public final class SetView<E> extends Object implements XGettingSet<E>
XGettingSet to only those of
XGettingSet, effectively making the wrapped XGettingSet instance immutable (or read-only)
if used through an instance of this class.
All methods declared in XGettingSet are transparently passed to the wrapped set.
All modifying methods declared in Collection and Set
(all variations of add~(), remove~() and retain~() as well as set() and clear()) immediately throw an
UnsupportedOperationException when called.
This concept can be very useful if a class wants to provide public read access to an internal set without either the danger of the set being modified from the outside or the need to copy the whole set on every access.
This is one of many useful concepts that are missing in the JDK Collections Framework and thus so far lead to either inefficient or unneccessary verbose program code (or both).
| Modifier and Type | Class and Description |
|---|---|
static class |
SetView.OldSetView<E> |
XGettingSet.Creator<E>XIterable.Executor<E>Copyable.Static| Constructor and Description |
|---|
SetView(XGettingSet<E> set) |
| Modifier and Type | Method and Description |
|---|---|
boolean |
applies(Predicate<? super E> predicate)
Tests each element of the collection on the given predicate.
|
boolean |
contains(E element)
Checks if the given element is contained in the collection.
|
boolean |
containsAll(XGettingCollection<? extends E> elements) |
boolean |
containsId(E element)
Special version of contains() that guarantees to use identity comparison (" == ") when searching for the
given element regardless of the collection's internal logic.
This method has the same behavior as XGettingCollection.containsSearched(Predicate) with a Predicate implementation
that checks for object identity. |
boolean |
containsSearched(Predicate<? super E> predicate) |
SetView<E> |
copy()
Creates a true copy of this collection which references the same elements as this collection does
at the time the method is called.
|
<C extends Consumer<? super E>> |
copyTo(C target)
Calls
Consumer.accept(Object) on the target Consumer for all the elements of this collection. |
long |
count(E element)
Count how many times this element matches another element in the collection
using the
Equalator. |
long |
countBy(Predicate<? super E> predicate)
Count how many matches are found using the given predicate on each element of the collection.
|
<C extends Consumer<? super E>> |
distinct(C target)
Calls
Consumer.accept(Object) on the target Consumer for all the unique/distinct
elements of this collection. |
<C extends Consumer<? super E>> |
distinct(C target,
Equalator<? super E> equalator)
Calls
Consumer.accept(Object) on the target Consumer for all the unique/distinct
elements of this collection. |
Equalator<? super E> |
equality() |
boolean |
equals(Object o)
Deprecated.
|
boolean |
equals(XGettingCollection<? extends E> samples,
Equalator<? super E> equalator) |
boolean |
equalsContent(XGettingCollection<? extends E> samples,
Equalator<? super E> equalator)
Returns
true if all elements of this list and the passed list are sequentially equal as defined
by the passed equalator. |
<C extends Consumer<? super E>> |
except(XGettingCollection<? extends E> other,
Equalator<? super E> equalator,
C target)
Calls
Consumer.accept(Object) on the target Consumer for each
element of this collection that is not contained in the other collection (through the given equalator). |
<C extends Consumer<? super E>> |
filterTo(C target,
Predicate<? super E> predicate)
Calls
Consumer.accept(Object) on the target Consumer for all the elements of this collection
which test true on the given predicate. |
E |
get()
Gets one element from the collection.
|
int |
hashCode()
Deprecated.
|
boolean |
hasVolatileElements()
Tells if this collection contains volatile elements.
An element is volatile, if it can become no longer reachable by the collection without being removed from the collection. |
XImmutableSet<E> |
immure()
Provides an instance of an immutable collection type with equal behavior and data as this instance.
|
<C extends Consumer<? super E>> |
intersect(XGettingCollection<? extends E> other,
Equalator<? super E> equalator,
C target)
Tests equality between each element of the two lists and calls
Consumer.accept(Object) on the target Consumer for the
equal elements.Therefore it effectively creates a mathematical intersection between the two collections. |
boolean |
isEmpty() |
boolean |
isFull() |
<P extends Consumer<? super E>> |
iterate(P procedure)
Executes the given procedure for each element of the
XIterable
until all elements have been processed or the action throws an
exception. |
Iterator<E> |
iterator() |
<A> A |
join(BiConsumer<? super E,? super A> joiner,
A aggregate)
Iterates over all elements of the collections and calls the joiner
with each element and the aggregate.
|
E |
max(Comparator<? super E> comparator) |
long |
maximumCapacity()
Returns the maximum amount of elements this carrier instance can contain.
