effekt VS xvm

I like it. Modern languages that distinguish between pure and impure programs like Flix, Koka, and Effekt do so on the type level instead of syntactically. This has three advantages:

The problem with checked exceptions been identified and solved. The same problem and solution applies to effect handlers. Effekt is a language with lexical effect handlers which doesn't have this problem. Consider the following program in Effekt:

Yes, for you this is the right decision. But for us going to CPS makes everything significantly easier and in cases where you do use control effects significantly faster. For our language Effekt we are exploring different tradeoffs in different backends.

This pattern they observe is nicely captured by effect handlers. These examples are written in Effekt.

This is beyond my level of expertise. But effect tracking? There are some cool languages out there that do that consistently! Search for "algebraic effects". My favorite is Koka. Effekt also seems to be a popular choice.

https://effekt-lang.org/ A research language with effect handlers and lightweight effect polymorphism

Examples are languages like Koka, Effekt, Links, or Unison. These languages come with a type-and-effect system: a function's type not only tell you which values the function accepts and which values it returns, but also which effects it has. This is relevant to your question, because throwing an exception is one such effect.

It seems that with Effekt we are pursuing the same goal, but coming from the opposite direction, perhaps one day we will meet in the middle :). We start from a purely functional language and carefully add effects like mutation.

- https://effekt-lang.org/

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: