Super-interactive ruby console.

sirb.rb

#!/usr/bin/env ruby
# -*- coding: UTF-8 -*-;

require 'io/console'
require 'ansi'

class Textbox
  def initialize(input=$stdin)
    @input = input
  end

  def process(ch)
    case ch
    when "¥027" # <C-W>
      @string = @string.rstrip.split(/¥b/)[0...-1].join
    when "¥b"
      @string = @string[0...-1]
    when "¥r"
      @string = ''
    when "¥003", "¥004"
      throw :exit, true
    else
      case ch
      when /[[:print:]]/
        @string += ch
      else
      end
    end
  end

  def main
    @input.raw do |io|
      yield @string = ""

      io.chars do |ch|
        prev = @string.dup
        return if catch(:exit) { process(ch); nil}
        next if @string == prev
        yield @string
      end
    end
  end
end

class SuperIrb
  def display(str)
    print ">> #{str}"
  end

  def nextline(l=nil)
    @current_line = l if l

    if @current_line >= $stdout.winsize.first
      throw :exit
    else
      puts left($stdout.winsize.last)
    end

    @current_line += 1
  end

  include ANSI::Code
  def main
    @input = Textbox.new($stdin)
    @input.main do |str|
      print cls
      print reset
      print move 0, 0

      display str

      next if str.empty?

      print save

      nextline(1)

      catch(:exit) do
        begin
          result = eval(str, TOPLEVEL_BINDING).inspect
        rescue SyntaxError => e
          result = e.inspect
        rescue => e
          result = e.inspect
        end

        result.each_line do |line|
          print line.strip
          nextline
        end
      end

      print restore
    end
  end
end

SuperIrb.new.main