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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      https://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.lang3.function;
19  
20  import java.io.IOException;
21  import java.io.UncheckedIOException;
22  import java.lang.reflect.UndeclaredThrowableException;
23  import java.util.Collection;
24  import java.util.Objects;
25  import java.util.Optional;
26  import java.util.concurrent.Callable;
27  import java.util.function.BiConsumer;
28  import java.util.function.BiFunction;
29  import java.util.function.BiPredicate;
30  import java.util.function.Consumer;
31  import java.util.function.Function;
32  import java.util.function.Predicate;
33  import java.util.function.Supplier;
34  import java.util.stream.Stream;
35  
36  import org.apache.commons.lang3.exception.ExceptionUtils;
37  import org.apache.commons.lang3.stream.Streams;
38  import org.apache.commons.lang3.stream.Streams.FailableStream;
39  
40  /**
41   * This class provides utility functions, and classes for working with the {@code java.util.function} package, or more
42   * generally, with Java 8 lambdas. More specifically, it attempts to address the fact that lambdas are supposed not to
43   * throw Exceptions, at least not checked Exceptions, like instances of {@link Exception}. This enforces the use of
44   * constructs like:
45   *
46   * <pre>{@code
47   * Consumer<java.lang.reflect.Method> consumer = m -&gt; {
48   *     try {
49   *         m.invoke(o, args);
50   *     } catch (Throwable t) {
51   *         throw Failable.rethrow(t);
52   *     }
53   * };
54   * }
55   * </pre>
56   *
57   * <p>
58   * By replacing a {@link java.util.function.Consumer Consumer&lt;O&gt;} with a {@link FailableConsumer
59   * FailableConsumer&lt;O,? extends Throwable&gt;}, this can be written like follows:
60   * </p>
61   *
62   * <pre>
63   * Functions.accept((m) -&gt; m.invoke(o, args));
64   * </pre>
65   *
66   * <p>
67   * Obviously, the second version is much more concise and the spirit of Lambda expressions is met better than the second
68   * version.
69   * </p>
70   *
71   * @since 3.11
72   */
73  public class Failable {
74  
75      /**
76       * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
77       *
78       * @param consumer the consumer to accept, may be null for a noop.
79       * @param object1 the first object to consume by {@code consumer}
80       * @param object2 the second object to consume by {@code consumer}
81       * @param <T> the type of the first argument the consumer accepts
82       * @param <U> the type of the second argument the consumer accepts
83       * @param <E> the type of checked exception the consumer may throw
84       */
85      public static <T, U, E extends Throwable> void accept(final FailableBiConsumer<T, U, E> consumer, final T object1,
86          final U object2) {
87          run(consumer, () -> consumer.accept(object1, object2));
88      }
89  
90      /**
91       * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
92       *
93       * @param consumer the consumer to accept, may be null for a noop.
94       * @param object the object to consume by {@code consumer}
95       * @param <T> the type the consumer accepts
96       * @param <E> the type of checked exception the consumer may throw
97       */
98      public static <T, E extends Throwable> void accept(final FailableConsumer<T, E> consumer, final T object) {
99          run(consumer, () -> consumer.accept(object));
100     }
101 
102     /**
103      * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
104      *
105      * @param consumer the consumer to accept, may be null for a noop.
106      * @param value the value to consume by {@code consumer}
107      * @param <E> the type of checked exception the consumer may throw
108      */
109     public static <E extends Throwable> void accept(final FailableDoubleConsumer<E> consumer, final double value) {
110         run(consumer, () -> consumer.accept(value));
111     }
112     /**
113      * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
114      *
115      * @param consumer the consumer to accept, may be null for a noop.
116      * @param value the value to consume by {@code consumer}
117      * @param <E> the type of checked exception the consumer may throw
118      */
119     public static <E extends Throwable> void accept(final FailableIntConsumer<E> consumer, final int value) {
120         run(consumer, () -> consumer.accept(value));
121     }
122 
123     /**
124      * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
125      *
126      * @param consumer the consumer to accept, may be null for a noop.
