An implementation of Scheme subset written in Ruby. It's based on the Stack-Based model introduced in Three Implementation Models for Scheme by R. Kent Dybvig. The model is implemented by a compiler and virtual machine.

• first class closures
• global variables
• integers/symbols/cons cell/true/false
• variadic function
• call/cc(limitation exists)
• if
• basic arithmetic functions(+ - * /)
• set!
• tail call optimization

$ gem install rb-scheme

$ rb-scheme

You can use rlwrap for readline

$ rlwrap rb-scheme

$ rb-scheme examples/nqueen.scm

• numeric(+, -, *, /)
• predicate(=, <, >, null?)
• lisp operations(cons, car, cdr, list)
• print(display, newline, print)

see examples folder

$ bundle install
$ rake test

The gem is available as open source under the terms of the MIT License.