src/main/java/org/codehaus/groovy/vmplugin/v8/PluginDefaultGroovyMethods.java - groovy - Git at Google

 /*
  *  Licensed to the Apache Software Foundation (ASF) under one
  *  or more contributor license agreements.  See the NOTICE file
  *  distributed with this work for additional information
  *  regarding copyright ownership.  The ASF licenses this file
  *  to you under the Apache License, Version 2.0 (the
  *  "License"); you may not use this file except in compliance
  *  with the License.  You may obtain a copy of the License at
  *
  *    http://www.apache.org/licenses/LICENSE-2.0
  *
  *  Unless required by applicable law or agreed to in writing,
  *  software distributed under the License is distributed on an
  *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  *  KIND, either express or implied.  See the License for the
  *  specific language governing permissions and limitations
  *  under the License.
  */
 package org.codehaus.groovy.vmplugin.v8;

 import groovy.lang.Closure;
 import groovy.transform.stc.ClosureParams;
 import groovy.transform.stc.FirstParam;

 import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.OptionalDouble;
 import java.util.OptionalInt;
 import java.util.OptionalLong;
 import java.util.Set;
 import java.util.Spliterator;
 import java.util.Spliterators;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 import java.util.function.DoubleFunction;
 import java.util.function.DoublePredicate;
 import java.util.function.IntFunction;
 import java.util.function.IntPredicate;
 import java.util.function.LongFunction;
 import java.util.function.LongPredicate;
 import java.util.function.ToDoubleFunction;
 import java.util.function.ToIntFunction;
 import java.util.function.ToLongFunction;
 import java.util.stream.BaseStream;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;

 /**
  * Defines new Groovy methods which appear on normal JDK 8
  * classes inside the Groovy environment.
  *
  * @since 2.5.0
  */
 public class PluginDefaultGroovyMethods {

     // No instances, static methods only
     private PluginDefaultGroovyMethods() {
     }

     /**
      * Coerce an {@code Optional} instance to a {@code boolean} value.
      * <pre class="groovyTestCase">
      * assert !Optional.empty().asBoolean()
      * assert Optional.of(1234).asBoolean()
      * </pre>
      *
      * @param optional the Optional
      * @return {@code true} if a value is present, otherwise {@code false}
      *
      * @since 2.5.0
      */
     public static boolean asBoolean(final Optional<?> optional) {
         return optional.isPresent();
     }

     /**
      * If a value is present in the {@code OptionalInt}, returns the value,
      * otherwise throws {@code NoSuchElementException}.
      * <pre class="groovyTestCase">
      * assert OptionalInt.of(1234).get() == 1234
      * </pre>
      *
      * @since 3.0.0
      */
     public static int get(final OptionalInt self) {
         return self.getAsInt();
     }

     /**
      * If a value is present in the {@code OptionalLong}, returns the value,
      * otherwise throws {@code NoSuchElementException}.
      * <pre class="groovyTestCase">
      * assert OptionalLong.of(1234L).get() == 1234L
      * </pre>
      *
      * @since 3.0.0
      */
     public static long get(final OptionalLong self) {
         return self.getAsLong();
     }

     /**
      * If a value is present in the {@code OptionalDouble}, returns the value,
      * otherwise throws {@code NoSuchElementException}.
      * <pre class="groovyTestCase">
      * assert OptionalDouble.of(Math.PI).get() == Math.PI
      * </pre>
      *
      * @since 3.0.0
      */
     public static double get(final OptionalDouble self) {
         return self.getAsDouble();
     }

     /**
      * Tests given value against specified type and changes generics of result.
      * This is equivalent to: <code>self.filter(it -> it instanceof Type).map(it -> (Type) it)</code>
      * <pre class="groovyTestCase">
      * assert !Optional.empty().filter(Number).isPresent()
      * assert !Optional.of('x').filter(Number).isPresent()
      * assert Optional.of(1234).filter(Number).isPresent()
      * assert Optional.of(1234).filter(Number).get().equals(1234)
      * </pre>
      *
      * @since 3.0.0
      */
     public static <T> Optional<T> filter(final Optional<?> self, final Class<T> type) {
         return self.filter(type::isInstance).map(type::cast);
     }

     /**
      * If a value is present in the {@code OptionalInt}, tests the value using
      * the given predicate and returns the optional if the test returns true or
      * else empty.
      * <pre class="groovyTestCase">
      * assert !OptionalInt.empty().filter(i -> true).isPresent()
      * assert  OptionalInt.of(1234).filter(i -> true).isPresent()
      * assert !OptionalInt.of(1234).filter(i -> false).isPresent()
      * assert  OptionalInt.of(1234).filter(i -> true).getAsInt() == 1234
      * </pre>
      *
      * @since 3.0.0
      */
     public static OptionalInt filter(final OptionalInt self, final IntPredicate test) {
         if (!self.isPresent() || !test.test(self.getAsInt())) {
             return OptionalInt.empty();
         }
         return self;
     }

