SI-9206 REPL custom continuation prompt

Because who doesn't want to customize their continuation prompt?

`scala -Dscala.repl.continue="..."` looks especially nice
with `-Dscala.color`.

Somewhat works when pasting, but the test rig for running a
transcript does not seek to support custom secondary prompts.

1 files changed, 10 insertions, 4 deletions

diff --git a/src/repl/scala/tools/nsc/interpreter/ReplProps.scala b/src/repl/scala/tools/nsc/interpreter/ReplProps.scala
index 8fac040a5e..c2da1f6eca 100644
--- a/src/repl/scala/tools/nsc/interpreter/ReplProps.scala
+++ b/src/repl/scala/tools/nsc/interpreter/ReplProps.scala
@@ -45,11 +45,17 @@ class ReplProps {
 
   // Handy system prop for shell prompt, or else pick it up from compiler.properties
   val promptString = Prop[String]("scala.repl.prompt").option getOrElse (if (info) "%nscala %s> " else shellPromptString)
-  def promptText   = enversion(promptString)
-  val prompt = {
-    import scala.io.AnsiColor.{ MAGENTA, RESET }
-    if (colorOk) s"$MAGENTA$promptText$RESET" else promptText
+  val promptText   = enversion(promptString)
+  val prompt       = encolor(promptText)
+
+  // Prompt for continued input, will be right-adjusted to width of the primary prompt
+  val continueString = Prop[String]("scala.repl.continue").option getOrElse "| "
+  val continueText   = {
+    val text   = enversion(continueString)
+    val margin = promptText.lines.toList.last.length - text.length
+    if (margin > 0) " " * margin + text else text
   }
+  val continuePrompt = encolor(continueText)
 
   //def welcome = enversion(Prop[String]("scala.repl.welcome") or shellWelcomeString)
   def welcome = enversion {