The actual value may be depend on the configuration of the concrete instance or may depend only on the implementation of the carrier (meaning it is constant for all instances of the implementation, e.g. |
E |
min(Comparator<? super E> comparator) |
boolean |
nullAllowed()
Defines if null-elements are allowed inside the collection or not.
|
boolean |
nullContained() |
SetView.OldSetView<E> |
old() |
long |
remainingCapacity() |
E |
search(Predicate<? super E> predicate)
Returns the first contained element matching the passed predicate.
|
E |
seek(E sample)
Returns the first contained element matching the passed sample as defined by the collection's equality logic
or null, if no fitting element is contained.
|
long |
size() |
Object[] |
toArray()
Returns an array containing all of the elements in this collection.
|
E[] |
toArray(Class<E> type)
Returns a typed array containing all of the elements in this collection.
|
<C extends Consumer<? super E>> |
union(XGettingCollection<? extends E> other,
Equalator<? super E> equalator,
C target)
Calls
Consumer.accept(Object) on the target Consumer for all the elements of this collection. |
SetView<E> |
view()
Creates a view of this collection and returns it.
|
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, waitintSizeforEach, spliteratorpublic SetView(XGettingSet<E> set)
public E get()
XGettingCollectionXGettingSequence, then it is
undefined which element is returned. If the collection is ordered, the element at index 0 is returned.get in interface XGettingCollection<E>public Equalator<? super E> equality()
equality in interface XGettingCollection<E>public boolean hasVolatileElements()
ExtendedCollectionWeakReference of SoftReference or implementations of collection entries
that remove the element contained in an entry by some means outside the collection.WeakReference instances that are added to a a simple (non-volatile) implementation of a
collection do not make the collection volatile, as the elements themselves (the reference instances) are still
strongly referenced.hasVolatileElements in interface ExtendedCollection<E>hasVolatileElements in interface XGettingCollection<E>true if the collection contains volatile elements.public boolean containsSearched(Predicate<? super E> predicate)
containsSearched in interface XGettingCollection<E>public boolean applies(Predicate<? super E> predicate)
XGettingCollectionapplies in interface XGettingCollection<E>predicate - that's tested on each element.public boolean nullAllowed()
ExtendedCollectionnullAllowed in interface ExtendedCollection<E>true if null is allowed inside the collection; false if notpublic boolean nullContained()
nullContained in interface XGettingCollection<E>public boolean containsAll(XGettingCollection<? extends E> elements)
containsAll in interface XGettingCollection<E>elements - to be searched in the collection.Equalator.public boolean contains(E element)
XGettingCollectionXGettingCollection.containsId(Object) method, this method
uses the internal Equalator defined by the collection itself.contains in interface XGettingCollection<E>element - to be searched in the collectionEqualator.public boolean containsId(E element)
XGettingCollectionXGettingCollection.containsSearched(Predicate) with a Predicate implementation
that checks for object identity. The only difference is a performance and usability advantagecontainsId in interface XGettingCollection<E>element - the element to be searched in the collection by identity.public SetView<E> copy()
XGettingCollectioncopy in interface XGettingCollection<E>copy in interface XGettingSet<E>copy in interface Copyablepublic <C extends Consumer<? super E>> C filterTo(C target, Predicate<? super E> predicate)
XGettingCollectionConsumer.accept(Object) on the target Consumer for all the elements of this collection
which test true on the given predicate.
Since all MicroStream Collections implement the Consumer interface,
new collections can be used as target.
Example:
BulkList<Integer> collection1 = BulkList.New(1,2,3); BulkList<Integer> filteredCollection = collection1.filterTo(BulkList.New(), e-> e % 2 == 0);Results in
filteredCollection containing 2.filterTo in interface XGettingCollection<E>C - type of the targettarget - on which the Consumer.accept(Object) is called for elements that test true.predicate - on which to test all elements.public <C extends Consumer<? super E>> C copyTo(C target)
XGettingCollectionConsumer.accept(Object) on the target Consumer for all the elements of this collection.
Since all MicroStream Collections implement the Consumer interface,
new collections can be used as target.
