# Latest **URL:** https://racket.discourse.group/latest.md?page=64 [Latest](https://racket.discourse.group/latest.md) · [Categories](https://racket.discourse.group/categories.md) · [Tags](https://racket.discourse.group/tags.md) **Page:** 65 --- ## [Discussion of Racket's LOP abilities in r/ProgrammingLanguages](https://racket.discourse.group/t/discussion-of-rackets-lop-abilities-in-r-programminglanguages/689)
**Author:** [@Decabytes](https://racket.discourse.group/u/Decabytes)\ **Replies:** 13\ **Last updated:** [February 26, 2022, 8:07am UTC](https://racket.discourse.group/t/discussion-of-rackets-lop-abilities-in-r-programminglanguages/689 "2022-02-26T08:07:13Z")
Full Disclosure I created the post but it got more traction than I was expecting. I think some of the grievances about syntax definitely lend more credibility to the Rhombus project. I'd be curious to see what those peop… --- ## [How to Organize Your Racket Library \[blog\]](https://racket.discourse.group/t/how-to-organize-your-racket-library-blog/717)
**Author:** [@countvajhula](https://racket.discourse.group/u/countvajhula)\ **Replies:** 11\ **Last updated:** [February 26, 2022, 6:30am UTC](https://racket.discourse.group/t/how-to-organize-your-racket-library-blog/717 "2022-02-26T06:30:33Z")
Fellow Racketeers in the trenches, Here is a "how to" blog post on the commonly-used-yet-undocumented lib/test/doc approach to organizing your Racket library: How to Organize Your Racket Library It also includes some … --- ## [Single Package vs Multiple (-lib -doc -test) & Convenience](https://racket.discourse.group/t/single-package-vs-multiple-lib-doc-test-convenience/693)
**Author:** [@simonls](https://racket.discourse.group/u/simonls)\ **Replies:** 29\ **Last updated:** [February 25, 2022, 6:10pm UTC](https://racket.discourse.group/t/single-package-vs-multiple-lib-doc-test-convenience/693 "2022-02-25T18:10:02Z")
Convenience Authoring vs Using Packages When I author a simple package with only a little bit of functionality, I really like the convenience of creating a single package and putting everything inside it. When I want to… --- ## [Mathler solver and terminal game](https://racket.discourse.group/t/mathler-solver-and-terminal-game/734)
**Author:** [@dannypsnl](https://racket.discourse.group/u/dannypsnl)\ **Replies:** 0\ **Last updated:** [February 25, 2022, 11:48am UTC](https://racket.discourse.group/t/mathler-solver-and-terminal-game/734 "2022-02-25T11:48:54Z")
package: mathler The project is for fun. One can start a game in the terminal by command mathler play or use command mathler solve to generate solutions interactively. --- ## [Add a -c "clean" flag to raco make?](https://racket.discourse.group/t/add-a-c-clean-flag-to-raco-make/178)
**Author:** [@badkins](https://racket.discourse.group/u/badkins)\ **Replies:** 10\ **Last updated:** [February 25, 2022, 2:25am UTC](https://racket.discourse.group/t/add-a-c-clean-flag-to-raco-make/178 "2022-02-25T02:25:18Z")
Does it make sense to add a -c "clean" flag to raco make ? I just got bit by a confusing issue where a file was happily referencing some exported symbols from another file that had been deleted. I realize I can write my… --- ## [Racket discord just hit 989 members](https://racket.discourse.group/t/racket-discord-just-hit-989-members/727)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 2\ **Last updated:** [February 24, 2022, 4:40pm UTC](https://racket.discourse.group/t/racket-discord-just-hit-989-members/727 "2022-02-24T16:40:34Z")
Racket discord just hit 989 members! :fastparrot: :racket: Racket discord invite link - come join us or invite a friend. FAQ: Discord it is a chat service similar to Slack in that it has channels for different topics… --- ## [How to start contributing to Typed Racket?](https://racket.discourse.group/t/how-to-start-contributing-to-typed-racket/720)
**Author:** [@scolobb](https://racket.discourse.group/u/scolobb)\ **Replies:** 2\ **Last updated:** [February 23, 2022, 10:25pm UTC](https://racket.discourse.group/t/how-to-start-contributing-to-typed-racket/720 "2022-02-23T22:25:01Z")
Hi, TL;DR: How to start contributing to Typed Racket? Full disclosure I am working on a library to support my research. I am quite fond of types and of Typed Racket, and I would like to write as much of Typed Racket a… --- ## [Creating singletons tasks in a job manager](https://racket.discourse.group/t/creating-singletons-tasks-in-a-job-manager/718)
