https://github.com/tyre/sorted_set

Sorted Set library for Elixir
https://github.com/tyre/sorted_set

Last synced: about 2 months ago
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Sorted Set library for Elixir

• Host: GitHub
• URL: https://github.com/tyre/sorted_set
• Owner: tyre
• License: mit
• Created: 2015-05-17T05:29:55.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2017-05-22T18:42:14.000Z (about 7 years ago)
• Last Synced: 2024-04-26T07:06:56.200Z (about 2 months ago)
• Language: Elixir
• Size: 227 KB
• Stars: 21
• Watchers: 2
• Forks: 8
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Lists

• awesome-elixir - sorted_set - Sorted Sets for Elixir. (Algorithms and Data structures)

README

        
# SortedSet

[![Hex.pm](https://img.shields.io/hexpm/v/sorted_set.svg)](https://hex.pm/packages/sorted_set) [![Travis](https://img.shields.io/travis/SenecaSystems/sorted_set.svg)](https://travis-ci.org/SenecaSystems/sorted_set)

A sorted set library for Elixir. Implements the

[Set](http://elixir-lang.org/docs/v1.0/elixir/Set.html) protocol.

## Installation

Add the following to `deps` section of your `mix.exs`:

  `{:sorted_set, "~> 1.0"}`

and then `mix deps.get`. That's it!

Generate the documentation with `mix docs`.

## About

Sorted sets are backed by a [red-black tree](http://en.wikipedia.org/wiki/Red%E2%80%93black_tree), providing lookup in O(log(n)). Size is tracked automatically, resulting in O(1)

performance.

## Basic Usage

`SortedSet` implements the `Set` behaviour, `Enumerable`, and `Collectable`.

```elixir

SortedSet.new()

|> Set.put(5)

|> Set.put(1)

|> Set.put(3)

|> Enum.reduce([], fn (element, acc) -> [element*2|acc] end)

|> Enum.reverse

# => [2, 6, 10]

```

## Custom Comparison

Sorted Set can also take a custom `:comparator` function to determine ordering. The

function should accept two terms and

  - return `0` if they are considered equal

  - return `-1` if the first is considered less than or before the second

  - return `1` if the first is considered greater than or after the second

This function is passed on to the underlying [red-black tree implementation](https://github.com/SenecaSystems/red_black_tree) implemetation. Otherwise, the

default Erlang term comparison is used (with an extra bit to handle edgecases — see note in [RedBlackTree](https://github.com/SenecaSystems/red_black_tree)

README.)

```elixir

SortedSet.new([:a, :b, :c], comparator: fn (term1, term2) ->

   RedBlackTree.compare_terms(term1, term2) * -1

 end)

# => #SortedSet<[:c, :b, :a]>

```