# Latest **URL:** https://racket.discourse.group/latest.md?page=45 [Latest](https://racket.discourse.group/latest.md) · [Categories](https://racket.discourse.group/categories.md) · [Tags](https://racket.discourse.group/tags.md) **Page:** 46 --- ## [Correctly using directory scope to install packages](https://racket.discourse.group/t/correctly-using-directory-scope-to-install-packages/1921)
**Author:** [@Occhioverde](https://racket.discourse.group/u/Occhioverde)\ **Replies:** 4\ **Last updated:** [May 21, 2023, 7:39am UTC](https://racket.discourse.group/t/correctly-using-directory-scope-to-install-packages/1921 "2023-05-21T07:39:14Z")
Good morning. I'm currently experimenting with directory scope in Raco with the objective of managing packets in a more efficient way, but I'm stuck with a strange behavior that I can't seem to understand just by lookin… --- ## [How to distribute programs that require Gregor?](https://racket.discourse.group/t/how-to-distribute-programs-that-require-gregor/1948)
**Author:** [@Dexter](https://racket.discourse.group/u/Dexter)\ **Replies:** 7\ **Last updated:** [May 21, 2023, 12:21pm UTC](https://racket.discourse.group/t/how-to-distribute-programs-that-require-gregor/1948 "2023-05-21T12:21:41Z")
Hello there, I had asked a question related to Gregor, and the fact that it is not currently possible to run a Racket program compiled on one system with Gregor on another system, if Gregor and Racket haven't been insta… --- ## [Accessing C constants from Racket](https://racket.discourse.group/t/accessing-c-constants-from-racket/1933)
**Author:** [@shawnw](https://racket.discourse.group/u/shawnw)\ **Replies:** 6\ **Last updated:** [May 21, 2023, 6:53am UTC](https://racket.discourse.group/t/accessing-c-constants-from-racket/1933 "2023-05-21T06:53:49Z")
The scenario: Trying to use the Racket FFI to call a C functions that have arguments whose values should be taken from one or more #define'd constants, that might be different numbers on different OSes, making just hard-… --- ## [Suggestions on compiling DSL to LLVM](https://racket.discourse.group/t/suggestions-on-compiling-dsl-to-llvm/1953)
**Author:** [@Ivan\_D](https://racket.discourse.group/u/Ivan_D)\ **Replies:** 2\ **Last updated:** [May 17, 2023, 8:15am UTC](https://racket.discourse.group/t/suggestions-on-compiling-dsl-to-llvm/1953 "2023-05-17T08:15:34Z")
Hello, Racketeers! I am trying to implement a small DSL targeted to LLVM and am having trouble finding the right resources. I have looked into several LLVM projects, but most of them appear to be abandoned or lack suffi… --- ## [Function not reading all the element in a list](https://racket.discourse.group/t/function-not-reading-all-the-element-in-a-list/1918)
**Author:** [@louberlu](https://racket.discourse.group/u/louberlu)\ **Replies:** 10\ **Last updated:** [May 13, 2023, 7:11pm UTC](https://racket.discourse.group/t/function-not-reading-all-the-element-in-a-list/1918 "2023-05-13T19:11:30Z")
Hi, I am not an English native, so, if you see any fault or incoherence, please correct me. I'm currently learning SCHEME language, and our teacher told us to create two programs: one which counts the number of occurre… --- ## [MB at the right in the status line of DrRacket](https://racket.discourse.group/t/mb-at-the-right-in-the-status-line-of-drracket/1934)
**Author:** [@joskoot](https://racket.discourse.group/u/joskoot)\ **Replies:** 2\ **Last updated:** [May 13, 2023, 10:52am UTC](https://racket.discourse.group/t/mb-at-the-right-in-the-status-line-of-drracket/1934 "2023-05-13T10:52:51Z")
What amount of memory is shown at the right in the status line of DrRacket? The Task Manager of Windows always shows a consumption of 200 to 300 MB more, even immediately after opening DrRacket without file. --- ## [How to reuse current-input-port after piping input from stdin](https://racket.discourse.group/t/how-to-reuse-current-input-port-after-piping-input-from-stdin/1926)
**Author:** [@LessThanZero](https://racket.discourse.group/u/LessThanZero)\ **Replies:** 7\ **Last updated:** [May 13, 2023, 5:47am UTC](https://racket.discourse.group/t/how-to-reuse-current-input-port-after-piping-input-from-stdin/1926 "2023-05-13T05:47:09Z")
Consider this test.rkt program: #lang racket (let loop () (display "\> ") (define input (read-line)) (displayln input) (loop)) When invoked as racket test.rkt it will just display whatever it gets from stdin: … --- ## [Uninstalling Racket From Shell Script and Installing Racket from Apt](https://racket.discourse.group/t/uninstalling-racket-from-shell-script-and-installing-racket-from-apt/1943)
