ExStream.java
package net.dapete.exceptional.stream;
import lombok.experimental.Delegate;
import net.dapete.exceptional.ExException;
import net.dapete.exceptional.function.*;
import org.jspecify.annotations.Nullable;
import java.util.Collection;
import java.util.Comparator;
import java.util.Optional;
import java.util.function.*;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import java.util.stream.Stream;
/**
* A Stream with additional functionality for functional interfaces that throw Exceptions.
* <p>
* Implements versions of all methods from Stream that use functional interfaces, using their counterparts with Exceptions instead, e.g.
* {@link #map(Class, ExFunction)} in parallel to {@link #map(Function)}.
* <p>
* If these functional interfaces throw a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream (except if it is itself such an operation).
*
* @param <T> the type of the stream elements
*/
public final class ExStream<T> implements Stream<T> {
@Delegate
private final Stream<T> stream;
private ExStream(Stream<T> stream) {
this.stream = stream;
}
/**
* Create an instance from an existing Stream.
*
* @param <T> the type of the stream elements
* @param stream existing stream
* @return instance from an existing Stream
*/
public static <T> ExStream<T> of(Stream<T> stream) {
return new ExStream<>(stream);
}
/**
* Create an instance from an existing DoubleStream.
*
* @param stream existing stream
* @return instance from an existing Stream
*/
public static ExStream<Double> of(DoubleStream stream) {
return new ExStream<>(stream.boxed());
}
/**
* Create an instance from an existing IntStream.
*
* @param stream existing stream
* @return instance from an existing Stream
*/
public static ExStream<Integer> of(IntStream stream) {
return new ExStream<>(stream.boxed());
}
/**
* Create an instance from an existing IntStream.
*
* @param stream existing stream
* @return instance from an existing Stream
*/
public static ExStream<Long> of(LongStream stream) {
return new ExStream<>(stream.boxed());
}
/**
* Create an instance from a collection.
*
* @param <T> the type of the stream elements
* @param collection collection
* @return instance from a collection
*/
public static <T> ExStream<T> of(Collection<T> collection) {
return of(collection.stream());
}
/* Static methods from Stream to create streams. */
/**
* Returns an empty instance.
*
* @param <T> the type of the stream elements
* @return an empty instance
*/
public static <T> ExStream<T> empty() {
return of(Stream.empty());
}
/**
* Returns an instance containing a single element.
*
* @param <T> the type of the stream elements
* @param t the single element
* @return an instance containing a single element
*/
public static <T> ExStream<T> of(T t) {
return of(Stream.of(t));
}
/**
* Returns an instance containing a single element, if non-null, otherwise returns an empty instance.
*
* @param <T> the type of stream elements
* @param t the single element
* @return a stream with a single element if the specified element is non-null, otherwise an empty stream
*/
public static <T> ExStream<T> ofNullable(@Nullable T t) {
return of(Stream.ofNullable(t));
}
/**
* Returns an instance whose elements are the specified values.
