Just an idea.. that follows up on a question I had last summer, or there abouts, regarding how feasible it would be to re-use the pants rule engine as a lib. Now that I’ve come to know things better, I think the answer could be “a lot easier than you initially though”. Consider the

RuleRunner

test util.. it pretty much does this already.. so I’ve got a little toy POC, that is a mix of the regular

PantsRunner

and the test

RuleRunner

, where I can create a scheduler session with some “backends” registered and then issue requests against that rule graph. Perfect! 😄 This gives me the possibility to write arbitrary applications, leveraging the structure and semantics of

@rule

methods for the core logic. Awesome! 🚀 As stated, it’s still on a toy level, so haven’t actually used this for anything meaningful yet.. that’ll be for the coming month to show how this scales up 😉

I'm interested in your findings 😄

Posted my toy POC of using Pants as an embedded rule engine in its current state on GitHub. This is the main file showcasing what the client application API could look like: https://github.com/kaos/underpants/blob/main/src/pr/main.py cc @bitter-ability-32190

I was actually thinking you could have a flavor that's engineless so you don't end up with 2 pants engines

Why use the engine as a lib rather than write a plugin?

To not restrict or impose pants way of handling command line options and invocation.

Sure, shipping the lib, will just have pants as a dependency, so it shouldn’t end up with two engines… (edited)

oh duh

This is really cool

neat! experiments to simplify the

Scheduler

API upstream are also very welcome… i’ve found in the past that making it as easy as possible to write tests without shim code is a good sign that the API is easy to use. and right now, RuleRunner abstracts/shims away a bunch of rough edges of

Scheduler

which could probably also be directly smoothed out

Great idea! And it might be easier to clean things up now that we use PyO3 so FFI is much easier to work with

this is a great idea! It can definitely help incremental adoption and make it faster to iterate on simple use cases while leveraging the power of the rules engine. The example shared above is a very familiar pattern for a majority of python engineers which can help get more interest in the community and what pants offers.