# Latest **URL:** https://racket.discourse.group/latest.md?page=29 [Latest](https://racket.discourse.group/latest.md) · [Categories](https://racket.discourse.group/categories.md) · [Tags](https://racket.discourse.group/tags.md) **Page:** 30 --- ## [Collect safe foreign procedure in another OS thread](https://racket.discourse.group/t/collect-safe-foreign-procedure-in-another-os-thread/2889)
**Author:** [@amirouche](https://racket.discourse.group/u/amirouche)\ **Replies:** 3\ **Last updated:** [May 30, 2024, 6:39am UTC](https://racket.discourse.group/t/collect-safe-foreign-procedure-in-another-os-thread/2889 "2024-05-30T06:39:14Z")
I struggle to create a Racket wrapper for FoundationDB C client. The Chez code rely on foreign-procedure's \_\_collect\_safe is there an equivalent available in Racket? --- ## [Typed Racket + Org-mode + Org tables and lists](https://racket.discourse.group/t/typed-racket-org-mode-org-tables-and-lists/2254)
**Author:** [@scolobb](https://racket.discourse.group/u/scolobb)\ **Replies:** 4\ **Last updated:** [May 29, 2024, 10:34am UTC](https://racket.discourse.group/t/typed-racket-org-mode-org-tables-and-lists/2254 "2024-05-29T10:34:23Z")
Hi, I would like to use Typed Racket in Org-mode code blocks with ob-racket-mode and produce Org lists and tables. (Untyped) Racket code works out of the box: #+BEGIN\_SRC racket :results table drawer '((a 1) (b 2)) #+… --- ## [Writing functions and reading them again](https://racket.discourse.group/t/writing-functions-and-reading-them-again/2938)
**Author:** [@hendrikboom3](https://racket.discourse.group/u/hendrikboom3)\ **Replies:** 2\ **Last updated:** [May 28, 2024, 8:07pm UTC](https://racket.discourse.group/t/writing-functions-and-reading-them-again/2938 "2024-05-28T20:07:13Z")
I have a data structure that contains Racket functions. I would like to be able to write it out to a file, and, later, read it in again -- a save-and-restore operation. But as far as I know, it is impossible to write o… --- ## [Is there plans for improving the performance of the generated code from the racket compiler?](https://racket.discourse.group/t/is-there-plans-for-improving-the-performance-of-the-generated-code-from-the-racket-compiler/2593)
**Author:** [@Jobhdez](https://racket.discourse.group/u/Jobhdez)\ **Replies:** 16\ **Last updated:** [May 28, 2024, 7:59pm UTC](https://racket.discourse.group/t/is-there-plans-for-improving-the-performance-of-the-generated-code-from-the-racket-compiler/2593 "2024-05-28T19:59:42Z")
Hello, Hope all is well. I am just curious if the racket core team has plans to making the generated code from the racket compiler faster. In a recent benchmark Racket vs Lisp SBCL - Which programs are fastest?, racket… --- ## [Spring Lisp Game Jam 2024](https://racket.discourse.group/t/spring-lisp-game-jam-2024/2869)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 1\ **Last updated:** [May 27, 2024, 12:53pm UTC](https://racket.discourse.group/t/spring-lisp-game-jam-2024/2869 "2024-05-27T12:53:05Z")
Racket is a lisp so why not represent in the Spring Lisp Game Jam 2024 https://itch.io/jam/spring-lisp-game-jam-2024 --- ## [Racket v8.13 is now available](https://racket.discourse.group/t/racket-v8-13-is-now-available/2928)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 3\ **Last updated:** [May 25, 2024, 8:58pm UTC](https://racket.discourse.group/t/racket-v8-13-is-now-available/2928 "2024-05-25T20:58:35Z")
We are pleased to announce Racket v8.13 is now available from https://download.racket-lang.org/. Terminal control in raco commands As of this release: The racket/treelist and racket/mutable-treelist libraries provi… --- ## [How to remove a menu bar from a frame?](https://racket.discourse.group/t/how-to-remove-a-menu-bar-from-a-frame/2934)
**Author:** [@cadence](https://racket.discourse.group/u/cadence)\ **Replies:** 9\ **Last updated:** [May 25, 2024, 12:42pm UTC](https://racket.discourse.group/t/how-to-remove-a-menu-bar-from-a-frame/2934 "2024-05-25T12:42:02Z")
For creating a menu bar, the documentation says: new menu-bar% - A menu-bar% object is created for a particular frame% object. A frame can have at most one menu bar; an exn:fail:contract exception is raised when a new … --- ## [Support on design of a simulator: multiple contexts with same variables](https://racket.discourse.group/t/support-on-design-of-a-simulator-multiple-contexts-with-same-variables/2932)
