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package org.zwobble.couscous.util;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import java.util.Iterator;
import java.util.List;
import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
public class ExtraLists {
public static <T> List<T> list() {
return ImmutableList.of();
}
public static <T> List<T> list(T value1) {
return ImmutableList.of(value1);
}
public static <T> List<T> list(T value1, T value2) {
return ImmutableList.of(value1, value2);
}
public static <T> List<T> list(T value1, T value2, T value3) {
return ImmutableList.of(value1, value2, value3);
}
public static <T> List<T> list(T... values) {
return ImmutableList.copyOf(values);
}
public static <T> List<T> cons(T value, Iterable<T> list) {
return concat(list(value), list);
}
public static <T> List<T> append(Iterable<? extends T> iterable, T value) {
return Stream.concat(ExtraIterables.stream(iterable), Stream.of(value)).collect(Collectors.toList());
}
public static <T> List<T> concat(Iterable<? extends T> first, Iterable<? extends T> second) {
return ImmutableList.copyOf(Iterables.concat(first, second));
}
public static <T> List<T> concat(Iterable<? extends T> first, Iterable<? extends T> second, Iterable<? extends T> third) {
return ImmutableList.copyOf(Iterables.concat(first, second, third));
}
@SuppressWarnings("unchecked")
public static <T, R extends T> List<R> ofType(List<T> list, Class<R> clazz) {
return (List<R>)list.stream()
.filter(clazz::isInstance)
.collect(Collectors.toList());
}
@SuppressWarnings("unchecked")
public static <T, R, E extends Exception> List<R> flatMap(
Stream<T> stream,
CheckedFunction<T, Iterable<R>, E> function) throws E {
try {
return stream
.flatMap(value -> {
try {
return StreamSupport.stream(function.apply(value).spliterator(), false);
} catch (Exception exception) {
throw new StashedException(exception);
}
})
.collect(Collectors.toList());
} catch (StashedException exception) {
throw (E)exception.exception;
}
}
public static <T> List<T> eagerFilter(Iterable<T> iterable, Predicate<T> predicate) {
return StreamSupport.stream(iterable.spliterator(), false)
.filter(predicate)
.collect(Collectors.toList());
}
public static <T, R> List<R> eagerMap(
Iterable<T> iterable,
Function<T, R> function) {
return StreamSupport.stream(iterable.spliterator(), false)
.map(function)
.collect(Collectors.toList());
}
public static <T, R> List<R> eagerMapWithIndex(
Iterable<T> iterable,
FunctionWithIndex<T, R> function)
{
ImmutableList.Builder<R> builder = ImmutableList.builder();
int index = 0;
Iterator<T> iterator = iterable.iterator();
while (iterator.hasNext()) {
builder.add(function.apply(iterator.next(), index));
index++;
}
return builder.build();
}
public interface FunctionWithIndex<T, R> {
R apply(T value, int index);
}
public static <T1, T2, R> List<R> eagerMap(
Iterable<T1> iterable1,
Iterable<T2> iterable2,
BiFunction<T1, T2, R> function)
{
Iterator<T1> iterator1 = iterable1.iterator();
Iterator<T2> iterator2 = iterable2.iterator();
ImmutableList.Builder<R> result = ImmutableList.builder();
while (iterator1.hasNext() && iterator2.hasNext()) {
result.add(function.apply(iterator1.next(), iterator2.next()));
}
if (iterator1.hasNext()) {
throw new RuntimeException("iterable1 longer than iterable2");
}
if (iterator2.hasNext()) {
throw new RuntimeException("iterable2 longer than iterable1");
}
return result.build();
}
public static <T, R> List<R> eagerFlatMap(
Iterable<T> iterable,
Function<T, Iterable<R>> function) {
return StreamSupport.stream(iterable.spliterator(), false)
.flatMap(element -> StreamSupport.stream(function.apply(element).spliterator(), false))
.collect(Collectors.toList());
}
@FunctionalInterface
public interface CheckedFunction<T, R, E extends Exception> {
R apply(T value) throws E;
}
private static class StashedException extends RuntimeException {
private static final long serialVersionUID = 1L;
private Exception exception;
private StashedException(Exception exception) {
this.exception = exception;
}
}
public static <T> List<T> copyOf(Iterable<T> iterable) {
return ImmutableList.copyOf(iterable);
}
public static <T> T getLast(T[] values) {
return values[values.length - 1];
}
public static <T> T getLast(List<T> values) {
return values.get(values.size() - 1);
}
}
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