Merge commit '03aaf05' into merge-2.11-to-2.12-sep-22

9 files changed, 405 insertions, 123 deletions

diff --git a/src/repl/scala/tools/nsc/interpreter/ILoop.scala b/src/repl/scala/tools/nsc/interpreter/ILoop.scala
index 612bdd98c9..6721ff6dd6 100644
--- a/src/repl/scala/tools/nsc/interpreter/ILoop.scala
+++ b/src/repl/scala/tools/nsc/interpreter/ILoop.scala
@@ -1,8 +1,7 @@
 /* NSC -- new Scala compiler
- * Copyright 2005-2013 LAMP/EPFL
+ * Copyright 2005-2015 LAMP/EPFL
  * @author Alexander Spoon
  */
-
 package scala
 package tools.nsc
 package interpreter
@@ -24,9 +23,9 @@ import io.AbstractFile
 import scala.collection.generic.Clearable
 import scala.concurrent.{ ExecutionContext, Await, Future, future }
 import ExecutionContext.Implicits._
-import java.io.{ BufferedReader, FileReader }
+import java.io.{ BufferedReader, FileReader, StringReader }
 
-import scala.util.{Try, Success, Failure}
+import scala.util.{ Try, Success, Failure }
 
 /** The Scala interactive shell.  It provides a read-eval-print loop
  *  around the Interpreter class.
@@ -657,12 +656,9 @@ class ILoop(in0: Option[BufferedReader], protected val out: JPrintWriter)
     unleashAndSetPhase()
     asyncEcho(isDuringInit, power.banner)
   }
-  private def unleashAndSetPhase() {
-    if (isReplPower) {
-      power.unleash()
-      // Set the phase to "typer"
-      intp beSilentDuring phaseCommand("typer")
-    }
+  private def unleashAndSetPhase() = if (isReplPower) {
+    power.unleash()
+    intp beSilentDuring phaseCommand("typer") // Set the phase to "typer"
   }
 
   def asyncEcho(async: Boolean, msg: => String) {
@@ -750,28 +746,9 @@ class ILoop(in0: Option[BufferedReader], protected val out: JPrintWriter)
     result
   }
 
-  private object paste extends Pasted {
-    import scala.util.matching.Regex.quote
-    val ContinuePrompt = replProps.continuePrompt
-    val ContinueString = replProps.continueText     // "     | "
-    val PromptString   = prompt.lines.toList.last
-    val anyPrompt = s"""\\s*(?:${quote(PromptString.trim)}|${quote(AltPromptString.trim)})\\s*""".r
-
-    def isPrompted(line: String)   = matchesPrompt(line)
-    def isPromptOnly(line: String) = line match { case anyPrompt() => true ; case _ => false }
-
-    def interpret(line: String): Unit = {
-      echo(line.trim)
-      intp interpret line
-      echo("")
-    }
-
-    def transcript(start: String) = {
-      echo("\n// Detected repl transcript paste: ctrl-D to finish.\n")
-      apply(Iterator(start) ++ readWhile(!isPromptOnly(_)))
-    }
-
-    def unapply(line: String): Boolean = isPrompted(line)
+  private object paste extends Pasted(prompt) {
+    def interpret(line: String) = intp interpret line
+    def echo(message: String)   = ILoop.this echo message
   }
 
   private object invocation {
@@ -786,30 +763,10 @@ class ILoop(in0: Option[BufferedReader], protected val out: JPrintWriter)
     * read, go ahead and interpret it.  Return the full string
     * to be recorded for replay, if any.
     */
-  def interpretStartingWith(code: String): Option[String] = {
+  final def interpretStartingWith(code: String): Option[String] = {
     // signal completion non-completion input has been received
     in.completion.resetVerbosity()
 
