--- a/jdk/src/java.base/share/classes/java/util/Optional.java Mon Oct 19 19:14:29 2015 +0200
+++ b/jdk/src/java.base/share/classes/java/util/Optional.java Mon Oct 19 11:28:50 2015 -0700
@@ -31,21 +31,22 @@
import java.util.stream.Stream;
/**
- * A container object which may or may not contain a non-null value.
- * If a value is present, {@code isPresent()} will return {@code true} and
- * {@code get()} will return the value.
+ * A container object which may or may not contain a non-{@code null} value.
+ * If a value is present, {@code isPresent()} returns {@code true} and
+ * {@code get()} returns the value.
*
* <p>Additional methods that depend on the presence or absence of a contained
* value are provided, such as {@link #orElse(java.lang.Object) orElse()}
- * (return a default value if value not present) and
- * {@link #ifPresent(java.util.function.Consumer) ifPresent()} (perform an
- * action if the value is present).
+ * (returns a default value if no value is present) and
+ * {@link #ifPresent(java.util.function.Consumer) ifPresent()} (performs an
+ * action if a value is present).
*
* <p>This is a <a href="../lang/doc-files/ValueBased.html">value-based</a>
* class; use of identity-sensitive operations (including reference equality
* ({@code ==}), identity hash code, or synchronization) on instances of
* {@code Optional} may have unpredictable results and should be avoided.
*
+ * @param <T> the type of value
* @since 1.8
*/
public final class Optional<T> {
@@ -71,14 +72,15 @@
/**
* Returns an empty {@code Optional} instance. No value is present for this
- * Optional.
+ * {@code Optional}.
*
- * @apiNote Though it may be tempting to do so, avoid testing if an object
- * is empty by comparing with {@code ==} against instances returned by
- * {@code Option.empty()}. There is no guarantee that it is a singleton.
+ * @apiNote
+ * Though it may be tempting to do so, avoid testing if an object is empty
+ * by comparing with {@code ==} against instances returned by
+ * {@code Optional.empty()}. There is no guarantee that it is a singleton.
* Instead, use {@link #isPresent()}.
*
- * @param <T> Type of the non-existent value
+ * @param <T> The type of the non-existent value
* @return an empty {@code Optional}
*/
public static<T> Optional<T> empty() {
@@ -88,47 +90,47 @@
}
/**
- * Constructs an instance with the value present.
+ * Constructs an instance with the described value.
*
- * @param value the non-null value to be present
- * @throws NullPointerException if value is null
+ * @param value the non-{@code null} value to describe
+ * @throws NullPointerException if value is {@code null}
*/
private Optional(T value) {
this.value = Objects.requireNonNull(value);
}
/**
- * Returns an {@code Optional} with the specified present non-null value.
+ * Returns an {@code Optional} describing the given non-{@code null}
+ * value.
*
- * @param <T> the class of the value
- * @param value the value to be present, which must be non-null
+ * @param value the value to describe, which must be non-{@code null}
+ * @param <T> the type of the value
* @return an {@code Optional} with the value present
- * @throws NullPointerException if value is null
+ * @throws NullPointerException if value is {@code null}
*/
public static <T> Optional<T> of(T value) {
return new Optional<>(value);
}
/**
- * Returns an {@code Optional} describing the specified value, if non-null,
- * otherwise returns an empty {@code Optional}.
+ * Returns an {@code Optional} describing the given value, if
+ * non-{@code null}, otherwise returns an empty {@code Optional}.
*
- * @param <T> the class of the value
- * @param value the possibly-null value to describe
+ * @param value the possibly-{@code null} value to describe
+ * @param <T> the type of the value
* @return an {@code Optional} with a present value if the specified value
- * is non-null, otherwise an empty {@code Optional}
+ * is non-{@code null}, otherwise an empty {@code Optional}
*/
public static <T> Optional<T> ofNullable(T value) {
return value == null ? empty() : of(value);
}
/**
- * If a value is present in this {@code Optional}, returns the value,
- * otherwise throws {@code NoSuchElementException}.
+ * If a value is present, returns the value, otherwise throws
+ * {@code NoSuchElementException}.
*
- * @return the non-null value held by this {@code Optional}
- * @throws NoSuchElementException if there is no value present
- *
+ * @return the non-{@code null} value described by this {@code Optional}
+ * @throws NoSuchElementException if no value is present
* @see Optional#isPresent()
*/
public T get() {
@@ -139,21 +141,21 @@
}
/**
- * Return {@code true} if there is a value present, otherwise {@code false}.
+ * If a value is present, returns {@code true}, otherwise {@code false}.
*
- * @return {@code true} if there is a value present, otherwise {@code false}
+ * @return {@code true} if a value is present, otherwise {@code false}
*/
public boolean isPresent() {
return value != null;
}
/**
- * If a value is present, perform the given action with the value,
- * otherwise do nothing.
+ * If a value is present, performs the given action with the value,
+ * otherwise does nothing.
*
- * @param action the action to be performed if a value is present
- * @throws NullPointerException if a value is present and {@code action} is
- * null
+ * @param action the action to be performed, if a value is present
+ * @throws NullPointerException if value is present and the given action is
+ * {@code null}
*/
public void ifPresent(Consumer<? super T> action) {
if (value != null) {
@@ -162,15 +164,16 @@
}
/**
- * If a value is present, perform the given action with the value,
- * otherwise perform the given empty-based action.
+ * If a value is present, performs the given action with the value,
+ * otherwise performs the given empty-based action.
*
- * @param action the action to be performed if a value is present
- * @param emptyAction the empty-based action to be performed if a value is
- * not present
- * @throws NullPointerException if a value is present and {@code action} is
- * null, or a value is not present and {@code emptyAction} is null.
- * @since 1.9
+ * @param action the action to be performed, if a value is present
+ * @param emptyAction the empty-based action to be performed, if no value is
+ * present
+ * @throws NullPointerException if a value is present and the given action
+ * is {@code null}, or no value is present and the given empty-based
+ * action is {@code null}.