**Author:** [@dstorrs](https://racket.discourse.group/u/dstorrs)\ **Replies:** 4\ **Last updated:** [February 23, 2022, 5:27pm UTC](https://racket.discourse.group/t/creating-singletons-tasks-in-a-job-manager/718 "2022-02-23T17:27:00Z")
tl;dr: I'd like a way to ensure that a particular instance of a struct is eq? across threads so it can be used for concurrency management. What would the best way be? Medium version: If a struct goes into a parameter… --- ## [Racket meet up Saturday 5 Feb 18:00 UTC](https://racket.discourse.group/t/racket-meet-up-saturday-5-feb-18-00-utc/581)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 4\ **Last updated:** [February 22, 2022, 4:26pm UTC](https://racket.discourse.group/t/racket-meet-up-saturday-5-feb-18-00-utc/581 "2022-02-22T16:26:01Z")
2022-02-05T18:00:00Z (UTC) Racket meet up Saturday 5 Feb 18:00 UTC https://gather.town/app/wH1EDG3McffLjrs0/racket-users When: First Saturday EVERY Month UTC: 18:00 Agenda: flexible, generally show-and-tell with Q&A … --- ## [Default .gitignore for Racket](https://racket.discourse.group/t/default-gitignore-for-racket/534)
**Author:** [@soegaard](https://racket.discourse.group/u/soegaard)\ **Replies:** 28\ **Last updated:** [February 22, 2022, 1:23pm UTC](https://racket.discourse.group/t/default-gitignore-for-racket/534 "2022-02-22T13:23:31Z")
The git command uses the file .gitignore to learn about files whose changes doesn't matter. Do you have one to share? Also, anyone up for the challenge of adding a default one for Racket on Github? --- ## [While PasteRack is offline check out the R16 trick bot on Discord](https://racket.discourse.group/t/while-pasterack-is-offline-check-out-the-r16-trick-bot-on-discord/714)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 2\ **Last updated:** [February 21, 2022, 10:00pm UTC](https://racket.discourse.group/t/while-pasterack-is-offline-check-out-the-r16-trick-bot-on-discord/714 "2022-02-21T22:00:06Z")
Sadly http://pasterack.org is currently off-line In the meantime why not try out the R16 "trick bot"! It saves snippets of code, which can then be recalled and executed on user-provided input. Many thanks to the creat… --- ## [Uses of improper lists?](https://racket.discourse.group/t/uses-of-improper-lists/712)
**Author:** [@Laurent.O](https://racket.discourse.group/u/Laurent.O)\ **Replies:** 8\ **Last updated:** [February 21, 2022, 9:35pm UTC](https://racket.discourse.group/t/uses-of-improper-lists/712 "2022-02-21T21:35:49Z")
This is likely a veeeery old question, but strangely I hadn't given much thought about it. Do people use improper lists such as (a b c . d) with more than 2 elements? I don't remember ever seeing such a use case. If no… --- ## [Filesystem-change-evt triggers twice](https://racket.discourse.group/t/filesystem-change-evt-triggers-twice/709)
**Author:** [@dstorrs](https://racket.discourse.group/u/dstorrs)\ **Replies:** 2\ **Last updated:** [February 19, 2022, 5:06pm UTC](https://racket.discourse.group/t/filesystem-change-evt-triggers-twice/709 "2022-02-19T17:06:02Z")
\#lang racket (require racket/runtime-path) (define-runtime-path here ".") (define the-path (build-path here "touchme.txt")) (let loop () (displayln "starting the loop...") (sync (filesystem-change-evt the-path)) … --- ## [How ellipsis works in macro?](https://racket.discourse.group/t/how-ellipsis-works-in-macro/692)
**Author:** [@chansey97](https://racket.discourse.group/u/chansey97)\ **Replies:** 7\ **Last updated:** [February 19, 2022, 6:50am UTC](https://racket.discourse.group/t/how-ellipsis-works-in-macro/692 "2022-02-19T06:50:58Z")
The ellipsis seems to work in the most obvious way, but it is still difficult to understand for me. Below I will explain my current understanding and provide a naive translation to map, but there are quite a few examples… --- ## [How can i use sets methods to sort sets and create sequences?](https://racket.discourse.group/t/how-can-i-use-sets-methods-to-sort-sets-and-create-sequences/708)
**Author:** [@osman44](https://racket.discourse.group/u/osman44)\ **Replies:** 2\ **Last updated:** [February 18, 2022, 9:09pm UTC](https://racket.discourse.group/t/how-can-i-use-sets-methods-to-sort-sets-and-create-sequences/708 "2022-02-18T21:09:00Z")
I am asking this question as i am struggling to use sets and i would like to better understand how to tackle this goal .My goal here is to to write a function which sorts the union of all my three sets in alphabetical … --- ## [Get to type (apply in-parallel lst)](https://racket.discourse.group/t/get-to-type-apply-in-parallel-lst/683)
