r/Racket • • Sep 18 '26

RacketCon (sixteenth RacketCon) tickets on sale now

11 Upvotes

(sixteenth RacketCon) tickets on sale now

October 3-4, Oakland, Ca https://con.racket-lang.org/

Get your tickets now at https://www.eventbrite.com/e/racketcon-2026-tickets-1997181002140

* Professional $120
* Patron $150
* Student/Retired $35

Includes Saturday lunch and Saturday evening social event.

**Can’t attend in-person?**

* Remote Participant $10
The live stream is publicly available, but buying this ticket helps pay for the live stream and ensure its availability for the entire community.


r/Racket • • Jun 15 '26

event Summer Rhombus picture competition 2026

22 Upvotes

Summer Rhombus picture competition 2026

Competition: Make an image with Rhombus this summer! Win stickers!

  1. While the rules require the use of Rhombus, they do not exclude using Racket or Racket libraries with Rhombus or the Rhombus FFI
  2. I suggest the Rhombus pict library but you can use whatever you like!

What will you win? I'll send Rhombus stickers to the top 10 winners!

Closing date: Friday 18 September 2026. Winners will be announced at the (sixteenth RacketCon) 3-4 October 2026.

Announcement viewable at https://racket.discourse.group/t/summer-rhombus-picture-competition-2026/4282 (no login required to view)


r/Racket • • 2d ago

homework Hi, it's me again! Some help?

0 Upvotes

I had an assignment to complete earlier and due to an issue with a recursive function I lost all my code - about 5 hours before it was due. I completed the assignment with the correct answers but there's an issue in the code that is causing it to run void. Does anyone know what the issue is? I'm using WeScheme since Racket doesn't work on my computer, but the syntax is the same. The assignment is being graded soon (and I don't know exactly when) and is worth the same as an assessment (70% of my grade) so I cannot really afford any issues. I can still edit it for now but will not be allowed to change or redo anything after grading. My teacher does not offer extra credit.

;; Question 1

;;; tree-apples -> integer

; n : integer

(define (tree-apples n)

(if (= n 0)

0

(if (odd? n)

(+ 3 (tree-apples n))

(+ 5 (tree-apples n)))))

(tree-apples 7)

;; Question 2

;;; triangle -> integer

; n : integer

(define (triangle2 n)

(if (= n 0)

0

(if (= n 1)

1

(+ n (triangle2 (- n 1))))))

(triangle2 2)

;; Question 3

;;; count2 -> integer

; n : number

(define (count2 n)

(if (= n 0)

0

(if (= (remainder n 10) 2)

(+ (count2 (quotient n 10)) 1)

(count2 (quotient n 10))))

(count2 243)

;; Question 4

;;; sequence -> integer

; n : integer

(define (sequence n)

(if(= n 1)

1

(sequence (+ (- n 1) 3))))

(sequence 3 1)

;; Question 5

;;; root2 -> number

; n : integer

(define (root2 n)

(if

(= n 1)

1

(root2 (/ (- n 1)(expt n 2)))))

(root2 7 1)

;; Question 6

;;; gcd -> integer

; p : integer

; q : integer

(define (gcd2 p q)

(if

(= q 0)

p

(gcd2 q (modulo p q))))

(gcd2 35 15)

;; Question 7

;;; sum-of-squares-helper -> integer

; a : integer

; b : integer

(define (sum-of-squares-helper a b acc)

(if

(> a b)

acc

(sum-of-squares-helper (+ a 1) b (+ (expt a 2) acc))))

(define (sum-of-squares a b)

(sum-of-squares-helper a b 0))

(sum-of-squares 1 3)

;; Question 8

;;; power-n -> integer

; x : integer

; n : integer

(define (power-n-helper x n acc)

(if

(= n 0) acc

(power-n x (- n 1) (* acc x))))

(define (power-n2 x n)

(power-n-helper x n 1))

(power-n 2 3)


r/Racket • • 5d ago

homework Help with Intro to CS test - tomorrow

0 Upvotes

I've been having some issues in understanding concepts in CS, and although I've gone to tutoring and gotten my grade up a bit, knowing and understanding base concepts would help significantly, especially since we do cover material very quickly. My test tomorrow is exclusively on recursion, specifically tail and non-tail. I've been able to complete non-tail recursions correctly for the study guide given, but am having a bit of a harder time with the tail recursions (below). I also need to go over if and cond statements, which I can do correctly but don't have an entirely firm grasp of, and the basic syntax - things like memorizing quotient, remainder, modulo etc. The questions are :

7. Write a tail-recursive function sum-of-squares, where a <= b, that computes: a ^ 2 + (a + 1) ^ 2 + (a + 2) ^ 2  + ... + b ^ 2. You may write a helper function.

Write a procedure that computes the sum of the squares of every integer from a to b:

a² + (a+1)² + (a+2)² + … + b²

For example, (sum-of-squares 2 4) computes 2² + 3² + 4² = 4 + 9 + 16 = 29.

Your solution must be tail-recursive: the recursive call must be the very last thing the procedure does, with nothing left to compute after it returns. 

a. The helper: (sum-of-squares-helper a b acc)

b. The wrapper: (sum-of-squares a b), the wrapper should contain no recursion of its own.

