customisable pretty-printing

[drdozer]

Could we have customisable pretty printing for failing assertions? As per our gitter discussion:

trait utest.testSuite {
  type Printer[_]
  def prettyprint[T : Printer](t: T): Iterator[String]

  ...
}

This would then allow things like:

object MyTestSuite extends TestSuite with PPrinter {
  ...
}

where PPrinter is something like:

trait PPrinter {
  self : TestSuite =>

  type Printer = pprint.PPrint
  def prettyprint[T: pprint.PPrint](t: T) = pprint.tokenize(t)
}

[lihaoyi]

fixed in 0.9.0-M2 that pretty-prints all values by default