sets
Functions for Set Manipulation
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 (==
).
Functions
new() -> set()
Returns a new empty set.
is_set(Set) -> boolean()
Set = term()
Returns true
if
is a set of
elements, otherwise false
.
to_list(Set) -> List
Set = set(Element)
List = [Element]
Returns the elements of
as a list.
The order of the returned elements is undefined.
is_element(Element, Set) -> boolean()
Set = set(Element)
Returns true
if
is an element of
, otherwise false
.
add_element(Element, Set1) -> Set2
Set1 = Set2 = set(Element)
Returns a new set formed from
with
inserted.
del_element(Element, Set1) -> Set2
Set1 = Set2 = set(Element)
Returns
, but with
removed.
union(Set1, Set2) -> Set3
Set1 = Set2 = Set3 = set(Element)
Returns the merged (union) set of
and
.
union(SetList) -> Set
Returns the merged (union) set of the list of sets.
intersection(Set1, Set2) -> Set3
Set1 = Set2 = Set3 = set(Element)
Returns the intersection of
and
.
intersection(SetList) -> Set
Returns the intersection of the non-empty list of sets.
is_disjoint(Set1, Set2) -> boolean()
Set1 = Set2 = set(Element)
Returns true
if
and
are disjoint (have no elements in common),
and false
otherwise.
subtract(Set1, Set2) -> Set3
Set1 = Set2 = Set3 = set(Element)
Returns only the elements of
which are not
also elements of
.
is_subset(Set1, Set2) -> boolean()
Set1 = Set2 = set(Element)
Returns true
when every element of
1 is
also a member of
, otherwise false
.
fold(Function, Acc0, Set) -> Acc1
Function = fun((Element, AccIn) -> AccOut)
Set = set(Element)
Acc0 = Acc1 = AccIn = AccOut = Acc
Fold
over every element in
returning the final value of the accumulator.
The evaluation order is undefined.
filter(Pred, Set1) -> Set2
Pred = fun((Element) -> boolean())
Set1 = Set2 = set(Element)
Filter elements in
with boolean function
.