While learning Treetop, I decided that a Brainfuck interpreter would be a nice place to start. So, I made treetop_bootstrap, which is a scaffold for Treetop projects, and then Brainfucktt, a fully featured Brainfuck interpreter.

Use it for learning Treetop, learning how Brainfuck works, for parsing Brainfuck code into an AST, or actually running Brainfuck code!