aymanizz / jlox-interpreter

A tree-walk interpreter from the book Crafting Interpreters

JLox Interpreter

This is an implementation of the JLox interpreter (A walk-tree interpreter) implemented in the first part of the book crafting interpreters.

In addition to the original implementation, this one includes solved challenges, as well as other features.

Differences From Lox Implemented in The Book

• String concatenation without explicit + operator
• Arrow style functions, (function () => "Hello World")()
• function instead of fun.
• inherits instead of <.
• print is a function not a statement.
• Two additional global functions: input and println.
• The function keyword is required before classes' methods.
• Most of the challenges are solved in this implementation. Some of the challenges not solved are:
  • Comma operator: although I implemented the comma operator at first, it caused grammar ambiguity later on. Resolving the grammar ambiguity for a little gain is just not worth it so I simply removed it.
  • Displaying results in the interactive interpreter without needing a print statement.
  • Getters and setters in classes.

How to Build The Interpreter

Clone this repo then run the command ./tools/build.sh from the project's root folder.

How to Run The Interpreter

After building the interpreter, run cd build && java jlox.Lox.

Learn It in 2 Minutes

See test file.