Async Execution

As Krikata is mainly intended for running commands, both the Language and all intermediate executions are inherently asynchronous, with all Promises being awaited before being passed to other functions.

If the program contains a repetition, there are two main ways of awaiting it. Either we regard it as a sequential process with every sub-expression being executed and awaited in order, or as a parallel process where all promises are started at the same time. The default behaviour using Repeat is sequential, parallel execution is possible using Parallel, which otherwise functions identically.

The difference can be seen in the following example.

const sleep = Type.fromFunc(Constant("sleep", () => setTimeout(10)));

const run = new Type<void>("run", [
  Func("repeat")
    .arg(new Repeat(sleep))
    .setExec(() => undefined),
  Func("parallel")
    .arg(new Parallel(sleep))
    .setExec(() => undefined),
]);

const lang = new Language("sleep", run);

> repeat sleep sleep sleep sleep sleep
took: 51.198ms
> parallel sleep sleep sleep sleep sleep
took: 9.398ms