-    def reallyInterpret = intp.interpret(code) match {
-      case IR.Error      => None
-      case IR.Success    => Some(code)
-      case IR.Incomplete if in.interactive && code.endsWith("\n\n") =>
-        echo("You typed two blank lines.  Starting a new command.")
-        None
-      case IR.Incomplete =>
-        in.readLine(paste.ContinuePrompt) match {
-          case null =>
-            // we know compilation is going to fail since we're at EOF and the
-            // parser thinks the input is still incomplete, but since this is
-            // a file being read non-interactively we want to fail.  So we send
-            // it straight to the compiler for the nice error message.
-            intp.compileString(code)
-            None
-
-          case line => interpretStartingWith(code + "\n" + line)
-        }
-    }
-
     /* Here we place ourselves between the user and the interpreter and examine
      * the input they are ostensibly submitting.  We intervene in several cases:
      *
@@ -822,9 +779,33 @@ class ILoop(in0: Option[BufferedReader], protected val out: JPrintWriter)
     code match {
       case ""                                       => None
       case lineComment()                            => None                 // line comment, do nothing
-      case paste() if !paste.running                => paste.transcript(code) ; None
+      case paste() if !paste.running                => paste.transcript(Iterator(code) ++ readWhile(!paste.isPromptOnly(_))) match {
+                                                         case Some(s) => interpretStartingWith(s)
+                                                         case _       => None
+                                                       }
       case invocation() if intp.mostRecentVar != "" => interpretStartingWith(intp.mostRecentVar + code)
-      case _                                        => reallyInterpret
+      case _                                        => intp.interpret(code) match {
+        case IR.Error      => None
+        case IR.Success    => Some(code)
+        case IR.Incomplete if in.interactive && code.endsWith("\n\n") =>
+          echo("You typed two blank lines.  Starting a new command.")
+          None
+        case IR.Incomplete =>
+          val saved = intp.partialInput
+          intp.partialInput = code + "\n"
+          try {
+            in.readLine(paste.ContinuePrompt) match {
+              case null =>
+                // we know compilation is going to fail since we're at EOF and the
+                // parser thinks the input is still incomplete, but since this is
+                // a file being read non-interactively we want to fail.  So we send
+                // it straight to the compiler for the nice error message.
+                intp.compileString(code)
+                None
+              case line => interpretStartingWith(s"$code\n$line")
+            }
+          } finally intp.partialInput = saved
+      }
     }
   }
 
@@ -840,9 +821,10 @@ class ILoop(in0: Option[BufferedReader], protected val out: JPrintWriter)
     case _ =>
   }
 
-  /** Tries to create a JLineReader, falling back to SimpleReader:
-   *  unless settings or properties are such that it should start
-   *  with SimpleReader.
+  /** Tries to create a JLineReader, falling back to SimpleReader,
+   *  unless settings or properties are such that it should start with SimpleReader.
+   *  The constructor of the InteractiveReader must take a Completion strategy,
+   *  supplied as a `() => Completion`; the Completion object provides a concrete Completer.
    */
   def chooseReader(settings: Settings): InteractiveReader = {
     if (settings.Xnojline || Properties.isEmacsShell) SimpleReader()
@@ -850,20 +832,25 @@ class ILoop(in0: Option[BufferedReader], protected val out: JPrintWriter)
       type Completer = () => Completion
       type ReaderMaker = Completer => InteractiveReader
 
-      def instantiate(className: String): ReaderMaker = completer => {
-        if (settings.debug) Console.println(s"Trying to instantiate a InteractiveReader from $className")
+      def instantiater(className: String): ReaderMaker = completer => {
+        if (settings.debug) Console.println(s"Trying to instantiate an InteractiveReader from $className")
         Class.forName(className).getConstructor(classOf[Completer]).
           newInstance(completer).
           asInstanceOf[InteractiveReader]
       }
 
-      def mkReader(maker: ReaderMaker) =
-        if (settings.noCompletion) maker(() => NoCompletion)
-        else maker(() => new JLineCompletion(intp)) // JLineCompletion is a misnomer -- it's not tied to jline
+      def mkReader(maker: ReaderMaker) = maker { () =>
+        settings.completion.value match {
+          case _ if settings.noCompletion => NoCompletion
+          case "none"   => NoCompletion
+          case "adhoc"  => new JLineCompletion(intp) // JLineCompletion is a misnomer; it's not tied to jline
+          case "pc" | _ => new PresentationCompilerCompleter(intp)
+        }
+      }
 
       def internalClass(kind: String) = s"scala.tools.nsc.interpreter.$kind.InteractiveReader"
       val readerClasses = sys.props.get("scala.repl.reader").toStream ++ Stream(internalClass("jline"), internalClass("jline_embedded"))
-      val readers = readerClasses map (cls => Try { mkReader(instantiate(cls)) })
+      val readers = readerClasses map (cls => Try { mkReader(instantiater(cls)) })
 
       val reader = (readers collect { case Success(reader) => reader } headOption) getOrElse SimpleReader()
 