*
* @param <T> the type of the stream elements
* @param values the elements of the new stream
* @return the new instance
*/
@SafeVarargs
public static <T> ExStream<T> of(T... values) {
return of(Stream.of(values));
}
/* Override all methods that usually return Stream to return an ExStream. */
@Override
public ExStream<T> filter(Predicate<? super T> predicate) {
return of(stream.filter(predicate));
}
@Override
public <R> ExStream<R> map(Function<? super T, ? extends R> mapper) {
return of(stream.map(mapper));
}
@Override
public <R> ExStream<R> flatMap(Function<? super T, ? extends Stream<? extends R>> mapper) {
return of(stream.flatMap(mapper));
}
@Override
public <R> ExStream<R> mapMulti(BiConsumer<? super T, ? super Consumer<R>> mapper) {
return of(stream.mapMulti(mapper));
}
@Override
public ExStream<T> distinct() {
return of(stream.distinct());
}
@Override
public ExStream<T> sorted() {
return of(stream.sorted());
}
@Override
public ExStream<T> sorted(Comparator<? super T> comparator) {
return of(stream.sorted(comparator));
}
@Override
public ExStream<T> peek(Consumer<? super T> action) {
return of(stream.peek(action));
}
@Override
public ExStream<T> limit(long maxSize) {
return of(stream.limit(maxSize));
}
@Override
public ExStream<T> skip(long n) {
return of(stream.skip(n));
}
@Override
public ExStream<T> takeWhile(Predicate<? super T> predicate) {
return of(stream.takeWhile(predicate));
}
@Override
public ExStream<T> dropWhile(Predicate<? super T> predicate) {
return of(stream.dropWhile(predicate));
}
/* Override all methods that usually return DoubleStream to return an ExDoubleStream. */
@Override
public ExDoubleStream mapToDouble(ToDoubleFunction<? super T> mapper) {
return ExDoubleStream.of(stream.mapToDouble(mapper));
}
@Override
public ExDoubleStream flatMapToDouble(Function<? super T, ? extends DoubleStream> mapper) {
return ExDoubleStream.of(stream.flatMapToDouble(mapper));
}
@Override
public ExDoubleStream mapMultiToDouble(BiConsumer<? super T, ? super DoubleConsumer> mapper) {
return ExDoubleStream.of(stream.mapMultiToDouble(mapper));
}
/* Override all methods that usually return IntStream to return an ExIntStream. */
@Override
public ExIntStream mapToInt(ToIntFunction<? super T> mapper) {
return ExIntStream.of(stream.mapToInt(mapper));
}
@Override
public ExIntStream flatMapToInt(Function<? super T, ? extends IntStream> mapper) {
return ExIntStream.of(stream.flatMapToInt(mapper));
}
@Override
public ExIntStream mapMultiToInt(BiConsumer<? super T, ? super IntConsumer> mapper) {
return ExIntStream.of(stream.mapMultiToInt(mapper));
}
/* Override all methods that usually return LongStream to return an ExLongStream. */
@Override
public ExLongStream mapToLong(ToLongFunction<? super T> mapper) {
return ExLongStream.of(stream.mapToLong(mapper));
}
@Override
public ExLongStream flatMapToLong(Function<? super T, ? extends LongStream> mapper) {
return ExLongStream.of(stream.flatMapToLong(mapper));
}
@Override
public ExLongStream mapMultiToLong(BiConsumer<? super T, ? super LongConsumer> mapper) {
return ExLongStream.of(stream.mapMultiToLong(mapper));
}
/* Implement versions of all methods from Stream that use functional interfaces, using their counterparts with Exceptions instead. */
/**
* Equivalent of {@link Stream#filter}.
* <p>
* If {@code predicate} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param predicate see {@link Stream#filter}
* @return see {@link Stream#filter}
*/
public <E extends Exception> ExStream<T> filter(Class<E> exceptionClass, ExPredicate<? super T, ? extends E> predicate) {
return filter(predicate.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#map(Function)}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <R> The element type of the new stream
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#map}
* @return see {@link Stream#map}
*/
public <R, E extends Exception> ExStream<R> map(
Class<E> exceptionClass, ExFunction<? super T, ? extends R, ? extends E> mapper) {
return map(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#mapToDouble}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#mapToDouble}
* @return see {@link Stream#mapToDouble}
*/
public <E extends Exception> ExDoubleStream mapToDouble(
Class<E> exceptionClass, ExToDoubleFunction<? super T, ? extends E> mapper) {
return mapToDouble(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#mapToInt}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#mapToInt}
* @return see {@link Stream#mapToInt}
*/
public <E extends Exception> ExIntStream mapToInt(Class<E> exceptionClass, ExToIntFunction<? super T, ? extends E> mapper) {
return mapToInt(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#mapToLong}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#mapToLong}
* @return see {@link Stream#mapToLong}
*/
public <E extends Exception> ExLongStream mapToLong(Class<E> exceptionClass, ExToLongFunction<? super T, ? extends E> mapper) {