     /**
      * If a value is present in the {@code OptionalLong}, tests the value using
      * the given predicate and returns the optional if the test returns true or
      * else empty.
      * <pre class="groovyTestCase">
      * assert !OptionalLong.empty().filter(n -> true).isPresent()
      * assert  OptionalLong.of(123L).filter(n -> true).isPresent()
      * assert !OptionalLong.of(123L).filter(n -> false).isPresent()
      * assert  OptionalLong.of(123L).filter(n -> true).getAsLong() == 123L
      * </pre>
      *
      * @since 3.0.0
      */
     public static OptionalLong filter(final OptionalLong self, final LongPredicate test) {
         if (!self.isPresent() || !test.test(self.getAsLong())) {
             return OptionalLong.empty();
         }
         return self;
     }

     /**
      * If a value is present in the {@code OptionalDouble}, tests the value using
      * the given predicate and returns the optional if the test returns true or
      * empty otherwise.
      * <pre class="groovyTestCase">
      * assert !OptionalDouble.empty().filter(n -> true).isPresent()
      * assert  OptionalDouble.of(Math.PI).filter(n -> true).isPresent()
      * assert !OptionalDouble.of(Math.PI).filter(n -> false).isPresent()
      * assert  OptionalDouble.of(Math.PI).filter(n -> true).getAsDouble() == Math.PI
      * </pre>
      *
      * @since 3.0.0
      */
     public static OptionalDouble filter(final OptionalDouble self, final DoublePredicate test) {
         if (!self.isPresent() || !test.test(self.getAsDouble())) {
             return OptionalDouble.empty();
         }
         return self;
     }

     /**
      * If a value is present in the {@code OptionalInt}, returns an {@code Optional}
      * consisting of the result of applying the given function to the value or else empty.
      * <pre class="groovyTestCase">
      * assert !OptionalInt.empty().mapToObj(x -> new Object()).isPresent()
      * assert  OptionalInt.of(1234).mapToObj(x -> new Object()).isPresent()
      * assert !OptionalInt.of(1234).mapToObj(x -> null).isPresent()
      * </pre>
      *
      * @since 3.0.0
      */
     public static <T> Optional<T> mapToObj(final OptionalInt self, final IntFunction<? extends T> mapper) {
         if (!self.isPresent()) {
             return Optional.empty();
         }
         return Optional.ofNullable(mapper.apply(self.getAsInt()));
     }

     /**
      * If a value is present in the {@code OptionalLong}, returns an {@code Optional}
      * consisting of the result of applying the given function to the value or else empty.
      * <pre class="groovyTestCase">
      * assert !OptionalLong.empty().mapToObj(x -> new Object()).isPresent()
      * assert  OptionalLong.of(123L).mapToObj(x -> new Object()).isPresent()
      * assert !OptionalLong.of(123L).mapToObj(x -> null).isPresent()
      * </pre>
      *
      * @since 3.0.0
      */
     public static <T> Optional<T> mapToObj(final OptionalLong self, final LongFunction<? extends T> mapper) {
         if (!self.isPresent()) {
             return Optional.empty();
         }
         return Optional.ofNullable(mapper.apply(self.getAsLong()));
     }

     /**
      * If a value is present in the {@code OptionalDouble}, returns an {@code Optional}
      * consisting of the result of applying the given function to the value or else empty.
      * <pre class="groovyTestCase">
      * assert !OptionalDouble.empty().mapToObj(x -> new Object()).isPresent()
      * assert  OptionalDouble.of(Math.PI).mapToObj(x -> new Object()).isPresent()
      * assert !OptionalDouble.of(Math.PI).mapToObj(x -> null).isPresent()
      * </pre>
      *
      * @since 3.0.0
      */
     public static <T> Optional<T> mapToObj(final OptionalDouble self, final DoubleFunction<? extends T> mapper) {
         if (!self.isPresent()) {
             return Optional.empty();
         }
         return Optional.ofNullable(mapper.apply(self.getAsDouble()));
     }

     /**
      * If a value is present in the {@code OptionalInt}, returns an {@code OptionalInt}
      * consisting of the result of applying the given function to the value or else empty.
      * <pre class="groovyTestCase">
      * assert !Optional.empty().mapToInt(x -> 42).isPresent()
      * assert  Optional.of('x').mapToInt(x -> 42).getAsInt() == 42
      * </pre>
      *
      * @since 3.0.0
      */
     public static <T> OptionalInt mapToInt(final Optional<T> self, final ToIntFunction<? super T> mapper) {
         if (!self.isPresent()) {
             return OptionalInt.empty();
         }
         return OptionalInt.of(mapper.applyAsInt(self.get()));
     }