+ * @since 9
*/
public void ifPresentOrElse(Consumer<? super T> action, Runnable emptyAction) {
if (value != null) {
@@ -182,14 +185,14 @@
/**
* If a value is present, and the value matches the given predicate,
- * return an {@code Optional} describing the value, otherwise return an
+ * returns an {@code Optional} describing the value, otherwise returns an
* empty {@code Optional}.
*
- * @param predicate a predicate to apply to the value, if present
- * @return an {@code Optional} describing the value of this {@code Optional}
- * if a value is present and the value matches the given predicate,
- * otherwise an empty {@code Optional}
- * @throws NullPointerException if the predicate is null
+ * @param predicate the predicate to apply to a value, if present
+ * @return an {@code Optional} describing the value of this
+ * {@code Optional}, if a value is present and the value matches the
+ * given predicate, otherwise an empty {@code Optional}
+ * @throws NullPointerException if the predicate is {@code null}
*/
public Optional<T> filter(Predicate<? super T> predicate) {
Objects.requireNonNull(predicate);
@@ -201,14 +204,18 @@
}
/**
- * If a value is present, apply the provided mapping function to it,
- * and if the result is non-null, return an {@code Optional} describing the
- * result. Otherwise return an empty {@code Optional}.
+ * If a value is present, returns an {@code Optional} describing (as if by
+ * {@link #ofNullable}) the result of applying the given mapping function to
+ * the value, otherwise returns an empty {@code Optional}.
*
- * @apiNote This method supports post-processing on optional values, without
+ * <p>If the mapping function returns a {@code null} result then this method
+ * returns an empty {@code Optional}.
+ *
+ * @apiNote
+ * This method supports post-processing on {@code Optional} values, without
* the need to explicitly check for a return status. For example, the
- * following code traverses a stream of file names, selects one that has
- * not yet been processed, and then opens that file, returning an
+ * following code traverses a stream of file names, selects one that has not
+ * yet been processed, and then opens that file, returning an
* {@code Optional<FileInputStream>}:
*
* <pre>{@code
@@ -222,12 +229,12 @@
* {@code map} returns an {@code Optional<FileInputStream>} for the desired
* file if one exists.
*
- * @param <U> The type of the result of the mapping function
- * @param mapper a mapping function to apply to the value, if present
+ * @param mapper the mapping function to apply to a value, if present
+ * @param <U> The type of the value returned from the mapping function
* @return an {@code Optional} describing the result of applying a mapping
- * function to the value of this {@code Optional}, if a value is present,
- * otherwise an empty {@code Optional}
- * @throws NullPointerException if the mapping function is null
+ * function to the value of this {@code Optional}, if a value is
+ * present, otherwise an empty {@code Optional}
+ * @throws NullPointerException if the mapping function is {@code null}
*/
public<U> Optional<U> map(Function<? super T, ? extends U> mapper) {
Objects.requireNonNull(mapper);
@@ -239,21 +246,23 @@
}
/**
- * If a value is present, apply the provided {@code Optional}-bearing
- * mapping function to it, return that result, otherwise return an empty
- * {@code Optional}. This method is similar to {@link #map(Function)},
- * but the provided mapper is one whose result is already an {@code Optional},
- * and if invoked, {@code flatMap} does not wrap it with an additional
+ * If a value is present, returns the result of applying the given
+ * {@code Optional}-bearing mapping function to the value, otherwise returns
+ * an empty {@code Optional}.
+ *
+ * <p>This method is similar to {@link #map(Function)}, but the mapping
+ * function is one whose result is already an {@code Optional}, and if
+ * invoked, {@code flatMap} does not wrap it within an additional
* {@code Optional}.
*
- * @param <U> The type parameter to the {@code Optional} returned by
- * @param mapper a mapping function to apply to the value, if present
- * the mapping function
+ * @param <U> The type of value of the {@code Optional} returned by the
+ * mapping function
+ * @param mapper the mapping function to apply to a value, if present
* @return the result of applying an {@code Optional}-bearing mapping
- * function to the value of this {@code Optional}, if a value is present,
- * otherwise an empty {@code Optional}
- * @throws NullPointerException if the mapping function is null or returns
- * a null result
+ * function to the value of this {@code Optional}, if a value is
+ * present, otherwise an empty {@code Optional}
+ * @throws NullPointerException if the mapping function is {@code null} or
+ * returns a {@code null} result
*/
public<U> Optional<U> flatMap(Function<? super T, Optional<U>> mapper) {
Objects.requireNonNull(mapper);
@@ -265,19 +274,41 @@
}
/**
- * If a value is present return a sequential {@link Stream} containing only
- * that value, otherwise return an empty {@code Stream}.
+ * If a value is present, returns an {@code Optional} describing the value,
+ * otherwise returns an {@code Optional} produced by the supplying function.
*
- * @apiNote This method can be used to transform a {@code Stream} of
- * optional elements to a {@code Stream} of present value elements:
+ * @param supplier the supplying function that produces an {@code Optional}
+ * to be returned
+ * @return returns an {@code Optional} describing the value of this
+ * {@code Optional}, if a value is present, otherwise an
+ * {@code Optional} produced by the supplying function.
+ * @throws NullPointerException if the supplying function is {@code null} or
+ * produces a {@code null} result
+ * @since 9
+ */
+ public Optional<T> or(Supplier<Optional<T>> supplier) {
+ Objects.requireNonNull(supplier);
+ if (isPresent()) {
+ return this;
+ } else {
+ return Objects.requireNonNull(supplier.get());
+ }
+ }
+
+ /**
+ * If a value is present, returns a sequential {@link Stream} containing
+ * only that value, otherwise returns an empty {@code Stream}.
*
+ * @apiNote
+ * This method can be used to transform a {@code Stream} of optional
+ * elements to a {@code Stream} of present value elements:
* <pre>{@code
* Stream<Optional<T>> os = ..
