TreeNode#find

[pitosalas]

I understand that TreeNode#each walks the whole subtree starting at itself.

I would have thought that TreeNode#find would search similarly as it also comes from Enumerable, but I must be misunderstanding. Can you explain?

[evolve75]

The each method is actually required in order for Enumerable to work. See details in the Enumerable module documentation.

This article describes the rationale behind Enumerable, and how to use it, in more detail.

As you can see from the method documentation for find, the intent of this method is to search the whole collection, and in the specific case for RubyTree, will definitely use the same semantics for the collection as TreeNode#each, i.e., will start searching from the node itself.

Perhaps an example will help:

require "rubytree"

if __FILE__ == $0
  root_node = Tree::TreeNode.new("ROOT", "Root Content")

  root_node << Tree::TreeNode.new("CHILD1", "Child1 Content") << Tree::TreeNode.new("GRANDCHILD1", "GrandChild1 Content")
  root_node << Tree::TreeNode.new("CHILD2", "Child2 Content")

  puts root_node.find {|node| node.name == "ROOT"} || "Not Found"  # Find the current node itself
  puts root_node.find {|node| node.name == "CHILD1"} || "Not Found" # Find another node in the collection
end

In this example, both the current node as well as another arbitrary node within the tree collection are found using TreeNode#find.

[pitosalas]

Again, Anupam, thanks for your usual comprehensive response!

• Pito Salas

On December 19, 2013 at 10:53:53 PM, Anupam Sengupta (notifications@github.com) wrote:

The each method is actually required in order for Enumerable to work. See details in the Enumerable module documentation.

This article describes the rationale behind Enumerable, and how to use it, in more detail.

As you can see from the method documentation for find, the intent of this method is to search the whole collection, and in the specific case for RubyTree, will definitely use the same semantics for the collection as TreeNode#each, i.e., will start searching from the node itself.

Perhaps an example will help:

require "rubytree"

if FILE == $0
root_node = Tree::TreeNode.new("ROOT", "Root Content")

root_node << Tree::TreeNode.new("CHILD1", "Child1 Content") << Tree::TreeNode.new("GRANDCHILD1", "GrandChild1 Content")
root_node << Tree::TreeNode.new("CHILD2", "Child2 Content")

puts root_node.find {|node| node.name == "ROOT"} || "Not Found" # Find the current node itself
puts root_node.find {|node| node.name == "CHILD1"} || "Not Found" # Find another node in the collection
end
In this example, both the current node as well as another arbitrary node within the tree collection are found using TreeNode#find.

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