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Coalesce.java
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Coalesce.java
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package uk.co.benjiweber.expressions;
import java.util.Optional;
import java.util.function.Supplier;
import static java.util.Arrays.asList;
public class Coalesce {
public static <T> T coalesce(Supplier<T>... ts) {
return asList(ts)
.stream()
.map(t -> t.get())
.filter(t -> t != null)
.findFirst()
.orElse(null);
}
public interface AnotherSupplier<T> extends Supplier<T> {}
public static <T> Optional<T> coalesce(AnotherSupplier<Optional<T>>... ts) {
return asList(ts)
.stream()
.map(t -> t.get())
.filter(t -> t.isPresent())
.findFirst()
.orElse(Optional.<T>empty());
}
public static <T> Optional<T> coalesce(Optional<T>... ts) {
return asList(ts)
.stream()
.filter(t -> t.isPresent())
.findFirst()
.orElse(Optional.<T>empty());
}
public static <T> T coalesce(T... ts) {
return asList(ts)
.stream()
.filter(t -> t != null)
.findFirst()
.orElse(null);
}
}