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Last Week in Pony February 12, 2023

This week, we are introducing a new regular entry for Last Week in Pony: “Community Resource Highlight”. The new section is replacing our previous “Highlighted Issues” section.

Ryan Hagenson and I discussed “Highlighted Issues” and decided that given how little traction we saw from the community picking up issues to work on the time he invests in each Last Week in Pony would be better spent on other content; our first stab at that content is “Community Resource Highlight”.

We’d love to hear your feedback in the Last Week in Pony stream on the Ponylang Zulip. Do you think the “Community Resource Highlight” will bring you value? Is there something else you’d rather see? Heck, perhaps even something you want to contribute? Let us know. If you aren’t getting value from LWIP then, it’s kind of pointless for us to spend time working on it. So, let us know and in the meantime, kick back, relax, put on John Lee Hooker’s “The Real Folk Blues” and get ready for the Super Bowl later today.

Items of Note

github_rest_api library

The Pony core team has release version 0.1.0 of the github_rest_api library. It’s an alpha-level library for working with GitHub’s REST API. Expect there to bugs and API changes. Those caveats aside, as the examples demonstrate, it is useful for some parts of the API surface already.

“New” JSON library

The json package has been removed from the standard library and now as a new home at

Exploring Ponylang libraries

We’ve added a topic on GitHub “pony-core-team-library” that will be added to all Pony libraries maintained by the Pony core team. Hopefully this makes it a little easier to find fully supported libraries. You can still go through the list of ponylang organization repositories, but that includes a lot of non-library content as well.

Pony Development Sync

Audio from the February 7th, 2023 sync is available.

Sync had a short agenda this week. Only a couple PRs and new issues to go over. Most of the time was spent going over an interesting Pony LLVM IR hacking problem that Nicolai Stawinoga joined the call to discuss. It’s an interesting project he has going on and if LLVM IR spelunking is your thing, have a watch.

Yup, “a watch” because this week’s sync comes with video so you can see all the shared screen fun that is the LLVM IR spelunking that starts sometime around 11 minutes into the call.

If you are interested in attending a Pony Development Sync, please do! We have it on Zoom specifically because Zoom is the friendliest platform that allows folks without an explicit invitation to join. Every week, a development sync reminder with full information about the sync is posted to the announce stream on the Ponylang Zulip. You can stay up-to-date with the sync schedule by subscribing to the sync calendar. We do our best to keep the calendar correctly updated.

Office Hours

We have an open Zoom meeting every Friday for the community to get together and well, do whatever they want. In theory, Sean T. Allen “owns” the meeting and will often set an agenda. Anyone is welcome to show up and participate. Got a Pony related problem you need help solving and prefer to do it synchronously? Give Office Hours a try.

The first 40 minutes or so of Office Hours were all over the place covering a variety of “computer adjacent” topics and then…

..and then Adrian Boyko blew it all up by bringing up subtyping and subsumption and he and Jason Carr had an extended conversation where Adrian asked a bunch of questions which Jason answered. Jason also gave his opinion on some type system changes he believes would be improvements and that he would like to see. George Steed’s A Principled Design of Capabilities in Pony was part of the jumping off into the larger type system conversation.

There was a large amount of type system related conversation that flowed from there. Too much to recap. If you are interested in type system related conversation, you should attend Office Hours meetings sometimes and you might get to exercise that inner nerd.

In order to get the last sentence correct, your author asked if he should use “geek” or “nerd” and then mentioned that “geek” came from “Geek Show” and well, that lead to o my, another long tangent.

We finally concluded with a conversation between Sean Allen and Red Davies about how to test the “Add support for the llvm: use scheme” PR.

Does any or all of that sound interesting, if yes, you should join us some time, there’s a calendar you can subscribe to to stay up-to-date with the schedule. We do our best to keep the calendar up-to-date.

And if it doesn’t sound interesting, you can join and steer the conversation in directions you find interesting, so really, there’s no excuse to not attend!


Community Resource Highlight

We like to take a moment in each Last Week in Pony to highlight a community resource. There are many community resources that can go unappreciated until just the right time when someone hops into the Ponylang Zulip asking a question or facing a problem we have all had at one time or another. Well here in Last Week in Pony, we make it just the right time to highlight one of our excellent community resources.

This week, we are highlighting the Pony Pattern a cookbook style guide to solving problem via common code patterns. Today we are looking at Accessing an Actor with Arbitrary Transactions.

This pattern solves the problem of needing arbitrary transactions on a Pony actor. Because Pony actors communicate asynchronously it is possible for messages to be interleaved in situations where atomic access is needed. The solution is shockingly simple once it “clicks”, but deceptively difficult to understand at first. It may be helpful for someone first looking at this pattern to understand that: 1) messages are always sent asynchronously from an actor to an actor, and 2) that all actors process their queue of messages in order. For an “Arbitrary Transaction”, we need to have synchronous access that avoids the queue. There is only one way to do this: we need a message type that views the actor as it view itself. Therefore this pattern defines a behavior (i.e., message type) that takes a lambda function argument that accepts a ref to the implementing actor type. This lambda will have synchronous access to the implementing actor for the duration of one message.


Major changes in Pony go through a community driven process where members of the community can write up “requests for change” that detail what they think should be changed and why. RFCs can range from simple to complex. We welcome your participation.

This week, a PR for the “remove json package from standard library” RFC was opened and merged.


Last Week In Pony is a weekly blog post to catch you up on the latest news for the Pony programming language. To learn more about Pony, check out our website, our Twitter account @ponylang, or our Zulip community.

Got something you think should be featured? There’s a GitHub issue for that! Add a comment to the open “Last Week in Pony” issue.

Interested in making a change, or keeping up with changes to Pony? Check out the RFC repo. Contributors welcome!