Gmonkey is and interpreted language written in go, implementated as described in Write an Interpreter in Go.
This repo contains the intrepreter for Gmonkey. I am near the end of second chapter in the book. So, it's not even a working interpreter as of now. But it's a work in progress.
Currenly you can checkout the lexer working in the REPL.
To run the REPL:
go run .
or go run main.go