http_server VS xvm

I use pony https://ponylang.io/ as a language - it's an Actor based language with GC where every actor has its own memory and is responsible for its own GC.

The main feature is its ability to safely share or move data around between actors in a way that is data-race and deadlock free. Pony doesn't use locks anyways :-)

A high level as to how it achieves this:

And it's not just the mathematics. The non-type-theoretic paradigm-upending let-it-crash-to-keep-code-correct resilience for which Erlang/Elixir is famous was one of the biggest eye-openers for me in my programming career (which began in 1972 when I was 12). Also, the simple behaviour and very high performance results of contemporary Actorish implementations, especially Akka.io and the in-some-ways-more-impressive ponylang.io and related ORCA GC ("concurrent and parallel garbage collector for actor programs ... does not require any STW steps, or synchronization mechanisms ... zero-copy message passing and sharing of mutable data ... data race free ... [no] read/write barriers"), are eye-catching affirmations of the Actor model's approach.

Being an unabashed Ponylang fanboy, I'd say that mutability is a separate question from the "actual" type. I'm simplifying a lot here, but generally in Pony you'd express this in a couple of different ways depending on whether you want the binding itself to be immutable or whether you only care about the instance itself:

There's an http server and a small "sinatra" like web framework.

- https://github.com/ponylang/http_server

- https://github.com/theodus/jennet

Someone might have done SQLite for Pony, but I'm not aware of it. Writing network protocol stuff in Pony is usually pretty easy and the C-FFI is usually pretty easy which generally makes writing database connectivity (for at least happy path basics) fairly easy. (Add lots of caveats here).

If you'd like to talk more in-depth, swing by the Zulip and myself and other folks from the community can help out with answers.

https://ponylang.zulipchat.com/

Have a look at the ecstasy library for the language definitions of these types.

2) Funky interfaces: This is an Ecstasy interface that declares abstract static members (e.g. functions), which can then be implemented on any class and overridden on any sub-class, such that they can be invoked by type (instead of this), and virtually resolved (late bound at runtime) based on the type known at compile time. The best known example, of course, is Hashable, because it has to guarantee that a type implements both equals() and hashCode() on the same class, and the implementation is tied to the type, and not to the this. (C# added a similar feature last year in version 11.)

I'm just going to warn you in advance that invocation is one of the hardest things in the compiler to make easy. In other words, the nicer your language's "developer experience" is around invocation, the more hell you're going to have to go through to get there. The AST nodes for Name( (NameExpression) and Invoke( (InvocationExpression) alone are 7kloc in the Ecstasy implementation, for example -- but the result is well worth it.

Ecstasy uses message passing automatically behind the scenes for asynchronous calls, but the message passing isn't visible at the language level (i.e. there is no "message object" or something like that visible). Basically, all Ecstasy code is executing on a fiber inside a service, and services are all running concurrently, so from any service realm to any service realm, the communication is by message.

Regarding Ecstasy, we did not set out to build a new language; we actually set out to solve a real world problem. Specifically, we wanted to be able to dramatically improve the density of workloads in data centers, by at least two orders of magnitude in the case of lightly used applications. Our initial goal was to create a runtime design that would support 10,000 stateful application instances on a single server. Let's call it the "a10k" problem 🤣 ... a tribute to the c10k problem from 1999. We refer to our goal as "zero carbon compute", i.e. we want to push the power and hardware cost for an application to as close to zero as possible; you can't reach zero, but you can get close. If we succeed, we will help reduce the electricity used in data centers over the next few decades by a significant percentage.

Generally, left to right, one character at a time. If you’re looking for example code, here’s a simple hand-built lexer.

Parts of Ecstasy are now implemented in Ecstasy. Here's the Lexer, for example.

Ecstasy

Ecstasy and the xvm were designed assuming an adaptive runtime compiler (similar in concept to the Hotspot compiler for Java), but not necessarily using a JIT.

A Future reference has the various capabilities that you'd imagine, taking lambdas for thenDo(), whenComplete(), etc. The reference, in the above example, is a local variable, so you just obtain it using the C-style & operator: