In my opinion, Java 8 and later versions (actually 9 and 10) lack of a piece to efficiently use Stream and other monads. Java does not have any kind of Try monad to handle errors during monad composition.
Why? Initially, I thought that was a lack of only the version 8, but I do not find any JEP to introduce it in the JDK.
Something like the following could be a starting point.
public class Try<T> {
private T value;
private Exception exception;
private Try(Supplier<T> supplier) {
try {
this.value = supplier.get();
} catch (Exception ) {
this.exception = ex;
}
}
Optional<T> toOptional() {
return Optional.ofNullable(value);
}
public static <T> Try<T> of(Supplier<T> supplier) {
return new Try<>(supplier);
}
// Some other interesting methods...
}
Maybe not anyone uses reactive streams, but during a stream transformation, you need some smart way to collect exceptions, without breaking the whole stream execution.
stream
.map(info -> {
// Code that can rise an exception
// Without the Try monad is tedious to handle exceptions!
})
.filter(/* something */)
.to(/* somewhere */)
Can anyone explain me why? Is it related to some other specification lack?
Thanks to all.
