class Tree
attr_reader :value
def initialize(value)
@value = value
@children = []
end
def <<(value)
subtree = Tree.new(value)
@children << subtree
return subtree
end
def each
yield value
@children.each do |child_node|
child_node.each { |e| yield e }
end
end
end
t = Tree.new("Parent")
puts child1 = t << "Child 1"
puts child1 << "Grandchild 1.1"
puts child1 << "Grandchild 1.2"
puts child2 = t << "Child 2"
puts child2 << "Grandchild 2.1"
t.each { |x| puts x }
# Parent
# Child 1
# Grandchild 1.1
# Grandchild 1.2
# Child 2
# Grandchild 2.1