* Stream<T> s = os.flatMap(Optional::stream)
* }</pre>
*
* @return the optional value as a {@code Stream}
- * @since 1.9
+ * @since 9
*/
public Stream<T> stream() {
if (!isPresent()) {
@@ -288,10 +319,11 @@
}
/**
- * Return the value if present, otherwise return {@code other}.
+ * If a value is present, returns the value, otherwise returns
+ * {@code other}.
*
- * @param other the value to be returned if there is no value present, may
- * be null
+ * @param other the value to be returned, if no value is present.
+ * May be {@code null}.
* @return the value, if present, otherwise {@code other}
*/
public T orElse(T other) {
@@ -299,34 +331,35 @@
}
/**
- * Return the value if present, otherwise invoke {@code other} and return
- * the result of that invocation.
+ * If a value is present, returns the value, otherwise returns the result
+ * produced by the supplying function.
*
- * @param other a {@code Supplier} whose result is returned if no value
- * is present
- * @return the value if present otherwise the result of {@code other.get()}
- * @throws NullPointerException if value is not present and {@code other} is
- * null
+ * @param supplier the supplying function that produces a value to be returned
+ * @return the value, if present, otherwise the result produced by the
+ * supplying function
+ * @throws NullPointerException if no value is present and the supplying
+ * function is {@code null}
*/
- public T orElseGet(Supplier<? extends T> other) {
- return value != null ? value : other.get();
+ public T orElseGet(Supplier<? extends T> supplier) {
+ return value != null ? value : supplier.get();
}
/**
- * Return the contained value, if present, otherwise throw an exception
- * to be created by the provided supplier.
+ * If a value is present, returns the value, otherwise throws an exception
+ * produced by the exception supplying function.
*
- * @apiNote A method reference to the exception constructor with an empty
- * argument list can be used as the supplier. For example,
+ * @apiNote
+ * A method reference to the exception constructor with an empty argument
+ * list can be used as the supplier. For example,
* {@code IllegalStateException::new}
*
* @param <X> Type of the exception to be thrown
- * @param exceptionSupplier The supplier which will return the exception to
- * be thrown
- * @return the present value
- * @throws X if there is no value present
- * @throws NullPointerException if no value is present and
- * {@code exceptionSupplier} is null
+ * @param exceptionSupplier the supplying function that produces an
+ * exception to be thrown
+ * @return the value, if present
+ * @throws X if no value is present
+ * @throws NullPointerException if no value is present and the exception
+ * supplying function is {@code null}
*/
public <X extends Throwable> T orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
if (value != null) {
@@ -337,8 +370,8 @@
}
/**
- * Indicates whether some other object is "equal to" this Optional. The
- * other object is considered equal if:
+ * Indicates whether some other object is "equal to" this {@code Optional}.
+ * The other object is considered equal if:
* <ul>
* <li>it is also an {@code Optional} and;
* <li>both instances have no value present or;
@@ -347,7 +380,7 @@
*
* @param obj an object to be tested for equality
* @return {@code true} if the other object is "equal to" this object
- * otherwise {@code false}
+ * otherwise {@code false}
*/
@Override
public boolean equals(Object obj) {
@@ -364,10 +397,11 @@
}
/**
- * Returns the hash code value of the present value, if any, or 0 (zero) if
- * no value is present.
+ * Returns the hash code of the value, if present, otherwise {@code 0}
+ * (zero) if no value is present.
*
- * @return hash code value of the present value or 0 if no value is present
+ * @return hash code value of the present value or {@code 0} if no value is
+ * present
*/
@Override
public int hashCode() {
@@ -375,13 +409,14 @@
}
/**
- * Returns a non-empty string representation of this Optional suitable for
- * debugging. The exact presentation format is unspecified and may vary
- * between implementations and versions.
+ * Returns a non-empty string representation of this {@code Optional}
+ * suitable for debugging. The exact presentation format is unspecified and
+ * may vary between implementations and versions.
*
- * @implSpec If a value is present the result must include its string
- * representation in the result. Empty and present Optionals must be
- * unambiguously differentiable.
+ * @implSpec
+ * If a value is present the result must include its string representation
+ * in the result. Empty and present {@code Optional}s must be unambiguously
+ * differentiable.
*
* @return the string representation of this instance
*/
--- a/jdk/src/java.base/share/classes/java/util/OptionalDouble.java Mon Oct 19 19:14:29 2015 +0200
+++ b/jdk/src/java.base/share/classes/java/util/OptionalDouble.java Mon Oct 19 11:28:50 2015 -0700
@@ -30,15 +30,15 @@
import java.util.stream.DoubleStream;
/**
- * A container object which may or may not contain a {@code double} value.
- * If a value is present, {@code isPresent()} will return {@code true} and
- * {@code getAsDouble()} will return the value.
+ * A container object which may or may not contain a {@code double} value. If a
+ * value is present, {@code isPresent()} returns {@code true} and
+ * {@code getAsDouble()} returns the value.
*
* <p>Additional methods that depend on the presence or absence of a contained
* value are provided, such as {@link #orElse(double) orElse()}
- * (return a default value if value not present) and
- * {@link #ifPresent(java.util.function.DoubleConsumer) ifPresent()} (perform an
- * action if the value is present).
+ * (returns a default value if no value is present) and
+ * {@link #ifPresent(java.util.function.DoubleConsumer) ifPresent()} (performs
+ * an action if a value is present).
*
* <p>This is a <a href="../lang/doc-files/ValueBased.html">value-based</a>
* class; use of identity-sensitive operations (including reference equality
@@ -71,12 +71,13 @@
}
/**
- * Returns an empty {@code OptionalDouble} instance. No value is present for this
- * OptionalDouble.
+ * Returns an empty {@code OptionalDouble} instance. No value is present
+ * for this {@code OptionalDouble}.
*
- * @apiNote Though it may be tempting to do so, avoid testing if an object
- * is empty by comparing with {@code ==} against instances returned by
- * {@code Option.empty()}. There is no guarantee that it is a singleton.