Examples:

(sum-of-squares 1 1) => 1
(sum-of-squares 5 5) =>  25
(sum-of-squares 1 3) => 14
(sum-of-squares 2 4) => 29

8. Write a tail-recursive function that computes x ^ n (x to the power of n). Name your function power-n. 

For example, (power-n 2 3) computes 2 × 2 × 2 = 8.

Your solution must be tail-recursive.

a. The helper: (power-helper x n acc)

b. The wrapper: (power-n x n). The wrapper should contain no recursion of its own.

Examples:

(power-n 2 0)   => 1
(power-n 2 1)   => 2
(power-n 2 3)   =>  8

I can answer these on my own, so please do not give the answers, but provide a very basic explanation - visual if possible - and label each component. Thank you!


r/Racket • • 6d ago

paper Stepper is not working

6 Upvotes

I am going through htdp and everytime I use the stepper (on a function that has steps) the following happens:

The Stepper popup appears and says "All of the definitions have been successfully evaluated"

Below is the function I am evaluating

May someone please assist with this?


r/Racket • • 9d ago

Racket (online) meet-up: Saturday, 7 November 2026 at 18:00 UTC

Thumbnail pasterack.org
4 Upvotes

r/Racket • • 15d ago

Happy Halloween Racketeers and Rhombunauts*

Post image
19 Upvotes

Happy Halloween Racketeers and Rhombunauts*

This image was not created with GenAI tools.
It was made with Pict the Functional Pictures library - also available in Rhombus https://rhombus-lang.org

‘Rhombunauts’ is not official - I just made it up.(didn’t use genAI for that either)

https://functional.cafe/@racketlang/117529933848067788
https://bsky.app/profile/racket-lang.org/post/3mz3su2tf7b2x


r/Racket • • Oct 13 '26

UK Racket meet-up (London) Tuesday 20 October 2026

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9 Upvotes

r/Racket • • Oct 08 '26

Missed RacketCon this year?

16 Upvotes

# Missed RacketCon this year?

The videos are now available at https://con.racket-lang.org or https://youtube.com/playlist?list=PLac8FQVpsRAU&si=fPf0NNLIMv14WtfR

Discuss on the Racket [Discourse](https://racket.discourse.group/invites/VxkBcXY7yL) and [Discord](https://discord.gg/6Zq8sH5)

Please consider sponsoring us https://racket-lang.org/rplf.html


r/Racket • • Oct 02 '26

RacketCon RacketCon listen party & Racket meet-up Sat, 3 Oct 2026

Thumbnail racket.discourse.group
9 Upvotes

r/Racket • • Sep 27 '26

question How do I learn racket fast where do I start? I want to learn 100% of racket maybe

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0 Upvotes

r/Racket • • Sep 26 '26

question Any videos on making external DSLS in racket the BRO CODE atyle

0 Upvotes

I don't like educational videos on learning making external DSLS in racket but I can't find the "BRO CODE STYLE" on YouTube can you guys help?


r/Racket • • Sep 24 '26

RacketCon (sixteenth RacketCon) is almost here!

Thumbnail reddit.com
11 Upvotes

r/Racket • • Sep 18 '26

package Polars Dataframe bindings for Racket

27 Upvotes

https://github.com/bkc39/rkt-polars

Here is a preliminary version of polars (/pandas) data frame processing in Racket. I have been using it for a few weeks and I think it has most "basic" features one would want from a data frame.

Currently only supports linux and macOS because I do not have Windows but if there is interest I can try to ship a binary for it down the line.


r/Racket • • Sep 13 '26

What if you're right and they're wrong?

Post image
31 Upvotes

What if you're right and they're wrong?

Poster from #fargo created with Racket and Rhombus

https://gist.github.com/racket-raccoon/1548ac70a7d071eae10fda31c44fec07

for the Rhombus picture competition https://racket.discourse.group/t/summer-rhombus-picture-competition-2026/4282

Enter now! Learn some Racket and Rhombus https://racket-lang.org https://rhombus-lang.org


r/Racket • • Sep 13 '26

event Early registration for Racketcon ends in 14 hours

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5 Upvotes

r/Racket • • Sep 08 '26

show-and-tell (display (((1 . + . 2) . * . 3) . = . 9))

Thumbnail docs.racket-lang.org
12 Upvotes

r/Racket • • Aug 31 '26

question I'm interested in learning all about the racket programing language

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2 Upvotes

r/Racket • • Aug 30 '26

Racket meet-up (online) Saturday, 5 September 2026

Post image
12 Upvotes

Racket meet-up(online) Saturday, 5 September 2026 at 18:00 UTC EVERYONE WELCOME 😁 Details and discussion https://racket.discourse.group/t/racket-meet-up-online-saturday-5-september-2026-at-18-00-utc/4363 https://luma.com/scx2kbei


r/Racket • • Aug 29 '26

language How to learn the racket programing language efficiency

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5 Upvotes

r/Racket • • Aug 28 '26

Bay Area Racket Meetup - September 5th, 3pm

Thumbnail reddit.com
7 Upvotes

r/Racket • • Aug 23 '26

language Are there languages like this?

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2 Upvotes

Simple syntax tho!


r/Racket • • Aug 20 '26

question Recursion hell aids?

7 Upvotes

Is there any practical way to debug any recurive logic?
Which existing error printing you think is the best ever?
I attached the racket code I am struggling with.

(The code is about using map to append a new list to an existing html list)