Example:
BulkList<Integer> collection1 = BulkList.New(1,2,3); BulkList<Integer> copiedCollection = collection1.copyTo(BulkList.New());Results in
copiedCollection containing 1, 2 and 3.copyTo in interface XGettingCollection<E>C - type of the targettarget - on which the Consumer.accept(Object) is called for all elements of this collection.public long count(E element)
XGettingCollectionEqualator.count in interface XGettingCollection<E>element - to countpublic long countBy(Predicate<? super E> predicate)
XGettingCollectioncountBy in interface XGettingCollection<E>predicate - defines which elements are counted and which are notpublic <C extends Consumer<? super E>> C distinct(C target, Equalator<? super E> equalator)
XGettingCollectionConsumer.accept(Object) on the target Consumer for all the unique/distinct
elements of this collection. This means the elements are not equal to each other.Equalator.
Since all MicroStream Collections implement the Consumer interface,
new collections can be used as target.
Example:
BulkList<Integer> collection1 = BulkList.New(1,2,2,3); BulkList<Integer> distinctCollection = collection1.distinct(BulkList.New(), Equalator.identity());Results in
distinctCollection containing 1, 2 and 3.distinct in interface XGettingCollection<E>C - type of the targettarget - on which the Consumer.accept(Object) is called for every distinct element of this collection.equalator - defines what distinct means (which elements are equal to one another)public <C extends Consumer<? super E>> C distinct(C target)
XGettingCollectionConsumer.accept(Object) on the target Consumer for all the unique/distinct
elements of this collection. This means the elements are not equal to each other.Equalator.
Since all MicroStream Collections implement the Consumer interface,
new collections can be used as target.
Example:
BulkList<Integer> collection1 = BulkList.New(1,2,2,3);
BulkList<Integer> distinctCollection = collection1.distinct(BulkList.New());
Results in distinctCollection containing 1, 2 and 3.
distinct in interface XGettingCollection<E>C - type of the targettarget - on which the Consumer.accept(Object) is called for every distinct element of this collection.public boolean equals(XGettingCollection<? extends E> samples, Equalator<? super E> equalator)
equals in interface XGettingCollection<E>samples - is the collection which is checked for equalityequalator - is used to check the equality of the collectionstrue if the passed collection is of the same type as this collection and
this.equalsContent(list, equalator) yields truepublic boolean equalsContent(XGettingCollection<? extends E> samples, Equalator<? super E> equalator)
XGettingCollectiontrue if all elements of this list and the passed list are sequentially equal as defined
by the passed equalator.
Note that for colletion types that don't have a defined order of elements, this method is hardly usable
(as is XGettingCollection.equals(Object) for them as defined in Collection). The core problem of comparing
collections that have no defined order is that they aren't really reliably comparable to any other collection.
equalsContent in interface XGettingCollection<E>samples - is the collection which is checked for equalityequalator - the equalator to use to determine the equality of each elementtrue if this list is equal to the passed list, false otherwisepublic <C extends Consumer<? super E>> C except(XGettingCollection<? extends E> other, Equalator<? super E> equalator, C target)
XGettingCollectionConsumer.accept(Object) on the target Consumer for each
element of this collection that is not contained in the other collection (through the given equalator).
Since all MicroStream Collections implement the Consumer interface,
new collections can be used as target.
Example:
BulkList<Integer> collection1 = BulkList.New(1,2,3); BulkList<Integer> collection2 = BulkList.New(2,3,4); BulkList<Integer> exceptCollection = collection1.except(collection2, Equalator.identity(), BulkList.New());Results in
exceptCollection containing 1.except in interface XGettingCollection<E>C - type of the targetother - collection whose elements are excluded from the target.equalator - which is used for the equal-tests.target - on which the Consumer.accept(Object) is called for elements not contained in the other collection.public final <P extends Consumer<? super E>> P iterate(P procedure)
XIterableXIterable
until all elements have been processed or the action throws an
exception. Unless otherwise specified by the implementing class,
procedures are performed in the order of iteration (if an iteration order
is specified). Exceptions thrown by the procedure are relayed to the
caller.Iterable.forEach(Consumer).public final <A> A join(BiConsumer<? super E,? super A> joiner, A aggregate)
XJoinablepublic <C extends Consumer<? super E>> C intersect(XGettingCollection<? extends E> other, Equalator<? super E> equalator, C target)
XGettingCollectionConsumer.accept(Object) on the target Consumer for the
equal elements.
Since all MicroStream Collections implement the Consumer interface,
new collections can be used as target.