**Author:** [@evdubs](https://racket.discourse.group/u/evdubs)\ **Replies:** 0\ **Last updated:** [May 12, 2023, 8:56pm UTC](https://racket.discourse.group/t/uninstalling-racket-from-shell-script-and-installing-racket-from-apt/1943 "2023-05-12T20:56:18Z")
A while ago, I installed Racket from the website (https://download.racket-lang.org/). I did the non-Unix distribution, so it did not come with the racket-uninstall script. I later decided to install Racket from apt so th… --- ## [Racket version 8.9 is now available from https://download.racket-lang.org/](https://racket.discourse.group/t/racket-version-8-9-is-now-available-from-https-download-racket-lang-org/1941)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 5\ **Last updated:** [May 12, 2023, 4:34pm UTC](https://racket.discourse.group/t/racket-version-8-9-is-now-available-from-https-download-racket-lang-org/1941 "2023-05-12T16:34:10Z")
Racket version 8.9 Racket version 8.9 is now available from https://download.racket-lang.org/ What's new As of this release: The HtDP student languages come with checked signatures. Programmers can express signatu… --- ## [Julia-style multiple dispatch](https://racket.discourse.group/t/julia-style-multiple-dispatch/1936)
**Author:** [@a11ce](https://racket.discourse.group/u/a11ce)\ **Replies:** 2\ **Last updated:** [May 11, 2023, 4:27am UTC](https://racket.discourse.group/t/julia-style-multiple-dispatch/1936 "2023-05-11T04:27:56Z")
Multiple dispatch is the ability to define multiple implementations of a function, chosen at runtime based on the arguments to each call. The dispatch package brings this to Racket, allowing lexically separate but associ… --- ## [Finding srcloc for modules in fully-expanded code](https://racket.discourse.group/t/finding-srcloc-for-modules-in-fully-expanded-code/1932)
**Author:** [@greghendershott](https://racket.discourse.group/u/greghendershott)\ **Replies:** 2\ **Last updated:** [May 10, 2023, 5:25pm UTC](https://racket.discourse.group/t/finding-srcloc-for-modules-in-fully-expanded-code/1932 "2023-05-10T17:25:26Z")
TL;DR: I can't figure out how to get original srclocs for spliced module+ forms in fully-expanded code. Background: Racket Mode has a run command much like Dr Racket: Run the module for the file, as well as optionally … --- ## [Call for Papers: ACM Workshop on Functional Art, Music, Modelling and Design (Deadline June 1)](https://racket.discourse.group/t/call-for-papers-acm-workshop-on-functional-art-music-modelling-and-design-deadline-june-1/1817)
**Author:** [@mike](https://racket.discourse.group/u/mike)\ **Replies:** 1\ **Last updated:** [May 10, 2023, 11:01am UTC](https://racket.discourse.group/t/call-for-papers-acm-workshop-on-functional-art-music-modelling-and-design-deadline-june-1/1817 "2023-05-10T11:01:16Z")
=============================================================================== 11th ACM SIGPLAN International Workshop on Functional Art, Music, Modelling and Design (FARM) Call for Papers, Demos, and Performanc… --- ## [Call for Papers, Functional Software Architecture - FP in the Large](https://racket.discourse.group/t/call-for-papers-functional-software-architecture-fp-in-the-large/1813)
**Author:** [@mike](https://racket.discourse.group/u/mike)\ **Replies:** 4\ **Last updated:** [May 10, 2023, 11:01am UTC](https://racket.discourse.group/t/call-for-papers-functional-software-architecture-fp-in-the-large/1813 "2023-05-10T11:01:00Z")
====================================================================== \*\*\* CALL FOR PAPERS -- FUNARCH 2023 \*\*\* First ACM SIGPLAN Workshop on Functional Software Architecture - FP in the Large 8th September… --- ## [Create New data types](https://racket.discourse.group/t/create-new-data-types/1911)
**Author:** [@mohanr](https://racket.discourse.group/u/mohanr)\ **Replies:** 6\ **Last updated:** [May 9, 2023, 2:09am UTC](https://racket.discourse.group/t/create-new-data-types/1911 "2023-05-09T02:09:51Z")
Hi, I tried to port a Haskell data type to racket. Can I create these types ? What is the equivalent racket structure ? (define-struct Error i e (\[ errorOffset : Offset \] \[ error : ErrorType… --- ## [Racket Mode emacs, test coverage not working on match?](https://racket.discourse.group/t/racket-mode-emacs-test-coverage-not-working-on-match/1898)
