https://github.com/piotrmurach/splay_tree
A self-balancing binary tree optimised for fast access to frequently used nodes.
https://github.com/piotrmurach/splay_tree
algorithm binarytree ruby ruby-gem splay-trees splaytree tree
Last synced: 4 months ago
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A self-balancing binary tree optimised for fast access to frequently used nodes.
- Host: GitHub
- URL: https://github.com/piotrmurach/splay_tree
- Owner: piotrmurach
- License: mit
- Created: 2014-12-27T22:18:48.000Z (almost 11 years ago)
- Default Branch: master
- Last Pushed: 2024-03-23T21:11:40.000Z (over 1 year ago)
- Last Synced: 2025-05-14T17:49:33.130Z (5 months ago)
- Topics: algorithm, binarytree, ruby, ruby-gem, splay-trees, splaytree, tree
- Language: Ruby
- Homepage:
- Size: 48.8 KB
- Stars: 24
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Funding: .github/FUNDING.yml
- License: LICENSE.txt
- Code of conduct: CODE_OF_CONDUCT.md
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README
# SplayTree
[][gem]
[][gh_actions_ci]
[][appveyor]
[][codeclimate]
[][coverage]
[][inchpages]
[gem]: https://badge.fury.io/rb/splay_tree
[gh_actions_ci]: https://github.com/piotrmurach/splay_tree/actions?query=workflow%3ACI
[appveyor]: https://ci.appveyor.com/project/piotrmurach/splay-tree
[codeclimate]: https://codeclimate.com/github/piotrmurach/splay_tree/maintainability
[coverage]: https://coveralls.io/github/piotrmurach/splay_tree
[inchpages]: https://inch-ci.org/github/piotrmurach/splay_tree
> A self-balancing binary tree optimised for fast access to frequently used nodes. Useful for implementing caches and garbage collection algorithms.
## Features
* Familiar `Hash` like access
* Easy instantiation with default value
## Installation
Add this line to your application's Gemfile:
```ruby
gem "splay_tree"
```
And then execute:
$ bundle
Or install it yourself as:
$ gem install splay_tree
## Contents
* [1. Usage](#1-usage)
* [1.1 insert](#11-insert)
* [1.2 fetch](#12-fetch)
* [1.3 default](#13-default)
* [1.4 delete](#14-delete)
* [1.5 empty?](#15-empty)
* [1.6 each](#16-each)
## 1. Usage
**SplayTree** operations are similar to that of `Hash`:
```ruby
tree = SplayTree.new
tree[:foo] = :bar
tree[:foo] # => :bar
tree.size # => 1
```
### 1.1 insert
To assign a value to a given key do the following:
```ruby
tree = SplayTree.new
tree[:foo] = 1
tree[:bar] = 2
```
Note: The inserted key will be subjected to splaying, which means the tree will be rearranged to help with quicker access on subsequent calls.
### 1.2 fetch
To retrieve a value at a given key do:
```ruby
tree = SplayTree.new
tree[:foo] # => nil
tree[:foo] = 1
tree[:foo] # => 1
```
Note: Frequently accessed keys will move nearer to the root where they can be accessed more quickly.
### 1.3 default
You can set a default value for a missing key. This can be done during initialization:
```ruby
tree = SplayTree.new
tree.default # => UndefinedValue
tree = SplayTree.new(1)
tree.default # => 1
tree[:foo] # => 1
```
Or using `default` method:
```ruby
tree = SplayTree.new
tree.default = 1
tree[:foo] # => 1
```
You can also use a block to set the default value:
```ruby
tree = SplayTree.new
tree.default_proc # => nil
tree = SplayTree.new { 1 }
tree.default_proc # => #
tree[:foo] # => 1
```
### 1.4 delete
In order to remove an entry from a splay tree use `delete` method. If a key is not found, the default value is returned, otherwise `nil`.
```ruby
tree = SplayTree.new
tree[:foo] = 1
tree.delete(:foo) # => 1
tree.delete(:bar) # => nil
```
### 1.5 empty?
Use `empty?` to check if a tree contains any elements:
```ruby
tree = SplayTree.new
tree.empty? # => true
tree[:foo] = 1
tree.empty? # => false
```
### 1.6 each
Use `each` method to iterate over all tree nodes like so:
```ruby
tree = SplayTree.new
tree[:foo] = 1
tree[:bar] = 2
tree.each { |key, value| puts "#{key}: #{value}" }
# =>
# bar: 2
# foo: 1
```
You can also use `each_key` and `each_value` to enumerate only keys or values:
```ruby
tree.each_key { |key| ... }
tree.each_value { |value| ... }
```
If no block is given, an enumerator is returned instead.
## Contributing
1. Fork it ( https://github.com/piotrmurach/splay_tree/fork )
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create a new Pull Request
## Code of Conduct
Everyone interacting in the SplayTree project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/piotrmurach/splay_tree/blob/master/CODE_OF_CONDUCT.md).
## Copyright
Copyright (c) 2014 Piotr Murach. See LICENSE for further details.