Nendo

日本語版 / Japanese

Nendo is a dynamic programming language built on top of Ruby environment. It is designed to be a macro language of Ruby. Nendo provides easy access to the whole Ruby environment.

Nendo is a dialect of Lisp. nendo means clay in Japanese. Lisp programming is reminiscent of a clay craft. I hope you will feel like playing with clay when you use Nendo.

Features

• Scheme-like Syntax: Uses S-expressions to enable true macros that are sealed as forbidden techniques in Ruby
• Direct Ruby Access: Access Ruby's standard libraries and gems using the dot (.) syntax
• List Processing Oriented: Powerful for complex data structures and tree manipulation
• Easy Installation: Pure Ruby implementation - just install the gem

Supported Libraries

SRFIs

• SRFI 1: List Library (map, filter, fold, ...)
• SRFI 2: AND-LET*
• SRFI 8: RECEIVE
• SRFI 9: Defining Record Types
• SRFI 26: Notation for Specializing Parameters (cut, cute)
• SRFI 46: Basic Syntax-rules Extensions
• SRFI 61: A more general COND clause
• SRFI 69: Basic hash tables

Ported from chibi-scheme and Gauche

• text.html-lite - Simple HTML document construction
• text.tree - Lazy text construction
• nendo.test - Unit testing (subset of gauche.test)
• rfc.json - JSON parsing and construction
• util.list - Additional list library
• util.match - Pattern matching (ported from chibi-scheme 0.3)
• util.combinations - Combination library

Installation

Requirements

• Ruby 2.3, 2.4, 2.7, 3.0, 3.1, 3.2, 3.3, 3.4
• JRuby 1.6.2+

Install from RubyGems

gem install nendo

Examples

Hello World

(print (+ "Hello " "World!"))
; => Hello World!

Even numbers filter

(filter
 (lambda (n)
   (= (% n 2) 0))
 '(1 2 3 4 5 6 7 8 9 10))
; => (2 4 6 8 10)

Accessing Ruby libraries

(require "date")
(let1 d (Date.new 0)
  (list (d.strftime "%x")
        (d.strftime "%s")))

Defining macros

(define when (macro form
   `(if ,(car form) (begin ,@(cdr form)))))

For Ruby Users

• S-expression syntax: Enables true macros and powerful DSL construction
• List processing: Ideal for complex data structures where object-oriented approaches fall short
• Seamless Ruby integration: Access the entire Ruby ecosystem

For Lisp Users

• Vast Ruby library ecosystem: Access all gems and Ruby libraries
• Cloud deployment ready: Works on Ruby-based PaaS platforms like Heroku
• Easy installation: Pure Ruby implementation, no complex dependencies

Source Code & Development

• GitHub Repository
• Travis CI

Projects Written in Nendo

• sekka - Japanese input method

Documentation

• Tutorial
• ReferenceManual

License

This software is open source, covered by a BSD-style license. Please read accompanying file COPYING.