diff --git a/src/repl/scala/tools/nsc/interpreter/IMain.scala b/src/repl/scala/tools/nsc/interpreter/IMain.scala
index 3b54f5274e..ef6ab4063a 100644
--- a/src/repl/scala/tools/nsc/interpreter/IMain.scala
+++ b/src/repl/scala/tools/nsc/interpreter/IMain.scala
@@ -15,10 +15,13 @@ import scala.concurrent.{ Future, ExecutionContext }
 import scala.reflect.runtime.{ universe => ru }
 import scala.reflect.{ ClassTag, classTag }
 import scala.reflect.internal.util.{ BatchSourceFile, SourceFile }
+import scala.tools.nsc.interactive
+import scala.tools.nsc.reporters.StoreReporter
+import scala.tools.nsc.util.ClassPath.DefaultJavaContext
 import scala.tools.util.PathResolverFactory
 import scala.tools.nsc.io.AbstractFile
 import scala.tools.nsc.typechecker.{ TypeStrings, StructuredTypeStrings }
-import scala.tools.nsc.util.{ ScalaClassLoader, stringFromReader, stringFromWriter, StackTraceOps, ClassPath, MergedClassPath }
+import scala.tools.nsc.util._
 import ScalaClassLoader.URLClassLoader
 import scala.tools.nsc.util.Exceptional.unwrap
 import scala.tools.nsc.backend.JavaPlatform
@@ -58,7 +61,7 @@ import java.io.File
  *  @author Moez A. Abdel-Gawad
  *  @author Lex Spoon
  */
-class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Settings, protected val out: JPrintWriter) extends AbstractScriptEngine with Compilable with Imports {
+class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Settings, protected val out: JPrintWriter) extends AbstractScriptEngine with Compilable with Imports with PresentationCompilation {
   imain =>
 
   setBindings(createBindings, ScriptContext.ENGINE_SCOPE)
@@ -77,6 +80,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
   private var _isInitialized: Future[Boolean] = null      // set up initialization future
   private var bindExceptions                  = true      // whether to bind the lastException variable
   private var _executionWrapper               = ""        // code to be wrapped around all lines
+  var partialInput: String = ""                           // code accumulated in multi-line REPL input
 
   /** We're going to go to some trouble to initialize the compiler asynchronously.
    *  It's critical that nothing call into it until it's been initialized or we will
@@ -446,7 +450,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
 
   /** Build a request from the user. `trees` is `line` after being parsed.
    */
-  private def buildRequest(line: String, trees: List[Tree]): Request = {
+  private[interpreter] def buildRequest(line: String, trees: List[Tree]): Request = {
     executingRequest = new Request(line, trees)
     executingRequest
   }
@@ -465,11 +469,12 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
     pos
   }
 
-  private def requestFromLine(line: String, synthetic: Boolean): Either[IR.Result, Request] = {
-    val content = line  //indentCode(line)
-    val trees = parse(content) match {
-      case parse.Incomplete     => return Left(IR.Incomplete)
-      case parse.Error          => return Left(IR.Error)
+  private[interpreter] def requestFromLine(line: String, synthetic: Boolean): Either[IR.Result, Request] = {
+    val content = line
+
+    val trees: List[global.Tree] = parse(content) match {
+      case parse.Incomplete(_)     => return Left(IR.Incomplete)
+      case parse.Error(_)          => return Left(IR.Error)
       case parse.Success(trees) => trees
     }
     repltrace(
@@ -854,7 +859,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
   }
 
   /** One line of code submitted by the user for interpretation */
-  class Request(val line: String, val trees: List[Tree]) {
+  class Request(val line: String, val trees: List[Tree], generousImports: Boolean = false) {
     def defines    = defHandlers flatMap (_.definedSymbols)
     def imports    = importedSymbols
     def value      = Some(handlers.last) filter (h => h.definesValue) map (h => definedSymbols(h.definesTerm.get)) getOrElse NoSymbol
@@ -888,7 +893,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
       * append to objectName to access anything bound by request.
       */
     lazy val ComputedImports(headerPreamble, importsPreamble, importsTrailer, accessPath) =
-      exitingTyper(importsCode(referencedNames.toSet, ObjectSourceCode, definesClass))
+      exitingTyper(importsCode(referencedNames.toSet, ObjectSourceCode, definesClass, generousImports))
 
     /** the line of code to compute */
     def toCompute = line
@@ -915,6 +920,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
         |${envLines mkString ("  ", ";\n  ", ";\n")}
         |$importsPreamble
         |${indentCode(toCompute)}""".stripMargin
+      def preambleLength = preamble.length - toCompute.length - 1
 
       val generate = (m: MemberHandler) => m extraCodeToEvaluate Request.this
 
@@ -954,7 +960,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
       def postwrap = s"}\nval $iw = new $iw\n"
     }
 
-    private lazy val ObjectSourceCode: Wrapper =
+    private[interpreter] lazy val ObjectSourceCode: Wrapper =
       if (isClassBased) new ClassBasedWrapper else new ObjectBasedWrapper
 
     private object ResultObjectSourceCode extends IMain.CodeAssembler[MemberHandler] {
@@ -1015,6 +1021,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
     }
 
     lazy val resultSymbol = lineRep.resolvePathToSymbol(fullAccessPath)
+
     def applyToResultMember[T](name: Name, f: Symbol => T) = exitingTyper(f(resultSymbol.info.nonPrivateDecl(name)))
 
     /* typeOf lookup with encoding */
@@ -1168,20 +1175,22 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
 