     /**
      * If a value is present in the {@code OptionalLong}, returns an {@code OptionalLong}
      * consisting of the result of applying the given function to the value or else empty.
      * <pre class="groovyTestCase">
      * assert !Optional.empty().mapToLong(x -> 42L).isPresent()
      * assert  Optional.of('x').mapToLong(x -> 42L).getAsLong() == 42L
      * </pre>
      *
      * @since 3.0.0
      */
     public static <T> OptionalLong mapToLong(final Optional<T> self, final ToLongFunction<? super T> mapper) {
         if (!self.isPresent()) {
             return OptionalLong.empty();
         }
         return OptionalLong.of(mapper.applyAsLong(self.get()));
     }

     /**
      * If a value is present in the {@code OptionalDouble}, returns an {@code OptionalDouble}
      * consisting of the result of applying the given function to the value or else empty.
      * <pre class="groovyTestCase">
      * assert !Optional.empty().mapToDouble(x -> Math.PI).isPresent()
      * assert  Optional.of('x').mapToDouble(x -> Math.PI).getAsDouble() == Math.PI
      * </pre>
      *
      * @since 3.0.0
      */
     public static <T> OptionalDouble mapToDouble(final Optional<T> self, final ToDoubleFunction<? super T> mapper) {
         if (!self.isPresent()) {
             return OptionalDouble.empty();
         }
         return OptionalDouble.of(mapper.applyAsDouble(self.get()));
     }

     /**
      * If the optional contains a value, returns an optional containing the transformed value obtained using the <code>transform</code> closure
      * or otherwise an empty optional.
      * <pre class="groovyTestCase">
      * assert Optional.of("foobar").collect{ it.size() }.get() == 6
      * assert !Optional.empty().collect{ it.size() }.isPresent()
      * </pre>
      *
      * @param self      an Optional
      * @param transform the closure used to transform the optional value if present
      * @return an Optional containing the transformed value or empty if the optional is empty or the transform returns null
      *
      * @since 3.0.0
      */
     public static <S,T> Optional<T> collect(final Optional<S> self, @ClosureParams(FirstParam.FirstGenericType.class) final Closure<T> transform) {
         Objects.requireNonNull(self);
         Objects.requireNonNull(transform);
         if (!self.isPresent()) {
             return Optional.empty();
         }
         return Optional.ofNullable(transform.call(self.get()));
     }

     /**
      * Returns a Future asynchronously returning a transformed result.
      * <pre class="_temp_disabled_groovyTestCase">
      * import java.util.concurrent.*
      * def executor = Executors.newSingleThreadExecutor()
      * Future<String> foobar = executor.submit{ "foobar" }
      * Future<Integer> foobarSize = foobar.collect{ it.size() }
      * assert foobarSize.get() == 6
      * executor.shutdown()
      * </pre>
      *
      * @param self      a Future
      * @param transform the closure used to transform the Future value
      * @return a Future allowing the transformed value to be obtained asynchronously
      *
      * @since 3.0.0
      */
     public static <S,T> Future<T> collect(final Future<S> self, @ClosureParams(FirstParam.FirstGenericType.class) final Closure<T> transform) {
         Objects.requireNonNull(self);
         Objects.requireNonNull(transform);
         return new TransformedFuture<T>(self, transform);
     }

     private static class TransformedFuture<E> implements Future<E> {
         private final Future delegate;
         private final Closure<E> transform;

         private TransformedFuture(final Future delegate, final Closure<E> transform) {
             this.delegate = delegate;
             this.transform = transform;
         }

         @Override
         public boolean cancel(final boolean mayInterruptIfRunning) {
             return delegate.cancel(mayInterruptIfRunning);
         }

         @Override
         public boolean isCancelled() {
             return delegate.isCancelled();
         }

         @Override
         public boolean isDone() {
             return delegate.isDone();
         }

         @Override
         public E get() throws InterruptedException, ExecutionException {
             return transform.call(delegate.get());
         }

         @Override
         public E get(final long timeout, final TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
             return transform.call(delegate.get(timeout, unit));
         }
     }

     /**
      * Accumulates the elements of stream into a new List.
      * @param stream the Stream
      * @param <T> the type of element
      * @return a new {@code java.util.List} instance
      *
      * @since 2.5.0
      */
     public static <T> List<T> toList(final Stream<T> stream) {
         return stream.collect(Collectors.<T>toList());
     }

