Building a High-Performance JSON Parser in Go with Egg
Egg: A Modern LL(1) Parser Generator for Go Parsing is a staple of computer science, yet finding the right tool for the job in Go often feels like a choice between heavy, complex frameworks or writing a brittle parser by hand. Enter egg (Expression Grammar Generator). egg is a new parser generator that prioritizes simplicity, performance, and Go-native conventions. It takes an EBNF grammar—very similar to the one used in the Go language specification—and generates a fast, dependency-light recursive descent parser. In this post, we’ll build a fully functional JSON parser from scratch to demonstrate how egg works, and we'll dive deep into its most controversial and powerful feature: its flat AST encoding. The Grammar: Familiar and Concise One of egg 's strengths is that it doesn't invent a complex new syntax. If you've read the Go language spec, you already know how to write an egg grammar. It combines lexical definitions (regex and literals) and syntax de...