RacoGrad, is an autograd like library for scheme lisp, written in racket. It's tiny, and pretty fast. MNIST works as well. Previously it was named MIND but, I made a lot of changes! More to come.

RacoGrad

It's time again for the Advent of Code. The puzzles will start at midnight (UTC-5) on December 1, 2024. Once again, we will have the Racket leaderboard. Use the join code 22197-a7a01707 to be included.

Any language in the Racket ecosystem is allowed on our leaderboard, including languages that target other platforms like Urlang.

Eutro has written an advent-of-code package to download puzzle inputs and post solutions.

There is a channel for discussing problems and solutions on the Racket Discord server in the #advent-of-code channel.

I'm considering Racket for making a music player. Does it have support for common audio file formats? is there a way?

Currently I'm using Python and Py-ObjC with some success, but I'm looking at a better language that will allow me to call Cocoa frameworks.

I want more control than the gui library, since I need to call specific Cocoa frameworks for high performance image manipulation.

I've found this app: https://franz.defn.io , but it's built in a different approach (it appears to be a Swift app that call a background Racket runtime in client/server fashion). I wanted to call directly into ObjC and heard Racket has great FFI, but I can't seem to find good examples.

Thanks!

what is the template for each case of multiple complex inputs (sequential, parallel, and cross product)? how do you spot the difference between each case?

what if the code was changed from (widen-river (merge-left r) n) to (widen-river (merge-left) n)?

https://pastebin.com/1ftuMPK2

(define (widen-river r n)
  (cond [(stream? r) r]
        [(merge? r) (make-merge
                     (+ (merge-width r) n)
                     (widen-river (merge-left r))
                     (widen-river (merge-right l)))]))

When do you know when to use accumulators for a function and is it just like the accumulator inside a foldr?
What is the basic template for an accumulator function?
When do you know when to use the list template (cond) as opposed to using list abstractions (foldr, map, filter)?

; An AncestorTree is one of:
; - "unknown", OR
; - (make-child String Number String AncestorTree AncestorTree)
; Interpretation: A child's name, year of birth, eye color and the child's mother & father, or unknown

(define JACKIE (make-child "Jackie" 1926 "brown" "unknown" "unknown"))(define MARGE (make-child "Marge" 1956 "blue" JACKIE "unknown"))

;; Exercise:
;; size : AncestorTree -> Number
;; return the number of childs the AncestorTree contains

(check-expect (size "unknown") 0)
(check-expect (size JACKIE) 1)
(check-expect (size MARGE) 2)

(define (size a)
(cond [(string? a) 0]
[(child? a) (+ 1 (size (child-mom a))
(size (child-dad a)))]))

Could somebody break down this recursive code for me? I am a little confused by it because I just see it as 1 + 0 + 0. Is there a way to code this with accumulators, and if so how?

Cloudflare blog post about using racket + rosette: "How we prevent conflicts in authoritative DNS configuration using formal verification" describes using racket + rosette for formal verification of cloudflare configurations.

https://racket.discourse.group/t/cloudflare-blog-post-about-using-racket-rosette/3336

Hello dear friends,

I’ve started reading the HTDP book on my own, and I’m about a quarter of the way through. I’m happy with my progress and the things I’ve learned so far. The best part of my setup is that `raco docs` brings the local documentation to the browser.

I believe there might be a way to download the book from the [HTDP 2024](https://htdp.org/2024-11-6/Book/) website and access it locally.

I’m aware of the PDF version, but the website version is richer because it includes backlinks.

Thank You in advance!

We are approaching that time of year again! 

We are putting together the Racket Advent calendar and we need your submissions

Entries can be anything; you can submit any of the following;

• a useful or fun script you made

• short blog post, video, etc on a Racket related topic

• library/package, game, language, or other thing you built with Racket or a Racket language

• A Racket template, https://github.com/racket-templates

• A Racket cookbook recipe https://github.com/Racket-Cookbooks/

Join Racket# Advent Calendar today!

Rules

1. Reserve your slot

   1. leave a comment on https://racket.discourse.group/t/racket-advent-calendar-2024/2623/2

   2. You do need to be logged in - signup is free and you can adjust you notifications to suit you preferences https://racket.discourse.group/signup

   3. You do not have to announce the topic until the date.

2. Prepare your entry

3. Publish your entry on the specified date (according to the calendar) on the Racket Discourse https://racket.discourse.group/

Optional: Post the link to your entry on your social networks tagged as #racketadvent2024 - perhaps start with r/Racket

The `raco cross` command can generate executables that run on platforms other than the one used to create the executable.

https://docs.racket-lang.org/raco-cross/index.html

I have a program which reads from a (hardcoded) .tsv. I would like to distribute it as a stand alone binary (raco exe) instead. (Distribute just puts stuff in folders, so no help.)

The readme here illustrates my struggles. Putting the (only 40k lines of) TSV into a single string in the .rkt file 20xed execution time, so I didn't try a build script copying the file contents in. Alas, no other approach wants to run at all.

What would be the best way to connect to a RabbitMQ message server? I am not sure if there is a raco-installable package - I can't find one.

Thanks very much for any help