Sets

Well-structured Sets for Elixir, offering a common interface with multiple implementations with varying performance guarantees that can be switched in your configuration.

By default, Sets ships with:

• Sets.Implementations.GbSet: A Set representation built on top of a Generalized Balanced Binary Tree. Wraps the Erlang :gb_sets library.
• Sets.Implementations.Ordset: A Set representation built on top of an ordered list. Wraps the Erlang :ordsets library.
• Sets.Implementations.UnspecifiedSet: A set representation whose internals are unspecified (and might change in future Erlang versions). Wraps the Erlang :sets library.
• MapSet: The Elixir set type that is part of Elixir's core library, built on top of the built-in hashmap type.

Protocols and behaviours

All sets that are part of Sets implement the following protocols:

• Sets.Protocol (implementing this for a different datatype allows you to use 99% of the functions of Sets directly on that datatype)
• Enumerable: Elixir's built-in folding protocol.
• Collectable: Elixir's built-in collecting protocol.
• Combinable: FunLand's combining semi-protocol.
• Reducable: FunLand's simplified folding semi-protocol.
• Extractable: Extractable's protocol extracting one element at a time.
• Insertable: Insertable's protocol to insert one element at a time.
• Inspect: A humanly readable visual representation of the set, regardless of the inner structual representation.

Creating your own Sets implementation:

If you want to create your own Sets implementation, create a module+struct that at least:

• Implements the Sets.Behaviour (@behaviour Sets.Behaviour).
• Implements the Sets.Protocol protocol.

Implementing the other protocols and behaviours listed in the Protocols section is very helpful as well, as it is possible that certain other libraries expect a set implementation to work with them.

Examples

    iex> Sets.new([1,2,3,4])
    #Sets.Implementations.GbSet<[1, 2, 3, 4]>

    iex> Sets.new([1,2,3,4], implementation: Sets.Implementations.Ordset)
    #Sets.Implementations.Ordset<[1, 2, 3, 4]>

    iex> Sets.new([1,2,3,4], implementation: MapSet)
    #MapSet<[1, 2, 3, 4]>

    iex> Sets.union(Sets.new([1,2]), Sets.new([1]))
    #Sets.Implementations.GbSet<[1, 2]>

Installation

The package can be installed by adding sets to your list of dependencies in mix.exs:

def deps do
  [
    {:sets, "~> 0.1.0"}
  ]
end

Documentation can be found at https://hexdocs.pm/sets.