**Author:** [@jlucero805](https://racket.discourse.group/u/jlucero805)\ **Replies:** 4\ **Last updated:** [May 6, 2023, 2:50pm UTC](https://racket.discourse.group/t/racket-mode-emacs-test-coverage-not-working-on-match/1898 "2023-05-06T14:50:41Z")
In racket-mode for emacs, there is a command racket-test, that can be run with test coverage using C-u C-u C-c C-t (Racket Mode). When running this, everything gets covered, besides match expressions. When using other … --- ## [How to set the stderr correctly?](https://racket.discourse.group/t/how-to-set-the-stderr-correctly/1922)
**Author:** [@Antigen-11](https://racket.discourse.group/u/Antigen-11)\ **Replies:** 2\ **Last updated:** [May 5, 2023, 12:21pm UTC](https://racket.discourse.group/t/how-to-set-the-stderr-correctly/1922 "2023-05-05T12:21:41Z")
According to the racket reference, When provided as a port, stdout is used for the launched process’s standard output, stdin is used for the process’s standard input, and stderr is used for the process’s standard error… --- ## [Racket v8.8 release](https://racket.discourse.group/t/racket-v8-8-release/1693)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 13\ **Last updated:** [May 5, 2023, 3:53am UTC](https://racket.discourse.group/t/racket-v8-8-release/1693 "2023-05-05T03:53:34Z")
Racket version 8.8 is now available from https://download.racket-lang.org/ As of this release: The dependent contract form, -\>i, supports a #:param element that specifies dependencies for parameter values that are… --- ## [Eval in a function](https://racket.discourse.group/t/eval-in-a-function/1896)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 21\ **Last updated:** [May 3, 2023, 10:00am UTC](https://racket.discourse.group/t/eval-in-a-function/1896 "2023-05-03T10:00:01Z")
hello, how can i make this eval working as in toplevel: #lang racket (define (foo) (define x 7) (eval (quote x))) Welcome to DrRacket, version 8.7 \[cs\]. Language: racket, with debugging; memory limit: 8192 MB. (… --- ## [Racket v8.9 Release Thread](https://racket.discourse.group/t/racket-v8-9-release-thread/1852)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 5\ **Last updated:** [May 2, 2023, 9:54pm UTC](https://racket.discourse.group/t/racket-v8-9-release-thread/1852 "2023-05-02T21:54:26Z")
The release process for v8.9 will begin in about 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: - 7th: Branch day, merge… --- ## [Is typed racket compilation slow when using prefab structs?](https://racket.discourse.group/t/is-typed-racket-compilation-slow-when-using-prefab-structs/1904)
**Author:** [@sebas](https://racket.discourse.group/u/sebas)\ **Replies:** 9\ **Last updated:** [May 2, 2023, 6:24pm UTC](https://racket.discourse.group/t/is-typed-racket-compilation-slow-when-using-prefab-structs/1904 "2023-05-02T18:24:12Z")
I was trying to write an AST using something like this: (define-type Exp (U Const Op ...)) (struct Const (...) #:prefab) without prefab it is ok, but when I added prefab it takes more than a minute from clicking Run t… --- ## [Can I change keyword syntax?](https://racket.discourse.group/t/can-i-change-keyword-syntax/1907)
**Author:** [@RobertC](https://racket.discourse.group/u/RobertC)\ **Replies:** 1\ **Last updated:** [May 1, 2023, 7:39pm UTC](https://racket.discourse.group/t/can-i-change-keyword-syntax/1907 "2023-05-01T19:39:44Z")
I'm new and poking around in the docs. Is there a way to adjust the language so that keywords are :foo, instead of #:foo? I really like using keyword arguments, but I don't like the look of the latter. --- ## [For\* remains looping when an inner suequence already is empty](https://racket.discourse.group/t/for-remains-looping-when-an-inner-suequence-already-is-empty/1901)
**Author:** [@joskoot](https://racket.discourse.group/u/joskoot)\ **Replies:** 3\ **Last updated:** [May 1, 2023, 7:46am UTC](https://racket.discourse.group/t/for-remains-looping-when-an-inner-suequence-already-is-empty/1901 "2023-05-01T07:46:38Z")
Consider: #lang racket/base (define r '()) (time (for\* ((i (in-range 10000000)) (k (in-list r))) (writeln (list i k)))) (time (for\* ((i (in-range 1 )) (k (in-list r))) (writeln (list i k)))) Produces: cpu time: … --- ## [Coordinate \`generator?\` with \`eval\`?](https://racket.discourse.group/t/coordinate-generator-with-eval/1900)
