1 files changed, 139 insertions, 0 deletions
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..4b0330aaf7
--- /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)
+}