127      * @param value the value to consume by {@code consumer}
128      * @param <E> the type of checked exception the consumer may throw
129      */
130     public static <E extends Throwable> void accept(final FailableLongConsumer<E> consumer, final long value) {
131         run(consumer, () -> consumer.accept(value));
132     }
133 
134     /**
135      * Applies a function and rethrows any exception as a {@link RuntimeException}.
136      *
137      * @param function the function to apply
138      * @param input1 the first input to apply {@code function} on
139      * @param input2 the second input to apply {@code function} on
140      * @param <T> the type of the first argument the function accepts
141      * @param <U> the type of the second argument the function accepts
142      * @param <R> the return type of the function
143      * @param <E> the type of checked exception the function may throw
144      * @return the value returned from the function
145      */
146     public static <T, U, R, E extends Throwable> R apply(final FailableBiFunction<T, U, R, E> function, final T input1,
147         final U input2) {
148         return get(() -> function.apply(input1, input2));
149     }
150 
151     /**
152      * Applies a function and rethrows any exception as a {@link RuntimeException}.
153      *
154      * @param function the function to apply
155      * @param input the input to apply {@code function} on
156      * @param <T> the type of the argument the function accepts
157      * @param <R> the return type of the function
158      * @param <E> the type of checked exception the function may throw
159      * @return the value returned from the function
160      */
161     public static <T, R, E extends Throwable> R apply(final FailableFunction<T, R, E> function, final T input) {
162         return get(() -> function.apply(input));
163     }
164 
165     /**
166      * Applies a function and rethrows any exception as a {@link RuntimeException}.
167      *
168      * @param function the function to apply
169      * @param left the first input to apply {@code function} on
170      * @param right the second input to apply {@code function} on
171      * @param <E> the type of checked exception the function may throw
172      * @return the value returned from the function
173      */
174     public static <E extends Throwable> double applyAsDouble(final FailableDoubleBinaryOperator<E> function,
175         final double left, final double right) {
176         return getAsDouble(() -> function.applyAsDouble(left, right));
177     }
178 
179     /**
180      * Applies a value to a function if the value isn't {@code null}, otherwise the method returns {@code null}. If the value isn't {@code null} then return the
181      * result of the applying function.
182      *
183      * <pre>{@code
184      * Failable.applyNonNull("a", String::toUpperCase)  = "A"
185      * Failable.applyNonNull(null, String::toUpperCase) = null
186      * Failable.applyNonNull("a", s -> null)            = null
187      * }</pre>
188      * <p>
189      * Useful when working with expressions that may return {@code null} as it allows a single-line expression without using temporary local variables or
190      * evaluating expressions twice. Provides an alternative to using {@link Optional} that is shorter and has less allocation.
191      * </p>
192      *
193      * @param <T>    The type of the input of this method and the function.
194      * @param <R>    The type of the result of the function and this method.
195      * @param <E>    The type of thrown exception or error.
196      * @param value  The value to apply the function to, may be {@code null}.
197      * @param mapper The function to apply, must not be {@code null}.
198      * @return The result of the function (which may be {@code null}) or {@code null} if the input value is {@code null}.
199      * @throws E Thrown by the given function.
200      * @see #applyNonNull(Object, FailableFunction, FailableFunction)
201      * @see #applyNonNull(Object, FailableFunction, FailableFunction, FailableFunction)
202      * @since 3.19.0
203      */
204     public static <T, R, E extends Throwable> R applyNonNull(final T value, final FailableFunction<? super T, ? extends R, E> mapper) throws E {
205         return value != null ? Objects.requireNonNull(mapper, "mapper").apply(value) : null;
206     }
207 
208     /**
209      * Applies values to a chain of functions, where a {@code null} can short-circuit each step. A function is only applied if the previous value is not
210      * {@code null}, otherwise this method returns {@code null}.