   /** Parse a line into and return parsing result (error, incomplete or success with list of trees) */
   object parse {
-    abstract sealed class Result
-    case object Error extends Result
-    case object Incomplete extends Result
+    abstract sealed class Result { def trees: List[Tree] }
+    case class Error(trees: List[Tree]) extends Result
+    case class Incomplete(trees: List[Tree]) extends Result
     case class Success(trees: List[Tree]) extends Result
 
     def apply(line: String): Result = debugging(s"""parse("$line")""")  {
       var isIncomplete = false
-      currentRun.parsing.withIncompleteHandler((_, _) => isIncomplete = true) {
+      def parse = {
         reporter.reset()
         val trees = newUnitParser(line).parseStats()
-        if (reporter.hasErrors) Error
-        else if (isIncomplete) Incomplete
+        if (reporter.hasErrors) Error(trees)
+        else if (isIncomplete) Incomplete(trees)
         else Success(trees)
       }
+      currentRun.parsing.withIncompleteHandler((_, _) => isIncomplete = true) {parse}
+
     }
   }
 
@@ -1264,6 +1273,8 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set
 /** Utility methods for the Interpreter. */
 object IMain {
   import java.util.Arrays.{ asList => asJavaList }
+  /** Dummy identifier fragement inserted at the cursor before presentation compilation. Needed to support completion of `global.def<TAB>` */
+  val DummyCursorFragment = "_CURSOR_"
 
   class Factory extends ScriptEngineFactory {
     @BeanProperty
@@ -1361,3 +1372,4 @@ object IMain {
     def stripImpl(str: String): String = naming.unmangle(str)
   }
 }
+
diff --git a/src/repl/scala/tools/nsc/interpreter/Imports.scala b/src/repl/scala/tools/nsc/interpreter/Imports.scala
index 5b231d94b6..5742c1d0d8 100644
--- a/src/repl/scala/tools/nsc/interpreter/Imports.scala
+++ b/src/repl/scala/tools/nsc/interpreter/Imports.scala
@@ -95,7 +95,8 @@ trait Imports {
    * last one imported is actually usable.
    */
   case class ComputedImports(header: String, prepend: String, append: String, access: String)
-  protected def importsCode(wanted: Set[Name], wrapper: Request#Wrapper, definesClass: Boolean): ComputedImports = {
+
+  protected def importsCode(wanted: Set[Name], wrapper: Request#Wrapper, definesClass: Boolean, generousImports: Boolean): ComputedImports = {
     val header, code, trailingBraces, accessPath = new StringBuilder
     val currentImps = mutable.HashSet[Name]()
     var predefEscapes = false      // only emit predef import header if name not resolved in history, loosely
@@ -116,8 +117,9 @@ trait Imports {
         def keepHandler(handler: MemberHandler) = handler match {
           // While defining classes in class based mode - implicits are not needed.
           case h: ImportHandler if isClassBased && definesClass => h.importedNames.exists(x => wanted.contains(x))
-          case _: ImportHandler => true
-          case x                => x.definesImplicit || (x.definedNames exists wanted)
+          case _: ImportHandler     => true
+          case x if generousImports => x.definesImplicit || (x.definedNames exists (d => wanted.exists(w => d.startsWith(w))))
+          case x                    => x.definesImplicit || (x.definedNames exists wanted)
         }
 
         reqs match {
diff --git a/src/repl/scala/tools/nsc/interpreter/JLineCompletion.scala b/src/repl/scala/tools/nsc/interpreter/JLineCompletion.scala
index d878988e26..e9b0234a4f 100644
--- a/src/repl/scala/tools/nsc/interpreter/JLineCompletion.scala
+++ b/src/repl/scala/tools/nsc/interpreter/JLineCompletion.scala
@@ -9,6 +9,7 @@ package interpreter
 import Completion._
 import scala.collection.mutable.ListBuffer
 import scala.reflect.internal.util.StringOps.longestCommonPrefix
+import scala.tools.nsc.interactive.Global
 