     /**
      * Accumulates the elements of stream into a new Set.
      * @param stream the Stream
      * @param <T> the type of element
      * @return a new {@code java.util.Set} instance
      *
      * @since 2.5.0
      */
     public static <T> Set<T> toSet(final Stream<T> stream) {
         return stream.collect(Collectors.<T>toSet());
     }

     /**
      * Accumulates the elements of stream into a new List.
      * @param stream the {@code java.util.stream.BaseStream}
      * @param <T> the type of element
      * @return a new {@code java.util.List} instance
      *
      * @since 2.5.0
      */
     public static <T> List<T> toList(final BaseStream<T, ? extends BaseStream> stream) {
         return StreamSupport.stream(
                 Spliterators.spliteratorUnknownSize(stream.iterator(), Spliterator.ORDERED),
                 false
         ).collect(Collectors.<T>toList());
     }

     /**
      * Accumulates the elements of stream into a new Set.
      * @param stream the {@code java.util.stream.BaseStream}
      * @param <T> the type of element
      * @return a new {@code java.util.Set} instance
      *
      * @since 2.5.0
      */
     public static <T> Set<T> toSet(final BaseStream<T, ? extends BaseStream> stream) {
         return StreamSupport.stream(
                 Spliterators.spliteratorUnknownSize(stream.iterator(), Spliterator.ORDERED),
                 false
         ).collect(Collectors.<T>toSet());
     }

     /**
      * Returns a sequential {@link Stream} with the specified array as its
      * source.
      *
      * @param <T> The type of the array elements
      * @param self The array, assumed to be unmodified during use
      * @return a {@code Stream} for the array
      *
      * @since 2.5.0
      */
     public static <T> Stream<T> stream(final T[] self) {
         return Arrays.stream(self);
     }

     /**
      * Returns a sequential {@link Stream} with the specified array as its
      * source.
      *
      * @param self The array, assumed to be unmodified during use
      * @return a {@code Stream} for the array
      *
      * @since 2.5.0
      */
     public static Stream<Integer> stream(final int[] self) {
         return IntStream.range(0, self.length).mapToObj(i -> self[i]);
     }

     /**
      * Returns a sequential {@link Stream} with the specified array as its
      * source.
      *
      * @param self The array, assumed to be unmodified during use
      * @return a {@code Stream} for the array
      *
      * @since 2.5.0
      */
     public static Stream<Long> stream(final long[] self) {
         return IntStream.range(0, self.length).mapToObj(i -> self[i]);
     }

     /**
      * Returns a sequential {@link Stream} with the specified array as its
      * source.
      *
      * @param self The array, assumed to be unmodified during use
      * @return a {@code Stream} for the array
      *
      * @since 2.5.0
      */
     public static Stream<Double> stream(final double[] self) {
         return IntStream.range(0, self.length).mapToObj(i -> self[i]);
     }

     /**
      * Returns a sequential {@link Stream} with the specified array as its
      * source.
      *
      * @param self The array, assumed to be unmodified during use
      * @return a {@code Stream} for the array
      *
      * @since 2.5.0
      */
     public static Stream<Character> stream(final char[] self) {
         return IntStream.range(0, self.length).mapToObj(i -> self[i]);
     }

     /**
      * Returns a sequential {@link Stream} with the specified array as its
      * source.
      *
      * @param self The array, assumed to be unmodified during use
      * @return a {@code Stream} for the array
      *
      * @since 2.5.0
      */
     public static Stream<Byte> stream(final byte[] self) {
         return IntStream.range(0, self.length).mapToObj(i -> self[i]);
     }

     /**
      * Returns a sequential {@link Stream} with the specified array as its
      * source.
      *
      * @param self The array, assumed to be unmodified during use
      * @return a {@code Stream} for the array
      *
      * @since 2.5.0
      */
     public static Stream<Short> stream(final short[] self) {
         return IntStream.range(0, self.length).mapToObj(i -> self[i]);
     }

     /**
      * Returns a sequential {@link Stream} with the specified array as its
      * source.
      *
      * @param self The array, assumed to be unmodified during use
      * @return a {@code Stream} for the array
      *
      * @since 2.5.0
      */
     public static Stream<Boolean> stream(final boolean[] self) {
         return IntStream.range(0, self.length).mapToObj(i -> self[i]);
     }

     /**
      * Returns a sequential {@link Stream} with the specified array as its
      * source.
      *
      * @param self The array, assumed to be unmodified during use
      * @return a {@code Stream} for the array
      *
      * @since 2.5.0
      */
     public static Stream<Float> stream(final float[] self) {
         return IntStream.range(0, self.length).mapToObj(i -> self[i]);
     }

