# Latest **URL:** https://racket.discourse.group/latest.md?page=7 [Latest](https://racket.discourse.group/latest.md) · [Categories](https://racket.discourse.group/categories.md) · [Tags](https://racket.discourse.group/tags.md) **Page:** 8 --- ## [\[TFP 2026\] 1st Call for Participation for the 27th International Symposium on Trends in Functional Programming, Odense, Denmark, January 27-29 2026 - TFPiE Jan 26](https://racket.discourse.group/t/tfp-2026-1st-call-for-participation-for-the-27th-international-symposium-on-trends-in-functional-programming-odense-denmark-january-27-29-2026-tfpie-jan-26/4056)
**Author:** [@peter88](https://racket.discourse.group/u/peter88)\ **Replies:** 0\ **Last updated:** [December 24, 2025, 3:37pm UTC](https://racket.discourse.group/t/tfp-2026-1st-call-for-participation-for-the-27th-international-symposium-on-trends-in-functional-programming-odense-denmark-january-27-29-2026-tfpie-jan-26/4056 "2025-12-24T15:37:27Z")
TFP 2026 -- Call For Participation (trendsfp.github.io) Venue TFPiE and TFP will take place in-person in Odense, Denmark, at the University of Southern Denmark. Dates Early registration: 31 December, 2025 Late reg… --- ## [Question about text in 2htdp/image teachpack](https://racket.discourse.group/t/question-about-text-in-2htdp-image-teachpack/4054)
**Author:** [@a-user](https://racket.discourse.group/u/a-user)\ **Replies:** 2\ **Last updated:** [December 24, 2025, 7:17am UTC](https://racket.discourse.group/t/question-about-text-in-2htdp-image-teachpack/4054 "2025-12-24T07:17:26Z")
In the documentation of text here, it says: The text size is measured in pixels, not points, so passing 24 to text should result in an image whose height is 24 (which might not be the case if the size were measured in p… --- ## [Using Redex as an interactive lambda-calculus workbench?](https://racket.discourse.group/t/using-redex-as-an-interactive-lambda-calculus-workbench/4053)
**Author:** [@msap](https://racket.discourse.group/u/msap)\ **Replies:** 1\ **Last updated:** [December 23, 2025, 3:26am UTC](https://racket.discourse.group/t/using-redex-as-an-interactive-lambda-calculus-workbench/4053 "2025-12-23T03:26:41Z")
I’m working through Lambda-Calculus and Combinators: An Introduction (Hindley & Seldin) and I’m looking for a locally installable Racket-based tool that can act as an interactive workbench for untyped lambda calculus an… --- ## [Running format procedure code example results in error](https://racket.discourse.group/t/running-format-procedure-code-example-results-in-error/4051)
**Author:** [@a-user](https://racket.discourse.group/u/a-user)\ **Replies:** 4\ **Last updated:** [December 22, 2025, 2:15pm UTC](https://racket.discourse.group/t/running-format-procedure-code-example-results-in-error/4051 "2025-12-22T14:15:20Z")
Typing one of the code example for format in DrRacket returns error. Racket version: 9.0 Language: BSL Documentation link: format Code: (format "the value of ~s is ~a" '(+ 1 1) (+ 1 1)) Error: quote: expected the na… --- ## [Teaching - when should \`local\` be introduced?](https://racket.discourse.group/t/teaching-when-should-local-be-introduced/4041)
**Author:** [@maueroats](https://racket.discourse.group/u/maueroats)\ **Replies:** 4\ **Last updated:** [December 19, 2025, 8:14am UTC](https://racket.discourse.group/t/teaching-when-should-local-be-introduced/4041 "2025-12-19T08:14:09Z")
Does it matter when local variables are introduced? (For reference, HtDP refers to local variables in III.16.2 Local Definitions.) One pro to waiting so long to introduce local definitions is that students are encourage… --- ## [Is there some reason --no-yield implies --version in \`racket\`?](https://racket.discourse.group/t/is-there-some-reason-no-yield-implies-version-in-racket/4048)
**Author:** [@wilbowma](https://racket.discourse.group/u/wilbowma)\ **Replies:** 1\ **Last updated:** [December 15, 2025, 11:17pm UTC](https://racket.discourse.group/t/is-there-some-reason-no-yield-implies-version-in-racket/4048 "2025-12-15T23:17:27Z")
I was messing around with Racket options and noticed that --no-yield always implies --version: racket/racket/src/cs/main.sps at d14920c4b4c62fe695ff00ea5a6e6a47df1d6cb3 · racket/racket · GitHub I'm not sure why that wou… --- ## [Pyffi with numpy (\<1.26) low-level lib and Python 3.1x](https://racket.discourse.group/t/pyffi-with-numpy-1-26-low-level-lib-and-python-3-1x/4036)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 40\ **Last updated:** [December 15, 2025, 1:32pm UTC](https://racket.discourse.group/t/pyffi-with-numpy-1-26-low-level-lib-and-python-3-1x/4036 "2025-12-15T13:32:52Z")