 // REPL completor - queries supplied interpreter for valid
 // completions based on current contents of buffer.
@@ -296,7 +297,6 @@ class JLineCompletion(val intp: IMain) extends Completion with CompletionOutput
     override def complete(buf: String, cursor: Int): Candidates = {
       verbosity = if (isConsecutiveTabs(buf, cursor)) verbosity + 1 else 0
       repldbg(f"%ncomplete($buf, $cursor%d) last = ($lastBuf, $lastCursor%d), verbosity: $verbosity")
-
       // we don't try lower priority completions unless higher ones return no results.
       def tryCompletion(p: Parsed, completionFunction: Parsed => List[String]): Option[Candidates] = {
         val winners = completionFunction(p)
diff --git a/src/repl/scala/tools/nsc/interpreter/MemberHandlers.scala b/src/repl/scala/tools/nsc/interpreter/MemberHandlers.scala
index bcba7b6dfd..4e45f6d615 100644
--- a/src/repl/scala/tools/nsc/interpreter/MemberHandlers.scala
+++ b/src/repl/scala/tools/nsc/interpreter/MemberHandlers.scala
@@ -35,7 +35,16 @@ trait MemberHandlers {
         // XXX this is obviously inadequate but it's going to require some effort
         // to get right.
         if (name.toString startsWith "x$") ()
-        else importVars += name
+        else {
+          importVars += name
+          // Needed to import `xxx` during line 2 of:
+          //   scala> val xxx = ""
+          //   scala> def foo: x<TAB>
+          if (name.endsWith(IMain.DummyCursorFragment)) {
+            val stripped = name.stripSuffix(IMain.DummyCursorFragment)
+            importVars += stripped
+          }
+        }
       case _        => super.traverse(ast)
     }
   }
diff --git a/src/repl/scala/tools/nsc/interpreter/Pasted.scala b/src/repl/scala/tools/nsc/interpreter/Pasted.scala
index f8d8c2ddb1..3a7eda1b77 100644
--- a/src/repl/scala/tools/nsc/interpreter/Pasted.scala
+++ b/src/repl/scala/tools/nsc/interpreter/Pasted.scala
@@ -15,19 +15,23 @@ package interpreter
  *  a transcript should itself be pasteable and should achieve
  *  the same result.
  */
-abstract class Pasted {
-  def interpret(line: String): Unit
-  def ContinueString: String
-  def PromptString: String
-  def AltPromptString: String = "scala> "
+abstract class Pasted(prompt: String) {
+  def interpret(line: String): IR.Result
+  def echo(message: String): Unit
 
-  /* `testBoth` cannot be a val, as `Pasted` is inherited by `object paste` in ILoop,
-    which would cause `val testBoth` to be initialized before `val PromptString` was.
+  val PromptString    = prompt.lines.toList.last
+  val AltPromptString = "scala> "
+  val ContinuePrompt  = replProps.continuePrompt
+  val ContinueString  = replProps.continueText     // "     | "
+  val anyPrompt = {
+    import scala.util.matching.Regex.quote
+    s"""\\s*(?:${quote(PromptString.trim)}|${quote(AltPromptString.trim)})\\s*""".r
+  }
+
+  def isPrompted(line: String)   = matchesPrompt(line)
+  def isPromptOnly(line: String) = line match { case anyPrompt() => true ; case _ => false }
 
-      object paste extends Pasted {
-        val PromptString   = prompt.lines.toList.last
-  */
-  private def testBoth = PromptString != AltPromptString
+  private val testBoth = PromptString != AltPromptString
   private val spacey   = " \t".toSet
 
   def matchesPrompt(line: String) = matchesString(line, PromptString) || testBoth && matchesString(line, AltPromptString)
@@ -91,13 +95,26 @@ abstract class Pasted {
       case _ => code
     }
 
-    def run(): Unit = {
-      println("// Replaying %d commands from transcript.\n" format cmds.size)
-      cmds foreach { cmd =>
-        print(ActualPromptString)
-        interpret(cmd)
-      }
+    def interpreted(line: String) = {
+      echo(line.trim)
+      val res = interpret(line)
+      if (res != IR.Incomplete) echo("")
+      res
+    }
+    def incompletely(cmd: String) = {
+      print(ActualPromptString)
+      interpreted(cmd) == IR.Incomplete
     }
+    def run(): Option[String] = {
+      echo(s"// Replaying ${cmds.size} commands from transcript.\n")
+      cmds find incompletely
+    }
+  }
+
+  // Run transcript and return incomplete line if any.
+  def transcript(lines: TraversableOnce[String]): Option[String] = {
+    echo("\n// Detected repl transcript. Paste more, or ctrl-D to finish.\n")
+    apply(lines)
   }
 
   /** Commands start on lines beginning with "scala>" and each successive
@@ -105,9 +122,10 @@ abstract class Pasted {
    *  Everything else is discarded.  When the end of the transcript is spotted,
    *  all the commands are replayed.
    */
-  def apply(lines: TraversableOnce[String]) = {
+  def apply(lines: TraversableOnce[String]): Option[String] = {
     isRunning = true
-    try new PasteAnalyzer(lines.toList) run()
+    try new PasteAnalyzer(lines.toList).run()
     finally isRunning = false
   }
+  def unapply(line: String): Boolean = isPrompted(line)
 }
diff --git a/src/repl/scala/tools/nsc/interpreter/Power.scala b/src/repl/scala/tools/nsc/interpreter/Power.scala
index 8d8140b638..a14a60d216 100644
--- a/src/repl/scala/tools/nsc/interpreter/Power.scala
+++ b/src/repl/scala/tools/nsc/interpreter/Power.scala
@@ -113,10 +113,13 @@ class Power[ReplValsImpl <: ReplVals : ru.TypeTag: ClassTag](val intp: IMain, re
     }
   }
 
