REPL element truncation should not silently truncate

[som-snytt]

reproduction steps

using Scala 2.13.4,

scala -Dscala.repl.maxprintstring=10000
Welcome to Scala 2.13.4 (OpenJDK 64-Bit Server VM, Java 15).
Type in expressions for evaluation. Or try :help.

scala> Iterator.from(1).take(10000).to(List)
[snip] 998, 999, 1000)

problem

The truncated collection is rendered without an ellipsis.

Reported at scala/scala3#11377

[som-snytt]

Added to the PR for REPL printing tweaks. Disappointed that PR isn't in the next milestone.

scala> Iterator.from(1).take(10000).to(List)
val res0: List[Int] = List(1, 2, 3, [snip -Ed] 139, 140, 141, ...)

scala> def vs = Iterator.from(1).take(10000)
def vs: Iterator[Int]

scala> List(vs,vs)
val res0: List[Iterator[Int]] = List(<iterator>, <iterator>)

scala> .map(_.toList)
val res1: List[List[Int]] = List(List(1, 2, 3, [snip -Ed] 139, 140, 141, ...), ...)

scala>

[bjornregnell]

@som-snytt The linked PR is covering more ground... Would a limited fix that just don't truncate silently have a bigger chance to be accepted, as the runtime behavior change is much more limited?

[SethTisue]

@som-snytt seconding Bjorn, can we interest you in submitting this fix as an independent PR? not there's no hope for the rest of #8885 (Dale and I are going through that right now), but regardless, afaics this part really ought to be its own PR