**Author:** [@db7](https://racket.discourse.group/u/db7)\ **Replies:** 6\ **Last updated:** [May 25, 2024, 10:47am UTC](https://racket.discourse.group/t/support-on-design-of-a-simulator-multiple-contexts-with-same-variables/2932 "2024-05-25T10:47:26Z")
Hi, in the process of learning Racket I‘ve started designing a small system simulator. Now I am stuck searching for an elegant way to solve the following issue. The simulator has an environment and multiple actors. The… --- ## [Racket version 8.7 is now available](https://racket.discourse.group/t/racket-version-8-7-is-now-available/1478)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 9\ **Last updated:** [May 24, 2024, 7:44pm UTC](https://racket.discourse.group/t/racket-version-8-7-is-now-available/1478 "2024-05-24T19:44:27Z")
Racket version 8.7 is now available from https://download.racket-lang.org/ As of this release: Typed Racket offers Shallow and Optional modes for its gradual types. These modes lower the cost of interacting with un… --- ## [Refining Pretty Style Mapping in Racket](https://racket.discourse.group/t/refining-pretty-style-mapping-in-racket/2931)
**Author:** [@NoahStoryM](https://racket.discourse.group/u/NoahStoryM)\ **Replies:** 1\ **Last updated:** [May 22, 2024, 4:56pm UTC](https://racket.discourse.group/t/refining-pretty-style-mapping-in-racket/2931 "2024-05-22T16:56:47Z")
The style mapping for a symbol controls the way that whitespace is inserted when printing a list that starts with the symbol. The current documentation introduces various symbols. I think there's room for improvement. … --- ## [Virtual hash table](https://racket.discourse.group/t/virtual-hash-table/2907)
**Author:** [@joskoot](https://racket.discourse.group/u/joskoot)\ **Replies:** 19\ **Last updated:** [May 21, 2024, 8:37pm UTC](https://racket.discourse.group/t/virtual-hash-table/2907 "2024-05-21T20:37:34Z")
Imagine a hash that can grow to too much data to be kept in ram. Should I rely on virtual memory? I have ideas how to make a mutable hash-table that is stored in a file and allows the garbage collector to remove value… --- ## [Renaming mechanism for Unicode \`λ\` in Racket](https://racket.discourse.group/t/renaming-mechanism-for-unicode-in-racket/2910)
**Author:** [@NoahStoryM](https://racket.discourse.group/u/NoahStoryM)\ **Replies:** 2\ **Last updated:** [May 20, 2024, 5:53pm UTC](https://racket.discourse.group/t/renaming-mechanism-for-unicode-in-racket/2910 "2024-05-20T17:53:00Z")
I'm considering whether it's necessary and beneficial to define λ through the renaming mechanism. @sorawee pointed out that lambda and λ are not treated as equivalent by free-identifier=?: #lang racket (module sub rack… --- ## [How to find insertions of any-wrap/c in TR code?](https://racket.discourse.group/t/how-to-find-insertions-of-any-wrap-c-in-tr-code/2921)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 8\ **Last updated:** [May 19, 2024, 6:15am UTC](https://racket.discourse.group/t/how-to-find-insertions-of-any-wrap-c-in-tr-code/2921 "2024-05-19T06:15:40Z")
I'm helping a student that's using Racket in a compilers class, and they're running into an error where any-wrap/c is being applied to a cyclic value. The student is definitely intending to create a cyclic structure, so … --- ## [My package socks5 wasn't built and I don't know why](https://racket.discourse.group/t/my-package-socks5-wasnt-built-and-i-dont-know-why/2905)
**Author:** [@cadence](https://racket.discourse.group/u/cadence)\ **Replies:** 3\ **Last updated:** [May 19, 2024, 1:33am UTC](https://racket.discourse.group/t/my-package-socks5-wasnt-built-and-i-dont-know-why/2905 "2024-05-19T01:33:45Z")
Documentation for my package socks5 isn't displayed any more. I think it's supposed to be put on the docs website by the package build server, but when I check the build logs, it just says "Killed". I tried installing so… --- ## [Live coding demo using Racket at DevOpsDaysKC](https://racket.discourse.group/t/live-coding-demo-using-racket-at-devopsdayskc/2922)
**Author:** [@markshead](https://racket.discourse.group/u/markshead)\ **Replies:** 0\ **Last updated:** [May 17, 2024, 2:11am UTC](https://racket.discourse.group/t/live-coding-demo-using-racket-at-devopsdayskc/2922 "2024-05-17T02:11:12Z")
My son and I presented at DevOpsDaysKC yesterday with a talk on pair programming and test-driven development. While the focus wasn't on the programming language, we used Racket because we thought most people could unders… --- ## [How to get last inserted row id in SQLite3?](https://racket.discourse.group/t/how-to-get-last-inserted-row-id-in-sqlite3/2924)