-  private def customBanner = replProps.powerBanner.option flatMap (f => io.File(f).safeSlurp())
+  private def customBanner = replProps.powerBanner.option flatMap {
+    case f if f.getName == "classic" => Some(classic)
+    case f => io.File(f).safeSlurp()
+  }
   private def customInit   = replProps.powerInitCode.option flatMap (f => io.File(f).safeSlurp())
 
-  def banner = customBanner getOrElse """
+  def classic = """
     |** Power User mode enabled - BEEP WHIR GYVE **
     |** :phase has been set to 'typer'.          **
     |** scala.tools.nsc._ has been imported      **
@@ -124,28 +127,30 @@ class Power[ReplValsImpl <: ReplVals : ru.TypeTag: ClassTag](val intp: IMain, re
     |** Try  :help, :vals, power.<tab>           **
   """.stripMargin.trim
 
-  private def initImports = List(
-    "scala.tools.nsc._",
-    "scala.collection.JavaConverters._",
-    "intp.global.{ error => _, _ }",
-    "definitions.{ getClass => _, _ }",
-    "power.rutil._",
-    "replImplicits._",
-    "treedsl.CODE._"
-  )
-
-  def init = customInit match {
-    case Some(x)  => x
-    case _        => initImports.mkString("import ", ", ", "")
-  }
+  def banner = customBanner getOrElse """
+    |Power mode enabled. :phase is at typer.
+    |import scala.tools.nsc._, intp.global._, definitions._
+    |Try :help or completions for vals._ and power._
+  """.stripMargin.trim
+
+  private def initImports =
+  """scala.tools.nsc._
+    |scala.collection.JavaConverters._
+    |intp.global.{ error => _, _ }
+    |definitions.{ getClass => _, _ }
+    |power.rutil._
+    |replImplicits._
+    |treedsl.CODE._""".stripMargin.lines
+
+  def init = customInit getOrElse initImports.mkString("import ", ", ", "")
 
