fj.data

Class Set<A>

java.lang.Object

fj.data.Set<A>

All Implemented Interfaces:

java.lang.Iterable<A>

public abstract class Set<A>
extends java.lang.Object
implements java.lang.Iterable<A>

Provides an in-memory, immutable set, implemented as a red/black tree.

Method Summary

Modifier and Type	Method and Description
<B> Set<B>	bind(Ord<B> o, F<A,Set<B>> f) Binds the given function across this set.
F<A,F<Set<A>,Set<A>>>	delete() First-class deletion function.
Set<A>	delete(A a) Deletes the given element from this set.
static <A> Set<A>	empty(Ord<A> ord) The empty set.
Set<A>	filter(F<A,java.lang.Boolean> f) Filters elements from this set by returning only elements which produce true when the given function is applied to them.
<B> B	foldMap(F<A,B> f, Monoid<B> m) Folds this Set using the given monoid.
static <A> F<A,F<Set<A>,Set<A>>>	insert() First-class insertion function.
Set<A>	insert(A x) Inserts the given element into this set.
static <A> F<Set<A>,F<Set<A>,Set<A>>>	intersect() A first class function for intersect(Set).
Set<A>	intersect(Set<A> s) Remove all elements from this set that do not occur in the given set.
boolean	isEmpty()
static <A> Set<A>	iterableSet(Ord<A> o, java.lang.Iterable<A> as) Return the elements of the given iterable as a set.
java.util.Iterator<A>	iterator() Returns an iterator over this set.
static <A> Set<A>	join(Ord<A> o, Set<Set<A>> s) Join a set of sets into a single set.
<B> Set<B>	map(Ord<B> o, F<A,B> f) Maps the given function across this set.
static <A> F<Set<A>,F<A,java.lang.Boolean>>	member() First-class membership check.
boolean	member(A x) Checks if the given element is a member of this set.
static <A> F<Set<A>,F<Set<A>,Set<A>>>	minus() A first class function for minus(Set).
Set<A>	minus(Set<A> s) Remove all elements from this set that occur in the given set.
Ord<A>	ord() Returns the order of this Set.
static <A> Set<A>	set(Ord<A> o, A... as) Constructs a set from the given elements.
static <A> Set<A>	single(Ord<A> o, A a) Returns a set with a single element.
int	size() Returns the size of this set.
P3<Set<A>,Option<A>,Set<A>>	split(A a) Splits this set at the given element.
boolean	subsetOf(Set<A> s) Returns true if this set is a subset of the given set.
List<A>	toList() Returns a list representation of this set.
Stream<A>	toStream() Returns a stream representation of this set.
static <A> F<Set<A>,F<Set<A>,Set<A>>>	union() A first class function for union(Set).
Set<A>	union(Set<A> s) Add all the elements of the given set to this set.
P2<java.lang.Boolean,Set<A>>	update(A a, F<A,A> f) Updates, with the given function, the first element in the set that is equal to the given element, according to the order.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

isEmpty

public final boolean isEmpty()

ord

public final Ord<A> ord()

Returns the order of this Set.

Returns:

the order of this Set.

update

public final P2<java.lang.Boolean,Set<A>> update(A a,
                                                 F<A,A> f)

Updates, with the given function, the first element in the set that is equal to the given element, according to the order.

Parameters:

a - An element to replace.

f - A function to transforms the found element.

Returns:

A pair of: (1) True if an element was found that matches the given element, otherwise false. (2) A new set with the given function applied to the first set element that was equal to the given element.

empty

public static <A> Set<A> empty(Ord<A> ord)

The empty set.

Parameters:

ord - An order for the type of elements.

Returns:

the empty set.

member

public final boolean member(A x)

Checks if the given element is a member of this set.

Parameters:

x - An element to check for membership in this set.

Returns:

true if the given element is a member of this set.

member

public static <A> F<Set<A>,F<A,java.lang.Boolean>> member()

First-class membership check.

Returns:

A function that returns true if the given element if a member of the given set.

insert

public final Set<A> insert(A x)

Inserts the given element into this set.

Parameters:

x - An element to insert into this set.

Returns:

A new set with the given element inserted.

insert

public static <A> F<A,F<Set<A>,Set<A>>> insert()

First-class insertion function.

Returns:

A function that inserts a given element into a given set.

iterator

public final java.util.Iterator<A> iterator()

Returns an iterator over this set.

Specified by:

iterator in interface java.lang.Iterable<A>

Returns:

an iterator over this set.

single

public static <A> Set<A> single(Ord<A> o,
                                A a)

Returns a set with a single element.