     /**
      * If a value is present in the {@link Optional}, returns a {@link Stream}
      * with the value as its source or else an empty stream.
      *
      * @since 3.0.0
      */
     public static <T> Stream<T> stream(final Optional<T> self) {
         return self.map(Stream::of).orElseGet(Stream::empty);
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/
	package org.codehaus.groovy.vmplugin.v8;

	import groovy.lang.Closure;
	import groovy.transform.stc.ClosureParams;
	import groovy.transform.stc.FirstParam;

	import java.util.Arrays;
	import java.util.List;
	import java.util.Objects;
	import java.util.Optional;
	import java.util.OptionalDouble;
	import java.util.OptionalInt;
	import java.util.OptionalLong;
	import java.util.Set;
	import java.util.Spliterator;
	import java.util.Spliterators;
	import java.util.concurrent.ExecutionException;
	import java.util.concurrent.Future;
	import java.util.concurrent.TimeUnit;
	import java.util.concurrent.TimeoutException;
	import java.util.function.DoubleFunction;
	import java.util.function.DoublePredicate;
	import java.util.function.IntFunction;
	import java.util.function.IntPredicate;
	import java.util.function.LongFunction;
	import java.util.function.LongPredicate;
	import java.util.function.ToDoubleFunction;
	import java.util.function.ToIntFunction;
	import java.util.function.ToLongFunction;
	import java.util.stream.BaseStream;
	import java.util.stream.Collectors;
	import java.util.stream.IntStream;
	import java.util.stream.Stream;
	import java.util.stream.StreamSupport;

	/**
	* Defines new Groovy methods which appear on normal JDK 8
	* classes inside the Groovy environment.
	*
	* @since 2.5.0
	*/
	public class PluginDefaultGroovyMethods {

	// No instances, static methods only
	private PluginDefaultGroovyMethods() {
	}

	/**
	* Coerce an {@code Optional} instance to a {@code boolean} value.
	* <pre class="groovyTestCase">
	* assert !Optional.empty().asBoolean()
	* assert Optional.of(1234).asBoolean()
	* </pre>
	*
	* @param optional the Optional
	* @return {@code true} if a value is present, otherwise {@code false}
	*
	* @since 2.5.0
	*/
	public static boolean asBoolean(final Optional<?> optional) {
	return optional.isPresent();
	}

	/**
	* If a value is present in the {@code OptionalInt}, returns the value,
	* otherwise throws {@code NoSuchElementException}.
	* <pre class="groovyTestCase">
	* assert OptionalInt.of(1234).get() == 1234
	* </pre>
	*
	* @since 3.0.0
	*/
	public static int get(final OptionalInt self) {
	return self.getAsInt();
	}

	/**
	* If a value is present in the {@code OptionalLong}, returns the value,
	* otherwise throws {@code NoSuchElementException}.
	* <pre class="groovyTestCase">
	* assert OptionalLong.of(1234L).get() == 1234L
	* </pre>
	*
	* @since 3.0.0
	*/
	public static long get(final OptionalLong self) {
	return self.getAsLong();
	}

	/**
	* If a value is present in the {@code OptionalDouble}, returns the value,
	* otherwise throws {@code NoSuchElementException}.
	* <pre class="groovyTestCase">
	* assert OptionalDouble.of(Math.PI).get() == Math.PI
	* </pre>
	*
	* @since 3.0.0
	*/
	public static double get(final OptionalDouble self) {
	return self.getAsDouble();
	}

	/**
	* Tests given value against specified type and changes generics of result.
	* This is equivalent to: <code>self.filter(it -> it instanceof Type).map(it -> (Type) it)</code>
	* <pre class="groovyTestCase">
	* assert !Optional.empty().filter(Number).isPresent()
	* assert !Optional.of('x').filter(Number).isPresent()
	* assert Optional.of(1234).filter(Number).isPresent()
	* assert Optional.of(1234).filter(Number).get().equals(1234)
	* </pre>
	*
	* @since 3.0.0
	*/
	public static <T> Optional<T> filter(final Optional<?> self, final Class<T> type) {
	return self.filter(type::isInstance).map(type::cast);
	}

	/**
	* If a value is present in the {@code OptionalInt}, tests the value using
	* the given predicate and returns the optional if the test returns true or
	* else empty.
	* <pre class="groovyTestCase">
	* assert !OptionalInt.empty().filter(i -> true).isPresent()
	* assert OptionalInt.of(1234).filter(i -> true).isPresent()
	* assert !OptionalInt.of(1234).filter(i -> false).isPresent()
	* assert OptionalInt.of(1234).filter(i -> true).getAsInt() == 1234
	* </pre>
	*
	* @since 3.0.0
	*/
	public static OptionalInt filter(final OptionalInt self, final IntPredicate test) {
	if (!self.isPresent() \|\| !test.test(self.getAsInt())) {
	return OptionalInt.empty();
	}
	return self;
	}

