pony-tutorial VS firefly-boot

I don't think that there is a book written about Pony, but the tutorial and the list of patterns (WIP) are all you need to learn the language.

[Pony](https://tutorial.ponylang.io/): actors, reference capabilities, object capabilities.

Pony is a relatively young but interesting language with capabilities-security.

Well, depends on how you define ownership. Pony 's type system has reference capabilities which let you define who's allowed to do what to a reference and part of it sort of deals with ownership (along the lines of "this actor is allowed to do Y to the reference, other actors are allowed to do Z"). You can eg. have methods that return an isolated value that guarantees that there are no other references to that value, meaning it's automatically thread safe. You can also define things as vals which says that they are globally immutable, refs which give the current actor read/write capabilities but can't be shared with other actors

The alternatives are:

- Division must be impure (because it can throw an exception)

- Division must be partial - i.e. return Option[Int].

Both seem worse compared to defining division by zero as zero. Coq, Lean, and Pony do the same. https://github.com/ponylang/pony-tutorial/blob/master/conten...

Firefly, curly braces:

I'm still working on Firefly, a language with first class capabilities.

Since there's no other way for `deleteDirectory` to obtain capabilities than to recieve them as arguments, `deleteDirectory` only has access to the file system.

[1] https://github.com/Ahnfelt/firefly-boot/tree/master/compiler

> Do you have more to share, like resources about capability-safe languages, or your ongoing work?

I can share an example from the main function of the [self hosting Firefly compiler](https://github.com/Ahnfelt/firefly-boot/tree/master/compiler):

    main(system: System): Unit {

I'm working on Firefly, which will compile to JS once bootstrapping is complete (almost there).

Still working on typechecking Firefly with the help of a friend.

Working on the type inference for Firefly. I don't have a lot of free time at the moment, so it's coming along slowly.

Firefly uses object capabilities for enforcing purity:

In Firefly, this is done without macros:

Firefly - self hosting, working on the type inference.