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package org.shedlang.compiler.util;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Comparator;
import java.util.List;
import java.util.function.BiFunction;
import java.util.function.Function;
public class Iterables {
private Iterables() {
}
public interface OnElement<T, E extends Exception> {
void accept(T value) throws E;
}
public interface Between<E extends Exception> {
void call() throws E;
}
public static <T, U> List<U> filterToType(Iterable<T> iterable, Class<U> clazz) {
var result = new ArrayList<U>();
for (var element : iterable) {
if (clazz.isInstance(element)) {
result.add(clazz.cast(element));
}
}
return result;
}
public static <T> T first(Iterable<T> iterable) {
return iterable.iterator().next();
}
public static <T, R> R foldLeft(
R initial,
Iterable<T> iterable,
BiFunction<R, T, R> combine
) {
R result = initial;
for (var element : iterable) {
result = combine.apply(result, element);
}
return result;
}
public static <T, E extends Exception> void forEachInterspersed(
Iterable<T> values,
OnElement<T, E> onElement,
Between<E> between
) throws E {
var first = true;
for (var value : values) {
if (!first) {
between.call();
}
onElement.accept(value);
first = false;
}
}
public static <T, K extends Comparable<? super K>> List<T> sortedBy(
Collection<T> collection,
Function<? super T, ? extends K> key
) {
return collection.stream().sorted(Comparator.comparing(key)).toList();
}
}
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