+ * @apiNote
+ * Though it may be tempting to do so, avoid testing if an object is empty
+ * by comparing with {@code ==} against instances returned by
+ * {@code OptionalDouble.empty()}. There is no guarantee that it is a singleton.
* Instead, use {@link #isPresent()}.
*
* @return an empty {@code OptionalDouble}.
@@ -86,9 +87,9 @@
}
/**
- * Construct an instance with the value present.
+ * Construct an instance with the described value.
*
- * @param value the double value to be present.
+ * @param value the double value to describe.
*/
private OptionalDouble(double value) {
this.isPresent = true;
@@ -96,9 +97,9 @@
}
/**
- * Return an {@code OptionalDouble} with the specified value present.
+ * Returns an {@code OptionalDouble} describing the given value.
*
- * @param value the value to be present
+ * @param value the value to describe
* @return an {@code OptionalDouble} with the value present
*/
public static OptionalDouble of(double value) {
@@ -106,12 +107,11 @@
}
/**
- * If a value is present in this {@code OptionalDouble}, returns the value,
- * otherwise throws {@code NoSuchElementException}.
+ * If a value is present, returns the value, otherwise throws
+ * {@code NoSuchElementException}.
*
- * @return the value held by this {@code OptionalDouble}
- * @throws NoSuchElementException if there is no value present
- *
+ * @return the value described by this {@code OptionalDouble}
+ * @throws NoSuchElementException if no value is present
* @see OptionalDouble#isPresent()
*/
public double getAsDouble() {
@@ -122,21 +122,21 @@
}
/**
- * Return {@code true} if there is a value present, otherwise {@code false}.
+ * If a value is present, returns {@code true}, otherwise {@code false}.
*
- * @return {@code true} if there is a value present, otherwise {@code false}
+ * @return {@code true} if a value is present, otherwise {@code false}
*/
public boolean isPresent() {
return isPresent;
}
/**
- * If a value is present, perform the given action with the value,
- * otherwise do nothing.
+ * If a value is present, performs the given action with the value,
+ * otherwise does nothing.
*
- * @param action the action to be performed if a value is present
- * @throws NullPointerException if a value is present and {@code action} is
- * null
+ * @param action the action to be performed, if a value is present
+ * @throws NullPointerException if value is present and the given action is
+ * {@code null}
*/
public void ifPresent(DoubleConsumer action) {
if (isPresent) {
@@ -145,15 +145,16 @@
}
/**
- * If a value is present, perform the given action with the value,
- * otherwise perform the given empty-based action.
+ * If a value is present, performs the given action with the value,
+ * otherwise performs the given empty-based action.
*
- * @param action the action to be performed if a value is present
- * @param emptyAction the empty-based action to be performed if a value is
- * not present
- * @throws NullPointerException if a value is present and {@code action} is
- * null, or a value is not present and {@code emptyAction} is null.
- * @since 1.9
+ * @param action the action to be performed, if a value is present
+ * @param emptyAction the empty-based action to be performed, if no value is
+ * present
+ * @throws NullPointerException if a value is present and the given action
+ * is {@code null}, or no value is present and the given empty-based
+ * action is {@code null}.
+ * @since 9
*/
public void ifPresentOrElse(DoubleConsumer action, Runnable emptyAction) {
if (isPresent) {
@@ -164,19 +165,20 @@
}
/**
- * If a value is present return a sequential {@link DoubleStream} containing
- * only that value, otherwise return an empty {@code DoubleStream}.
+ * If a value is present, returns a sequential {@link DoubleStream}
+ * containing only that value, otherwise returns an empty
+ * {@code DoubleStream}.
*
- * @apiNote This method can be used to transform a {@code Stream} of
- * optional doubles to a {@code DoubleStream} of present doubles:
- *
+ * @apiNote
+ * This method can be used to transform a {@code Stream} of optional doubles
+ * to a {@code DoubleStream} of present doubles:
* <pre>{@code
* Stream<OptionalDouble> os = ..
* DoubleStream s = os.flatMapToDouble(OptionalDouble::stream)
* }</pre>
*
* @return the optional value as a {@code DoubleStream}
- * @since 1.9
+ * @since 9
*/
public DoubleStream stream() {
if (isPresent) {
@@ -187,9 +189,10 @@
}
/**
- * Return the value if present, otherwise return {@code other}.
+ * If a value is present, returns the value, otherwise returns
+ * {@code other}.
*
- * @param other the value to be returned if there is no value present
+ * @param other the value to be returned, if no value is present
* @return the value, if present, otherwise {@code other}
*/
public double orElse(double other) {
@@ -197,34 +200,35 @@
}
/**
- * Return the value if present, otherwise invoke {@code other} and return
- * the result of that invocation.
+ * If a value is present, returns the value, otherwise returns the result
+ * produced by the supplying function.
*
- * @param other a {@code DoubleSupplier} whose result is returned if no value
- * is present
- * @return the value if present otherwise the result of {@code other.getAsDouble()}
- * @throws NullPointerException if value is not present and {@code other} is
- * null
+ * @param supplier the supplying function that produces a value to be returned
+ * @return the value, if present, otherwise the result produced by the
+ * supplying function
+ * @throws NullPointerException if no value is present and the supplying
+ * function is {@code null}
*/
- public double orElseGet(DoubleSupplier other) {
- return isPresent ? value : other.getAsDouble();
+ public double orElseGet(DoubleSupplier supplier) {
+ return isPresent ? value : supplier.getAsDouble();
}
/**
- * Return the contained value, if present, otherwise throw an exception
- * to be created by the provided supplier.
+ * If a value is present, returns the value, otherwise throws an exception
+ * produced by the exception supplying function.