Parameters:

o - An order for the type of element.

a - An element to put in a set.

Returns:

A new set with the given element in it.

map

public final <B> Set<B> map(Ord<B> o,
                            F<A,B> f)

Maps the given function across this set.

Parameters:

o - An order for the elements of the new set.

f - A function to map across this set.

Returns:

The set of the results of applying the given function to the elements of this set.

foldMap

public final <B> B foldMap(F<A,B> f,
                           Monoid<B> m)

Folds this Set using the given monoid.

Parameters:

f - A transformation from this Set's elements, to the monoid.

m - The monoid to fold this Set with.

Returns:

The result of folding the Set with the given monoid.

toList

public final List<A> toList()

Returns a list representation of this set.

Returns:

a list representation of this set.

toStream

public final Stream<A> toStream()

Returns a stream representation of this set.

Returns:

a stream representation of this set.

bind

public final <B> Set<B> bind(Ord<B> o,
                             F<A,Set<B>> f)

Binds the given function across this set.

Parameters:

o - An order for the elements of the target set.

f - A function to bind across this set.

Returns:

A new set after applying the given function and joining the resulting sets.

union

public final Set<A> union(Set<A> s)

Add all the elements of the given set to this set.

Parameters:

s - A set to add to this set.

Returns:

A new set containing all elements of both sets.

union

public static <A> F<Set<A>,F<Set<A>,Set<A>>> union()

A first class function for union(Set).

Returns:

A function that adds all the elements of one set to another set.

See Also:

union(Set)

filter

public final Set<A> filter(F<A,java.lang.Boolean> f)

Filters elements from this set by returning only elements which produce true when the given function is applied to them.

Parameters:

f - The predicate function to filter on.

Returns:

A new set whose elements all match the given predicate.

delete

public final Set<A> delete(A a)

Deletes the given element from this set.

Parameters:

a - an element to remove.

Returns:

A new set containing all the elements of this set, except the given element.

delete

public final F<A,F<Set<A>,Set<A>>> delete()

First-class deletion function.

Returns:

A function that deletes a given element from a given set.

intersect

public final Set<A> intersect(Set<A> s)

Remove all elements from this set that do not occur in the given set.

Parameters:

s - A set of elements to retain.

Returns:

A new set which is the intersection of this set and the given set.

intersect

public static <A> F<Set<A>,F<Set<A>,Set<A>>> intersect()

A first class function for intersect(Set).

Returns:

A function that intersects two given sets.

See Also:

intersect(Set)

minus

public final Set<A> minus(Set<A> s)

Remove all elements from this set that occur in the given set.

Parameters:

s - A set of elements to delete.

Returns:

A new set which contains only the elements of this set that do not occur in the given set.

minus

public static <A> F<Set<A>,F<Set<A>,Set<A>>> minus()

A first class function for minus(Set).

Returns:

A function that removes all elements of one set from another set.

See Also:

minus(Set)

size

public final int size()

Returns the size of this set.

Returns:

The number of elements in this set.

split

public final P3<Set<A>,Option<A>,Set<A>> split(A a)

Splits this set at the given element. Returns a product-3 of:

• A set containing all the elements of this set which are less than the given value.
• An option of a value equal to the given value, if one was found in this set, otherwise None.
• A set containing all the elements of this set which are greater than the given value.

Parameters:

a - A value at which to split this set.

Returns:

Two sets and an optional value, where all elements in the first set are less than the given value and all the elements in the second set are greater than the given value, and the optional value is the given value if found, otherwise None.

subsetOf

public final boolean subsetOf(Set<A> s)

Returns true if this set is a subset of the given set.

Parameters:

s - A set which is a superset of this set if this method returns true.

Returns:

true if this set is a subset of the given set.

join

public static <A> Set<A> join(Ord<A> o,
                              Set<Set<A>> s)

Join a set of sets into a single set.

Parameters:

s - A set of sets.

o - An order for the elements of the new set.

Returns:

A new set which is the join of the given set of sets.

iterableSet

public static <A> Set<A> iterableSet(Ord<A> o,
                                     java.lang.Iterable<A> as)

Return the elements of the given iterable as a set.

Parameters:

o - An order for the elements of the new set.

as - An iterable of elements to add to a set.

Returns:

A new set containing the elements of the given iterable.

set

public static <A> Set<A> set(Ord<A> o,
                             A... as)

Constructs a set from the given elements.

Parameters:

o - An order for the elements of the new set.

as - The elements to add to a set.

Returns:

A new set containing the elements of the given iterable.