211      *
212      * <pre>{@code
213      * Failable.applyNonNull(" a ", String::toUpperCase, String::trim) = "A"
214      * Failable.applyNonNull(null, String::toUpperCase, String::trim)  = null
215      * Failable.applyNonNull(" a ", s -> null, String::trim)           = null
216      * Failable.applyNonNull(" a ", String::toUpperCase, s -> null)    = null
217      * }</pre>
218      * <p>
219      * Useful when working with expressions that may return {@code null} as it allows a single-line expression without using temporary local variables or
220      * evaluating expressions twice. Provides an alternative to using {@link Optional} that is shorter and has less allocation.
221      * </p>
222      *
223      * @param <T>     The type of the input of this method and the first function.
224      * @param <U>     The type of the result of the first function and the input to the second function.
225      * @param <R>     The type of the result of the second function and this method.
226      * @param <E1>    The type of thrown exception or error by the first function.
227      * @param <E2>    The type of thrown exception or error by the second function.
228      * @param value1  The value to apply the functions to, may be {@code null}.
229      * @param mapper1 The first function to apply, must not be {@code null}.
230      * @param mapper2 The second function to apply, must not be {@code null}.
231      * @return The result of the final function (which may be {@code null}) or {@code null} if the input value or any intermediate value is {@code null}.
232      * @throws E1 Thrown by the first function.
233      * @throws E2 Thrown by the second function.
234      * @see #applyNonNull(Object, FailableFunction)
235      * @see #applyNonNull(Object, FailableFunction, FailableFunction, FailableFunction)
236      * @since 3.19.0
237      */
238     public static <T, U, R, E1 extends Throwable, E2 extends Throwable> R applyNonNull(final T value1,
239             final FailableFunction<? super T, ? extends U, E1> mapper1, final FailableFunction<? super U, ? extends R, E2> mapper2) throws E1, E2 {
240         return applyNonNull(applyNonNull(value1, mapper1), mapper2);
241     }
242 
243     /**
244      * Applies values to a chain of functions, where a {@code null} can short-circuit each step. A function is only applied if the previous value is not
245      * {@code null}, otherwise this method returns {@code null}.
246      *
247      * <pre>{@code
248      * Failable.applyNonNull(" abc ", String::toUpperCase, String::trim, StringUtils::reverse) = "CBA"
249      * Failable.applyNonNull(null, String::toUpperCase, String::trim, StringUtils::reverse)    = null
250      * Failable.applyNonNull(" abc ", s -> null, String::trim, StringUtils::reverse)           = null
251      * Failable.applyNonNull(" abc ", String::toUpperCase, s -> null, StringUtils::reverse)    = null
252      * Failable.applyNonNull(" abc ", String::toUpperCase, String::trim, s -> null)            = null
253      * }</pre>
254      * <p>
255      * Useful when working with expressions that may return {@code null} as it allows a single-line expression without using temporary local variables or
256      * evaluating expressions twice. Provides an alternative to using {@link Optional} that is shorter and has less allocation.
257      * </p>
258      *
259      * @param <T>     The type of the input of this method and the first function.
260      * @param <U>     The type of the result of the first function and the input to the second function.
261      * @param <V>     The type of the result of the second function and the input to the third function.
262      * @param <R>     The type of the result of the third function and this method.
263      * @param <E1>    The type of thrown exception or error by the first function.
264      * @param <E2>    The type of thrown exception or error by the second function.
265      * @param <E3>    The type of thrown exception or error by the second function.
266      * @param value1  The value to apply the first function, may be {@code null}.
267      * @param mapper1 The first function to apply, must not be {@code null}.
268      * @param mapper2 The second function to apply, must not be {@code null}.
269      * @param mapper3 The third function to apply, must not be {@code null}.
270      * @return The result of the final function (which may be {@code null}) or {@code null} if the input value or any intermediate value is {@code null}.
271      * @throws E1 Thrown by the first function.
272      * @throws E2 Thrown by the second function.
273      * @throws E3 Thrown by the third function.
