Captures

- capture
- the default is "managed" / automatic as in TS, which means we don't have to think about captures, but incur some allocation cost

function offset(amount: int32): (value: int32) => int32 {
    return (value) => value + amount;
}
Capture Modes

- on demand when desired we can specify @capture for lambdas / nested functions
- @capture with "move", "borrow", "copy","manage", ..
- @capture("manage") preserves identity, @capture("borrow") borrows the original binding, @capture("copy") snapshots it, and @capture("move") transfers it

@capture({
    default: "copy",
    socket: "move",
    logger: "borrow",
    this: "borrow",
})
return (message) => {
    logger.info("sending");
    return socket.write(`${this.prefix}: ${message}`);
};
- "repeatable" is the default multiplicity, while "once" is affine and consumed by its first invocation
- closures preserve lexical this and use Function<Parameters, Return, Multiplicity>;

- lambdas (fat pointers with env)
- Function, ^Function, and &Function use managed, owned, and borrowed environments
- repeatable calls require &Function or stronger access and preserve the environment
- &readonly Function cannot be called; &exclusive Function grants the required mutable access
- only ^Function<Parameters, Return, "once"> is valid; its call consumes the callable