Move `scala.util.Try` and `scala.util.Either` to `scala` package.

[He-Pin]

Problem

Currently, these standard types are not top level and live in scala.util.* package. They should live in the top level.

Perposal

Move scala.util.Try and scala.util.Either to scala package,and annotation type alias in scala.util's package object to keep code compile,until we decide what's next move.

[He-Pin]

Also refs :scala/scala-dev#323

[dwijnand]

They should live in the top level.

Why?

Note that Either is already aliased in the scala package object (and Try isn't).

(edit: there's some discussion on this in scala/scala#7425)

[He-Pin]

@dwijnand I first came out with this idea and there is some discussion in scala/scala#5677 too.

scala.util (Try and Either move to the scala package)

I think these common types live in scala.util seems a little wired and especially there are many other not that much common sibling types live there.

[He-Pin]

BTW, there is https://github.com/vavr-io/vavr/tree/master/vavr/src/main/java/io/vavr/control which mostly alias with scala's type layout, cc @danieldietrich .

[som-snytt]

I think you mean scala.util.chaining._. I feel like I'm not living as well as I ought.

Now there is -Yimports:scala.util,scala.util.chaining which at least takes the sting out of REPL sessions.

[SethTisue]

perhaps we could have made a different decision here initially, but I don't see good cost/benefit in changing it now

[som-snytt]

As mentioned, discussion on PRs:
scala/scala#7425
scala/scala#7549

The latter unmerged PR represents consensus opinion, the unmerged will of the people. (scala.Try, scala.Try.Success, etc)

Counterfactual 2.13:
scala/scala#7425 (comment)

Also reduced ambition of library reducing diet, so "eliminate scala.util" is not in play:
scala/scala#5830

To coin a phrase,

we've run out of time in the 2.13 cycle — let's pick this up again for 2.14

Also Seth:

I'm convinced (by Seb and Nth) that this should wait for 2.14 and be part of a package of related changes rather happening independently.

Scala 3 is picking up steam on library changes, Result type.

There are related issues in Scala 3 about namespace for annotations.