**Author:** [@Antigen-11](https://racket.discourse.group/u/Antigen-11)\ **Replies:** 4\ **Last updated:** [May 1, 2023, 12:20am UTC](https://racket.discourse.group/t/coordinate-generator-with-eval/1900 "2023-05-01T00:20:45Z")
I want to use eval to produce a generator and enforce generator? on the result of the evaluation. But it seems that the result is just an ordinary procedure instead of a generator. Welcome to Racket v8.8.0.8 \[cs\]. \> (d… --- ## [Untitled Maze Game (Pacman)](https://racket.discourse.group/t/untitled-maze-game-pacman/1838)
**Author:** [@soegaard](https://racket.discourse.group/u/soegaard)\ **Replies:** 2\ **Last updated:** [April 30, 2023, 8:33pm UTC](https://racket.discourse.group/t/untitled-maze-game-pacman/1838 "2023-04-30T20:33:32Z")
Hi All, At RacketFest I quickly showed a slide with a Pacman game. The game shows how to use Sketching to make a retro style game. To get a consistent look, all drawing operations is redirected to a small bitmap of… --- ## [Racket meet-up Saturday 6 May at 18:00 UTC :racket:](https://racket.discourse.group/t/racket-meet-up-saturday-6-may-at-18-00-utc/1757)
**Author:** [@spdegabrielle](https://racket.discourse.group/u/spdegabrielle)\ **Replies:** 0\ **Last updated:** [April 29, 2023, 6:00pm UTC](https://racket.discourse.group/t/racket-meet-up-saturday-6-may-at-18-00-utc/1757 "2023-04-29T18:00:11Z")
Racket meet-up Saturday 6 May at 18:00 UTC :racket: At this meet-up: Show and tell News & rumours AOB #lang rage emoji This meet-up will be held at https://meet.jit.si/Racketmeet-up (this is our first time using… --- ## [Function contracts for multiple return values](https://racket.discourse.group/t/function-contracts-for-multiple-return-values/284)
**Author:** [@badkins](https://racket.discourse.group/u/badkins)\ **Replies:** 13\ **Last updated:** [April 27, 2023, 1:26pm UTC](https://racket.discourse.group/t/function-contracts-for-multiple-return-values/284 "2023-04-27T13:26:43Z")
I would like to specify the following (which doesn't work) for the return values of a function: (or/c (values t1 t2) (values t3 t4)) In other words, I'd like to verify that either the function returns two values … --- ## [Macro syntax error in some Scheme](https://racket.discourse.group/t/macro-syntax-error-in-some-scheme/1895)
**Author:** [@damien\_mattei](https://racket.discourse.group/u/damien_mattei)\ **Replies:** 2\ **Last updated:** [April 27, 2023, 1:15pm UTC](https://racket.discourse.group/t/macro-syntax-error-in-some-scheme/1895 "2023-04-27T13:15:02Z")
hello, why this macro good for Guile is not correct for Racket or Chicken: (define-macro (quote-all . Largs) (if (null? Largs) \`(quote ,Largs) \`(cons (quote ,(car Largs)) (quote-all ,@(cdr Largs))))) err… --- ## [Unable to create a Windows registry 'folder'](https://racket.discourse.group/t/unable-to-create-a-windows-registry-folder/1893)
**Author:** [@Dexter](https://racket.discourse.group/u/Dexter)\ **Replies:** 4\ **Last updated:** [April 26, 2023, 10:23pm UTC](https://racket.discourse.group/t/unable-to-create-a-windows-registry-folder/1893 "2023-04-26T22:23:51Z")
I tried every possible combination of params to write-resource to no avail. All I want to do is create a folder in HKEY\_CLASSES\_ROOT, and write entries into it. I tried: (write-resource "HKEY\_CLASSES\_ROOT\\\\MyFolder" "… --- ## [Need! More! Stickers!](https://racket.discourse.group/t/need-more-stickers/1697)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 9\ **Last updated:** [April 26, 2023, 5:11am UTC](https://racket.discourse.group/t/need-more-stickers/1697 "2023-04-26T05:11:39Z")
I need more racket stickers. I could shop around and set this up myself, but I'm guessing someone else has already done it? I do see ... but this seems a wee bit expensive. John --- ## [Yay fmt ! Title must be 15 chars. Yay Fmt again!](https://racket.discourse.group/t/yay-fmt-title-must-be-15-chars-yay-fmt-again/1889)
**Author:** [@jbclements](https://racket.discourse.group/u/jbclements)\ **Replies:** 4\ **Last updated:** [April 25, 2023, 10:30pm UTC](https://racket.discourse.group/t/yay-fmt-title-must-be-15-chars-yay-fmt-again/1889 "2023-04-25T22:30:26Z")
Apropos of writing-code-to-write-exams-and-assignments, I'm super-on-board with fmt, and I can't wait until the unstable interface becomes more stable. For now I'm just going to use it anyway.... Again, many thanks for … [Previous page](https://racket.discourse.group/latest.md?page=44) [Next page](https://racket.discourse.group/latest.md?page=46)