yufengwng / coro

coro

Coro: a language with first-class support for coroutines.

The goal is to design and build a language that implements "asymmetric coroutines", as described in [1], supporting the core create/resume/yield operations. The language is meant to be a "toy" programming language, but the implementation should be mostly working well.

Example

# A simple generator that yields natural numbers.

def nat = {
  let n = -1;
  while true do {
    let n = n + 1;
    yield n;
  } end
}

let co = create nat

let i = 0
while i < 10 do {
  print (resume co);
  let i = i + 1;
} end

Building and Testing

Use cargo to build, run, and test the implementation. There is also a Makefile for your convenience. There are a few debug features you can pass to cargo:

• ast - prints the AST after parsing
• dbg - general debugging, prints out result values, coroutine status, etc.
• instr - print the compiled linear instructions for each function
• stack - print the value stack while executing instructions

You can pass these to Cargo like so:

$ cargo run --features=ast,dbg,instr,stack

References

[1] A. L. D. Moura and R. Ierusalimschy, “Revisiting coroutines,” ACM Trans. Program. Lang. Syst., vol. 31, no. 2, Feb. 2009, issn: 0164-0925. [Online]. Available: https://doi.acm.org/10.1145/1462166.1462167.