Hi, I try to use pyffi but i have a Mac with Python 3.9 by default from Apple and Python 3.12 for work for depandancies with some scientific libraries. pyffi is searching for version 3.10 so i did: /Applications/Racket… --- ## [Pyffi and infix version of Conway's Game of Life](https://racket.discourse.group/t/pyffi-and-infix-version-of-conways-game-of-life/4046)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 0\ **Last updated:** [December 13, 2025, 4:50pm UTC](https://racket.discourse.group/t/pyffi-and-infix-version-of-conways-game-of-life/4046 "2025-12-13T16:50:25Z")
From outdoor to screen i wrote today an infix version of the program Conway's Game of Life that was in pyffi-test : the 2 versions are here: test-numpy-game-of-life+.rkt #lang reader SRFI-105 ; you can use SRFI-105 or … --- ## [Pyffi: ref procedure](https://racket.discourse.group/t/pyffi-ref-procedure/4045)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 4\ **Last updated:** [December 12, 2025, 4:24pm UTC](https://racket.discourse.group/t/pyffi-ref-procedure/4045 "2025-12-12T16:24:43Z")
Where does the ref procedure defined? i can not find it in the code ,nor in numpy or python and not in the documentation. It seems used to access a line like in an ndarray: (define Z (numpy.array '\[\[0 0 0 0 0 0\] … --- ## [Using a list as argument to a procedure which needs separate arguments -- "unwrapping a list"](https://racket.discourse.group/t/using-a-list-as-argument-to-a-procedure-which-needs-separate-arguments-unwrapping-a-list/4044)
**Author:** [@meijeru](https://racket.discourse.group/u/meijeru)\ **Replies:** 2\ **Last updated:** [December 12, 2025, 2:07pm UTC](https://racket.discourse.group/t/using-a-list-as-argument-to-a-procedure-which-needs-separate-arguments-unwrapping-a-list/4044 "2025-12-12T14:07:12Z")
I would like to have the procedures min/max work on LISTS of numbers rather than on a series of individual numbers. Thus: (min '\[3 1 2 0\]) = 0, where now I have to write (min 3 1 2 0). This is all fine for literal series… --- ## [Ordering relations between non-numbers](https://racket.discourse.group/t/ordering-relations-between-non-numbers/4040)
**Author:** [@meijeru](https://racket.discourse.group/u/meijeru)\ **Replies:** 2\ **Last updated:** [December 12, 2025, 1:26pm UTC](https://racket.discourse.group/t/ordering-relations-between-non-numbers/4040 "2025-12-12T13:26:43Z")
I would like to be able to compare two lists, strings, and in general sequences for their ordering: smaller than or greater than. I don't see a procedure for that in the current version. --- ## [Pyffi : how to test type of numpy.ndarray](https://racket.discourse.group/t/pyffi-how-to-test-type-of-numpy-ndarray/4043)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 2\ **Last updated:** [December 12, 2025, 11:03am UTC](https://racket.discourse.group/t/pyffi-how-to-test-type-of-numpy-ndarray/4043 "2025-12-12T11:03:12Z")
Hi, i want to test type of a variable to compare with numpy.ndarray, as far i tried: (builtins.type numpy.ndarray) . . ../../../pyffi4python3.xx/pyffi/pyffi-lib/pyffi/python-attributes.rkt:191:7: rp: got: #\ **Author:** [@felipetavares](https://racket.discourse.group/u/felipetavares)\ **Replies:** 32\ **Last updated:** [December 12, 2025, 9:10am UTC](https://racket.discourse.group/t/advent-of-code-2025-discussions/4035 "2025-12-12T09:10:39Z") Hello all! Thread to post Advent of Code solutions and discussions around them. For day 1 I am pretty happy with most of my solution, except that I have this function: (define field-size 100) (define (zero-crossings i… --- ## [Ansi colour output in drracket](https://racket.discourse.group/t/ansi-colour-output-in-drracket/4015)
**Author:** [@hendrikboom3](https://racket.discourse.group/u/hendrikboom3)\ **Replies:** 8\ **Last updated:** [December 9, 2025, 3:37pm UTC](https://racket.discourse.group/t/ansi-colour-output-in-drracket/4015 "2025-12-09T15:37:06Z")
I run the following in drracket: #lang racket/base (require ansi-color) (printf "plain text~n") (with-colors 'red (lambda () (printf "red text~n"))) (with-colors 'green (lambda () (printf "green text~n"))) In the outpu… --- ## [One argument array-for-each, array-every, and array-any?](https://racket.discourse.group/t/one-argument-array-for-each-array-every-and-array-any/4004)