274      * @see #applyNonNull(Object, FailableFunction)
275      * @see #applyNonNull(Object, FailableFunction, FailableFunction)
276      * @since 3.19.0
277      */
278     public static <T, U, V, R, E1 extends Throwable, E2 extends Throwable, E3 extends Throwable> R applyNonNull(final T value1,
279             final FailableFunction<? super T, ? extends U, E1> mapper1, final FailableFunction<? super U, ? extends V, E2> mapper2,
280             final FailableFunction<? super V, ? extends R, E3> mapper3) throws E1, E2, E3 {
281         return applyNonNull(applyNonNull(applyNonNull(value1, mapper1), mapper2), mapper3);
282     }
283 
284     /**
285      * Converts the given {@link FailableBiConsumer} into a standard {@link BiConsumer}.
286      *
287      * @param <T> the type of the first argument of the consumers
288      * @param <U> the type of the second argument of the consumers
289      * @param consumer a failable {@link BiConsumer}
290      * @return a standard {@link BiConsumer}
291      */
292     public static <T, U> BiConsumer<T, U> asBiConsumer(final FailableBiConsumer<T, U, ?> consumer) {
293         return (input1, input2) -> accept(consumer, input1, input2);
294     }
295 
296     /**
297      * Converts the given {@link FailableBiFunction} into a standard {@link BiFunction}.
298      *
299      * @param <T> the type of the first argument of the input of the functions
300      * @param <U> the type of the second argument of the input of the functions
301      * @param <R> the type of the output of the functions
302      * @param function a {@link FailableBiFunction}
303      * @return a standard {@link BiFunction}
304      */
305     public static <T, U, R> BiFunction<T, U, R> asBiFunction(final FailableBiFunction<T, U, R, ?> function) {
306         return (input1, input2) -> apply(function, input1, input2);
307     }
308 
309     /**
310      * Converts the given {@link FailableBiPredicate} into a standard {@link BiPredicate}.
311      *
312      * @param <T> the type of the first argument used by the predicates
313      * @param <U> the type of the second argument used by the predicates
314      * @param predicate a {@link FailableBiPredicate}
315      * @return a standard {@link BiPredicate}
316      */
317     public static <T, U> BiPredicate<T, U> asBiPredicate(final FailableBiPredicate<T, U, ?> predicate) {
318         return (input1, input2) -> test(predicate, input1, input2);
319     }
320 
321     /**
322      * Converts the given {@link FailableCallable} into a standard {@link Callable}.
323      *
324      * @param <V> the type used by the callables
325      * @param callable a {@link FailableCallable}
326      * @return a standard {@link Callable}
327      */
328     public static <V> Callable<V> asCallable(final FailableCallable<V, ?> callable) {
329         return () -> call(callable);
330     }
331 
332     /**
333      * Converts the given {@link FailableConsumer} into a standard {@link Consumer}.
334      *
335      * @param <T> the type used by the consumers
336      * @param consumer a {@link FailableConsumer}
337      * @return a standard {@link Consumer}
338      */
339     public static <T> Consumer<T> asConsumer(final FailableConsumer<T, ?> consumer) {
340         return input -> accept(consumer, input);
341     }
342 
343     /**
344      * Converts the given {@link FailableFunction} into a standard {@link Function}.
345      *
346      * @param <T> the type of the input of the functions
347      * @param <R> the type of the output of the functions
348      * @param function a {code FailableFunction}
349      * @return a standard {@link Function}
350      */
351     public static <T, R> Function<T, R> asFunction(final FailableFunction<T, R, ?> function) {
352         return input -> apply(function, input);
353     }
354 
355     /**
356      * Converts the given {@link FailablePredicate} into a standard {@link Predicate}.
357      *
358      * @param <T> the type used by the predicates
359      * @param predicate a {@link FailablePredicate}
360      * @return a standard {@link Predicate}
361      */
362     public static <T> Predicate<T> asPredicate(final FailablePredicate<T, ?> predicate) {
363         return input -> test(predicate, input);
364     }
365 
366     /**
367      * Converts the given {@link FailableRunnable} into a standard {@link Runnable}.
368      *
369      * @param runnable a {@link FailableRunnable}
370      * @return a standard {@link Runnable}
371      */
372     public static Runnable asRunnable(final FailableRunnable<?> runnable) {
373         return () -> run(runnable);
374     }
375 
376     /**
377      * Converts the given {@link FailableSupplier} into a standard {@link Supplier}.