return mapToLong(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#flatMap}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <R> The element type of the new stream
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#flatMap}
* @return see {@link Stream#flatMap}
*/
public <R, E extends Exception> ExStream<R> flatMap(
Class<E> exceptionClass, ExFunction<? super T, ? extends Stream<? extends R>, ? extends E> mapper) {
return flatMap(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#flatMapToDouble}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#flatMapToDouble}
* @return see {@link Stream#flatMapToDouble}
*/
public <E extends Exception> ExDoubleStream flatMapToDouble(
Class<E> exceptionClass, ExFunction<? super T, ? extends DoubleStream, ? extends E> mapper) {
return flatMapToDouble(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#flatMapToInt}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#flatMapToInt}
* @return see {@link Stream#flatMapToInt}
*/
public <E extends Exception> ExIntStream flatMapToInt(
Class<E> exceptionClass, ExFunction<? super T, ? extends IntStream, ? extends E> mapper) {
return flatMapToInt(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#flatMapToLong}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#flatMapToLong}
* @return see {@link Stream#flatMapToLong}
*/
public <E extends Exception> ExLongStream flatMapToLong(
Class<E> exceptionClass, ExFunction<? super T, ? extends LongStream, ? extends E> mapper) {
return flatMapToLong(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#mapMulti}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <R> The element type of the new stream
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#mapMulti}
* @return see {@link Stream#mapMulti}
*/
public <R, E extends Exception> ExStream<R> mapMulti(
Class<E> exceptionClass, ExBiConsumer<? super T, ? super Consumer<R>, ? extends E> mapper) {
return mapMulti(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#mapMultiToDouble}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#mapMultiToDouble}
* @return see {@link Stream#mapMultiToDouble}
*/
public <E extends Exception> ExDoubleStream mapMultiToDouble(
Class<E> exceptionClass, ExBiConsumer<? super T, ? super DoubleConsumer, ? extends E> mapper) {
return mapMultiToDouble(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#mapMultiToInt}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#mapMultiToInt}
* @return see {@link Stream#mapMultiToInt}
*/
public <E extends Exception> ExIntStream mapMultiToInt(
Class<E> exceptionClass, ExBiConsumer<? super T, ? super IntConsumer, ? extends E> mapper) {
return mapMultiToInt(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#mapMultiToLong}.
* <p>
* If {@code mapper} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when a method is called, but only when a <em>terminal operation</em> or a
* <em>stateful intermediate operation</em> is used on the stream.
*
* @param <E> The exception type thrown by {@code mapper}
* @param exceptionClass The exception class for {@link E}
* @param mapper see {@link Stream#mapMultiToLong}
* @return see {@link Stream#mapMultiToLong}
*/
public <E extends Exception> ExLongStream mapMultiToLong(
Class<E> exceptionClass, ExBiConsumer<? super T, ? super LongConsumer, ? extends E> mapper) {
return mapMultiToLong(mapper.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#peek}.
* <p>
* If {@code action} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
*
* @param <E> The exception type thrown by {@code action}
* @param exceptionClass The exception class for {@link E}
* @param action see {@link Stream#peek}
* @return see {@link Stream#peek}
*/
public <E extends Exception> ExStream<T> peek(Class<E> exceptionClass, ExConsumer<? super T, ? extends E> action) {
return peek(action.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#takeWhile}.
* <p>
* If {@code predicate} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
*
* @param <E> The exception type thrown by {@code predicate}
* @param exceptionClass The exception class for {@link E}
* @param predicate see {@link Stream#takeWhile}
* @return see {@link Stream#takeWhile}
*/
public <E extends Exception> ExStream<T> takeWhile(Class<E> exceptionClass, ExPredicate<? super T, ? extends E> predicate) {
return takeWhile(predicate.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#dropWhile}.
* <p>
* If {@code predicate} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
* <p>
* Note that this exception will likely not be thrown when this method is called, but only when a <em>terminal operation</em> like {@link Stream#toList()}
* is used on the stream.
*
* @param <E> The exception type thrown by {@code predicate}
* @param exceptionClass The exception class for {@link E}
* @param predicate see {@link Stream#dropWhile}
* @return see {@link Stream#dropWhile}
*/
public <E extends Exception> ExStream<T> dropWhile(Class<E> exceptionClass, ExPredicate<? super T, ? extends E> predicate) {
return dropWhile(predicate.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#forEach}.
