RuPkl: Pkl parser for Ruby

[taichi-ishitani]

Hi,

I'm developing a Pkl parser named RuPkl for Ruby.
https://github.com/taichi-ishitani/rupkl

RuPkl can load a Pkl code string into a Ruby structure like below.

require 'rupkl'

pkl = <<~'PKL'
  // From:
  // https://pkl-lang.org/main/current/language-tutorial/01_basic_config.html
  name = "Pkl: Configure your Systems in New Ways"
  attendants = 100
  isInteractive = true
  amountLearned = 13.37
PKL

RuPkl.load(pkl)
# =>
# {:name=>"Pkl:Configure your Systems in New Ways",
#  :attendants=>100,
#  :isInteractive=>true,
#  :amountLearned=>13.37}

I've confirmted that RuPkl can load Pkl code strings in "Tutorial: Basic Configuration" and released v0.1.0!
https://rubygems.org/gems/rupkl

[holzensp]

This looks fun. The first chapter the tutorial uses almost exclusively Pcf, which is a syntactic subset of Pkl. What's your ultimate goal for this parser? What are you going to do with uninterpreted things (for/when generators, amends clauses, member predicates, etc.)?

[taichi-ishitani]

@holzensp ,
Thank you for your reply!

What's your ultimate goal for this parser?
What are you going to do with uninterpreted things (for/when generators, amends clauses, member predicates, etc.)?

Of cause, the ultimate goal is implementing all features of Pkl.
Next step is enhancing RuPkl to be able to parse Pkl code strings in the 2nd chapter of the tutorial. So I will implement the amends feature.

[holzensp]

A full re-implementation?? Of course, you're more than welcome to it, but I think that's considerably more work than it's worth.

[taichi-ishitani]

Yes, I know. So I'm focusing parsing Pkl code strings in the tutorial for now.

[bioball]

Have you considered writing language bindings for Ruby instead? For details, see our documentation

Pkl is an interpreted language. For a full implementation, you'll need to implement an interpreter, not just parse. If that's your goal, carry on! But note that we don't have a language specification, and there's certain behaviors of Pkl today that will change before we get to our 1.0 release.

[taichi-ishitani]

I'm planning to integrate RuPkl and my Ruby app and I'd like to keep its install flow simply.
Therefore, I'm deolping pure Ruby parser but not language binding.

[taichi-ishitani]

Today, I released RuPkl v0.2.0!
https://github.com/taichi-ishitani/rupkl/releases/tag/v0.2.0

This release includes following new features:

• Support Mapping and Listing structures
• Support amend and new expressions
• Support method definition
• Implement some built-in properties and methods

[taichi-ishitani]

Today, I released RuPkl v0.3.0!
https://github.com/taichi-ishitani/rupkl/releases/tag/v0.3.0

This release includes following new features.

• Add following classes
  • List
  • Set
  • Map
  • Pair
  • IntSeq
  • Regex
  • RegexMatch
  • DataSize
  • Duration
• Support For and When generators
• Support If expression

[sandstrom]

I was happy to see rupkl, because I was looking for ruby bindings for Pkl. But it seems like rupkl isn't language bindings, it's a re-implementation of the parser? Is that a correct understanding @taichi-ishitani

(that's fine, but not what I was looking for)

[sandstrom]

Alright, got it! Just a suggestion!

Thanks for taking time responding 😄

[bioball]

FYI: our language bindings don't necessarily require the Pkl runtime to be shipped with your application. One way to use Pkl is to first bake Pkl data into pkl-binary during your application's build time, and then simply parse directly from that binary format into configuration objects.

We have examples for how to do this with Swift, Go, Java and Kotlin.

[sandstrom]

@bioball With the advent of coding agents, have that changed you view supporting more language bindings within the project itself? For example bindings for Ruby?

Ruby is both a fairly popular backend language (Stripe, Shopify, etc) and also used for system work which is configuration heavy (Brew, Chef, etc).

[bioball]

I'm not opposed to first-class Ruby language bindings, but I think at the moment this is lower priority than the other work we have going on. However, this can change if there's enough community support for it.

The most thumb'd language binding right now is for Python: #9

I don't think we even have a ruby one right now. Feel free to create it!

Also, I'd definitely welcome a community-maintained language binding for Ruby.

[sandstrom]

@bioball Alright, thanks for clarifying!