-  /** Starts up power mode and runs whatever is in init.
+  /** Quietly starts up power mode and runs whatever is in init.
    */
   def unleash(): Unit = beQuietDuring {
     // First we create the ReplVals instance and bind it to $r
     intp.bind("$r", replVals)
     // Then we import everything from $r.
-    intp interpret ("import " + intp.originalPath("$r") + "._")
+    intp interpret s"import ${ intp.originalPath("$r") }._"
     // And whatever else there is to do.
     init.lines foreach (intp interpret _)
   }
diff --git a/src/repl/scala/tools/nsc/interpreter/PresentationCompilation.scala b/src/repl/scala/tools/nsc/interpreter/PresentationCompilation.scala
new file mode 100644
index 0000000000..3a2177a4cb
--- /dev/null
+++ b/src/repl/scala/tools/nsc/interpreter/PresentationCompilation.scala
@@ -0,0 +1,110 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2015 LAMP/EPFL
+ * @author Martin Odersky
+ */
+package scala.tools.nsc.interpreter
+
+import scala.reflect.internal.util.RangePosition
+import scala.tools.nsc.backend.JavaPlatform
+import scala.tools.nsc.{interactive, Settings}
+import scala.tools.nsc.io._
+import scala.tools.nsc.reporters.StoreReporter
+import scala.tools.nsc.util.ClassPath.DefaultJavaContext
+import scala.tools.nsc.util.{DirectoryClassPath, MergedClassPath}
+
+trait PresentationCompilation {
+  self: IMain =>
+
+  /** Typecheck a line of REPL input, suitably wrapped with "interpreter wrapper" objects/classes, with the
+    * presentation compiler. The result of this method gives access to the typechecked tree and to autocompletion
+    * suggestions.
+    *
+    * The caller is responsible for calling [[PresentationCompileResult#cleanup]] to dispose of the compiler instance.
+    */
+  private[scala] def presentationCompile(line: String): Either[IR.Result, PresentationCompileResult] = {
+    if (global == null) Left(IR.Error)
+    else {
+      // special case for:
+      //
+      // scala> 1
+      // scala> .toInt
+      //
+      // and for multi-line input.
+      val line1 = partialInput + (if (Completion.looksLikeInvocation(line)) { self.mostRecentVar + line } else line)
+      val compiler = newPresentationCompiler()
+      val trees = compiler.newUnitParser(line1).parseStats()
+      val importer = global.mkImporter(compiler)
+      val request = new Request(line1, trees map (t => importer.importTree(t)), generousImports = true)
+      val wrappedCode: String = request.ObjectSourceCode(request.handlers)
+      val unit = compiler.newCompilationUnit(wrappedCode)
+      import compiler._
+      val richUnit = new RichCompilationUnit(unit.source)
+      unitOfFile(richUnit.source.file) = richUnit
+      enteringTyper(typeCheck(richUnit))
+      val result = PresentationCompileResult(compiler)(richUnit, request.ObjectSourceCode.preambleLength + line1.length - line.length)
+      Right(result)
+    }
+  }
+
+  /** Create an instance of the presentation compiler with a classpath comprising the REPL's configured classpath
+    * and the classes output by previously compiled REPL lines.
+    *
+    * You may directly interact with this compiler from any thread, although you must not access it concurrently
+    * from multiple threads.
+    *
+    * You may downcast the `reporter` to `StoreReporter` to access type errors.
+    */
+  def newPresentationCompiler(): interactive.Global = {
+    val replOutClasspath: DirectoryClassPath = new DirectoryClassPath(replOutput.dir, DefaultJavaContext)
+    val mergedClasspath = new MergedClassPath[AbstractFile](replOutClasspath :: global.platform.classPath :: Nil, DefaultJavaContext)
+    def copySettings: Settings = {
+      val s = new Settings(_ => () /* ignores "bad option -nc" errors, etc */)
+      s.processArguments(global.settings.recreateArgs, processAll = false)
+      s.YpresentationAnyThread.value = true
+      s
+    }
+    val storeReporter: StoreReporter = new StoreReporter
+    val interactiveGlobal = new interactive.Global(copySettings, storeReporter) { self =>
+      override lazy val platform: ThisPlatform = new JavaPlatform {
+        val global: self.type = self
+
+        override def classPath: PlatformClassPath = mergedClasspath
+      }
+    }
+    new interactiveGlobal.TyperRun()
+    interactiveGlobal
+  }
+
+  abstract class PresentationCompileResult {
+    val compiler: scala.tools.nsc.interactive.Global
+    def unit: compiler.RichCompilationUnit
+    /** The length of synthetic code the precedes the user writtn code */
+    def preambleLength: Int
+    def cleanup(): Unit = {
+      compiler.askShutdown()
+    }
+    import compiler.CompletionResult
+
+    def completionsAt(cursor: Int): CompletionResult = {
+      val pos = unit.source.position(preambleLength + cursor)
+      compiler.completionsAt(pos)
+    }
+    def typedTreeAt(code: String, selectionStart: Int, selectionEnd: Int): compiler.Tree = {
+      val start = selectionStart + preambleLength
+      val end   = selectionEnd + preambleLength
+      val pos   = new RangePosition(unit.source, start, start, end)
+      compiler.typedTreeAt(pos)
+    }
+  }
+
+  object PresentationCompileResult {
+    def apply(compiler0: interactive.Global)(unit0: compiler0.RichCompilationUnit, preambleLength0: Int) = new PresentationCompileResult {
+
+      override val compiler = compiler0
+
+      override def unit = unit0.asInstanceOf[compiler.RichCompilationUnit]
+
+      override def preambleLength = preambleLength0
+    }
+  }
+}
diff --git a/src/repl/scala/tools/nsc/interpreter/PresentationCompilerCompleter.scala b/src/repl/scala/tools/nsc/interpreter/PresentationCompilerCompleter.scala
new file mode 100644
index 0000000000..0fb3236966
--- /dev/null
+++ b/src/repl/scala/tools/nsc/interpreter/PresentationCompilerCompleter.scala
@@ -0,0 +1,139 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2013 LAMP/EPFL
+ * @author Martin Odersky
+ */
+package scala.tools.nsc.interpreter
+
+import scala.reflect.internal.Flags