**Author:** [@Gambiteer](https://racket.discourse.group/u/Gambiteer)\ **Replies:** 5\ **Last updated:** [December 8, 2025, 9:45pm UTC](https://racket.discourse.group/t/one-argument-array-for-each-array-every-and-array-any/4004 "2025-12-08T21:45:08Z")
NumPy basically limits array broadcasting to pointwise operations, or array-map. I think that in a Scheme/Racket library without array comprehensions, one would need to implement broadcasting for arguments to array-fold… --- ## [Types in phase 1?](https://racket.discourse.group/t/types-in-phase-1/4038)
**Author:** [@hendrikboom3](https://racket.discourse.group/u/hendrikboom3)\ **Replies:** 1\ **Last updated:** [December 8, 2025, 2:27am UTC](https://racket.discourse.group/t/types-in-phase-1/4038 "2025-12-08T02:27:29Z")
Is there a technical reason why code for phase 1 is in plain Racket, even when phase 0 can be in typed Racket? --- ## [Racket meet-up: Saturday, 6 December 2025](https://racket.discourse.group/t/racket-meet-up-saturday-6-december-2025/4022)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 3\ **Last updated:** [December 7, 2025, 5:07pm UTC](https://racket.discourse.group/t/racket-meet-up-saturday-6-december-2025/4022 "2025-12-07T17:07:36Z")
Everyone is welcome to join us for the :racket: Racket meet-up: Saturday, 6 December 2025 at 18:00 UTC In your timezone: 2025-12-06T18:00:00Z (UTC). (converter). At this meet-up: Racket 9! Advent of Code RacketCon202… --- ## [Inside-out Procedures with Bruijn](https://racket.discourse.group/t/inside-out-procedures-with-bruijn/4028)
**Author:** [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\ **Replies:** 1\ **Last updated:** [December 5, 2025, 5:11pm UTC](https://racket.discourse.group/t/inside-out-procedures-with-bruijn/4028 "2025-12-05T17:11:03Z")
Hi, Racket Discourse. I have been tinkering with the syntax of the bruijn language recently, and I thought I'd share some of the bits I've found interesting so far. The language uses De Bruijn index-notation to name va… --- ## [Stopping the main thread](https://racket.discourse.group/t/stopping-the-main-thread/4037)
**Author:** [@hendrikboom3](https://racket.discourse.group/u/hendrikboom3)\ **Replies:** 5\ **Last updated:** [December 3, 2025, 9:43pm UTC](https://racket.discourse.group/t/stopping-the-main-thread/4037 "2025-12-03T21:43:24Z")
My main thread sets up some GUI, and needs to cede the stage for the GUI to take over. I wrote #lang racket (require racket/gui/base) (require racket/class) (define my-canvas% (class canvas% ; The base class is canva… --- ## [Com-register-event-callback fails, is the myssink.dll component not compatible with windows 10 or office 2016?](https://racket.discourse.group/t/com-register-event-callback-fails-is-the-myssink-dll-component-not-compatible-with-windows-10-or-office-2016/4034)
**Author:** [@subdudu](https://racket.discourse.group/u/subdudu)\ **Replies:** 0\ **Last updated:** [November 30, 2025, 11:34am UTC](https://racket.discourse.group/t/com-register-event-callback-fails-is-the-myssink-dll-component-not-compatible-with-windows-10-or-office-2016/4034 "2025-11-30T11:34:09Z")
I need to control excel's behavior when I use excel doing some task. I run this script: #lang racket (require ffi/com) (define app (com-create-instance "Excel.Application")) (define wbs (com-get-property app "Workbooks"… --- ## [Help with (imap-connect ...) using oauth2 (and maybe tls)?](https://racket.discourse.group/t/help-with-imap-connect-using-oauth2-and-maybe-tls/4033)
**Author:** [@tbhanson](https://racket.discourse.group/u/tbhanson)\ **Replies:** 1\ **Last updated:** [November 29, 2025, 12:52pm UTC](https://racket.discourse.group/t/help-with-imap-connect-using-oauth2-and-maybe-tls/4033 "2025-11-29T12:52:42Z")
hi, I've successfully connected to imap servers without using oauth2 but am now trying to do so with oauth2 (and maybe tls). My attempt seems to be timing out (but it also seems to be prompting me for input, as though I… --- ## [Update and setup?](https://racket.discourse.group/t/update-and-setup/4032)
**Author:** [@joskoot](https://racket.discourse.group/u/joskoot)\ **Replies:** 0\ **Last updated:** [November 29, 2025, 10:49am UTC](https://racket.discourse.group/t/update-and-setup/4032 "2025-11-29T10:49:21Z")
I use 'do what I mean' in file/package manager of DrRacket after changing a github. Sometimes I see 'update', other times 'update and setup '. Both work. What is the difference between the two? ~~~~ --- ## [Amazing Lisp/Scheme](https://racket.discourse.group/t/amazing-lisp-scheme/4031)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 0\ **Last updated:** [November 29, 2025, 9:07am UTC](https://racket.discourse.group/t/amazing-lisp-scheme/4031 "2025-11-29T09:07:20Z")
