ruby - 干掉这段 Ruby 代码

Question

我怎样才能干掉这段代码？

module TraverseTree
  def inorder_traverse root
    return nil unless root
    result = []
    result.concat inorder_traverse root.left if root.left
    result.push root.val
    result.concat inorder_traverse root.right if root.right
    result
  end

  def preorder_traverse root
    return nil unless root
    result = []
    result.push root.val
    result.concat preorder_traverse root.left if root.left
    result.concat preorder_traverse root.right if root.right
    result
  end

  def postorder_traverse root
    return nil unless root
    result = []
    result.concat postorder_traverse root.left if root.left
    result.concat postorder_traverse root.right if root.right
    result.push root.val
    result
  end
end

有没有一种好方法可以根据函数名称以编程方式对代码进行排序？

谢谢!!

Answer 1

def traverse_recurse(root, options)
  return unless root
  options[:preorder].call(root.val) if options[:preorder]
  traverse_recurse(root.left, options)
  options[:inorder].call(root.val) if options[:inorder]
  traverse_recurse(root.right, options)
  options[:postorder].call(root.val) if options[:postorder]
end

def traverse_collect(root, type)
  result = []
  traverse_recurse(root, type => lambda { |val| result.push(val) })
  result
end

def preorder_traverse(root)
  traverse_collect(root, :preorder)
end

def inorder_traverse(root)
  traverse_collect(root, :inorder)
end

def postorder_traverse(root)
  traverse_collect(root, :postorder)
end