*
- * @apiNote A method reference to the exception constructor with an empty
- * argument list can be used as the supplier. For example,
+ * @apiNote
+ * A method reference to the exception constructor with an empty argument
+ * list can be used as the supplier. For example,
* {@code IllegalStateException::new}
*
* @param <X> Type of the exception to be thrown
- * @param exceptionSupplier The supplier which will return the exception to
- * be thrown
- * @return the present value
- * @throws X if there is no value present
- * @throws NullPointerException if no value is present and
- * {@code exceptionSupplier} is null
+ * @param exceptionSupplier the supplying function that produces an
+ * exception to be thrown
+ * @return the value, if present
+ * @throws X if no value is present
+ * @throws NullPointerException if no value is present and the exception
+ * supplying function is {@code null}
*/
public<X extends Throwable> double orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
if (isPresent) {
@@ -235,17 +239,18 @@
}
/**
- * Indicates whether some other object is "equal to" this OptionalDouble. The
- * other object is considered equal if:
+ * Indicates whether some other object is "equal to" this
+ * {@code OptionalDouble}. The other object is considered equal if:
* <ul>
* <li>it is also an {@code OptionalDouble} and;
* <li>both instances have no value present or;
- * <li>the present values are "equal to" each other via {@code Double.compare() == 0}.
+ * <li>the present values are "equal to" each other via
+ * {@code Double.compare() == 0}.
* </ul>
*
* @param obj an object to be tested for equality
* @return {@code true} if the other object is "equal to" this object
- * otherwise {@code false}
+ * otherwise {@code false}
*/
@Override
public boolean equals(Object obj) {
@@ -264,10 +269,11 @@
}
/**
- * Returns the hash code value of the present value, if any, or 0 (zero) if
- * no value is present.
+ * Returns the hash code of the value, if present, otherwise {@code 0}
+ * (zero) if no value is present.
*
- * @return hash code value of the present value or 0 if no value is present
+ * @return hash code value of the present value or {@code 0} if no value is
+ * present
*/
@Override
public int hashCode() {
@@ -275,14 +281,13 @@
}
/**
- * {@inheritDoc}
+ * Returns a non-empty string representation of this {@code OptionalDouble}
+ * suitable for debugging. The exact presentation format is unspecified and
+ * may vary between implementations and versions.
*
- * Returns a non-empty string representation of this object suitable for
- * debugging. The exact presentation format is unspecified and may vary
- * between implementations and versions.
- *
- * @implSpec If a value is present the result must include its string
- * representation in the result. Empty and present instances must be
+ * @implSpec
+ * If a value is present the result must include its string representation
+ * in the result. Empty and present {@code OptionalDouble}s must be
* unambiguously differentiable.
*
* @return the string representation of this instance
--- a/jdk/src/java.base/share/classes/java/util/OptionalInt.java Mon Oct 19 19:14:29 2015 +0200
+++ b/jdk/src/java.base/share/classes/java/util/OptionalInt.java Mon Oct 19 11:28:50 2015 -0700
@@ -30,15 +30,15 @@
import java.util.stream.IntStream;
/**
- * A container object which may or may not contain a {@code int} value.
- * If a value is present, {@code isPresent()} will return {@code true} and
- * {@code getAsInt()} will return the value.
+ * A container object which may or may not contain an {@code int} value. If a
+ * value is present, {@code isPresent()} returns {@code true} and
+ * {@code getAsInt()} returns the value.
*
* <p>Additional methods that depend on the presence or absence of a contained
* value are provided, such as {@link #orElse(int) orElse()}
- * (return a default value if value not present) and
- * {@link #ifPresent(java.util.function.IntConsumer) ifPresent()} (perform an
- * action if the value is present).
+ * (returns a default value if no value is present) and
+ * {@link #ifPresent(java.util.function.IntConsumer) ifPresent()} (performs an
+ * action if a value is present).
*
* <p>This is a <a href="../lang/doc-files/ValueBased.html">value-based</a>
* class; use of identity-sensitive operations (including reference equality
@@ -71,24 +71,25 @@
}
/**
- * Returns an empty {@code OptionalInt} instance. No value is present for this
- * OptionalInt.
+ * Returns an empty {@code OptionalInt} instance. No value is present for
+ * this {@code OptionalInt}.
*
- * @apiNote Though it may be tempting to do so, avoid testing if an object
- * is empty by comparing with {@code ==} against instances returned by
- * {@code Option.empty()}. There is no guarantee that it is a singleton.
+ * @apiNote
+ * Though it may be tempting to do so, avoid testing if an object is empty
+ * by comparing with {@code ==} against instances returned by
+ * {@code OptionalInt.empty()}. There is no guarantee that it is a singleton.
* Instead, use {@link #isPresent()}.
*
- * @return an empty {@code OptionalInt}
+ * @return an empty {@code OptionalInt}
*/
public static OptionalInt empty() {
return EMPTY;
}
/**
- * Construct an instance with the value present.
+ * Construct an instance with the described value.
*
- * @param value the int value to be present
+ * @param value the int value to describe
*/
private OptionalInt(int value) {
this.isPresent = true;
@@ -96,9 +97,9 @@
}
/**
- * Return an {@code OptionalInt} with the specified value present.
+ * Returns an {@code OptionalInt} describing the given value.
*
- * @param value the value to be present
+ * @param value the value to describe
* @return an {@code OptionalInt} with the value present
*/
public static OptionalInt of(int value) {
@@ -106,12 +107,11 @@
}
/**
- * If a value is present in this {@code OptionalInt}, returns the value,
- * otherwise throws {@code NoSuchElementException}.
+ * If a value is present, returns the value, otherwise throws
+ * {@code NoSuchElementException}.
*
- * @return the value held by this {@code OptionalInt}
- * @throws NoSuchElementException if there is no value present
- *
+ * @return the value described by this {@code OptionalInt}
+ * @throws NoSuchElementException if no value is present
* @see OptionalInt#isPresent()
*/
public int getAsInt() {
@@ -122,21 +122,21 @@
}
/**
- * Return {@code true} if there is a value present, otherwise {@code false}.
+ * If a value is present, returns {@code true}, otherwise {@code false}.
