Schemerald is a Scheme R5RS interpreter written in Ruby.

Currently implemented R5RS features include:

• Boolean literals: #t and #f
• Numeric literals for integers, reals, rationals and complexes
• string literals
• Proper and improper lists
• Definition and assignment: define, set!
• Lambdas
• Conditionals: if, cond
• Binding constructs: let
• Quoting
• Delayed evaluation: delay and force
• Equivalance predicates: eqv?, eq?, equal?
• Numeric library: number?, complex?, real?, rational?, integer?, =, <, >, <=, >=, zero?, positive?, negative?, odd?, even?, max, min, +, *, -, /, abs, quotient, remainder, modulo, lcm, floor, ceiling, sqrt
• Boolean library: and, or, not, boolean?
• List library: pair?, cons, car, cdr, set-car!, set-cdr!, null?, list?, list
• Symbol library: symbol?, symbol->string, string->symbol
• String library: string?, string-length, string-ref, string=?, string-ci=?, string<?, string>?, string<=?, string>=?, string-ci<?, string-ci>?, string-ci<=?, string-ci>=?, substring, string-append, string-copy
• Control features: procedure?, apply, eval

gem install schemerald

To start a REPL session:

Interpreter.new.repl

To exit a REPL session:

> exit

(The MIT License)

Copyright (C) 2014 Ventsislav Velkov ( vntzyv@gmail.com )

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.