**Author:** [@scolobb](https://racket.discourse.group/u/scolobb)\ **Replies:** 5\ **Last updated:** [February 18, 2022, 2:53pm UTC](https://racket.discourse.group/t/get-to-type-apply-in-parallel-lst/683 "2022-02-18T14:53:04Z")
Hi, I am trying to type the following function: (: lists-transpose (All (a) (-\> (Listof (Listof a)) (Listof (Listof a))))) (define (lists-transpose lsts) (sequence-\>list (in-values-sequence (apply in-parallel lst))))… --- ## [When to use Typed Racket vs Contracts](https://racket.discourse.group/t/when-to-use-typed-racket-vs-contracts/691)
**Author:** [@Decabytes](https://racket.discourse.group/u/Decabytes)\ **Replies:** 6\ **Last updated:** [February 18, 2022, 2:38pm UTC](https://racket.discourse.group/t/when-to-use-typed-racket-vs-contracts/691 "2022-02-18T14:38:07Z")
I’m currently using the Racket wrapped library for C library Raylib and one problem that I’m running into is that when I pass the wrong types to a function the whole program crashes. I’ve never used them before, but it s… --- ## [Tips for building native libraries for Racket?](https://racket.discourse.group/t/tips-for-building-native-libraries-for-racket/706)
**Author:** [@simonls](https://racket.discourse.group/u/simonls)\ **Replies:** 5\ **Last updated:** [February 18, 2022, 3:40am UTC](https://racket.discourse.group/t/tips-for-building-native-libraries-for-racket/706 "2022-02-18T03:40:40Z")
In this thread I have described how I solved my problem (ffi bindings are difficult to create) by creating a wrapper library around freetype (simpler to create ffi bindings): But to be silly and quote myself: So this… --- ## [FFI define-cstruct recursive dependencies on types](https://racket.discourse.group/t/ffi-define-cstruct-recursive-dependencies-on-types/353)
**Author:** [@simonls](https://racket.discourse.group/u/simonls)\ **Replies:** 4\ **Last updated:** [February 17, 2022, 10:24pm UTC](https://racket.discourse.group/t/ffi-define-cstruct-recursive-dependencies-on-types/353 "2022-02-17T22:24:48Z")
I am trying to use define-cstruct 1.4 C Structs to define many cstructs some of those have pointers to other cstructs. My actual code is quite big, but I think it boils down to being able to define mutually recursive cst… --- ## [How-do-i-show-results-of-two-functions-in-another-function](https://racket.discourse.group/t/how-do-i-show-results-of-two-functions-in-another-function/705)
**Author:** [@osman44](https://racket.discourse.group/u/osman44)\ **Replies:** 1\ **Last updated:** [February 17, 2022, 12:58am UTC](https://racket.discourse.group/t/how-do-i-show-results-of-two-functions-in-another-function/705 "2022-02-17T00:58:25Z")
I have been as a part of a school assignment been coding a program on racket,which is similar to the tfl route planner. My objective is to create a function which takes the results from the two functions, for example for… --- ## [Need help using set-union](https://racket.discourse.group/t/need-help-using-set-union/703)
**Author:** [@osman44](https://racket.discourse.group/u/osman44)\ **Replies:** 4\ **Last updated:** [February 16, 2022, 7:43pm UTC](https://racket.discourse.group/t/need-help-using-set-union/703 "2022-02-16T19:43:56Z")
i have written this code which basically checks if the user has submitted and empty input (which returns and error) or inputs a letter which does not belong in neither of three sets,and if its successful it will return… --- ## [Define-attributes macro, is this useful, ideas for improvements?](https://racket.discourse.group/t/define-attributes-macro-is-this-useful-ideas-for-improvements/300)
**Author:** [@simonls](https://racket.discourse.group/u/simonls)\ **Replies:** 9\ **Last updated:** [February 16, 2022, 5:22pm UTC](https://racket.discourse.group/t/define-attributes-macro-is-this-useful-ideas-for-improvements/300 "2022-02-16T17:22:08Z")
I had a define-attributes macro for a while now in a project, I don't use it a whole lot, but where I do it seems to make the code less verbose. But I think my understanding of source locations is still not the best so t… --- ## [\`raco pkg new\` License not recognized by github](https://racket.discourse.group/t/raco-pkg-new-license-not-recognized-by-github/700)
**Author:** [@simonls](https://racket.discourse.group/u/simonls)\ **Replies:** 0\ **Last updated:** [February 16, 2022, 6:15am UTC](https://racket.discourse.group/t/raco-pkg-new-license-not-recognized-by-github/700 "2022-02-16T06:15:07Z")
This is the first time I have used the raco pkg new command to create my new package. (before I created them manually) I noticed that for my manually created packages the license is recognized by github and shown with a… --- ## [Is rainbow-delimiters-mode possible in DrRacket? ](https://racket.discourse.group/t/is-rainbow-delimiters-mode-possible-in-drracket/697)
