Set behaviour

Introduction #

This module specifies the Set API expected to be implemented by different representations.

It also provides functions that redirect to the underlying Set, allowing a developer to work with different Set implementations using one API.

To create a new set, use the new functions defined by each set type:

HashSet.new  #=> creates an empty HashSet

In the examples below, set_impl means a specific Set implementation, for example HashSet.

Protocols

Sets are required to implement both Enumerable and Collectable protocols.

Match

Sets are required to implement all operations using the match (===) operator.

Source

Types #

value :: any

values :: [value]

t :: %{}

Functions #

delete(set, value)

(function)

Specs

Deletes value from set.

Examples

iex> s = Enum.into([1, 2, 3], set_impl.new)
iex> Set.delete(s, 4) |> Enum.sort
[1, 2, 3]

iex> s = Enum.into([1, 2, 3], set_impl.new)
iex> Set.delete(s, 2) |> Enum.sort
[1, 3]

difference(set1, set2)

(function)

Specs

  • difference(t, t) :: t

Returns a set that is set1 without the members of set2.

Notice this function is polymorphic as it calculates the difference for of any type. Each set implementation also provides a difference function, but they can only work with sets of the same type.

Examples

iex> Set.difference(Enum.into([1,2], set_impl.new), Enum.into([2,3,4], set_impl.new)) |> Enum.sort
[1]

disjoint?(set1, set2)

(function)

Specs

  • disjoint?(t, t) :: boolean

Checks if set1 and set2 have no members in common.

Notice this function is polymorphic as it checks for disjoint sets of any type. Each set implementation also provides a disjoint? function, but they can only work with sets of the same type.

Examples

iex> Set.disjoint?(Enum.into([1, 2], set_impl.new), Enum.into([3, 4], set_impl.new))
true

iex> Set.disjoint?(Enum.into([1, 2], set_impl.new), Enum.into([2, 3], set_impl.new))
false

equal?(set1, set2)

(function)

Specs

  • equal?(t, t) :: boolean

Check if two sets are equal using ===.

Notice this function is polymorphic as it compares sets of any type. Each set implementation also provides an equal? function, but they can only work with sets of the same type.

Examples

iex> Set.equal?(Enum.into([1, 2], set_impl.new), Enum.into([2, 1, 1], set_impl.new))
true

iex> Set.equal?(Enum.into([1, 2], set_impl.new), Enum.into([3, 4], set_impl.new))
false

intersection(set1, set2)

(function)

Specs

  • intersection(t, t) :: t

Returns a set containing only members in common between set1 and set2.

Notice this function is polymorphic as it calculates the intersection of any type. Each set implementation also provides a intersection function, but they can only work with sets of the same type.

Examples

iex> Set.intersection(Enum.into([1,2], set_impl.new), Enum.into([2,3,4], set_impl.new)) |> Enum.sort
[2]

iex> Set.intersection(Enum.into([1,2], set_impl.new), Enum.into([3,4], set_impl.new)) |> Enum.sort
[]

member?(set, value)

(function)

Specs

  • member?(t, value) :: boolean

Checks if set contains value.

Examples

iex> Set.member?(Enum.into([1, 2, 3], set_impl.new), 2)
true

iex> Set.member?(Enum.into([1, 2, 3], set_impl.new), 4)
false

put(set, value)

(function)

Specs

Inserts value into set if it does not already contain it.

Examples

iex> Set.put(Enum.into([1, 2, 3], set_impl.new), 3) |> Enum.sort
[1, 2, 3]

iex> Set.put(Enum.into([1, 2, 3], set_impl.new), 4) |> Enum.sort
[1, 2, 3, 4]

size(set)

(function)

Specs

  • size(t) :: non_neg_integer

Returns the number of elements in set.

Examples

iex> Set.size(Enum.into([1, 2, 3], set_impl.new))
3

subset?(set1, set2)

(function)

Specs

  • subset?(t, t) :: boolean

Checks if set1's members are all contained in set2.

Notice this function is polymorphic as it checks the subset for any type. Each set implementation also provides a subset? function, but they can only work with sets of the same type.

Examples

iex> Set.subset?(Enum.into([1, 2], set_impl.new), Enum.into([1, 2, 3], set_impl.new))
true

iex> Set.subset?(Enum.into([1, 2, 3], set_impl.new), Enum.into([1, 2], set_impl.new))
false

to_list(set)

(function)

Specs

  • to_list(t) :: list

Converts set to a list.

Examples

iex> set_impl.to_list(Enum.into([1, 2, 3], set_impl.new)) |> Enum.sort
[1,2,3]

union(set1, set2)

(function)

Specs

  • union(t, t) :: t

Returns a set containing all members of set1 and set2.

Notice this function is polymorphic as it calculates the union of any type. Each set implementation also provides a union function, but they can only work with sets of the same type.

Examples

iex> Set.union(Enum.into([1,2], set_impl.new), Enum.into([2,3,4], set_impl.new)) |> Enum.sort
[1,2,3,4]

Callbacks #

delete/2

(callback)

Specs

difference/2

(callback)

Specs

  • difference(t, t) :: t

disjoint?/2

(callback)

Specs

  • disjoint?(t, t) :: boolean

equal?/2

(callback)

Specs

  • equal?(t, t) :: boolean

intersection/2

(callback)

Specs

  • intersection(t, t) :: t

member?/2

(callback)

Specs

  • member?(t, value) :: boolean

new/0

(callback)

Specs

  • new :: t

put/2

(callback)

Specs

size/1

(callback)

Specs

  • size(t) :: non_neg_integer

subset?/2

(callback)

Specs

  • subset?(t, t) :: boolean

to_list/1

(callback)

Specs

  • to_list(t) :: list

union/2

(callback)

Specs

  • union(t, t) :: t