This is probably an odd question: is there a way to make a function contract that checks a parameter at the time of function call? I’m guessing that some kind of chaperone is needed?

See #:pre in ->i

To clarify, I was referring to the README.md in the aforementioned fork, not the main frog repo.

@greg thanks for your efforts on Frog. I spent a few hours moving some old blog posts into it, and I think it will do nicely for what I need. Unless I stumble into some showstopper (highly unlikely), I expect I’ll move my main blog over to it. I noticed a comment (maybe on github?) about a forum, but what do you think about simply having a #frog channel in this Slack for Frog users to communicate? That seems pretty low friction to me.

Thanks for clarifying, but I did understand you were talking about the fork’s readme. I was just reminiscing.

I don’t have any thoughts about a #frog channel here. Probably I wouldn’t monitor it but if other folks find it useful that’s great.

The current “app treadmill” I’ve been on for some years now is Racket Mode. There’s still a lot to do, with that, and that’s about the limit of my focus lately.

Hi, so I am working on adding some functionality to a Racket package. I am trying to add a function to package “X”, a function such as (define (myBasicTestFunction) (printf "Hello from Package X")) My question is after I have updated the source file, how to I then build it so that the changes are “live”? So if I ran >racket myTestProg.rkt Which looks like #lang racket (require X) (myBasicTestFunction)

how did you install “X”? And where is the file that you edited?

X is any arbitrary package that comes with Racket under share/pkgs and the file is any source file in said package

Say that package X is sgl under share/pkgs/sgl and the file was sgl.rkt

so at the bottom of sgl.rkt I added ... (define (myBasicTestFunction) (printf "Hello from Package X"))

and now myTestProg.rkt would look like #lang racket (require sgl) (myBasicTestFunction)

so if I run >racket myTestProg.rkt it outputs >racket myTestProg.rkt myTestProg.rkt:3:1 myBasicTestFunction: unbound identifier in: myBasicTestFunction location...: myTestProg.rkt:3:1

How do I rebuild the package so that my changes are “live”?

raco setup --pkgs sgl might work, but more importantly, you should never edit any file in share/pkgs. Instead, run raco pkg update --clone sgl at your working directory to create a copy of sgl that you can edit.

gonna test and sign-into slack from the vm I am working in

ok so I know what you are saying about not editing share/pkgs, I read that in the documentation, I do run into problems when running raco pkg update --clone sgl however. >raco pkg update --clone sgl Inferred package name from given `--clone' path package: sgl given path: sgl Inferred package scope: installation raco pkg update: package is not currently installed from a repository package: sgl current installation: (catalog sgl)

I can just use git to clone the repo and then “point” raco to the local copy right?

It’s likely that you will get an installation conflict if you just use git to clone the repo fresh.

I installed Racket from source, which might explain why raco pkg update --clone sgl works for me and not for you. I don’t know what’s the right solution for you though.

Though this paragraph:

> This same approach will generally work if you’re starting from a distribution installer instead of the checkout of the Racket sources from the main Git repository. from https://docs.racket-lang.org/racket-build-guide/contribute.html

suggests that it should work…

I built racket from source also…. I downloaded it from https://download.racket-lang.org/ and selected Unix-Source + built packages and then ran mkdir build cd build ../configure make make install

Oh, by built from source, I meant clone Racket from GitHub.

If I were you, I will go with a different route:

• Download Minimal Racket from https://download.racket-lang.org/ (which does not come with sgl).
• git clone <https://github.com/racket/sgl.git>
• cd sgl
• /path/to/minimal-racket/bin/raco pkg install

Ok I will try that

does make clean remove the current installation of racket?

I don’t know.. I have never done that.

ok I just didn’t want to have to roll back the VM that far back

so should I download Source + built packages or just Source?

Oh, there’s no need to download source

Well, depends on what platform you are in.

For example, I’m using Mac OS, so I just download dmg installer

IIRC Linux has a .sh installer.

Note that this should be minimal Racket, not full Racket.

Good luck, I gotta go now.

yeah I got it

thanks for your help

So I have downloaded and installed minimal racket, cloned the package sgl, and installed it using raco pkg install. I can see it via raco pkg show which outputs Installation-wide: Package Checksum Source racket-lib 28d0cbe906278e8dc6549010f0f422c5bcde25f4 catalog racket-lib User-specific for installation "7.9": Package Checksum Source sgl link /home/mint/sgl [115 auto-installed packages not shown] anytime I make a change to a source file in the sgl directory i.e adding a basic function to sgl.rkt such as (define (myFunction) (printf "Hello from sgl")) I have been using raco setup --pkgs sgl to compile/build/etc the package. However, racket does not seem to reflect the changes that I have made to the source file. As demonstrated from so: $ racket Welcome to Racket v7.9 [bc]. > (require sgl) > (myFunction) ; myFunction: undefined; ; cannot reference an identifier before its definition ; in module: top-level ; [,bt for context] > How do I compile or build the source code that then is reflected in the actual racket runtime?

Did you provide myFunction?

And just to make sure we are on the same page, the racket executable starts the minimal Racket that you just downloaded, correct?

1. What do you mean by provide?
2. It is the only racket that is currently installed on the system so yes…

Sorry for the delayed responses I am making a pizza

Say you are editing https://github.com/racket/sgl/blob/master/main.rkt

If you change the code to:

#lang scheme/base (require (prefix-in gl- "sgl.rkt")) (provide (all-from-out "sgl.rkt") my-function) (define (my-function) (displayln "Hello from sgl")) Then you should be able to use my-function when you (require sgl).

ok I will test

so yeah that works!

Welcome to Racket v7.9 [bc]. > (require sgl) > (my-function) Hello from sgl >

Do you perhaps know why that works from main.rkt and not from sgl.rkt?

The file main.rkt prefixed all exported symbols from sgl.rkt with gl-

So try gl-myFunction?

But note that you need to provide from sgl.rkt too.

Alternatively, when you require, you should reference sgl.rkt via (require sgl/sgl)

For the latter, you don’t need to prefix symbols with gl-

I was reading about the prefix stuff but adding the function (define (my-function) (displayln "Hello from sgl")) to sgl.rkt and then calling it from racket still was not available even when (requiring sgl/sgl) Welcome to Racket v7.9 [bc]. > (require sgl/sgl) > (my-function) ; my-function: undefined; ; cannot reference an identifier before its definition ; in module: top-level ; [,bt for context] > (gl-my-function) ; gl-my-function: undefined; ; cannot reference an identifier before its definition ; in module: top-level ; [,bt for context] >

ok

I found out why

the signature inside of sgl.rkt needs to look like so (provide my-function) (define (my-function) (displayln "Hello from sgl")) and the calling site need to be like so (require sgl) (gl-my-function) Hello from sgl

Thank you for all your help I feel much better about the whole ordeal