	/**
	* If a value is present in the {@code OptionalLong}, tests the value using
	* the given predicate and returns the optional if the test returns true or
	* else empty.
	* <pre class="groovyTestCase">
	* assert !OptionalLong.empty().filter(n -> true).isPresent()
	* assert OptionalLong.of(123L).filter(n -> true).isPresent()
	* assert !OptionalLong.of(123L).filter(n -> false).isPresent()
	* assert OptionalLong.of(123L).filter(n -> true).getAsLong() == 123L
	* </pre>
	*
	* @since 3.0.0
	*/
	public static OptionalLong filter(final OptionalLong self, final LongPredicate test) {
	if (!self.isPresent() \|\| !test.test(self.getAsLong())) {
	return OptionalLong.empty();
	}
	return self;
	}

	/**
	* If a value is present in the {@code OptionalDouble}, tests the value using
	* the given predicate and returns the optional if the test returns true or
	* empty otherwise.
	* <pre class="groovyTestCase">
	* assert !OptionalDouble.empty().filter(n -> true).isPresent()
	* assert OptionalDouble.of(Math.PI).filter(n -> true).isPresent()
	* assert !OptionalDouble.of(Math.PI).filter(n -> false).isPresent()
	* assert OptionalDouble.of(Math.PI).filter(n -> true).getAsDouble() == Math.PI
	* </pre>
	*
	* @since 3.0.0
	*/
	public static OptionalDouble filter(final OptionalDouble self, final DoublePredicate test) {
	if (!self.isPresent() \|\| !test.test(self.getAsDouble())) {
	return OptionalDouble.empty();
	}
	return self;
	}

	/**
	* If a value is present in the {@code OptionalInt}, returns an {@code Optional}
	* consisting of the result of applying the given function to the value or else empty.
	* <pre class="groovyTestCase">
	* assert !OptionalInt.empty().mapToObj(x -> new Object()).isPresent()
	* assert OptionalInt.of(1234).mapToObj(x -> new Object()).isPresent()
	* assert !OptionalInt.of(1234).mapToObj(x -> null).isPresent()
	* </pre>
	*
	* @since 3.0.0
	*/
	public static <T> Optional<T> mapToObj(final OptionalInt self, final IntFunction<? extends T> mapper) {
	if (!self.isPresent()) {
	return Optional.empty();
	}
	return Optional.ofNullable(mapper.apply(self.getAsInt()));
	}

	/**
	* If a value is present in the {@code OptionalLong}, returns an {@code Optional}
	* consisting of the result of applying the given function to the value or else empty.
	* <pre class="groovyTestCase">
	* assert !OptionalLong.empty().mapToObj(x -> new Object()).isPresent()
	* assert OptionalLong.of(123L).mapToObj(x -> new Object()).isPresent()
	* assert !OptionalLong.of(123L).mapToObj(x -> null).isPresent()
	* </pre>
	*
	* @since 3.0.0
	*/
	public static <T> Optional<T> mapToObj(final OptionalLong self, final LongFunction<? extends T> mapper) {
	if (!self.isPresent()) {
	return Optional.empty();
	}
	return Optional.ofNullable(mapper.apply(self.getAsLong()));
	}

	/**
	* If a value is present in the {@code OptionalDouble}, returns an {@code Optional}
	* consisting of the result of applying the given function to the value or else empty.
	* <pre class="groovyTestCase">
	* assert !OptionalDouble.empty().mapToObj(x -> new Object()).isPresent()
	* assert OptionalDouble.of(Math.PI).mapToObj(x -> new Object()).isPresent()
	* assert !OptionalDouble.of(Math.PI).mapToObj(x -> null).isPresent()
	* </pre>
	*
	* @since 3.0.0
	*/
	public static <T> Optional<T> mapToObj(final OptionalDouble self, final DoubleFunction<? extends T> mapper) {
	if (!self.isPresent()) {
	return Optional.empty();
	}
	return Optional.ofNullable(mapper.apply(self.getAsDouble()));
	}

	/**
	* If a value is present in the {@code OptionalInt}, returns an {@code OptionalInt}
	* consisting of the result of applying the given function to the value or else empty.
	* <pre class="groovyTestCase">
	* assert !Optional.empty().mapToInt(x -> 42).isPresent()
	* assert Optional.of('x').mapToInt(x -> 42).getAsInt() == 42
	* </pre>
	*
	* @since 3.0.0
	*/
	public static <T> OptionalInt mapToInt(final Optional<T> self, final ToIntFunction<? super T> mapper) {
	if (!self.isPresent()) {
	return OptionalInt.empty();
	}
	return OptionalInt.of(mapper.applyAsInt(self.get()));
	}

