An Introduction to Ruby Parsing with Prism

Prism is Ruby's new parser that unifies parsing across all Ruby implementations and tools. This guide walks through building two practical examples: a transpiler that converts Ruby code to Emoruby (emoji-based syntax), and an automated refactoring tool that converts Struct definitions to Data classes. It covers lexing tokens, parsing Abstract Syntax Trees, using the Visitor pattern to traverse nodes, and handling edge cases like mutation detection. The tutorial demonstrates how Prism's consistent API enables developers to build code analysis tools, transpilers, and custom refactoring scripts.