class Array
    def each_group(n)
        (length / n).times do |i|
            yield self[i * n .. (i + 1) * n - 1]
        end
    end
end

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10].each_group(3) do |trio|
    p trio
end

class Test
    puts "Hello from the Test Class!"
end

class MyProgram
    class Foo
        attr_reader :bar
        def initialize (bar)
            @bar = bar
        end
    end
    puts "Hello, from the MyProgram Class, where we have"
    puts "just defined the Foo class. Prepare yourselves,"
    puts "for we are just about to create a Foo object"
    puts "within the MyProgram class!\n"
   
    inside_foo = Foo.new(42)
    puts "The value of 'bar' within the 'inside_foo' object is: #{inside_foo.bar}"
   
    puts "\nSuccess! We have created a Foo object and accessed"
    puts "it, all as we would normally do, but from within"
    puts "the MyProgram Class."
end

puts "\nThat was some journey; but we've made it to the"
puts "outside world alive! Now that we're out here,"
puts "let's do a little testing.\n"
puts "First, let's try to create a Foo object from the outside"

outside_foo = MyProgram::Foo.new(4)
puts "The value of 'bar' within the 'outside_foo' object is: #{outside_foo.bar}"

puts "\nSuccess! Once again, we have created and"
puts "accessed a Foo object."

puts "Hello World"

class Object
    puts "Hello World"
end

class Person
    def initialize(name_str)
        @names = name_str.split
       
        if @names.length == 2
            instance_eval {
                def first
                    @names.first
                end
                def last
                    @names.last
                end
            }
        end
    end
end

clapton = Person.new("Eric Clapton")
puts clapton.first
puts clapton.last

elvis = Person.new("Elvis")
puts elvis.first
puts elvis.last

module FromIRC
    def privmsg(irc_input)
        # Example irc_input: "Minsc PRIVMSG wtd Hey wtd!"
        # The above string is a simplified version
        #   of what the IRC servers use. It means,
        #   "Minsc" sends the "PRIVMSG" command with two
        #   arguments. The first is the receiver, "wtd".
        #   The second is the text, "Hey wtd!"
        words = irc_input.split
        "#{words.first}: #{words[3 .. -1].join(" ")}"
    end
end

class Channel
    include FromIRC
    def initialize
        # Open the log file for appending
        @log_file = File.open("log.txt", "a")
    end
    def log(text)
        @log_file.puts text
    end
    private :log
   
    # Create a slightly modified version of all
    #   the FromIRC methods.
    # Create them as instance methods, though we
    #   use class_eval to do this, because we're
    #   working at the class level (notice we're not
    #   within any instance methods, like in the last
    #   example).
    FromIRC.public_instance_methods.each do |method_str|
        class_eval "def #{method_str}(irc_input); log super(irc_input); end"
    end
end


Channel.new.privmsg("Minsc PRIVMSG wtd Hey wtd!")

class Foo
    def bar
        puts "Barrrrry"
    end
    alias qux bar
end

foo = Foo.new
foo.qux
foo.bar

class Foo
    def bar
        puts "Barrrrry"
    end
    alias_method(:qux, :bar)
end

foo = Foo.new
foo.qux
foo.bar

class String
   
    # Rename the 'inspect' method to 'old_inspect'
    alias old_inspect inspect
   
    # Overwrite the 'inspect' method with our definition
    def inspect
        "Value at ID #{self.object_id} is #{old_inspect}"
    end
end
foo = "The Wind Cries Mary"
puts foo.inspect

class Foo
    def baz
        puts "Barrry"
    end
end

class Bar < Foo
    alias foo_baz baz
    def baz
        super
        puts "From the Bar class"
    end
end

Bar.new.foo_baz
puts "----"
Bar.new.baz

class Foo
    def bar
        puts "Barrrrry"
    end
    undef bar
end

Foo.new.bar

class Person
    def initialize(name_str)
        @name = name_str.split
        if @name.length == 2
            instance_eval {
                def first() @name.first end
                def last() @name.last end
            }
        end
    end
    def name=(new_name)
        @name = new_name.split
        if @name.length != 2
            instance_eval { undef first, last }
        end
    end
end

musician = Person.new("Eric Clapton")
puts musician.first
puts musician.last
musician.name = "John Lennon"
puts musician.first
puts musician.last
musician.name = "Sting"
puts musician.first
puts musician.last

class Parent
    def yar
        puts "YARR!! ~Dad"
    end
end

class Child < Parent
    def yar
        puts "Yar... ~Child"
    end
end

class Child
    undef yar
end
Child.new.yar

class Child
    remove_method :yar
end
Child.new.yar