Comment by hdpe
Great list, even if I disagree with many of the ratings!
But astonished that Optional isn't mentioned either there or in the comments. A second way to represent no-value, with unclear and holy-war-ushering guidance on when to use, and the not exactly terse syntax I see everywhere:
Optional<Ick> ickOpt = Optional.ofNullable(ickGiver.newIck()); ickOpt.flatMap(IckWtfer::wtf).ifPresentOrElse((Wtf wtf) -> unreadable(wtf)), () -> { log.warn("in what universe is this clearer than a simple if == null statement?!"); });
Well, it can make some chained function composition easier.
vs You could maybe move the null check inside the method in the former and it cleans it up a bit, but in the latter you can have methods that are explicitly marked as taking NonNull in their type signature which is nice.