378      *
379      * @param <T> the type supplied by the suppliers
380      * @param supplier a {@link FailableSupplier}
381      * @return a standard {@link Supplier}
382      */
383     public static <T> Supplier<T> asSupplier(final FailableSupplier<T, ?> supplier) {
384         return () -> get(supplier);
385     }
386 
387     /**
388      * Calls a callable and rethrows any exception as a {@link RuntimeException}.
389      *
390      * @param callable the callable to call
391      * @param <V> the return type of the callable
392      * @param <E> the type of checked exception the callable may throw
393      * @return the value returned from the callable
394      */
395     public static <V, E extends Throwable> V call(final FailableCallable<V, E> callable) {
396         return get(callable::call);
397     }
398 
399     /**
400      * Invokes a supplier, and returns the result.
401      *
402      * @param supplier The supplier to invoke.
403      * @param <T> The suppliers output type.
404      * @param <E> The type of checked exception, which the supplier can throw.
405      * @return The object, which has been created by the supplier
406      */
407     public static <T, E extends Throwable> T get(final FailableSupplier<T, E> supplier) {
408         try {
409             return supplier.get();
410         } catch (final Throwable t) {
411             throw rethrow(t);
412         }
413     }
414 
415     /**
416      * Invokes a boolean supplier, and returns the result.
417      *
418      * @param supplier The boolean supplier to invoke.
419      * @param <E> The type of checked exception, which the supplier can throw.
420      * @return The boolean, which has been created by the supplier
421      */
422     public static <E extends Throwable> boolean getAsBoolean(final FailableBooleanSupplier<E> supplier) {
423         try {
424             return supplier.getAsBoolean();
425         } catch (final Throwable t) {
426             throw rethrow(t);
427         }
428     }
429 
430     /**
431      * Invokes a double supplier, and returns the result.
432      *
433      * @param supplier The double supplier to invoke.
434      * @param <E> The type of checked exception, which the supplier can throw.
435      * @return The double, which has been created by the supplier
436      */
437     public static <E extends Throwable> double getAsDouble(final FailableDoubleSupplier<E> supplier) {
438         try {
439             return supplier.getAsDouble();
440         } catch (final Throwable t) {
441             throw rethrow(t);
442         }
443     }
444 
445     /**
446      * Invokes an int supplier, and returns the result.
447      *
448      * @param supplier The int supplier to invoke.
449      * @param <E> The type of checked exception, which the supplier can throw.
450      * @return The int, which has been created by the supplier
451      */
452     public static <E extends Throwable> int getAsInt(final FailableIntSupplier<E> supplier) {
453         try {
454             return supplier.getAsInt();
455         } catch (final Throwable t) {
456             throw rethrow(t);
457         }
458     }
459 
460     /**
461      * Invokes a long supplier, and returns the result.
462      *
463      * @param supplier The long supplier to invoke.
464      * @param <E> The type of checked exception, which the supplier can throw.
465      * @return The long, which has been created by the supplier
466      */
467     public static <E extends Throwable> long getAsLong(final FailableLongSupplier<E> supplier) {
468         try {
469             return supplier.getAsLong();
470         } catch (final Throwable t) {
471             throw rethrow(t);
472         }
473     }
474 
475     /**
476      * Invokes a short supplier, and returns the result.
477      *
478      * @param supplier The short supplier to invoke.
479      * @param <E> The type of checked exception, which the supplier can throw.
