From: Robert Dober <robert.dober@...>
Date: 2008-03-03T15:22:54+09:00
Subject: Re: [QUIZ] Hello, world? (#158)

Just wanted to say "Hello" ;)


# Probably my only solution that makes sense ;)
puts "hello, world!".split.map{ |x| x.capitalize }.join(' ')

# Amazingly you can do << with ints to strings
puts [?H, ?e, ?l, ?l, ?o, ?,, ?\s, ?W, ?o, ?r, ?l, ?d, ?!].
  inject(""){|s,char| s << char}

# A tribute to perl ;)
def method_missing *args, &blk
  puts "Hello, World"
end

croak


# You cannot add strings and ints
begin
puts [?h, ?e, ?l, ?l, ?o, ?,, ?\s, ?w, ?o, ?r, ?l, ?d, ?!].
  inject(""){|s,char| s + char}
  abort "If you do not succeed..."
rescue
  puts "!dlroW ,olleH".reverse
end
#

# What Mixins can do for you
module Hello
  def hello_world
    "Hello,"
  end
end

module World
  def hello_world
    super <<
    " World!"
  end
end

class HelloWorld
  extend Hello
  extend World
  def self.hello_world
    puts super
  end
end

HelloWorld.hello_world

# Abusing Kernel
module Kernel
  alias_method :_puts, :puts
  def puts *args, &blk
    _puts "Hello, World!"
  end
end

puts


# Metaprogramming on classes
class A
  def self.inherited dummy
    print "Hello,"
  end
end

class B < A
  class << self
    def inherited dummy
      print " World!"
    end
  end
end

class << C = Class::new( B )
  def inherited dummy
    puts
  end
end

Class::new C


# A Hommage to James' Gödel Quiz and showing that Integers are immutable
class Integer
  def inject_chars istring, &blk
    return istring if zero?
    ( self / 256 ).inject_chars( blk.call( istring, self % 256 ), &blk )
  end
end
puts 2645608968345021733469237830984.inject_chars(""){ |s,n| s+n.chr }


#
#

# A more sensible approach of abusing Kernel::puts ;)
module Sensible
  def puts *args
    return Kernel::puts( *args ) unless args.empty?
    Kernel::puts "Hello, World!"
  end
end

include Sensible
puts
puts "Hello, Ruby Quiz!"

# A functional approach, introducing the splash
def print_strings *strings
  return puts if strings.empty?
  print strings.shift
  print_strings *strings
end

print_strings %{Hello, World!}

# Blocks and Procs, split(//)
module Printable
  def to_proc
    lambda {
      each do |elem| print elem end
    }
  end
end
Array.send :include, Printable

def yielder
  yield
end

yielder &("Hello, World!" << 10).split(//)

# A radical and viral solution
ObjectSpace.each_object(Module) do |mod|
  mod.send :define_method, :hello_world do puts "Hello, World!" end
end

42.hello_world
Object.hello_world
nil.hello_world

(A = Class::new).hello_world


-- 
http://ruby-smalltalk.blogspot.com/

---
Whereof one cannot speak, thereof one must be silent.
Ludwig Wittgenstein