*
- * @return {@code true} if there is a value present, otherwise {@code false}
+ * @return {@code true} if a value is present, otherwise {@code false}
*/
public boolean isPresent() {
return isPresent;
}
/**
- * If a value is present, perform the given action with the value,
- * otherwise do nothing.
+ * If a value is present, performs the given action with the value,
+ * otherwise does nothing.
*
- * @param action the action to be performed if a value is present
- * @throws NullPointerException if value is present and {@code action} is
- * null
+ * @param action the action to be performed, if a value is present
+ * @throws NullPointerException if value is present and the given action is
+ * {@code null}
*/
public void ifPresent(IntConsumer action) {
if (isPresent) {
@@ -145,15 +145,16 @@
}
/**
- * If a value is present, perform the given action with the value,
- * otherwise perform the given empty-based action.
+ * If a value is present, performs the given action with the value,
+ * otherwise performs the given empty-based action.
*
- * @param action the action to be performed if a value is present
- * @param emptyAction the empty-based action to be performed if a value is
- * not present
- * @throws NullPointerException if a value is present and {@code action} is
- * null, or a value is not present and {@code emptyAction} is null.
- * @since 1.9
+ * @param action the action to be performed, if a value is present
+ * @param emptyAction the empty-based action to be performed, if no value is
+ * present
+ * @throws NullPointerException if a value is present and the given action
+ * is {@code null}, or no value is present and the given empty-based
+ * action is {@code null}.
+ * @since 9
*/
public void ifPresentOrElse(IntConsumer action, Runnable emptyAction) {
if (isPresent) {
@@ -164,19 +165,19 @@
}
/**
- * If a value is present return a sequential {@link IntStream} containing
- * only that value, otherwise return an empty {@code IntStream}.
+ * If a value is present, returns a sequential {@link IntStream} containing
+ * only that value, otherwise returns an empty {@code IntStream}.
*
- * @apiNote This method can be used to transform a {@code Stream} of
- * optional integers to an {@code IntStream} of present integers:
- *
+ * @apiNote
+ * This method can be used to transform a {@code Stream} of optional
+ * integers to an {@code IntStream} of present integers:
* <pre>{@code
* Stream<OptionalInt> os = ..
* IntStream s = os.flatMapToInt(OptionalInt::stream)
* }</pre>
*
* @return the optional value as an {@code IntStream}
- * @since 1.9
+ * @since 9
*/
public IntStream stream() {
if (isPresent) {
@@ -187,9 +188,10 @@
}
/**
- * Return the value if present, otherwise return {@code other}.
+ * If a value is present, returns the value, otherwise returns
+ * {@code other}.
*
- * @param other the value to be returned if there is no value present
+ * @param other the value to be returned, if no value is present
* @return the value, if present, otherwise {@code other}
*/
public int orElse(int other) {
@@ -197,34 +199,35 @@
}
/**
- * Return the value if present, otherwise invoke {@code other} and return
- * the result of that invocation.
+ * If a value is present, returns the value, otherwise returns the result
+ * produced by the supplying function.
*
- * @param other a {@code IntSupplier} whose result is returned if no value
- * is present
- * @return the value if present otherwise the result of {@code other.getAsInt()}
- * @throws NullPointerException if value is not present and {@code other} is
- * null
+ * @param supplier the supplying function that produces a value to be returned
+ * @return the value, if present, otherwise the result produced by the
+ * supplying function
+ * @throws NullPointerException if no value is present and the supplying
+ * function is {@code null}
*/
- public int orElseGet(IntSupplier other) {
- return isPresent ? value : other.getAsInt();
+ public int orElseGet(IntSupplier supplier) {
+ return isPresent ? value : supplier.getAsInt();
}
/**
- * Return the contained value, if present, otherwise throw an exception
- * to be created by the provided supplier.
+ * If a value is present, returns the value, otherwise throws an exception
+ * produced by the exception supplying function.
*
- * @apiNote A method reference to the exception constructor with an empty
- * argument list can be used as the supplier. For example,
+ * @apiNote
+ * A method reference to the exception constructor with an empty argument
+ * list can be used as the supplier. For example,
* {@code IllegalStateException::new}
*
* @param <X> Type of the exception to be thrown
- * @param exceptionSupplier The supplier which will return the exception to
- * be thrown
- * @return the present value
- * @throws X if there is no value present
- * @throws NullPointerException if no value is present and
- * {@code exceptionSupplier} is null
+ * @param exceptionSupplier the supplying function that produces an
+ * exception to be thrown
+ * @return the value, if present
+ * @throws X if no value is present
+ * @throws NullPointerException if no value is present and the exception
+ * supplying function is {@code null}
*/
public<X extends Throwable> int orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
if (isPresent) {
@@ -235,8 +238,8 @@
}
/**
- * Indicates whether some other object is "equal to" this OptionalInt. The
- * other object is considered equal if:
+ * Indicates whether some other object is "equal to" this
+ * {@code OptionalInt}. The other object is considered equal if:
* <ul>
* <li>it is also an {@code OptionalInt} and;
* <li>both instances have no value present or;
@@ -245,7 +248,7 @@
*
* @param obj an object to be tested for equality
* @return {@code true} if the other object is "equal to" this object
- * otherwise {@code false}
+ * otherwise {@code false}
*/
@Override
public boolean equals(Object obj) {
@@ -264,10 +267,11 @@
}
/**
- * Returns the hash code value of the present value, if any, or 0 (zero) if
- * no value is present.
+ * Returns the hash code of the value, if present, otherwise {@code 0}
+ * (zero) if no value is present.
*
- * @return hash code value of the present value or 0 if no value is present
+ * @return hash code value of the present value or {@code 0} if no value is
+ * present
*/
@Override
public int hashCode() {
@@ -275,14 +279,13 @@
}
/**
- * {@inheritDoc}
+ * Returns a non-empty string representation of this {@code OptionalInt}
+ * suitable for debugging. The exact presentation format is unspecified and
+ * may vary between implementations and versions.
*
- * Returns a non-empty string representation of this object suitable for
- * debugging. The exact presentation format is unspecified and may vary
- * between implementations and versions.