480      * @return The short, which has been created by the supplier
481      */
482     public static <E extends Throwable> short getAsShort(final FailableShortSupplier<E> supplier) {
483         try {
484             return supplier.getAsShort();
485         } catch (final Throwable t) {
486             throw rethrow(t);
487         }
488     }
489 
490     /**
491      * Rethrows a {@link Throwable} as an unchecked exception. If the argument is already unchecked, namely a
492      * {@link RuntimeException} or {@link Error} then the argument will be rethrown without modification. If the
493      * exception is {@link IOException} then it will be wrapped into a {@link UncheckedIOException}. In every other
494      * cases the exception will be wrapped into a {@code
495      * UndeclaredThrowableException}
496      *
497      * <p>
498      * Note that there is a declared return type for this method, even though it never returns. The reason for that is
499      * to support the usual pattern:
500      * </p>
501      *
502      * <pre>
503      * throw rethrow(myUncheckedException);
504      * </pre>
505      *
506      * <p>
507      * instead of just calling the method. This pattern may help the Java compiler to recognize that at that point an
508      * exception will be thrown and the code flow analysis will not demand otherwise mandatory commands that could
509      * follow the method call, like a {@code return} statement from a value returning method.
510      * </p>
511      *
512      * @param throwable The throwable to rethrow possibly wrapped into an unchecked exception
513      * @return Never returns anything, this method never terminates normally.
514      */
515     public static RuntimeException rethrow(final Throwable throwable) {
516         Objects.requireNonNull(throwable, "throwable");
517         ExceptionUtils.throwUnchecked(throwable);
518         if (throwable instanceof IOException) {
519             throw new UncheckedIOException((IOException) throwable);
520         }
521         throw new UndeclaredThrowableException(throwable);
522     }
523 
524     /**
525      * Runs a runnable and rethrows any exception as a {@link RuntimeException}.
526      *
527      * @param runnable The runnable to run, may be null for a noop.
528      * @param <E> the type of checked exception the runnable may throw.
529      */
530     public static <E extends Throwable> void run(final FailableRunnable<E> runnable) {
531         if (runnable != null) {
532             try {
533                 runnable.run();
534             } catch (final Throwable t) {
535                 throw rethrow(t);
536             }
537         }
538     }
539 
540     private static <E extends Throwable> void run(final Object test, final FailableRunnable<E> runnable) {
541         if (runnable != null && test != null) {
542             try {
543                 runnable.run();
544             } catch (final Throwable t) {
545                 throw rethrow(t);
546             }
547         }
548     }
549 
550     /**
551      * Converts the given collection into a {@link FailableStream}. The {@link FailableStream} consists of the
552      * collections elements. Shortcut for
553      *
554      * <pre>
555      * Functions.stream(collection.stream());
556      * </pre>
557      *
558      * @param collection The collection, which is being converted into a {@link FailableStream}.
559      * @param <E> The collections element type. (In turn, the result streams element type.)
560      * @return The created {@link FailableStream}.
561      */
562     public static <E> FailableStream<E> stream(final Collection<E> collection) {
563         return new FailableStream<>(collection.stream());
564     }
565 
566     /**
567      * Converts the given stream into a {@link FailableStream}. The {@link FailableStream} consists of the same
568      * elements, than the input stream. However, failable lambdas, like {@link FailablePredicate},
569      * {@link FailableFunction}, and {@link FailableConsumer} may be applied, rather than {@link Predicate},
570      * {@link Function}, {@link Consumer}, etc.
571      *
572      * @param stream The stream, which is being converted into a {@link FailableStream}.
573      * @param <T> The streams element type.
574      * @return The created {@link FailableStream}.
575      */
576     public static <T> FailableStream<T> stream(final Stream<T> stream) {
577         return new FailableStream<>(stream);
578     }
579 
580     /**
581      * Tests a predicate and rethrows any exception as a {@link RuntimeException}.
582      *
583      * @param predicate the predicate to test
584      * @param object1 the first input to test by {@code predicate}
585      * @param object2 the second input to test by {@code predicate}
586      * @param <T> the type of the first argument the predicate tests
587      * @param <U> the type of the second argument the predicate tests
588      * @param <E> the type of checked exception the predicate may throw
589      * @return the boolean value returned by the predicate
590      */
591     public static <T, U, E extends Throwable> boolean test(final FailableBiPredicate<T, U, E> predicate,
592         final T object1, final U object2) {
593         return getAsBoolean(() -> predicate.test(object1, object2));
594     }
595 
596     /**
597      * Tests a predicate and rethrows any exception as a {@link RuntimeException}.
