Module com.jongsoft.lang

Package com.jongsoft.lang.collection

Interface Set<T>

Type Parameters:

T - the entity type contained in the set

All Superinterfaces:

Collection<T>, Foldable<T>, java.lang.Iterable<T>, List<T>, java.io.Serializable, Streamable<T>, Traversable<T>, Value<T>

public interface Set<T>
extends List<T>

The set is an extension of the Collection interface that guarantees only unique elements are contained within the set. How uniqueness is guaranteed varies pending the implementing class. Currently the following implementations are supported:

• Collections.Set(Object[]), an implementation that uses the entities hash
• Collections.SortedSet(), a set where all elements are sorted based on a Comparator

Single change operations

Operation	Description
append(Object)	Add element to end of the sequence
remove(int)	Remove an element by its index

Collection based operations

Operation	Description
complement(Iterable) complement(Iterable[])	Creates a set with elements only contained in this
intersect(Iterable) intersect(Iterable[])	Creates a set containing elements that are both in this and the provided iterables
map(Function)	Create a new sequence with the mapped values
filter(Predicate)	Create a new set with values matching the predicate
reject(Predicate)	Create a new sequence without the rejected values matching the predicate
union(Iterable)	Combine this sequence of elements with the provided iterable

Since:

0.0.3

Method Summary

Modifier and Type	Method	Description
Set<T>	append(T value)	Create a new list containing all elements in this instance and appending the provided value to the end of the new list.
default Set<T>	complement(java.lang.Iterable<T> iterable)	Creates a new set that contains elements that are only in this, but not contained within iterable.
Set<T>	complement(java.lang.Iterable<T>... iterables)	Creates a new set that contains elements that are only in this, but not contained within any of the iterables.
Set<T>	distinctBy(java.util.Comparator<T> comparator)	Creates a distinct list based upon the provided comparator.
Set<T>	filter(java.util.function.Predicate<T> predicate)	Filter out an element if it does not match the supplied predicate.
default T	head()	Fetch the head of the collection and return it.
default Set<T>	intersect(java.lang.Iterable<T> iterable)	Creates a set that contains only the elements that are in both this and the provided iterable.
Set<T>	intersect(java.lang.Iterable<T>... iterables)	Creates a set that contains only the elements that are in all collections and this.
<U> Set<U>	map(java.util.function.Function<T,U> mapper)	Perform a mapping operation on the elements in the stream.
Set<T>	orElse(java.lang.Iterable<? extends T> other)	Returns either this if it is non empty, otherwise will return the provided other.
Set<T>	orElse(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)	Returns either this if it is non empty, otherwise the provided supplier is evaluated and returned.
default Set<T>	reject(java.util.function.Predicate<T> predicate)	Return a list that removes all elements that match the predicate provided.
Set<T>	remove(int index)	Removes an element from the list and returns a new instance of the list.
Set<T>	tail()	Build a new collection with all elements except for the head.
java.util.Set<T>	toJava()	Transform this collection into one supported natively in Java.
Set<T>	union(java.lang.Iterable<T> iterable)	Create a new sequence with all elements of this sequence combined with the elements of the provided iterable.

Methods inherited from interface com.jongsoft.lang.collection.Collection

containsAll, count, first, foldLeft, foldRight, get, isEmpty, isSingleValued, last, reduceLeft, size, split, summing

Methods inherited from interface com.jongsoft.lang.collection.Foldable

fold, reduce

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface com.jongsoft.lang.collection.List

firstIndexWhere, get, groupBy, indexOf, pipeline

Methods inherited from interface com.jongsoft.lang.collection.Traversable

average, iterator, sum

Methods inherited from interface com.jongsoft.lang.Value

all, contains, exists, none, stream

Method Detail

append

Set<T> append(T value)

Description copied from interface: List

Create a new list containing all elements in this instance and appending the provided value to the end of the new list.

Example:

 // will result in a list with 2, 3, 4, 1
    List(2, 3, 4).append(1)
 

Specified by:

append in interface List<T>

Parameters:

value - the value to append to the list

Returns:

the new list with the value appended

distinctBy

Set<T> distinctBy(java.util.Comparator<T> comparator)

Description copied from interface: List

Creates a distinct list based upon the provided comparator. If a duplicate is found only the first match will be included in the returned list.

Specified by:

distinctBy in interface List<T>

Parameters:

comparator - the comparator to use for distinct check

Returns:

the distinct list

complement

default Set<T> complement(java.lang.Iterable<T> iterable)

Creates a new set that contains elements that are only in this, but not contained within iterable.

Example:

 // the example would be a Set(1, 2)
   Set result = Set(1, 2, 3).complement(Set(3, 4));
 

Parameters:

iterable - the iterable to perform the complement with

Returns:

the product of the complement operation

complement

Set<T> complement(java.lang.Iterable<T>... iterables)

Creates a new set that contains elements that are only in this, but not contained within any of the iterables.

