay! ... but then sad face)](https://racket.discourse.group/t/macos-shell-drr-open-file-quality-of-life-improvement-yay-but-then-sad-face/3273)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 7\ **Last updated:** [December 31, 2024, 9:31pm UTC](https://racket.discourse.group/t/macos-shell-drr-open-file-quality-of-life-improvement-yay-but-then-sad-face/3273 "2024-12-31T21:31:59Z")
SUPER TL;DR: fix doesn't work! TL;DR: see fix at end! As I chug through daily work, I realize that one serious time-saver for me would be the ability to use a shell command to open a file in DrRacket. So, for instance,… --- ## [Acos behaves differently on #s \> 1.0 in TR?](https://racket.discourse.group/t/acos-behaves-differently-on-s-1-0-in-tr/3453)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 4\ **Last updated:** [December 31, 2024, 1:03pm UTC](https://racket.discourse.group/t/acos-behaves-differently-on-s-1-0-in-tr/3453 "2024-12-31T13:03:39Z")
In Typed Racket, the acos function appears to guarantee a Flonum result, and returns +0.nan for numbers larger than 1.0. This is different from Racket and Rhombus, that return a complex number. Is this difference documen… --- ## [New reaction emoji :plusone:](https://racket.discourse.group/t/new-reaction-emoji/3454)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 8\ **Last updated:** [December 31, 2024, 9:42am UTC](https://racket.discourse.group/t/new-reaction-emoji/3454 "2024-12-31T09:42:24Z")
We have added a new emoji and reaction :plusone: It was made with pict and the r16 trick-bot because I doesn’t have access to my laptop !rkt eval (require pict file/convertible racket/draw) (~\> "+1" (text (cons 'bo… --- ## [Understanding building and compile times in DrRacket](https://racket.discourse.group/t/understanding-building-and-compile-times-in-drracket/3450)
**Author:** [@AlexG](https://racket.discourse.group/u/AlexG)\ **Replies:** 11\ **Last updated:** [December 29, 2024, 6:37pm UTC](https://racket.discourse.group/t/understanding-building-and-compile-times-in-drracket/3450 "2024-12-29T18:37:23Z")
I am on my first not completely trivial Racket project, and it was going really fine. Nothing too demanding, maybe twenty files or so, \< 100k source code, though it's meant to get bigger. I also use two libraries outsid… --- ## [~else (Rhombus) not searchable token?](https://racket.discourse.group/t/else-rhombus-not-searchable-token/3449)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 2\ **Last updated:** [December 29, 2024, 3:10am UTC](https://racket.discourse.group/t/else-rhombus-not-searchable-token/3449 "2024-12-29T03:10:57Z")
Is there a good reason why searching for "~else" in both local raco docs and on docs.racket-lang.org does not produce any results? If this is an easy pull request I'll make it. --- ## [Error report: in handling values arity](https://racket.discourse.group/t/error-report-in-handling-values-arity/3448)
**Author:** [@danprager](https://racket.discourse.group/u/danprager)\ **Replies:** 3\ **Last updated:** [December 26, 2024, 7:00pm UTC](https://racket.discourse.group/t/error-report-in-handling-values-arity/3448 "2024-12-26T19:00:27Z")
Minimal example: #lang racket (define (f x y) (values x y)) (define a (f 1 2)) ; error - as opposed to e.g. (define-values (a b) (f 1 2)) At least in Dr Racket, the error message lacks the usual "X" link to the sou… --- ## [\_fixnum slow? (despite docs)](https://racket.discourse.group/t/fixnum-slow-despite-docs/3409)
**Author:** [@Laurent.O](https://racket.discourse.group/u/Laurent.O)\ **Replies:** 11\ **Last updated:** [December 26, 2024, 1:17pm UTC](https://racket.discourse.group/t/fixnum-slow-despite-docs/3409 "2024-12-26T13:17:21Z")
I was trying to figure out why my uses of ptr-ref were 10x slower than vector-ref. The main reason appears to be that \_fixnum is (much) slower than the rest, like \_ulong. #lang racket/base (require ffi/unsafe) (define… --- ## [Enabled new discourse spam detection feature](https://racket.discourse.group/t/enabled-new-discourse-spam-detection-feature/3444)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [December 24, 2024, 3:15pm UTC](https://racket.discourse.group/t/enabled-new-discourse-spam-detection-feature/3444 "2024-12-24T15:15:09Z")