598      *
599      * @param predicate the predicate to test
600      * @param object the input to test by {@code predicate}
601      * @param <T> the type of argument the predicate tests
602      * @param <E> the type of checked exception the predicate may throw
603      * @return the boolean value returned by the predicate
604      */
605     public static <T, E extends Throwable> boolean test(final FailablePredicate<T, E> predicate, final T object) {
606         return getAsBoolean(() -> predicate.test(object));
607     }
608 
609     /**
610      * A simple try-with-resources implementation, that can be used, if your objects do not implement the
611      * {@link AutoCloseable} interface. The method executes the {@code action}. The method guarantees, that <em>all</em>
612      * the {@code resources} are being executed, in the given order, afterwards, and regardless of success, or failure.
613      * If either the original action, or any of the resource action fails, then the <em>first</em> failure (AKA
614      * {@link Throwable}) is rethrown. Example use:
615      *
616      * <pre>{@code
617      * final FileInputStream fis = new FileInputStream("my.file");
618      * Functions.tryWithResources(useInputStream(fis), null, () -> fis.close());
619      * }</pre>
620      *
621      * @param action The action to execute. This object <em>will</em> always be invoked.
622      * @param errorHandler An optional error handler, which will be invoked finally, if any error occurred. The error
623      *        handler will receive the first error, AKA {@link Throwable}.
624      * @param resources The resource actions to execute. <em>All</em> resource actions will be invoked, in the given
625      *        order. A resource action is an instance of {@link FailableRunnable}, which will be executed.
626      * @see #tryWithResources(FailableRunnable, FailableRunnable...)
627      */
628     @SafeVarargs
629     public static void tryWithResources(final FailableRunnable<? extends Throwable> action,
630         final FailableConsumer<Throwable, ? extends Throwable> errorHandler,
631         final FailableRunnable<? extends Throwable>... resources) {
632         final FailableConsumer<Throwable, ? extends Throwable> actualErrorHandler;
633         if (errorHandler == null) {
634             actualErrorHandler = Failable::rethrow;
635         } else {
636             actualErrorHandler = errorHandler;
637         }
638         Streams.of(resources).forEach(r -> Objects.requireNonNull(r, "runnable"));
639         Throwable th = null;
640         try {
641             action.run();
642         } catch (final Throwable t) {
643             th = t;
644         }
645         if (resources != null) {
646             for (final FailableRunnable<?> runnable : resources) {
647                 try {
648                     runnable.run();
649                 } catch (final Throwable t) {
650                     if (th == null) {
651                         th = t;
652                     }
653                 }
654             }
655         }
656         if (th != null) {
657             try {
658                 actualErrorHandler.accept(th);
659             } catch (final Throwable t) {
660                 throw rethrow(t);
661             }
662         }
663     }
664 
665     /**
666      * A simple try-with-resources implementation, that can be used, if your objects do not implement the
667      * {@link AutoCloseable} interface. The method executes the {@code action}. The method guarantees, that <em>all</em>
668      * the {@code resources} are being executed, in the given order, afterwards, and regardless of success, or failure.
669      * If either the original action, or any of the resource action fails, then the <em>first</em> failure (AKA
670      * {@link Throwable}) is rethrown. Example use:
671      *
672      * <pre>{@code
673      * final FileInputStream fis = new FileInputStream("my.file");
674      * Functions.tryWithResources(useInputStream(fis), () -> fis.close());
675      * }</pre>
676      *
677      * @param action The action to execute. This object <em>will</em> always be invoked.
678      * @param resources The resource actions to execute. <em>All</em> resource actions will be invoked, in the given
679      *        order. A resource action is an instance of {@link FailableRunnable}, which will be executed.
680      * @see #tryWithResources(FailableRunnable, FailableConsumer, FailableRunnable...)
681      */
682     @SafeVarargs
683     public static void tryWithResources(final FailableRunnable<? extends Throwable> action, final FailableRunnable<? extends Throwable>... resources) {
684         tryWithResources(action, null, resources);
685     }
686 
687     private Failable() {
688         // empty
689     }
690 
691 }