bearophile wrote: > Lutger: >>Can't nullable / non-nullable be done in library?< > > Yes, of course, people in the Scheme language have shown that you can do > almost everything in library code. But to do that you need (beside fixing > D library code, because the default now becomes non-null object > references) a "pluggable type system", that is you must be able to plug-in > a new piece of type system. > > You can do that with a meta (programmable) type-system like Haskell one, > or with some kind of true plug-in (think about the "neutral" > function/argument type annotations of Python3, that are a simple example > of machinery that can be used to plug-in a library defined type system). I > don't see both such things to be added to D2 anytime soon because they are > complex, quite more complex than nonnullable object references. > > So I'm looking for just the ""small"" change in the type system plus the > short leading "?" syntax. > > If D developers aren't interested in such thing, then a DEP can be written > and then marked as officially refused, to avoid wasting future time > discussing about this idea (this is another quite important purpose of > Python PEPs, to mark ideas as refused and avoid discussing something > hopeless over and over again). > > Bye, > bearophile
Isn't .C#'s Nullable<T> a library thing? (It's quite useful for database crap) I mean, it's not as ambitious as non-nullable by default, but couldn't we develop a Nullable and NonNullable template with the tools we have today in D? (I'm not sure). Would that be good enough?