- *
- * @implSpec If a value is present the result must include its string
- * representation in the result. Empty and present instances must be
+ * @implSpec
+ * If a value is present the result must include its string representation
+ * in the result. Empty and present {@code OptionalInt}s must be
* unambiguously differentiable.
*
* @return the string representation of this instance
--- a/jdk/src/java.base/share/classes/java/util/OptionalLong.java Mon Oct 19 19:14:29 2015 +0200
+++ b/jdk/src/java.base/share/classes/java/util/OptionalLong.java Mon Oct 19 11:28:50 2015 -0700
@@ -30,15 +30,15 @@
import java.util.stream.LongStream;
/**
- * A container object which may or may not contain a {@code long} value.
- * If a value is present, {@code isPresent()} will return {@code true} and
- * {@code getAsLong()} will return the value.
+ * A container object which may or may not contain a {@code long} value. If a
+ * value is present, {@code isPresent()} returns {@code true} and
+ * {@code getAsLong()} returns the value.
*
* <p>Additional methods that depend on the presence or absence of a contained
* value are provided, such as {@link #orElse(long) orElse()}
- * (return a default value if value not present) and
- * {@link #ifPresent(java.util.function.LongConsumer) ifPresent()} (perform an
- * action if the value is present).
+ * (returns a default value if no value is present) and
+ * {@link #ifPresent(java.util.function.LongConsumer) ifPresent()} (performs an
+ * action if a value is present).
*
* <p>This is a <a href="../lang/doc-files/ValueBased.html">value-based</a>
* class; use of identity-sensitive operations (including reference equality
@@ -71,24 +71,25 @@
}
/**
- * Returns an empty {@code OptionalLong} instance. No value is present for this
- * OptionalLong.
+ * Returns an empty {@code OptionalLong} instance. No value is present for
+ * this {@code OptionalLong}.
*
- * @apiNote Though it may be tempting to do so, avoid testing if an object
- * is empty by comparing with {@code ==} against instances returned by
- * {@code Option.empty()}. There is no guarantee that it is a singleton.
+ * @apiNote
+ * Though it may be tempting to do so, avoid testing if an object is empty
+ * by comparing with {@code ==} against instances returned by
+ * {@code OptionalLong.empty()}. There is no guarantee that it is a singleton.
* Instead, use {@link #isPresent()}.
*
- * @return an empty {@code OptionalLong}.
+ * @return an empty {@code OptionalLong}.
*/
public static OptionalLong empty() {
return EMPTY;
}
/**
- * Construct an instance with the value present.
+ * Construct an instance with the described value.
*
- * @param value the long value to be present
+ * @param value the long value to describe
*/
private OptionalLong(long value) {
this.isPresent = true;
@@ -96,9 +97,9 @@
}
/**
- * Return an {@code OptionalLong} with the specified value present.
+ * Returns an {@code OptionalLong} describing the given value.
*
- * @param value the value to be present
+ * @param value the value to describe
* @return an {@code OptionalLong} with the value present
*/
public static OptionalLong of(long value) {
@@ -106,12 +107,11 @@
}
/**
- * If a value is present in this {@code OptionalLong}, returns the value,
- * otherwise throws {@code NoSuchElementException}.
+ * If a value is present, returns the value, otherwise throws
+ * {@code NoSuchElementException}.
*
- * @return the value held by this {@code OptionalLong}
- * @throws NoSuchElementException if there is no value present
- *
+ * @return the value described by this {@code OptionalLong}
+ * @throws NoSuchElementException if no value is present
* @see OptionalLong#isPresent()
*/
public long getAsLong() {
@@ -122,21 +122,21 @@
}
/**
- * Return {@code true} if there is a value present, otherwise {@code false}.
+ * If a value is present, returns {@code true}, otherwise {@code false}.
*
- * @return {@code true} if there is a value present, otherwise {@code false}
+ * @return {@code true} if a value is present, otherwise {@code false}
*/
public boolean isPresent() {
return isPresent;
}
/**
- * If a value is present, perform the given action with the value,
- * otherwise do nothing.
+ * If a value is present, performs the given action with the value,
+ * otherwise does nothing.
*
- * @param action the action to be performed if a value is present
- * @throws NullPointerException if a value is present and {@code action} is
- * null
+ * @param action the action to be performed, if a value is present
+ * @throws NullPointerException if value is present and the given action is
+ * {@code null}
*/
public void ifPresent(LongConsumer action) {
if (isPresent) {
@@ -145,15 +145,16 @@
}
/**
- * If a value is present, perform the given action with the value,
- * otherwise perform the given empty-based action.
+ * If a value is present, performs the given action with the value,
+ * otherwise performs the given empty-based action.
*
- * @param action the action to be performed if a value is present
- * @param emptyAction the empty-based action to be performed if a value is
- * not present
- * @throws NullPointerException if a value is present and {@code action} is
- * null, or a value is not present and {@code emptyAction} is null.
- * @since 1.9
+ * @param action the action to be performed, if a value is present
+ * @param emptyAction the empty-based action to be performed, if no value is
+ * present
+ * @throws NullPointerException if a value is present and the given action
+ * is {@code null}, or no value is present and the given empty-based
+ * action is {@code null}.
+ * @since 9
*/
public void ifPresentOrElse(LongConsumer action, Runnable emptyAction) {
if (isPresent) {
@@ -164,19 +165,19 @@
}
/**
- * If a value is present return a sequential {@link LongStream} containing
- * only that value, otherwise return an empty {@code LongStream}.
+ * If a value is present, returns a sequential {@link LongStream} containing
+ * only that value, otherwise returns an empty {@code LongStream}.
*
- * @apiNote This method can be used to transform a {@code Stream} of
- * optional longs to a {@code LongStream} of present longs:
- *
+ * @apiNote
+ * This method can be used to transform a {@code Stream} of optional longs
+ * to an {@code LongStream} of present longs:
* <pre>{@code
* Stream<OptionalLong> os = ..
