Contents

defmodule CustomSet do
  defstruct map: Map.new

  @opaque t :: %__MODULE__{map: map}

  @spec new(Enum.t) :: t
  def new(enumerable) do
    %CustomSet{map: Map.new(enumerable, fn (x) -> {x, true} end)}
  end

  @spec empty?(t) :: boolean
  def empty?(%CustomSet{map: map}) do
    Map.keys(map) |> Enum.empty?
  end

  @spec contains?(t, any) :: boolean
  def contains?(%CustomSet{map: map}, element) do
    Map.has_key?(map, element)
  end

  @spec subset?(t, t) :: boolean
  def subset?(%CustomSet{map: map1}, %CustomSet{map: map2}) do
    if map_size(map1) <= map_size(map2) do
      Map.keys(map1) |> do_subset?(map2)
    else
      false
    end
  end

  defp do_subset?([], _), do: true
  defp do_subset?([key | rest], map2) do
    if Map.has_key?(map2, key) do
      do_subset?(rest, map2)
    else
      false
    end
  end

  @spec disjoint?(t, t) :: boolean
  def disjoint?(%CustomSet{map: map1}, %CustomSet{map: map2}) do
    total_size = map_size(map1) + map_size(map2)
    merged_size = map_size(Map.merge(map1, map2))
    total_size == merged_size
  end

  @spec equal?(t, t) :: boolean
  def equal?(%CustomSet{map: map1}, %CustomSet{map: map2}) do
    Map.equal?(map1, map2)
  end

  @spec add(t, any) :: t
  def add(%CustomSet{map: map}, element) do
    %CustomSet{map: Map.put(map, element, true)}
  end

  @spec intersection(t, t) :: t
  def intersection(%CustomSet{map: map1}, %CustomSet{map: map2}) do
    {map1, map2} = order_by_size(map1, map2)
    %CustomSet{map: Map.take(map2, Map.keys(map1))}
  end

  defp order_by_size(map1, map2) when map_size(map1) > map_size(map2), do: {map2, map1}
  defp order_by_size(map1, map2), do: {map1, map2}

  @spec difference(t, t) :: t
  def difference(%CustomSet{map: map1}, %CustomSet{map: map2}) do
    %CustomSet{map: Map.drop(map1, Map.keys(map2))}
  end

  @spec union(t, t) :: t
  def union(%CustomSet{map: map1}, %CustomSet{map: map2}) do
    %CustomSet{map: Map.merge(map1, map2)}
  end
end

Version data entries

327 entries across 327 versions & 1 rubygems

Version	Path
trackler-2.2.1.109	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.108	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.107	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.106	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.105	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.104	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.103	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.102	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.101	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.100	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.99	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.98	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.97	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.96	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.95	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.94	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.93	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.92	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.91	tracks/elixir/exercises/custom-set/example.exs
trackler-2.2.1.90	tracks/elixir/exercises/custom-set/example.exs