Example:
BulkList<Integer> collection1 = BulkList.New(1,2,3); BulkList<Integer> collection2 = BulkList.New(2,3,4); BulkList<Integer> intersection = collection1.intersect(collection2, Equalator.identity(), BulkList.New());Results in
intersection containing 2 and 3.intersect in interface XGettingCollection<E>C - type of the targetother - collection to intersect with.equalator - which is used for the equal-tests.target - on which the Consumer.accept(Object) is called for equal elements.public E max(Comparator<? super E> comparator)
max in interface XGettingCollection<E>public E min(Comparator<? super E> comparator)
min in interface XGettingCollection<E>public E seek(E sample)
XGettingCollectionXGettingCollection.contains(Object) with a different return type. For collections with data-dependant equality,
the returned element might be the same as the passed one or a data-wise equal one, depending on the content
of the collection)seek in interface XGettingCollection<E>sample - to seek in the collectionpublic E search(Predicate<? super E> predicate)
XGettingCollectionsearch in interface XGettingCollection<E>predicate - defines which element is searchedpublic E[] toArray(Class<E> type)
XGettingCollectionThe returned array will be "safe" in that no references to it are maintained by this list. (In other words, this method must allocate a new array). The caller is thus free to modify the returned array.
This method acts as bridge between MicroStream-based collections and Java-native-based APIs.
toArray in interface XGettingCollection<E>type - the Class representing type E at runtime.public <C extends Consumer<? super E>> C union(XGettingCollection<? extends E> other, Equalator<? super E> equalator, C target)
XGettingCollectionConsumer.accept(Object) on the target Consumer for all the elements of this collection.
And calls it for all elements of the other collection, that are not already in this collection
(defined by the given Equalator)
Since all MicroStream Collections implement the Consumer interface,
new collections can be used as target.
Example:
BulkList<Integer> collection1 = BulkList.New(1,2,3); BulkList<Integer> collection2 = BulkList.New(2,3,4); BulkList<Integer> union = collection1.union(collection2, Equalator.identity(), BulkList.New());Results in
union containing 1, 2, 3 and 4.union in interface XGettingCollection<E>C - type of the targetother - collection to build a union with.equalator - which is used for the equal-tests.target - on which the Consumer.accept(Object) is called for all unified elements.@Deprecated public int hashCode()
hashCode in interface XGettingCollection<E>hashCode in class Object@Deprecated public boolean equals(Object o)
XGettingCollectionCollection.
Note that it is this interface's author opinion that the whole concept of equals() in standard Java, especially
in the collection implementations, is flawed.
The reason is because all different kinds of comparison types that actually depend on the situation
have to be mixed up in a harcoded fashion in one method, from identity comparison over
data indentity comparison to content comparison.
In order to get the right behavior in every situation, one has to distinct between different types of equality
This means several things:
1.) You can't just say for example an ArrayList is the "same" as a LinkedList just because they contain the
same content.
There are different implementations for a good reason, so you have to distinct them when comparing.
There are simple code examples which create massive misbehavior that will catastrophically ruin the runtime
behavior of a programm due to this error in Java / JDK / Sun / whatever.
2.) You can't always determine equality of two collections by determining equality of each element as
Collection defines it.
As a conclusion: don't use this method!
Be clear what type of comparison you really need, then use one of the following methods
and proper comparators:
XGettingCollection.equals(XGettingCollection, Equalator)
XGettingCollection.equalsContent(XGettingCollection, Equalator)
equals in interface XGettingCollection<E>equals in class Objecto - the reference object with which to compare.public long size()
size in interface Sizedsize in interface XGettingCollection<E>public long maximumCapacity()
CapacityCarryingInteger.MAX_VALUE)maximumCapacity in interface CapacityCarryingpublic boolean isFull()
isFull in interface CapacityCarryingpublic long remainingCapacity()
remainingCapacity in interface CapacityCarryingpublic Object[] toArray()
XGettingCollectionThe returned array will be "safe" in that no references to it are maintained by this list. (In other words, this method must allocate a new array). The caller is thus free to modify the returned array.
This method acts as bridge between MicroStream-based collections and Java-native-based APIs.
toArray in interface XGettingCollection<E>public XImmutableSet<E> immure()
XGettingCollectionIf this instance already is of an immutable collection type, it returns itself.
immure in interface XGettingCollection<E>immure in interface XGettingSet<E>public SetView.OldSetView<E> old()
old in interface XGettingCollection<E>public SetView<E> view()
XGettingCollection
A view is different from immutable collection (XGettingCollection.immure())
in the way, that changes in this collection are still affecting the view.
The immutable collection on the other hand has no reference to this collection
and changes therefore do not affect the immutable collection.
view in interface XGettingCollection<E>Copyright © 2022 MicroStream Software. All rights reserved.