sets(3)

NAME
sets - Functions for Set Manipulation

DESCRIPTION

Sets are collections of elements with no duplicate elements. The representation of a set is not defined.

This module provides exactly the same interface as the module ordsets but with a defined representation. One difference is that while this module considers two elements as different if they do not match (=:=), ordsets considers two elements as different if and only if they do not compare equal (==).

DATA TYPES
set(Element)

    As returned by new/0.
set() = set(term())

EXPORTS

new() -> set()

    Returns a new empty set.

is_set(Set) -> boolean()

    Types:
        Set = term()

    Returns true if Set is a set of elements, otherwise false.

size(Set) -> integer() >= 0

    Types:
        Set = set()

    Returns the number of elements in Set.

to_list(Set) -> List

    Types:
        Set = set(Element)
        List = [Element]

    Returns the elements of Set as a list. The order of the returned elements is undefined.

from_list(List) -> Set

    Types:
        List = [Element]
        Set = set(Element)

    Returns a set of the elements in List.

is_element(Element, Set) -> boolean()

    Types:
        Set = set(Element)

    Returns true if Element is an element of Set, otherwise false.

add_element(Element, Set1) -> Set2

    Types:
        Set1 = Set2 = set(Element)

    Returns a new set formed from Set1 with Element inserted.

del_element(Element, Set1) -> Set2

    Types:
        Set1 = Set2 = set(Element)

    Returns Set1, but with Element removed.

union(Set1, Set2) -> Set3

    Types:
        Set1 = Set2 = Set3 = set(Element)

    Returns the merged (union) set of Set1 and Set2.

union(SetList) -> Set

    Types:
        SetList = [set(Element)]
        Set = set(Element)

    Returns the merged (union) set of the list of sets.

intersection(Set1, Set2) -> Set3

    Types:
        Set1 = Set2 = Set3 = set(Element)

    Returns the intersection of Set1 and Set2.

intersection(SetList) -> Set

    Types:
        SetList = [set(Element), ...]
        Set = set(Element)

    Returns the intersection of the non-empty list of sets.

is_disjoint(Set1, Set2) -> boolean()

    Types:
        Set1 = Set2 = set(Element)

    Returns true if Set1 and Set2 are disjoint (have no elements in common), and false otherwise.

subtract(Set1, Set2) -> Set3

    Types:
        Set1 = Set2 = Set3 = set(Element)

    Returns only the elements of Set1 which are not also elements of Set2.

is_subset(Set1, Set2) -> boolean()

    Types:
        Set1 = Set2 = set(Element)

    Returns true when every element of Set11 is also a member of Set2, otherwise false.

fold(Function, Acc0, Set) -> Acc1

    Types:
        Function = fun((Element, AccIn) -> AccOut)
        Set = set(Element)
        Acc0 = Acc1 = AccIn = AccOut = Acc

    Fold Function over every element in Set returning the final value of the accumulator. The evaluation order is undefined.

filter(Pred, Set1) -> Set2

    Types:
        Pred = fun((Element) -> boolean())
        Set1 = Set2 = set(Element)

    Filter elements in Set1 with boolean function Pred.

SEE ALSO

ordsets(3), gb_sets(3)