**Author:** [@Tomek](https://racket.discourse.group/u/Tomek)\ **Replies:** 4\ **Last updated:** [May 17, 2024, 10:09am UTC](https://racket.discourse.group/t/how-to-get-last-inserted-row-id-in-sqlite3/2924 "2024-05-17T10:09:54Z")
Simple question: how can I get the (last) inserted row id using SQLite3 with Racket and the db module/package (whatever it is called)? In SQLite3 there's the sqlite3\_last\_insert\_rowid function. Is there any equivalent i… --- ## [Racket v8.13 Release Thread](https://racket.discourse.group/t/racket-v8-13-release-thread/2857)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 30\ **Last updated:** [May 14, 2024, 8:36pm UTC](https://racket.discourse.group/t/racket-v8-13-release-thread/2857 "2024-05-14T20:36:39Z")
The release process for v8.13 will begin in less than 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: - 10th: Branch day,… --- ## [Surprising identifier binding ambiguity error with nested splicing-local (possible bug)](https://racket.discourse.group/t/surprising-identifier-binding-ambiguity-error-with-nested-splicing-local-possible-bug/2912)
**Author:** [@gregr](https://racket.discourse.group/u/gregr)\ **Replies:** 1\ **Last updated:** [May 14, 2024, 5:53am UTC](https://racket.discourse.group/t/surprising-identifier-binding-ambiguity-error-with-nested-splicing-local-possible-bug/2912 "2024-05-14T05:53:29Z")
I encountered a surprising identifier binding ambiguity error when using splicing-local within the body of another splicing-local. Am I misusing splicing-local, or is this a bug? Here's a small reproduction of the prob… --- ## [Interesting discussion on hacker news (21-April-2024)](https://racket.discourse.group/t/interesting-discussion-on-hacker-news-21-april-2024/2884)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 15\ **Last updated:** [May 14, 2024, 12:36am UTC](https://racket.discourse.group/t/interesting-discussion-on-hacker-news-21-april-2024/2884 "2024-05-14T00:36:22Z")
Interesting because of the difference between what other people believe about Racket the artefact/language/community - and what I believe. While there are many great comments, I also saw what I believe are common miscon… --- ## [Alarm-evt performance difference between windows 10 and ubuntu 23.04](https://racket.discourse.group/t/alarm-evt-performance-difference-between-windows-10-and-ubuntu-23-04/2901)
**Author:** [@uu27183141](https://racket.discourse.group/u/uu27183141)\ **Replies:** 2\ **Last updated:** [May 11, 2024, 1:17pm UTC](https://racket.discourse.group/t/alarm-evt-performance-difference-between-windows-10-and-ubuntu-23-04/2901 "2024-05-11T13:17:51Z")
Hi. I have a question about alarm-evt. Below is example code. (module b racket (define (f) (sync/enable-break (handle-evt (alarm-evt (+ (current-inexact-milliseconds) … --- ## [Constructor style pretty printing](https://racket.discourse.group/t/constructor-style-pretty-printing/2904)
**Author:** [@shhyou](https://racket.discourse.group/u/shhyou)\ **Replies:** 4\ **Last updated:** [May 9, 2024, 4:24pm UTC](https://racket.discourse.group/t/constructor-style-pretty-printing/2904 "2024-05-09T16:24:03Z")
In HtDP, the structs are printed using the (make-XXX ...) constructor style either by default in REPL or via print. How do I get the same behavior for pretty printing? I have been able to print values in constructor sty… --- ## [Adding more Unicode λ forms to Racket](https://racket.discourse.group/t/adding-more-unicode-forms-to-racket/2911)
**Author:** [@NoahStoryM](https://racket.discourse.group/u/NoahStoryM)\ **Replies:** 2\ **Last updated:** [May 9, 2024, 9:30am UTC](https://racket.discourse.group/t/adding-more-unicode-forms-to-racket/2911 "2024-05-09T09:30:39Z")
I am proposing to introduce additional Unicode λ forms such as case-λ, #%plain-λ, and match-λ\[\*\]\[\*\] to Racket, which seems like a minimal and safe change. I would appreciate your thoughts on this proposal: Do you find… --- ## [Using pdf-read package to extract text from pdf file](https://racket.discourse.group/t/using-pdf-read-package-to-extract-text-from-pdf-file/2685)
