Roole

• Techs
  • Node.js
  • PEG
• URL hgl.github.io/roole-doc

Roole was my first deep dive into compiler architecture. I initially hand-wrote a parser, but eventually switched to using a parsing expression grammar (PEG) parser generator for better maintainability.

It was also an early experiment in programming language design. While Roole is just a CSS preprocessing language, it’s powerful enough to be Turing complete.

A notable feature is its built-in CSS auto-prefixing, predating tools like Autoprefixer.

Roole was designed with a small core and a plugin architecture — econceptually similar to how the unified ecosystem is structured.