gistfile1.rb

require "irb"

IRB.init_config(__FILE__)

# Muchos hackos! I probably initialize IRB in the wrong way...
def IRB.CurrentContext
  o = Object.new
  def o.last_value
    ''
  end
  o
end

module Kernel
  private
  
  def break!(&block)
    raise ArgumentError, "Need to give at least an empty block for context to work." unless block
    # Probably catching the wrong object or something else, because typing either `exit' or `quit'
    # should not exit the application but rather continue where we left off.
    catch(:IRB_EXIT) { IRB::Irb.new(IRB::WorkSpace.new(block.binding)).eval_input }
  end
end

class Foo
  def initialize(val)
    @val = val
    x = 10
    foo = :foo
    
    break! {}
  end
  
  def i_is_a_method!
    "Original value was `#{@val}'"
  end
end

p Foo.new('Hello macabre world!')

# Ruby 1.8:
#
# % ruby irb_test.rb
# irb(#<Foo:0x3c258>):001:0> foo
# => :foo
# irb(#<Foo:0x3c258>):002:0> x
# => 10
# irb(#<Foo:0x3c258>):003:0> i_is_a_method!
# => "Original value was `Hello macabre world!'"
# irb(#<Foo:0x3c258>):004:0>

# Ruby 1.9:
#
# % ruby19 irb_test.rb
# irb(#<Foo:0x4290a0>):001:0> foo
# => :foo
# irb(#<Foo:0x4290a0>):002:0> x
# => 10
# irb(#<Foo:0x4290a0>):003:0> i_is_a_method!
# => "Original value was `Hello macabre world!'"
# irb(#<Foo:0x4290a0>):004:0>

# MacRuby 0.5 (experimental)
#
# % ./miniruby -I lib irb_test.rb
# irb: warn: can't alias exit from irb_exit.
# irb(#<Proc:0x800393940>):001:0> foo
# => :foo
# irb(#<Proc:0x800393940>):002:0> x
# => 10
# irb(#<Proc:0x800393940>):003:0> i_is_a_method!
# NoMethodError: undefined method `i_is_a_method!' for #<Proc:0x800393940>
#   from 0:in `eval:'
#   from 0:in `evaluate:'
#   from 0:in `evaluate:'
#   from 0:in `signal_status:'
#   from 0:in `class_eval:'
#   from 0:in `each_top_level_statement'
#   from 0:in `eval_input'
#   from 0:in `break!'
#   from 0:in `initialize:'
#   from 0:in `__new__:'