trie.rb

class Tree

  def initialize
    @alphabet = ('a'..'z').to_a
    @alphabet -= %w( p )
    create_first_children
  end

  def create_first_children
    @alphabet.each do |character|
p character
      self.class.send(:define_method, character.to_sym) {
        return Node.new(:value => character)
      }
    end
  end

  def enter_new_word(word)
    path = []
    characters = word.split("")
    characters.each do |character|
      if path.empty?
        path << self.send(character)
      elsif path[-1].respond_to?(character)
        path << path[-1].send(character)
      else
        path << path[-1].create_new_child(character)
      end
    end
    path[-1].word = word
  end

  def look_for_word(word)
    path = []
    characters = word.split("")
    characters.each do |character|
      if path.empty?
        path << self.send(character)
      elsif path[-1].respond_to?(character) == false
        break p 'word not found'
      else
        path << path[-1].send(character)
      end
    end
    return path[-1].word
  end

end

class Node

  attr_accessor :value, :word

  def initialize(params = {})
    @value = params[:value]
    @word = nil
  end

  def create_new_child(character)
    new_child = Node.new(:value => character)
    self.class.send(:define_method, character) { return new_child }
  end

end

dictionary = Tree.new
p 'the word hello does not exist in our dictionary'
dictionary.look_for_word('hello')
p 'we will now add hello to our dictionary'
dictionary.enter_new_word('hello')
# p 'we will now search for hello in our dictionary'
# dictionary.look_for_word('hello')