What Rask is

A systems language built around one bet: if references can’t be stored, lifetime annotations stop being necessary.

Borrow a value for a call or an expression and it works the way you’d expect. Put the borrow in a struct field, or return it, and there’s no syntax for what you’re asking — which is the point. Nothing outlives the thing it points at, so there’s nothing to track, and signatures carry types and nothing else.

Somewhere between Rust and Go. Closer to Rust on safety, closer to Go on ceremony.

import fs
import io

func grep(path: string, pat: string) -> void or io.IoError {
    mut file = try fs.open(path)
    ensure file.close()

    let text = try file.read_text()
    for line in text.lines() {
        if line.contains(pat) { println(line) }
    }
}

Three rules meet in those eight lines. fs.open hands back a linear resource the compiler makes you consume exactly once. ensure defers that consumption to the end of the scope. try returns early on failure — and because the consumption is already scheduled, leaving early still closes the file. No defer discipline to remember, no destructor running out of sight.

Where to start

Rask is pre-0.1 and a solo project. Expect gaps in these chapters and bugs in the compiler; the issue tracker is the honest picture.

New here. Install it, write your first program, then read the chapters under Learn the language. They take one concept at a time and say why each rule is the way it is, which is the part the specs leave out. There are also exercises in the repo. Nothing to install to look around: the playground runs Rask in the browser.

Already writing Rask. The language card is the whole language on one page for looking a rule up. The example programs are complete and CI-checked. The specs are the normative wording when the other two disagree.

Here for the design. The writing is the long-form argument; CORE_DESIGN.md is the principles it falls out of, and RULINGS.md is how open questions get settled.