HashTree

The HashTree module contains the Set and Map classes that implements a tree where each node acts as a hash over child nodes. HashTree::Set stores the key internally while HashTree::Map use an external key

HashTree is still work-in-progress

Basic usage. Read the source for full(er) documentation

require 'hash_tree'

class MyNode < HashTree::Set
  attr_reader :name
end

# Create a root node
root = MyNode.new(nil, "ROOT")

# Build hierarchy through constructor
child1 = MyNode.new(root, "CHILD1")
child11 = MyNode.new(child1, "CHILD11")

# Build hierarchy using #attach
child2 = MyNode.new(root, "CHILD2")
child1.attach(child12)

# Parent object
root.parent   # -> nil
child1.parent # -> root

# Lookup value
puts child1["CHILD1"] # -> "CHILD1"

# Check if key exists
child1.key?("CHILD11") # -> true
child1.key?("no key")  # -> false

# Get the root object
child11.root # -> root

# List of parents up to the root element
child11.parents # -> [child1, root]

# List of ancestors from the root down to parent
child11.ancestors # -> [root, child1]

# String of dot-separated keys leading from the root down to self
child11.path # -> "CHILD1.CHILD11"

# Recursively lookup element by string dot-separated keys
root.dot("CHILD1.CHILD11") -> child11

HashTree caches properties to avoid repetitive recursive lookups in #parents, #ancestors etc. The cache is reset every time a node is attached to or detached from a parent

Add this line to your application's Gemfile:

gem 'hash_tree'

And then execute:

$ bundle

Or install it yourself as:

$ gem install hash_tree

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/clrgit/hash_tree.