I never really understood all the power of Lisp/Scheme syntax associated with the quote facility to represent and use data in a human readable way. We often talk about homoiconicity as the first quality of Lisp/Scheme. … --- ## [Plans for non-blocking I/O?](https://racket.discourse.group/t/plans-for-non-blocking-i-o/4026)
**Author:** [@ndykman](https://racket.discourse.group/u/ndykman)\ **Replies:** 8\ **Last updated:** [November 29, 2025, 2:42am UTC](https://racket.discourse.group/t/plans-for-non-blocking-i-o/4026 "2025-11-29T02:42:25Z")
Thanks to the amazing effort to get OS threads and thread pooling into Racket, this is now something to discuss. Non-blocking I/O is well on it's way being supported in most languages and is already the default (TypeScri… --- ## [TOML library with writer](https://racket.discourse.group/t/toml-library-with-writer/2495)
**Author:** [@bzyeung](https://racket.discourse.group/u/bzyeung)\ **Replies:** 4\ **Last updated:** [November 28, 2025, 5:47pm UTC](https://racket.discourse.group/t/toml-library-with-writer/2495 "2025-11-28T17:47:59Z")
Don't know how many of you are interested in TOML, but the Racket TOML library has been updated and is v1.0 compliant now. An eye is on the upcoming TOML v1.1 so that it shouldn't take too long to update it once the spe… --- ## [How to debug macros?](https://racket.discourse.group/t/how-to-debug-macros/4027)
**Author:** [@hendrikboom3](https://racket.discourse.group/u/hendrikboom3)\ **Replies:** 4\ **Last updated:** [November 27, 2025, 7:06pm UTC](https://racket.discourse.group/t/how-to-debug-macros/4027 "2025-11-27T19:06:21Z")
I get this message: . . ../../../../../usr/local/racket/collects/racket/private/kw.rkt:1263:25: application: not a procedure; expected a procedure that can be applied to arguments given: #\ It suggests to me th… --- ## [Racket v9.0 is now available](https://racket.discourse.group/t/racket-v9-0-is-now-available/3968)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 8\ **Last updated:** [November 27, 2025, 2:11am UTC](https://racket.discourse.group/t/racket-v9-0-is-now-available/3968 "2025-11-27T02:11:05Z")
We are pleased to announce Racket v9.0 is now available from https://download.racket-lang.org/. Racket 9.0 is here! A major release is always exciting and Racket 9.0 is no exception in that it introduces Parallel Threa… --- ## ["Variadic" Lambda Calculus Abstractions](https://racket.discourse.group/t/variadic-lambda-calculus-abstractions/4021)
**Author:** [@bakgatviooldoos](https://racket.discourse.group/u/bakgatviooldoos)\ **Replies:** 4\ **Last updated:** [November 25, 2025, 9:39am UTC](https://racket.discourse.group/t/variadic-lambda-calculus-abstractions/4021 "2025-11-25T09:39:20Z")
Hi, Racket Discourse. I guess this is more of a theoretical question than a Racket question, per se, but the audience is well-placed, nonetheless. I am thinking about how one would implement "sugar" for variadic lambda… --- ## [BibTeX language](https://racket.discourse.group/t/bibtex-language/4023)
**Author:** [@dominik.pantucek](https://racket.discourse.group/u/dominik.pantucek)\ **Replies:** 2\ **Last updated:** [November 24, 2025, 4:14pm UTC](https://racket.discourse.group/t/bibtex-language/4023 "2025-11-24T16:14:51Z")
Hello fellow Racketeers, as a part of my research, my BibTeX bibliography file started quickly growing both in terms of the number of entries and also in terms of the content included in each entry (for example all the … --- ## [Functional Coffee - Coffee without side-effects](https://racket.discourse.group/t/functional-coffee-coffee-without-side-effects/4025)
**Author:** [@JustinZed](https://racket.discourse.group/u/JustinZed)\ **Replies:** 0\ **Last updated:** [November 24, 2025, 4:33am UTC](https://racket.discourse.group/t/functional-coffee-coffee-without-side-effects/4025 "2025-11-24T04:33:49Z")
Not affiliated, I just saw this and thought it was funny. Do mushroom and protein 'functional' coffees have health benefits? [Previous page](https://racket.discourse.group/latest.md?page=6) [Next page](https://racket.discourse.group/latest.md?page=8)