Hi, Discourse just release a new spam detection system so I have switched it on because the old one has incorrectly identified legitimate posts as spam. Hopefully the new spam detection will improve the situation. If … --- ## [Racket Zulip chat thing](https://racket.discourse.group/t/racket-zulip-chat-thing/3442)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [December 24, 2024, 1:15pm UTC](https://racket.discourse.group/t/racket-zulip-chat-thing/3442 "2024-12-24T13:15:36Z")
Some people have mentioned they like Zulip: so here is a completely unofficial zulip instance for Racket: It is chat service, but unlike discord or irc the chat history public. Creation inspired by the https://plai.… --- ## [Basic Scheme stream question](https://racket.discourse.group/t/basic-scheme-stream-question/3439)
**Author:** [@AlexG](https://racket.discourse.group/u/AlexG)\ **Replies:** 7\ **Last updated:** [December 24, 2024, 11:27am UTC](https://racket.discourse.group/t/basic-scheme-stream-question/3439 "2024-12-24T11:27:33Z")
I wonder if any Scheme-whizz can help out with this basically noob question. Implementing the Catalan numbers using streams, why is the 2nd solution so much faster (factor of ~4) than the 1st and the 3rd? Technically t… --- ## [Is there a scheme implementation where the Garbage Collector is built within that Scheme?](https://racket.discourse.group/t/is-there-a-scheme-implementation-where-the-garbage-collector-is-built-within-that-scheme/3432)
**Author:** [@YongaTechnic](https://racket.discourse.group/u/YongaTechnic)\ **Replies:** 4\ **Last updated:** [December 21, 2024, 1:52am UTC](https://racket.discourse.group/t/is-there-a-scheme-implementation-where-the-garbage-collector-is-built-within-that-scheme/3432 "2024-12-21T01:52:40Z")
I am looking for a scheme implementation where the garbage collector is not built in a low level system programming language like C, but within the scheme itself? Can you point me in the right direction? Thanks --- ## [If I am to implement a continuous memory data structure like arrays or vectors in Scheme](https://racket.discourse.group/t/if-i-am-to-implement-a-continuous-memory-data-structure-like-arrays-or-vectors-in-scheme/3431)
**Author:** [@YongaTechnic](https://racket.discourse.group/u/YongaTechnic)\ **Replies:** 6\ **Last updated:** [December 19, 2024, 5:43pm UTC](https://racket.discourse.group/t/if-i-am-to-implement-a-continuous-memory-data-structure-like-arrays-or-vectors-in-scheme/3431 "2024-12-19T17:43:34Z")
Hi, How can someone allocate a continuous memory in scheme, and implement a vector like data structure with O(1) access without using lists in Scheme? Thanks --- ## [\[TFP (and TFPiE) 2025\] Call For Participation (January 13-16, Oxford, UK)](https://racket.discourse.group/t/tfp-and-tfpie-2025-call-for-participation-january-13-16-oxford-uk/3427)
**Author:** [@peter88](https://racket.discourse.group/u/peter88)\ **Replies:** 0\ **Last updated:** [December 18, 2024, 8:20am UTC](https://racket.discourse.group/t/tfp-and-tfpie-2025-call-for-participation-january-13-16-oxford-uk/3427 "2024-12-18T08:20:00Z")
TFP 2025 -- Call For Participation (trendsfp.github.io) Venue TFPiE and TFP will take place in-person in the Wolfson Building of the Department of Computer Science at the University of Oxford. Dates Early registration:… --- ## [Racket in Microsoft store?](https://racket.discourse.group/t/racket-in-microsoft-store/3397)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 2\ **Last updated:** [December 18, 2024, 1:44am UTC](https://racket.discourse.group/t/racket-in-microsoft-store/3397 "2024-12-18T01:44:41Z")