	/**
	* If a value is present in the {@code OptionalLong}, returns an {@code OptionalLong}
	* consisting of the result of applying the given function to the value or else empty.
	* <pre class="groovyTestCase">
	* assert !Optional.empty().mapToLong(x -> 42L).isPresent()
	* assert Optional.of('x').mapToLong(x -> 42L).getAsLong() == 42L
	* </pre>
	*
	* @since 3.0.0
	*/
	public static <T> OptionalLong mapToLong(final Optional<T> self, final ToLongFunction<? super T> mapper) {
	if (!self.isPresent()) {
	return OptionalLong.empty();
	}
	return OptionalLong.of(mapper.applyAsLong(self.get()));
	}

	/**
	* If a value is present in the {@code OptionalDouble}, returns an {@code OptionalDouble}
	* consisting of the result of applying the given function to the value or else empty.
	* <pre class="groovyTestCase">
	* assert !Optional.empty().mapToDouble(x -> Math.PI).isPresent()
	* assert Optional.of('x').mapToDouble(x -> Math.PI).getAsDouble() == Math.PI
	* </pre>
	*
	* @since 3.0.0
	*/
	public static <T> OptionalDouble mapToDouble(final Optional<T> self, final ToDoubleFunction<? super T> mapper) {
	if (!self.isPresent()) {
	return OptionalDouble.empty();
	}
	return OptionalDouble.of(mapper.applyAsDouble(self.get()));
	}

	/**
	* If the optional contains a value, returns an optional containing the transformed value obtained using the <code>transform</code> closure
	* or otherwise an empty optional.
	* <pre class="groovyTestCase">
	* assert Optional.of("foobar").collect{ it.size() }.get() == 6
	* assert !Optional.empty().collect{ it.size() }.isPresent()
	* </pre>
	*
	* @param self an Optional
	* @param transform the closure used to transform the optional value if present
	* @return an Optional containing the transformed value or empty if the optional is empty or the transform returns null
	*
	* @since 3.0.0
	*/
	public static <S,T> Optional<T> collect(final Optional<S> self, @ClosureParams(FirstParam.FirstGenericType.class) final Closure<T> transform) {
	Objects.requireNonNull(self);
	Objects.requireNonNull(transform);
	if (!self.isPresent()) {
	return Optional.empty();
	}
	return Optional.ofNullable(transform.call(self.get()));
	}

	/**
	* Returns a Future asynchronously returning a transformed result.
	* <pre class="_temp_disabled_groovyTestCase">
	* import java.util.concurrent.*
	* def executor = Executors.newSingleThreadExecutor()
	* Future<String> foobar = executor.submit{ "foobar" }
	* Future<Integer> foobarSize = foobar.collect{ it.size() }
	* assert foobarSize.get() == 6
	* executor.shutdown()
	* </pre>
	*
	* @param self a Future
	* @param transform the closure used to transform the Future value
	* @return a Future allowing the transformed value to be obtained asynchronously
	*
	* @since 3.0.0
	*/
	public static <S,T> Future<T> collect(final Future<S> self, @ClosureParams(FirstParam.FirstGenericType.class) final Closure<T> transform) {
	Objects.requireNonNull(self);
	Objects.requireNonNull(transform);
	return new TransformedFuture<T>(self, transform);
	}

	private static class TransformedFuture<E> implements Future<E> {
	private final Future delegate;
	private final Closure<E> transform;

	private TransformedFuture(final Future delegate, final Closure<E> transform) {
	this.delegate = delegate;
	this.transform = transform;
	}

	@Override
	public boolean cancel(final boolean mayInterruptIfRunning) {
	return delegate.cancel(mayInterruptIfRunning);
	}

	@Override
	public boolean isCancelled() {
	return delegate.isCancelled();
	}

	@Override
	public boolean isDone() {
	return delegate.isDone();
	}

	@Override
	public E get() throws InterruptedException, ExecutionException {
	return transform.call(delegate.get());
	}

	@Override
	public E get(final long timeout, final TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
	return transform.call(delegate.get(timeout, unit));
	}
	}

	/**
	* Accumulates the elements of stream into a new List.
	* @param stream the Stream
	* @param <T> the type of element
	* @return a new {@code java.util.List} instance
	*
	* @since 2.5.0
	*/
	public static <T> List<T> toList(final Stream<T> stream) {
	return stream.collect(Collectors.<T>toList());
	}

	/**
	* Accumulates the elements of stream into a new Set.
	* @param stream the Stream
	* @param <T> the type of element
	* @return a new {@code java.util.Set} instance
	*
	* @since 2.5.0
	*/
	public static <T> Set<T> toSet(final Stream<T> stream) {
	return stream.collect(Collectors.<T>toSet());
	}

