The Book
The language from the first program to a server, chapter by chapter.
Lyric: native programs, plainly written.
A statically typed language for applications, command-line tools and servers. It compiles through C to one binary per program, runs its tasks on coroutines with their own stacks, and says in a function's signature what it throws.
fn handle(req: Request): Response throws Error {
let path = req.uri.path;
if (path == "/items" && req.method == Method.Get) {
return try Response.withJson(items.toArray());
}
if (path == "/items" && req.method == Method.Post) {
let fresh = try req.json<NewItem>();
let item = Item { id = items.length() + 1, name = fresh.name, price = fresh.price };
items.push(item);
var r = try Response.withJson(item, 201);
r.headers.set("Location", f"/items/{item.id}");
return r;
}
if (path.startsWith("/items/")) {
let id = try int.parse(path.splitOnce("/items/")!.1);
for (item in items) {
if (item.id == id) {
return try Response.withJson(item);
}
}
return try Response.withJson(Problem { error = f"no item {id}" }, 404);
}
return try Response.withJson(Problem { error = f"no {path}" }, 404);
}Native binaries
A program builds into one executable for Linux, macOS or Windows — no virtual machine to install beside it.
Concurrency without colouring
A task runs on a stack of its own, so any function may wait for input or output; none is marked async.
Errors in the signature
A function names what it throws; a caller handles it or passes it on with try — no error leaves unseen.
Standard library
Every module, type and function of std.
Specification
The rules of the language, precisely.