It was noted recently by @dominik.pantucek that the latest Racket triggers the (rather scary IMO)windows smartscreen dialog despite being fully signed etc. I asked how hard it would be to get something in Microsoft Sto… --- ## [Installing racket-cas](https://racket.discourse.group/t/installing-racket-cas/3367)
**Author:** [@AlexG](https://racket.discourse.group/u/AlexG)\ **Replies:** 18\ **Last updated:** [December 17, 2024, 5:42pm UTC](https://racket.discourse.group/t/installing-racket-cas/3367 "2024-12-17T17:42:49Z")
I finally got round to trying @soegaard 's racket-cas and on the whole it seems OK but I'm not sure I've installed it correctly, there are some minor issues and the docs seem unclear. I downloaded the zip from github an… --- ## [My Racket page: Project Euler problems 1..50 and a lot of Gamble probabilistic programming models](https://racket.discourse.group/t/my-racket-page-project-euler-problems-1-50-and-a-lot-of-gamble-probabilistic-programming-models/3180)
**Author:** [@hakank](https://racket.discourse.group/u/hakank)\ **Replies:** 6\ **Last updated:** [December 17, 2024, 4:24pm UTC](https://racket.discourse.group/t/my-racket-page-project-euler-problems-1-50-and-a-lot-of-gamble-probabilistic-programming-models/3180 "2024-12-17T16:24:15Z")
(I'm still a little embarrassed about my newbie question earlier, but nowadays I only focus on Racket and don't mix with other Lisps, except for Emacs Lisp occasionally. I still do newbie mistakes, but not very often tha… --- ## [Typed Struct Property: Problem with prop:custom-write](https://racket.discourse.group/t/typed-struct-property-problem-with-prop-custom-write/3419)
**Author:** [@wurmli](https://racket.discourse.group/u/wurmli)\ **Replies:** 6\ **Last updated:** [December 16, 2024, 12:01pm UTC](https://racket.discourse.group/t/typed-struct-property-problem-with-prop-custom-write/3419 "2024-12-16T12:01:38Z")
This is probably a question for Suzanne Soy. I tried her struct type properties, but the result is not exactly what I expected. #lang typed/racket (: display-point (-\> Point Output-Port (U #t #f 0 1) Any)) (define (di… --- ## [Finite state automaton for parsing](https://racket.discourse.group/t/finite-state-automaton-for-parsing/3421)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 0\ **Last updated:** [December 15, 2024, 6:19pm UTC](https://racket.discourse.group/t/finite-state-automaton-for-parsing/3421 "2024-12-15T18:19:29Z")
Hi, on this end of week i decided to update a bit my infix parser to allow some expressions as in other language, i take in example Python: Python 3.12.3 (main, Nov 6 2024, 18:32:19) \[GCC 13.2.0\] on linux Type "help",… --- ## [GitHub issue tracker should continue to label \`good-first-issue\`s](https://racket.discourse.group/t/github-issue-tracker-should-continue-to-label-good-first-issue-s/3265)
**Author:** [@xiaoyu2006](https://racket.discourse.group/u/xiaoyu2006)\ **Replies:** 4\ **Last updated:** [December 15, 2024, 12:53pm UTC](https://racket.discourse.group/t/github-issue-tracker-should-continue-to-label-good-first-issue-s/3265 "2024-12-15T12:53:27Z")
On a post few days ago @spdegabrielle was asked how can beginners start contributing to Racket and his response included going to GitHub racket/racket and looking for good-first-issues. However even clicking on the link … --- ## [Good-first-issue revisited](https://racket.discourse.group/t/good-first-issue-revisited/3396)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [December 6, 2024, 12:41am UTC](https://racket.discourse.group/t/good-first-issue-revisited/3396 "2024-12-06T00:41:25Z")
How to make best use of GitHub tags to help new contributors cross that first hurdle came up in the ‘meta’ comments starting at \[Feature Request\] Ability to compile individual packages with \`raco setup\` · Issue #5129 · r… [Previous page](https://racket.discourse.group/latest.md?page=18) [Next page](https://racket.discourse.group/latest.md?page=20)