A peek at the roadmap for pattern matching and more

[John Rose]

On Aug 13, 2020, at 4:11 PM, forax at univ-mlv.fr wrote:
> 
> For me it's like having a complex lock on the front door and wanting to have the same mechanism on the opposite side of the front door (to go out) because you already know how to unlock the front door.

Ow!  Tough crowd.

As you may have noted from my previous note, I’m
also concerned with managing, not single or double
or triple doors, but cases where there are too many
doors to go through all at once.  This is where languages
add optional and named arguments.  And once having
done so, I do admit that we could use such a new thing
profitably to manage wide multi-component data flows
both in and out of methods, if the symmetry argument
holds.  And we could leave constructor blocks where
they always have been, in a corner.

My proposals double down on the *asymmetric*
way Java delivers multiple values out of blocks,
compared to how they are sent into blocks by
position-argument-to-parameter binding.

Brian’s point about symmetry is that it can be
a siren song:  You put tuples in one place for
symmetry (with argument lists) and suddenly
you risk having a new kind of value, neither
primitive nor class nor array.  (Arrays are the
old tuple; you really want to do that again?)
Tuples incur technical debt which makes
the symmetry proposal expensive, which is
why we are looking at other options as well.

— John