lake-stdlib

Standard library for the Lake programming language. Pure Lake source — no Rust, no FFI per module — everything lives on top of the runtime functions the compiler ships with.

Modules

module	exports	uses
std.io	print, println, eprint, eprintln	rt_write, len
std.math	abs, min, max, mod	(none — pure compute)
std.sys	exit	rt_exit
std.tcp	listen, accept, recv, send, close	rt_listen_tcp, rt_accept_async, rt_recv_async, rt_send_async, rt_close, len

Every machine here is pub. Internal helpers (none yet) would be private by default.

Most TCP wrappers are ret-typed — let conn = accept(srv) blocks the caller until the underlying io_uring CQE arrives, the same way the underlying rt_accept_async parks a direct caller. The wrapper costs one extra mailbox roundtrip; for tight per-byte loops bypass the stdlib and call rt_* directly.

Output ordering

std.io machines (print, println, eprint, eprintln) are all ret-typed. This gives you a per-call choice:

println("a")       // async — fire-and-forget; output order is
println("b")       // whatever the scheduler picks
println("c")
//
// $ ./prog
// c
// b
// a   ← typical: scheduler runs in LIFO order

pin println("a")   // sync — block until the wrapper actor
pin println("b")   // finishes its rt_write and replies
pin println("c")
//
// $ ./prog
// a
// b
// c   ← guaranteed

pin <expr> is sugar for let __pin_<id> = <expr>: it forces the ret-machine sync return path and discards the value. Use let r = M(args) when you want to capture the returned value.

The pin form costs one mailbox roundtrip (~µs on the current scheduler) per call. Programs that want guaranteed sequential output in a hot loop should bypass the stdlib and call rt_write directly — it's a blocking syscall, no actor involved.

Installation

There is no package manager yet. Two ways to expose this library to your projects:

Per-library env var (recommended)

export STD_PATH=/path/to/lake-stdlib/std

The Lake compiler resolves +std.io.println by looking for a file <STD_PATH>/io.lake (the std segment is consumed by the env var name).

Generic search path

export LAKE_PATH=/path/to/lake-stdlib

Each segment of the import path appears verbatim under LAKE_PATH, so +std.io.println resolves to <LAKE_PATH>/std/io.lake.

Both can be set; resolution order is project root → <NAME>_PATH → LAKE_PATH.

Usage

+std.io.{ println }

main is {
  _ -> {
    println("hello from lake-stdlib")
  }
}

$ STD_PATH=/path/to/lake-stdlib/std lakec my_app.lake -r
$ ./build/my_app
hello from lake-stdlib

Examples

examples/hello/ — minimal program that imports println and prints a greeting.

examples/echo/ — TCP echo server using std.tcp.{ listen, accept, send, close }.

examples/http_print/ — listens on :8080, prints every incoming HTTP request to stdout, replies with a tiny HTTP/1.0 200 OK. Demonstrates the full recv → print → send → close flow over the stdlib.

$ STD_PATH=/path/to/lake-stdlib/std \
    lakec examples/http_print/main.lake -r
$ ./examples/http_print/build/main &
listening on :8080
$ curl -s http://127.0.0.1:8080/hello
hi
$ # server printed:
GET /hello HTTP/1.1
Host: 127.0.0.1:8080
User-Agent: curl/...
Accept: */*

License

MIT.

Status

Bootstrap stage. Functions are minimal; expect rapid churn until Lake gains:

• typed PIDs (so message types are checked at compile time)
• generic types (so result(T, E) and option(T) can be modeled)
• struct / sum types (so list, result, option can be implemented)

Until then, this library covers the ergonomic primitives that the existing language already supports cleanly.