* <p>
* If {@code action} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
*
* @param <E> The exception type thrown by {@code action}
* @param exceptionClass The exception class for {@link E}
* @param action see {@link Stream#forEach}
*/
public <E extends Exception> void forEach(Class<E> exceptionClass, ExConsumer<? super T, ? extends E> action) {
forEach(action.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#forEachOrdered}.
* <p>
* If {@code action} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
*
* @param <E> The exception type thrown by {@code action}
* @param exceptionClass The exception class for {@link E}
* @param action see {@link Stream#forEachOrdered}
*/
public <E extends Exception> void forEachOrdered(Class<E> exceptionClass, ExConsumer<? super T, ? extends E> action) {
forEachOrdered(action.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#reduce(BinaryOperator)}.
* <p>
* If {@code accumulator} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
*
* @param <E> The exception type thrown by {@code accumulator}
* @param exceptionClass The exception class for {@link E}
* @param accumulator see {@link Stream#reduce(BinaryOperator)}
* @return see {@link Stream#reduce(BinaryOperator)}
*/
public <E extends Exception> Optional<T> reduce(Class<E> exceptionClass, ExBinaryOperator<T, ? extends E> accumulator) {
return reduce(accumulator.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#reduce(Object, BinaryOperator)}.
* <p>
* If {@code accumulator} throws a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
*
* @param <E> The exception type thrown by {@code accumulator}
* @param exceptionClass The exception class for {@link E}
* @param identity see {@link Stream#reduce(Object, BiFunction, BinaryOperator)}
* @param accumulator see {@link Stream#reduce(Object, BinaryOperator)}
* @return see {@link Stream#reduce(Object, BinaryOperator)}
*/
public <E extends Exception> T reduce(Class<E> exceptionClass, T identity, ExBinaryOperator<T, ? extends E> accumulator) {
return reduce(identity, accumulator.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#reduce(Object, BiFunction, BinaryOperator)}.
* <p>
* If {@code accumulator} or {@code combiner} throw a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
*
* @param <U> the element type of the new stream
* @param <E> The exception type thrown by {@code accumulator} or {@code combiner}
* @param exceptionClass The exception class for {@link E}
* @param identity see {@link Stream#reduce(Object, BiFunction, BinaryOperator)}
* @param accumulator see {@link Stream#reduce(Object, BiFunction, BinaryOperator)}
* @param combiner see {@link Stream#reduce(Object, BiFunction, BinaryOperator)}
* @return see {@link Stream#reduce(Object, BiFunction, BinaryOperator)}
*/
public <U, E extends Exception> U reduce(
Class<E> exceptionClass, U identity, ExBiFunction<U, ? super T, U, ? extends E> accumulator, ExBinaryOperator<U, ? extends E> combiner) {
return reduce(identity, accumulator.wrap(exceptionClass), combiner.wrap(exceptionClass));
}
/**
* Equivalent of {@link Stream#collect(Supplier, BiConsumer, BiConsumer)}.
* <p>
* If {@code supplier}, {@code accumulator} or {@code combiner} throw a checked exception, a {@link ExException} will be thrown instead.
* This will have the original exception as its {@link ExException#getCause() cause}.
*
* @param <R> the type of the mutable result container
* @param <E> The exception type thrown by {@code supplier}, {@code accumulator} or {@code combiner}
* @param exceptionClass The exception class for {@link E}
* @param supplier see {@link Stream#collect(Supplier, BiConsumer, BiConsumer)}
* @param accumulator see {@link Stream#collect(Supplier, BiConsumer, BiConsumer)}
* @param combiner see {@link Stream#collect(Supplier, BiConsumer, BiConsumer)}
* @return see {@link Stream#collect(Supplier, BiConsumer, BiConsumer)}
*/
public <R, E extends Exception> R collect(
Class<E> exceptionClass, ExSupplier<R, ? extends E> supplier, ExBiConsumer<R, ? super T, ? extends E> accumulator,
ExBiConsumer<R, R, ? extends E> combiner) {
return collect(supplier.wrap(exceptionClass), accumulator.wrap(exceptionClass), combiner.wrap(exceptionClass));
}
}