	/**
	* Accumulates the elements of stream into a new List.
	* @param stream the {@code java.util.stream.BaseStream}
	* @param <T> the type of element
	* @return a new {@code java.util.List} instance
	*
	* @since 2.5.0
	*/
	public static <T> List<T> toList(final BaseStream<T, ? extends BaseStream> stream) {
	return StreamSupport.stream(
	Spliterators.spliteratorUnknownSize(stream.iterator(), Spliterator.ORDERED),
	false
	).collect(Collectors.<T>toList());
	}

	/**
	* Accumulates the elements of stream into a new Set.
	* @param stream the {@code java.util.stream.BaseStream}
	* @param <T> the type of element
	* @return a new {@code java.util.Set} instance
	*
	* @since 2.5.0
	*/
	public static <T> Set<T> toSet(final BaseStream<T, ? extends BaseStream> stream) {
	return StreamSupport.stream(
	Spliterators.spliteratorUnknownSize(stream.iterator(), Spliterator.ORDERED),
	false
	).collect(Collectors.<T>toSet());
	}

	/**
	* Returns a sequential {@link Stream} with the specified array as its
	* source.
	*
	* @param <T> The type of the array elements
	* @param self The array, assumed to be unmodified during use
	* @return a {@code Stream} for the array
	*
	* @since 2.5.0
	*/
	public static <T> Stream<T> stream(final T[] self) {
	return Arrays.stream(self);
	}

	/**
	* Returns a sequential {@link Stream} with the specified array as its
	* source.
	*
	* @param self The array, assumed to be unmodified during use
	* @return a {@code Stream} for the array
	*
	* @since 2.5.0
	*/
	public static Stream<Integer> stream(final int[] self) {
	return IntStream.range(0, self.length).mapToObj(i -> self[i]);
	}

	/**
	* Returns a sequential {@link Stream} with the specified array as its
	* source.
	*
	* @param self The array, assumed to be unmodified during use
	* @return a {@code Stream} for the array
	*
	* @since 2.5.0
	*/
	public static Stream<Long> stream(final long[] self) {
	return IntStream.range(0, self.length).mapToObj(i -> self[i]);
	}

	/**
	* Returns a sequential {@link Stream} with the specified array as its
	* source.
	*
	* @param self The array, assumed to be unmodified during use
	* @return a {@code Stream} for the array
	*
	* @since 2.5.0
	*/
	public static Stream<Double> stream(final double[] self) {
	return IntStream.range(0, self.length).mapToObj(i -> self[i]);
	}

	/**
	* Returns a sequential {@link Stream} with the specified array as its
	* source.
	*
	* @param self The array, assumed to be unmodified during use
	* @return a {@code Stream} for the array
	*
	* @since 2.5.0
	*/
	public static Stream<Character> stream(final char[] self) {
	return IntStream.range(0, self.length).mapToObj(i -> self[i]);
	}

	/**
	* Returns a sequential {@link Stream} with the specified array as its
	* source.
	*
	* @param self The array, assumed to be unmodified during use
	* @return a {@code Stream} for the array
	*
	* @since 2.5.0
	*/
	public static Stream<Byte> stream(final byte[] self) {
	return IntStream.range(0, self.length).mapToObj(i -> self[i]);
	}

	/**
	* Returns a sequential {@link Stream} with the specified array as its
	* source.
	*
	* @param self The array, assumed to be unmodified during use
	* @return a {@code Stream} for the array
	*
	* @since 2.5.0
	*/
	public static Stream<Short> stream(final short[] self) {
	return IntStream.range(0, self.length).mapToObj(i -> self[i]);
	}

	/**
	* Returns a sequential {@link Stream} with the specified array as its
	* source.
	*
	* @param self The array, assumed to be unmodified during use
	* @return a {@code Stream} for the array
	*
	* @since 2.5.0
	*/
	public static Stream<Boolean> stream(final boolean[] self) {
	return IntStream.range(0, self.length).mapToObj(i -> self[i]);
	}

	/**
	* Returns a sequential {@link Stream} with the specified array as its
	* source.
	*
	* @param self The array, assumed to be unmodified during use
	* @return a {@code Stream} for the array
	*
	* @since 2.5.0
	*/
	public static Stream<Float> stream(final float[] self) {
	return IntStream.range(0, self.length).mapToObj(i -> self[i]);
	}

	/**
	* If a value is present in the {@link Optional}, returns a {@link Stream}
	* with the value as its source or else an empty stream.
	*
	* @since 3.0.0
	*/
	public static <T> Stream<T> stream(final Optional<T> self) {
	return self.map(Stream::of).orElseGet(Stream::empty);
	}
	}