ordsets(3)

MODULE
ordsets - Functions for Manipulating Sets as Ordered Lists

DESCRIPTION

Sets are collections of elements with no duplicate elements. An ordset is a representation of a set, where an ordered list is used to store the elements of the set. An ordered list is more efficient than an unordered list.

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

DATA TYPES
ordered_set()
  as returned by new/0

EXPORTS

new() -> Ordset

    Types
        Ordset = ordered_set()

    Returns a new empty ordered set.

is_set(Ordset) -> bool()

    Types
        Ordset = term()

    Returns true if Ordset is an ordered set of elements, otherwise false.

size(Ordset) -> int()

    Types
        Ordset = term()

    Returns the number of elements in Ordset.

to_list(Ordset) -> List

    Types
        Ordset = ordered_set()
        List = [term()]

    Returns the elements of Ordset as a list.

from_list(List) -> Ordset

    Types
        List = [term()]
        Ordset = ordered_set()

    Returns an ordered set of the elements in List.

is_element(Element, Ordset) -> bool()

    Types
        Element = term()
        Ordset = ordered_set()

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

add_element(Element, Ordset1) -> Ordset2

    Types
        Element = term()
        Ordset1 = Ordset2 = ordered_set()

    Returns a new ordered set formed from Ordset1 with Element inserted.

del_element(Element, Ordset1) -> Ordset2

    Types
        Element = term()
        Ordset1 = Ordset2 = ordered_set()

    Returns Ordset1, but with Element removed.

union(Ordset1, Ordset2) -> Ordset3

    Types
        Ordset1 = Ordset2 = Ordset3 = ordered_set()

    Returns the merged (union) set of Ordset1 and Ordset2.

union(OrdsetList) -> Ordset

    Types
        OrdsetList = [ordered_set()]
        Ordset = ordered_set()

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

intersection(Ordset1, Ordset2) -> Ordset3

    Types
        Ordset1 = Ordset2 = Ordset3 = ordered_set()

    Returns the intersection of Ordset1 and Ordset2.

intersection(OrdsetList) -> Ordset

    Types
        OrdsetList = [ordered_set()]
        Ordset = ordered_set()

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

subtract(Ordset1, Ordset2) -> Ordset3

    Types
        Ordset1 = Ordset2 = Ordset3 = ordered_set()

    Returns only the elements of Ordset1 which are not also elements of Ordset2.

is_subset(Ordset1, Ordset2) -> bool()

    Types
        Ordset1 = Ordset2 = ordered_set()

    Returns true when every element of Ordset1 is also a member of Ordset2, otherwise false.

fold(Function, Acc0, Ordset) -> Acc1

    Types
        Function = fun (E, AccIn) -> AccOut
        Acc0 = Acc1 = AccIn = AccOut = term()
        Ordset = ordered_set()

    Fold Function over every element in Ordset returning the final value of the accumulator.

filter(Pred, Ordset1) -> Set2

    Types
        Pred = fun (E) -> bool()
        Set1 = Set2 = ordered_set()

    Filter elements in Set1 with boolean function Fun.

SEE ALSO

gb_sets(3), sets(3)