On Sat, Aug 25, 2012 at 4:46 PM, Matthew Pocock <

+1 -- I suspect getting there from here is difficult in practice (due to
scads of existing code), but this makes oodles of sense in principle.  If
the only real reason Scala supports null is interop (and I think that's
true of good idiomatic Scala), it should be treated as such and made
explicit.  And changing the *default* behaviour from with-null to
without-null would lead folks to better and safer code pretty efficiently.
 Programmers are lazy, so we really should avoid having an easy, lazy path
to using nulls.

I'm rather conscious of this at the moment.  I'm finally doing Scala
full-time for the time being, and caught myself last week initializing a
variable with null because it saved me a line.  I did a double-take an hour
later and Optioned it, but it did drive home that most folks will sometimes
take the lazy road if it's available.  The beauty of Scala is largely that
the most concise approach is typically the most *correct* one -- this is a
rare exception currently.  Making null *inconvenient* would likely be a
boon in the long run.

Has anybody written a compiler plugin to do this?  Adding a plugin, then a
switch, and encouraging folks to use it, seems like a safe and sensible
step here.  (I'd require usage of it in my startup...)