* LongStream s = os.flatMapToLong(OptionalLong::stream)
* }</pre>
*
- * @return the optional value as a {@code LongStream}
- * @since 1.9
+ * @return the optional value as an {@code LongStream}
+ * @since 9
*/
public LongStream stream() {
if (isPresent) {
@@ -187,9 +188,10 @@
}
/**
- * Return the value if present, otherwise return {@code other}.
+ * If a value is present, returns the value, otherwise returns
+ * {@code other}.
*
- * @param other the value to be returned if there is no value present
+ * @param other the value to be returned, if no value is present
* @return the value, if present, otherwise {@code other}
*/
public long orElse(long other) {
@@ -197,34 +199,35 @@
}
/**
- * Return the value if present, otherwise invoke {@code other} and return
- * the result of that invocation.
+ * If a value is present, returns the value, otherwise returns the result
+ * produced by the supplying function.
*
- * @param other a {@code LongSupplier} whose result is returned if no value
- * is present
- * @return the value if present otherwise the result of {@code other.getAsLong()}
- * @throws NullPointerException if value is not present and {@code other} is
- * null
+ * @param supplier the supplying function that produces a value to be returned
+ * @return the value, if present, otherwise the result produced by the
+ * supplying function
+ * @throws NullPointerException if no value is present and the supplying
+ * function is {@code null}
*/
- public long orElseGet(LongSupplier other) {
- return isPresent ? value : other.getAsLong();
+ public long orElseGet(LongSupplier supplier) {
+ return isPresent ? value : supplier.getAsLong();
}
/**
- * Return the contained value, if present, otherwise throw an exception
- * to be created by the provided supplier.
+ * If a value is present, returns the value, otherwise throws an exception
+ * produced by the exception supplying function.
*
- * @apiNote A method reference to the exception constructor with an empty
- * argument list can be used as the supplier. For example,
+ * @apiNote
+ * A method reference to the exception constructor with an empty argument
+ * list can be used as the supplier. For example,
* {@code IllegalStateException::new}
*
* @param <X> Type of the exception to be thrown
- * @param exceptionSupplier The supplier which will return the exception to
- * be thrown
- * @return the present value
- * @throws X if there is no value present
- * @throws NullPointerException if no value is present and
- * {@code exceptionSupplier} is null
+ * @param exceptionSupplier the supplying function that produces an
+ * exception to be thrown
+ * @return the value, if present
+ * @throws X if no value is present
+ * @throws NullPointerException if no value is present and the exception
+ * supplying function is {@code null}
*/
public<X extends Throwable> long orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
if (isPresent) {
@@ -235,8 +238,8 @@
}
/**
- * Indicates whether some other object is "equal to" this OptionalLong. The
- * other object is considered equal if:
+ * Indicates whether some other object is "equal to" this
+ * {@code OptionalLong}. The other object is considered equal if:
* <ul>
* <li>it is also an {@code OptionalLong} and;
* <li>both instances have no value present or;
@@ -245,7 +248,7 @@
*
* @param obj an object to be tested for equality
* @return {@code true} if the other object is "equal to" this object
- * otherwise {@code false}
+ * otherwise {@code false}
*/
@Override
public boolean equals(Object obj) {
@@ -264,10 +267,11 @@
}
/**
- * Returns the hash code value of the present value, if any, or 0 (zero) if
- * no value is present.
+ * Returns the hash code of the value, if present, otherwise {@code 0}
+ * (zero) if no value is present.
*
- * @return hash code value of the present value or 0 if no value is present
+ * @return hash code value of the present value or {@code 0} if no value is
+ * present
*/
@Override
public int hashCode() {
@@ -275,14 +279,13 @@
}
/**
- * {@inheritDoc}
+ * Returns a non-empty string representation of this {@code OptionalLong}
+ * suitable for debugging. The exact presentation format is unspecified and
+ * may vary between implementations and versions.
*
- * Returns a non-empty string representation of this object suitable for
- * debugging. The exact presentation format is unspecified and may vary
- * between implementations and versions.
- *
- * @implSpec If a value is present the result must include its string
- * representation in the result. Empty and present instances must be
+ * @implSpec
+ * If a value is present the result must include its string representation
+ * in the result. Empty and present {@code OptionalLong}s must be
* unambiguously differentiable.
*
* @return the string representation of this instance
--- a/jdk/test/java/util/Optional/Basic.java Mon Oct 19 19:14:29 2015 +0200
+++ b/jdk/test/java/util/Optional/Basic.java Mon Oct 19 11:28:50 2015 -0700
@@ -294,6 +294,46 @@
}
@Test(groups = "unit")
+ public void testOr() {
+ Optional<String> empty = Optional.empty();
+ Optional<String> duke = Optional.of("Duke");
+
+ // Null supplier
+ try {
+ Optional<String> b = empty.or(null);
+ fail("Should throw NPE on null supplier");
+ } catch (NullPointerException npe) {
+ // expected
+ }
+
+ // Supply null
+ try {
+ Optional<String> b = empty.or(() -> null);
+ fail("Should throw NPE when supplier returns null");
+ } catch (NullPointerException npe) {
+ // expected
+ }
+
+ // Non-empty won't invoke supplier
+ try {
+ Optional<String> b = duke.or(() -> null);
+ assertTrue(b.isPresent());
+ } catch (NullPointerException npe) {
+ fail("Supplier should not be invoked");
+ }
+
+ // Supply for empty
+ Optional<String> suppliedDuke = empty.or(() -> duke);
+ assertTrue(suppliedDuke.isPresent());
+ assertSame(suppliedDuke, duke);
+
+ // Supply for non-empty
+ Optional<String> actualDuke = duke.or(() -> Optional.of("Other Duke"));
+ assertTrue(actualDuke.isPresent());
+ assertSame(actualDuke, duke);
+ }
+
+ @Test(groups = "unit")
public void testStream() {
{
Stream<String> s = Optional.<String>empty().stream();