**Author:** [@jolyon](https://racket.discourse.group/u/jolyon)\ **Replies:** 4\ **Last updated:** [February 15, 2022, 11:11pm UTC](https://racket.discourse.group/t/is-rainbow-delimiters-mode-possible-in-drracket/697 "2022-02-15T23:11:10Z")
Forgive a possibly newbish question; I have just discovered drracket, and am loving it! One thing I am missing from emacs a lot is rainbow-delimiters-mode. Is there a way to simulate this in drracket? This would make … --- ## ["libintl.9.dylib cannot be verified" error with MacOS executable](https://racket.discourse.group/t/libintl-9-dylib-cannot-be-verified-error-with-macos-executable/690)
**Author:** [@jjsimpso](https://racket.discourse.group/u/jjsimpso)\ **Replies:** 2\ **Last updated:** [February 15, 2022, 12:19am UTC](https://racket.discourse.group/t/libintl-9-dylib-cannot-be-verified-error-with-macos-executable/690 "2022-02-15T00:19:29Z")
I have an application that I am cross-compiling binaries for. The MacOS binary is giving this error: Full details at macOS suspicious of libintl.9.dylib · Issue #2 · jjsimpso/molasses · GitHub. I cross compiled this … --- ## [Racket Mode users: Want to try new "multi back end" branch?](https://racket.discourse.group/t/racket-mode-users-want-to-try-new-multi-back-end-branch/631)
**Author:** [@greghendershott](https://racket.discourse.group/u/greghendershott)\ **Replies:** 7\ **Last updated:** [February 14, 2022, 3:20pm UTC](https://racket.discourse.group/t/racket-mode-users-want-to-try-new-multi-back-end-branch/631 "2022-02-14T15:20:40Z")
I have a branch I've been working on for 5 months, off and on, that lets Racket Mode work with multiple back ends; this arose from PR 533. Here's an explanation of the new "architecture". If it needs more work, I'd lik… --- ## [Using \`draw-bitmap\` and \`draw-bitmap-section\` with transparent color images](https://racket.discourse.group/t/using-draw-bitmap-and-draw-bitmap-section-with-transparent-color-images/694)
**Author:** [@soegaard](https://racket.discourse.group/u/soegaard)\ **Replies:** 2\ **Last updated:** [February 14, 2022, 3:06pm UTC](https://racket.discourse.group/t/using-draw-bitmap-and-draw-bitmap-section-with-transparent-color-images/694 "2022-02-14T15:06:40Z")
Hi All, I need help to draw a "sprite" (small bitmap) on top of a bitmap. The sprite in question is consists of a transparent background and has a solid yellow circle in the center. My test program looks like this (sc… --- ## [A question about free-identifier=?](https://racket.discourse.group/t/a-question-about-free-identifier/685)
**Author:** [@chansey97](https://racket.discourse.group/u/chansey97)\ **Replies:** 5\ **Last updated:** [February 13, 2022, 11:28pm UTC](https://racket.discourse.group/t/a-question-about-free-identifier/685 "2022-02-13T23:28:39Z")
I am learning Racket macro. I have a question about free-identifier=?. Why the following code return #t? (free-identifier=? #'car (let (\[car 8\]) #'car)) ;; #t Does the #'car under the let access the same binding? Th… --- ## [Syntax-case, require, file](https://racket.discourse.group/t/syntax-case-require-file/687)
**Author:** [@Kalimehtar](https://racket.discourse.group/u/Kalimehtar)\ **Replies:** 4\ **Last updated:** [February 13, 2022, 3:16pm UTC](https://racket.discourse.group/t/syntax-case-require-file/687 "2022-02-13T15:16:35Z")
Why (define-syntax (require-file stx) (syntax-case stx () \[(\_ x) #'(require (file x))\])) doesn't work (it compiles, but doesn't import identifiers)? (define-syntax (require-file\* stx) (syntax-case stx () … --- ## [Suggestion: track if your modules have been installed from pkg server](https://racket.discourse.group/t/suggestion-track-if-your-modules-have-been-installed-from-pkg-server/675)
**Author:** [@dstorrs](https://racket.discourse.group/u/dstorrs)\ **Replies:** 3\ **Last updated:** [February 12, 2022, 12:10am UTC](https://racket.discourse.group/t/suggestion-track-if-your-modules-have-been-installed-from-pkg-server/675 "2022-02-12T00:10:28Z")
I often find myself wondering if the packages I've posted are in use by anyone. In part for the egoboo but also because if they aren't in use by anyone else then backwards compatibility isn't as important a consideratio… [Previous page](https://racket.discourse.group/latest.md?page=63) [Next page](https://racket.discourse.group/latest.md?page=65)