tree class of Ruby

class Tree
  include Enumerable
  
  attr_accessor :left, :right
  
  def initialize(str)
    @str = str
  end
  
  def each
    left.each {|t| yield t } if left
    right.each{|t| yield t } if right
    yield @str
  end
  
end

t1 = Tree.new('a')
t1.left = Tree.new('a_left')
t1.right = Tree.new('a_right')
t1.left.left = Tree.new('a_left_left')
t1.right.left = Tree.new('a_right_left')
t1.right.right = Tree.new('a_right_right')

t1.each {|t| puts t}

# >> a_left_left
# >> a_left
# >> a_right_left
# >> a_right_right
# >> a_right
# >> a

Ruby's module mixin

# All you have to do is write an iterator called each, which returns the elements of our collection in turn. Mix in Enumerable, and suddenly your class supports things such as map, include?, and find_all?. If the objects in your collection implement meaningful ordering semantics using the <=> method, you’ll also get methods such as min, max, and sort.

class A
  include Comparable
  include Enumerable
  attr :n
  
  def initialize(n)
    @n = n  
  end
  
  def each
    (1..@n).each do |i|
      yield i
    end
  end
  
  def <=>(b)
    self.n <=> b.n
  end
end

a = A.new(3)
b = A.new(4)

m = a.map {|i| i.to_s + __LINE__.to_s}

p m

n = a > b

p n

Ruby Catch Throw Test

catch :label do
  (1..10).each do |i|
    (11..13).each do |j|
      puts 'i=' + i.to_s + ', j=' + j.to_s
      throw :label if i == 3 and j == 12
    end
  end
end
  
puts 'over'