Awesome

<p align="center"> <img src="images/scallion.png" width="300px" alt="SCALL1ON" /> </p>

Overview

Scallion is a library for writing parsers and pretty printers for LL(1) languages in Scala.

Documentation

A comprehensive Scaladoc API is available online.

Parsing Algorithm

Scallion uses a novel parsing algorithm that we have described in the PLDI'20 paper: Zippy LL(1) Parsing with Derivatives. The algorithm has been formally proven correct in Coq.

Examples

JSON: This example showcases how to build a basic JSON parser using Scallion.
Lambda Calculus: This example shows how to get a pretty printer almost for free alongside your parser.
Calculator: This example shows how to use the operators combinator to easily handle operators with various associativities and priorities.
Roman Numerals: This example presents a simple parser and pretty printer for roman numerals.