Example:

 // the example would be a Set(1, 2)
   Set result = Set(1, 2, 3).complement(Set(3, 4));
 

Parameters:

iterables - the iterables to perform the complement with

Returns:

the product of the complement operation

filter

Set<T> filter(java.util.function.Predicate<T> predicate)

Description copied from interface: Streamable

Filter out an element if it does not match the supplied predicate. This operation will iterate over all elements and return a new set containing only the elements where the predicate returns true for.

Specified by:

filter in interface Collection<T>

Specified by:

filter in interface List<T>

Specified by:

filter in interface Streamable<T>

Specified by:

filter in interface Traversable<T>

Parameters:

predicate - the predicate to apply to the contents of this

Returns:

the filtered value

head

default T head()

Description copied from interface: Collection

Fetch the head of the collection and return it. The following operations will all return the same value for a non empty collection.

  Collection(0, 1).get();
   Collection(0, 1).head();
 

The caller must verify the collection is not empty using either Collection.size() or Collection.isEmpty() to prevent a NoSuchElementException to be thrown.

Specified by:

head in interface Collection<T>

Returns:

the first element in the collection

intersect

default Set<T> intersect(java.lang.Iterable<T> iterable)

Creates a set that contains only the elements that are in both this and the provided iterable.

Example:

 // the example would be a Set(3)
   Set result = Set(1, 2, 3).intersect(Set(3, 4));
 

Parameters:

iterable - the iterable to perform the intersects with

Returns:

the product of the intersect operation

intersect

Set<T> intersect(java.lang.Iterable<T>... iterables)

Creates a set that contains only the elements that are in all collections and this.

We say that A intersects (meets) B at an element x if x belongs to A and B. We say that A intersects (meets) B if A intersects B at some element. A intersects B if their intersection is inhabited.

Example:

 // the example would be a Set(3)
   Set result = Set(1, 2, 3).intersect(Set(3, 4));
 

Parameters:

iterables - the set of iterables the intersection should be calculated on

Returns:

the product of the intersect operation

map

<U> Set<U> map(java.util.function.Function<T,U> mapper)

Description copied from interface: Streamable

Perform a mapping operation on the elements in the stream.

This operation will loop over all elements in the stream and apply the mapper method. The mapped values will be returned in as a new stream of elements.

Specified by:

map in interface Collection<T>

Specified by:

map in interface List<T>

Specified by:

map in interface Streamable<T>

Specified by:

map in interface Traversable<T>

Type Parameters:

U - the type of object expected as a result

Parameters:

mapper - the mapping functionality

Returns:

the mapped object

orElse

Set<T> orElse(java.lang.Iterable<? extends T> other)

Description copied from interface: Traversable

Returns either this if it is non empty, otherwise will return the provided other.

Specified by:

orElse in interface Collection<T>

Specified by:

orElse in interface List<T>

Specified by:

orElse in interface Traversable<T>

Parameters:

other - the alternative

Returns:

this Traversable if non empty, or other

orElse

Set<T> orElse(java.util.function.Supplier<? extends java.lang.Iterable<? extends T>> supplier)

Description copied from interface: Traversable

Returns either this if it is non empty, otherwise the provided supplier is evaluated and returned.

Specified by:

orElse in interface Collection<T>

Specified by:

orElse in interface List<T>

Specified by:

orElse in interface Traversable<T>

Parameters:

supplier - the supplier to generate the other

Returns:

this (@code Traversable} if non empty, otherwise other

reject

default Set<T> reject(java.util.function.Predicate<T> predicate)

Description copied from interface: Traversable

Return a list that removes all elements that match the predicate provided.

Specified by:

reject in interface Collection<T>

Specified by:

reject in interface List<T>

Specified by:

reject in interface Traversable<T>

Parameters:

predicate - the predicate to use

Returns:

the elements that do not match the predicate

remove

Set<T> remove(int index)

Description copied from interface: List

Removes an element from the list and returns a new instance of the list.

Specified by:

remove in interface List<T>

Parameters:

index - the index of the element to be removed

Returns:

the new instance of the list without the element at the provided index

tail

Set<T> tail()

Description copied from interface: Collection

Build a new collection with all elements except for the head. If there is only one element present then an empty collection will be returned. If the operation is called on an empty collection an NoSuchElementException will be thrown.

Specified by:

tail in interface Collection<T>

Specified by:

tail in interface List<T>

Returns:

a collection containing the tail

toJava

java.util.Set<T> toJava()

Transform this collection into one supported natively in Java.

Returns:

the native java collection

union

Set<T> union(java.lang.Iterable<T> iterable)

Description copied from interface: List

Create a new sequence with all elements of this sequence combined with the elements of the provided iterable. The elements in this sequence will be added before the provided iterable in the returned sequence.

Example:

 // the example would be a List(1, 2, 3, 4)
   List<Integer> result = List(1, 2).union(List(3, 4));
 

Specified by:

union in interface List<T>

Parameters:

iterable - the elements to be added

Returns:

the new list containing a union between this and the iterable