+import scala.reflect.internal.util.StringOps
+import scala.tools.nsc.interpreter.Completion.{ScalaCompleter, Candidates}
+import scala.util.control.NonFatal
+
+class PresentationCompilerCompleter(intp: IMain) extends Completion with ScalaCompleter {
+  import PresentationCompilerCompleter._
+  import intp.{PresentationCompileResult => Result}
+
+  private type Handler = Result => Candidates
+
+  private var lastRequest = NoRequest
+  private var tabCount = 0
+  private var lastCommonPrefixCompletion: Option[String] = None
+
+  def resetVerbosity(): Unit = { tabCount = 0 ; lastRequest = NoRequest }
+  def completer(): ScalaCompleter = this
+
+  // A convenience for testing
+  def complete(before: String, after: String = ""): Candidates = complete(before + after, before.length)
+  override def complete(buf: String, cursor: Int): Candidates = {
+    val request = Request(buf, cursor)
+    if (request == lastRequest)
+      tabCount += 1
+    else {
+      tabCount = 0
+      lastRequest = request
+    }
+
+    // secret handshakes
+    val slashPrint  = """.*// *print *""".r
+    val slashTypeAt = """.*// *typeAt *(\d+) *(\d+) *""".r
+    val Cursor = IMain.DummyCursorFragment
+
+    def print(result: Result) = {
+      val offset = result.preambleLength
+      val pos1 = result.unit.source.position(offset).withEnd(offset + buf.length)
+      import result.compiler._
+      val tree = new Locator(pos1) locateIn result.unit.body match {
+        case Template(_, _, constructor :: (rest :+ last)) => if (rest.isEmpty) last else Block(rest, last)
+        case t => t
+      }
+      val printed = showCode(tree) + " // : " + tree.tpe.safeToString
+      Candidates(cursor, "" :: printed :: Nil)
+    }
+    def typeAt(result: Result, start: Int, end: Int) = {
+      val tpString = result.compiler.exitingTyper(result.typedTreeAt(buf, start, end).tpe.toString)
+      Candidates(cursor, "" :: tpString :: Nil)
+    }
+    def candidates(result: Result): Candidates = {
+      import result.compiler._
+      import CompletionResult._
+      def defStringCandidates(matching: List[Member], name: Name): Candidates = {
+        val defStrings = for {
+          member <- matching
+          if member.symNameDropLocal == name
+          sym <- member.sym.alternatives
+          sugared = sym.sugaredSymbolOrSelf
+        } yield {
+            val tp = member.prefix memberType sym
+            sugared.defStringSeenAs(tp)
+          }
+        Candidates(cursor, "" :: defStrings.distinct)
+      }
+      val found = result.completionsAt(cursor) match {
+        case NoResults => Completion.NoCandidates
+        case r =>
+          def shouldHide(m: Member): Boolean = {
+            val isUniversal = definitions.isUniversalMember(m.sym)
+            def viaUniversalExtensionMethod = m match {
+              case t: TypeMember if t.implicitlyAdded && t.viaView.info.params.head.info.bounds.isEmptyBounds => true
+              case _ => false
+            }
+            (
+                 isUniversal && nme.isReplWrapperName(m.prefix.typeSymbol.name)
+              || isUniversal && tabCount == 0 && r.name.isEmpty
+              || viaUniversalExtensionMethod && tabCount == 0 && r.name.isEmpty
+            )
+          }
+
+          val matching = r.matchingResults().filterNot(shouldHide)
+          val tabAfterCommonPrefixCompletion = lastCommonPrefixCompletion.contains(buf.substring(0, cursor)) && matching.exists(_.symNameDropLocal == r.name)
+          val doubleTab = tabCount > 0 && matching.forall(_.symNameDropLocal == r.name)
+          if (tabAfterCommonPrefixCompletion || doubleTab) defStringCandidates(matching, r.name)
+          else if (matching.isEmpty) {
+            // Lenient matching based on camel case and on eliding JavaBean "get" / "is" boilerplate
+            val camelMatches: List[Member] = r.matchingResults(CompletionResult.camelMatch(_)).filterNot(shouldHide)
+            val memberCompletions = camelMatches.map(_.symNameDropLocal.decoded).distinct.sorted
+            def allowCompletion = (
+                 (memberCompletions.size == 1)
+              || CompletionResult.camelMatch(r.name)(r.name.newName(StringOps.longestCommonPrefix(memberCompletions)))
+            )
+            if (memberCompletions.isEmpty) Completion.NoCandidates
+            else if (allowCompletion) Candidates(cursor - r.positionDelta, memberCompletions)
+            else Candidates(cursor, "" :: memberCompletions)
+          } else if (matching.nonEmpty && matching.forall(_.symNameDropLocal == r.name))
+            Completion.NoCandidates // don't offer completion if the only option has been fully typed already
+          else {
+            // regular completion
+            val memberCompletions: List[String] = matching.map(_.symNameDropLocal.decoded).distinct.sorted
+            Candidates(cursor - r.positionDelta, memberCompletions)
+          }
+      }
+      lastCommonPrefixCompletion =
+        if (found != Completion.NoCandidates && buf.length >= found.cursor)
+          Some(buf.substring(0, found.cursor) + StringOps.longestCommonPrefix(found.candidates))
+        else
+          None
+      found
+    }
+    val buf1 = buf.patch(cursor, Cursor, 0)
+    try {
+      intp.presentationCompile(buf1) match {
+        case Left(_) => Completion.NoCandidates
+        case Right(result) => try {
+          buf match {
+            case slashPrint() if cursor == buf.length => print(result)
+            case slashTypeAt(start, end) if cursor == buf.length => typeAt(result, start.toInt, end.toInt)
+            case _ => candidates(result)
+          }
+        } finally result.cleanup()
+      }
+    } catch {
+      case NonFatal(e) =>
+        if (isReplDebug) e.printStackTrace()
+        Completion.NoCandidates
+    }
+  }
+}
+object PresentationCompilerCompleter {
+  private case class Request(line: String, cursor: Int)
+  private val NoRequest = Request("", -1)
+}