InsertOrderedSet

An InsertOrderedSet is a data structure with the following properties:

1. Contains unique values.
2. O(1) manipulation operations (e.g. insert, delete)
3. Preserves insertion order when converting to a list.

This data structure loosely conforms to the Set protocol, I'll be adding full support soon.

Installation

If available in Hex, the package can be installed as:

1. Add insert_ordered_set to your list of dependencies in mix.exs:

   def deps do

    [{:insert_ordered_set, "~> 0.0.1"}]

   end

2. Ensure insert_ordered_set is started before your application:

   def application do

    [applications: [:insert_ordered_set]]

   end

Usage

Currently supported Set methods:

• delete/2
• member?/2
• new/0
• new/1
• put/2
• size/1
• to_list/1

I've added an additional method wherein you can tell the to_list function to produce the list in :asc (insertion order) or :desc (reverse insertion order) order.

• to_list/2

Unique values

[1, 1, 2]
|> InsertOrderedSet.new
|> InsertOrderedSet.to_list  # [ 1, 2 ]

Insertion order preservation

Try the following with MapSet:

["b", "c", "a"]
|> InsertOrderedSet.new
|> InsertOrderedSet.to_list  # ["b", "c", "a"]

Retrieve list in reverse insertion order

["b", "c", "a"]
|> InsertOrderedSet.new
|> InsertOrderedSet.to_list(:desc)  # ["a", "c", "b"]

TODO

• Implement the rest of the Set protocol.
• Adopt the Enumerable protocol.
• Add @doc annotations.
• Add typespecs.