public static <
T,
V1 extends Comparable<? super V1>,
V2 extends Comparable<? super V2>,
V3 extends Comparable<? super V3>>
SerializableComparator<T> fromFunctions(
Function<? super T, ? extends V1> one,
Function<? super T, ? extends V2> two,
Function<? super T, ? extends V3> three) {
return Comparators.chain(
Comparators.<T, V1>byFunction(one),
Comparators.<T, V2>byFunction(two),
Comparators.<T, V3>byFunction(three));
}
@Override
@Test
public void toSortedBagBy() {
ImmutableBag<String> immutableBag = this.newBag();
MutableSortedBag<String> sortedBag = immutableBag.toSortedBagBy(String::valueOf);
TreeBag<Object> expectedBag = TreeBag.newBag(Comparators.byFunction(String::valueOf));
Verify.assertSortedBagsEqual(expectedBag, sortedBag);
}
@Test
public void toSortedBagBy_empty() {
ImmutableBag<Integer> immutableBag = Bags.immutable.of();
Function<Integer, Integer> function = object -> object * -1;
MutableSortedBag<Integer> sortedBag = immutableBag.toSortedBagBy(function);
sortedBag.addOccurrences(1, 3);
sortedBag.addOccurrences(10, 2);
Verify.assertSortedBagsEqual(
TreeBag.newBagWith(Comparators.byFunction(function), 10, 10, 1, 1, 1), sortedBag);
}
public static <T, V extends Comparable<? super V>> SerializableComparator<T> byFunction(
Function<? super T, ? extends V> function) {
if (function instanceof IntFunction) {
return Functions.toIntComparator((IntFunction<T>) function);
}
if (function instanceof DoubleFunction) {
return Functions.toDoubleComparator((DoubleFunction<T>) function);
}
if (function instanceof LongFunction) {
return Functions.toLongComparator((LongFunction<T>) function);
}
return Comparators.byFunction(function, naturalOrder());
}
public <V extends Comparable<? super V>> T maxBy(Function<? super T, ? extends V> function) {
return Iterate.max(this, Comparators.byFunction(function));
}
public <V extends Comparable<? super V>> MutableSortedSet<T> toSortedSetBy(
Function<? super T, ? extends V> function) {
return this.toSortedSet(Comparators.byFunction(function));
}
public static <T, V extends Comparable<? super V>> SerializableComparator<T> fromFunctions(
Function<? super T, ? extends V> one) {
return Comparators.byFunction(one);
}