**Author:** [@encomer](https://racket.discourse.group/u/encomer)\ **Replies:** 25\ **Last updated:** [May 8, 2024, 8:13pm UTC](https://racket.discourse.group/t/using-pdf-read-package-to-extract-text-from-pdf-file/2685 "2024-05-08T20:13:28Z")
Using the following code en DrRacket, in a PC with Windows 10: #lang racket (require pdf-read) When running, generates the following message: ..\\..\\..\\Program Files\\Racket\\collects\\ffi\\unsafe.rkt:131:0: ffi-lib: coul… --- ## [Self-documented Racket source code](https://racket.discourse.group/t/self-documented-racket-source-code/2820)
**Author:** [@Tyrn](https://racket.discourse.group/u/Tyrn)\ **Replies:** 12\ **Last updated:** [May 8, 2024, 12:31pm UTC](https://racket.discourse.group/t/self-documented-racket-source-code/2820 "2024-05-08T12:31:36Z")
Hi, Inspecting bits and pieces that come my way I learned that there are no docstrings in Racket. One can write his docs with Scribble (how?), upload it online and even see the relevant docs in an IDE while hovering one… --- ## [Parser combinator in Typed Racket: how to define the type constructor for the parser?](https://racket.discourse.group/t/parser-combinator-in-typed-racket-how-to-define-the-type-constructor-for-the-parser/2909)
**Author:** [@yossarian](https://racket.discourse.group/u/yossarian)\ **Replies:** 1\ **Last updated:** [May 7, 2024, 4:06pm UTC](https://racket.discourse.group/t/parser-combinator-in-typed-racket-how-to-define-the-type-constructor-for-the-parser/2909 "2024-05-07T16:06:35Z")
I am trying to translate the nice Haskell tutorial by Stephen Diehl on parser combinators in Typed Racket. However, I am already stuck when trying to define the parametric Parser type. Haskell: newtype Parser a = Parser… --- ## [Choosing good names](https://racket.discourse.group/t/choosing-good-names/2900)
**Author:** [@hendrikboom3](https://racket.discourse.group/u/hendrikboom3)\ **Replies:** 4\ **Last updated:** [May 6, 2024, 6:16pm UTC](https://racket.discourse.group/t/choosing-good-names/2900 "2024-05-06T18:16:17Z")
Choosing good names is said to be one of the most difficult things to so in programming. I'm looking for some advice here. Let's say I want to talk about an onion in a Racket program. It's somewhat obvious to call it … --- ## [Performance comparison between (append (reverse a) b)) and (foldl cons b a))](https://racket.discourse.group/t/performance-comparison-between-append-reverse-a-b-and-foldl-cons-b-a/2903)
**Author:** [@NeraSnow](https://racket.discourse.group/u/NeraSnow)\ **Replies:** 7\ **Last updated:** [May 6, 2024, 2:40pm UTC](https://racket.discourse.group/t/performance-comparison-between-append-reverse-a-b-and-foldl-cons-b-a/2903 "2024-05-06T14:40:23Z")
I have the following code example. I am wondering if method1 is slower than method2? I want to write a benchmark program, but I don't have any prior experience in this. #lang racket (define (method1 a b) (append (rev… --- ## [Racket HYBRID meet-up: Saturday, 4 May, 2024 at 18:00 UTC](https://racket.discourse.group/t/racket-hybrid-meet-up-saturday-4-may-2024-at-18-00-utc/2868)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 3\ **Last updated:** [May 4, 2024, 8:39pm UTC](https://racket.discourse.group/t/racket-hybrid-meet-up-saturday-4-may-2024-at-18-00-utc/2868 "2024-05-04T20:39:15Z")
Racket HYBRID meet-up LONDON and ONLINE Saturday, 4 May, 2024 at 18:00 UTC This is a chance for folks to present their work in progress and chat in a relaxed atmosphere. At this event: Sid (@countvajhula ) will be … --- ## [Use Git directly for versioning?](https://racket.discourse.group/t/use-git-directly-for-versioning/2896)
**Author:** [@countvajhula](https://racket.discourse.group/u/countvajhula)\ **Replies:** 6\ **Last updated:** [May 3, 2024, 11:08pm UTC](https://racket.discourse.group/t/use-git-directly-for-versioning/2896 "2024-05-03T23:08:29Z")
I recently posted the discussion from a recent Qi meeting on the subject of versioning in the Racket package management ecosystem, and whether it would be useful to be able to indicate a Git version directly on the user … --- ## [Raco pkg install progress bars!](https://racket.discourse.group/t/raco-pkg-install-progress-bars/2897)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 0\ **Last updated:** [May 2, 2024, 6:56am UTC](https://racket.discourse.group/t/raco-pkg-install-progress-bars/2897 "2024-05-02T06:56:20Z")
Cool! I just went from v8.12 to nightly, and I'm seeing the fun new progress bars on raco pkg install. Very nice. [Previous page](https://racket.discourse.group/latest.md?page=28) [Next page](https://racket.discourse.group/latest.md?page=30)