ordsets
(stdlib)Functions for Manipulating Sets as Ordered Lists
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
Functions
new() -> Ordset
Ordset = ordered_set()
Returns a new empty ordered set.
is_set(Ordset) -> bool()
Ordset = term()
Returns true
if Ordset
is an ordered set of
elements, otherwise false
.
size(Ordset) -> int()
Ordset = term()
Returns the number of elements in Ordset
.
to_list(Ordset) -> List
Ordset = ordered_set()
List = [term()]
Returns the elements of Ordset
as a list.
from_list(List) -> Ordset
List = [term()]
Ordset = ordered_set()
Returns an ordered set of the elements in List
.
is_element(Element, Ordset) -> bool()
Element = term()
Ordset = ordered_set()
Returns true
if Element
is an element of
Ordset
, otherwise false
.
add_element(Element, Ordset1) -> Ordset2
Element = term()
Ordset1 = Ordset2 = ordered_set()
Returns a new ordered set formed from Ordset1
with
Element
inserted.
del_element(Element, Ordset1) -> Ordset2
Element = term()
Ordset1 = Ordset2 = ordered_set()
Returns Ordset1
, but with Element
removed.
union(Ordset1, Ordset2) -> Ordset3
Ordset1 = Ordset2 = Ordset3 = ordered_set()
Returns the merged (union) set of Ordset1
and
Ordset2
.
union(OrdsetList) -> Ordset
OrdsetList = [ordered_set()]
Ordset = ordered_set()
Returns the merged (union) set of the list of sets.
intersection(Ordset1, Ordset2) -> Ordset3
Ordset1 = Ordset2 = Ordset3 = ordered_set()
Returns the intersection of Ordset1
and
Ordset2
.
intersection(OrdsetList) -> Ordset
OrdsetList = [ordered_set()]
Ordset = ordered_set()
Returns the intersection of the non-empty list of sets.
is_disjoint(Ordset1, Ordset2) -> bool()
Ordset1 = Ordset2 = ordered_set()
Returns true
if Ordset1
and
Ordset2
are disjoint (have no elements in common),
and false
otherwise.
subtract(Ordset1, Ordset2) -> Ordset3
Ordset1 = Ordset2 = Ordset3 = ordered_set()
Returns only the elements of Ordset1
which are not
also elements of Ordset2
.
is_subset(Ordset1, Ordset2) -> bool()
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
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
Pred = fun (E) -> bool()
Set1 = Set2 = ordered_set()
Filter elements in Set1
with boolean function
Fun
.