ordsets(3erl)						     Erlang Module Definition						     ordsets(3erl)

NAME

       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.

       is_disjoint(Ordset1, Ordset2) -> bool()

	      Types  Ordset1 = Ordset2 = ordered_set()

	      Returns true if Ordset1 and Ordset2 are disjoint (have no elements in common), and false otherwise.

       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 Ordset 1 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(3erl) , sets(3erl)

Ericsson AB							   stdlib 1.17.3						     ordsets(3erl)