Whoops, bad import.
Please replace the following line with the one after it.
> import java.util.function.Function;
> import java.util.function.*;
On Tue, Oct 3, 2023 at 3:09 AM David Alayachew <davidalayac...@gmail.com>
wrote:
> Hello all,
>
> I have an idea that I want to run by you all -- a new method on
> java.util.function.Function to capture ternary operations.
>
> Here is a mockup of what I wanted to do.
>
> >
> > import java.util.function.Function;
> >
> > @FunctionalInterface
> > public interface Function2<I, O> extends Function<I, O>
> > {
> >
> > public static <I, O> Function<I, O> ternary
> > (
> > Predicate<I> test,
> > Function<I, O> trueOutput,
> > Function<I, O> falseOutput
> > )
> > {
> >
> > return
> > (I input) ->
> > test.test(input)
> > ? trueOutput.apply(input)
> > : falseOutput.apply(input)
> > ;
> >
> > }
> >
> > }
> >
>
> I think this is useful for a few reasons.
>
> * This composes, just like the ternary operator itself.
>
> * It pairs well with Function.identity() and method references to clearly
> (but concisely) communicate intent.
>
> * Ternary operations are common, so this will find great use by
> developers of all sorts.
>
> There is at least one part I don't quite like about this design - what if
> one (or both!) of your outputs is not a functional transformation of the
> input?
>
> For example, String username = id.isBlank() ? "UNKNOWN" : lookup(id);
>
> Obviously, this is easy to work around - simply ignore the input of the
> function. But you lose clarity and simplicity that way. I would put a note
> in the javadoc that says that this method should only be used in instances
> where both outputs are a functional transformation of the input. That way,
> intent is clarified. But if we go that route, maybe this function should
> get a better name to capture that? testThenApply? ternaryTransform?
> ternaryApply?
>
> Thank you for your time and help!
> David Alayachew
>
