Exponential compilation time of "1" + 1 + "1" + ...

[OlivierBlanvillain]

The following complies in 11s:

object O {
  def f: String = {
    "1" + 1 + "1" + 1 +
    "1" + 1 + "1" + 1 +
    "1" + 1 + "1" + 1 +
    "1" + 1 + "1" + 1 +
    "1" + 1 + "1" + 1 +
    "1" + 1 + "1" + 1
  }
}

[DarkDimius]

@OlivierBlanvillain in which phase is it spending time? is it tailrec?

[OlivierBlanvillain]

Yes it's spending time in tailrec doing lots of isSubType calls

[DarkDimius]

Thanks for minimizing. I'll have a look at this after PLDI deadline.