Modularized the repl.

Following in the footsteps of scaladoc and interactive.
The interpreter sources move into src/repl, and are given
a separate build target. As with the others, at present
they are still packaged into scala-compiler.jar.

A summary of changes:

 - repl requires use of ReplGlobal (this was already implied)
 - macro code's repl-specific classloader hack pulled into overridable
   method and overridden in ReplGlobal
 - removed -Ygen-javap option to eliminate backend's dependency on javap
 - removed -Yrepl-debug option (can still be enabled with -Dscala.repl.debug)
 - pushed javap code into src/repl so javax.tools dependency can bee
   weakened to the repl only
 - removed some "show pickled" related code which hasn't worked right
   in a while and isn't the right way to do it anymore anyway. Will
   return to fix showPickled and provide it with some tests.

1 files changed, 181 insertions, 0 deletions

diff --git a/src/repl/scala/tools/nsc/interpreter/Imports.scala b/src/repl/scala/tools/nsc/interpreter/Imports.scala
new file mode 100644
index 0000000000..ff7bfd432c
--- /dev/null
+++ b/src/repl/scala/tools/nsc/interpreter/Imports.scala
@@ -0,0 +1,181 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2013 LAMP/EPFL
+ * @author  Paul Phillips
+ */
+
+package scala.tools.nsc
+package interpreter
+
+import scala.collection.{ mutable, immutable }
+
+trait Imports {
+  self: IMain =>
+
+  import global._
+  import definitions.{ ObjectClass, ScalaPackage, JavaLangPackage, PredefModule }
+  import memberHandlers._
+
+  /** Synthetic import handlers for the language defined imports. */
+  private def makeWildcardImportHandler(sym: Symbol): ImportHandler = {
+    val hd :: tl = sym.fullName.split('.').toList map newTermName
+    val tree = Import(
+      tl.foldLeft(Ident(hd): Tree)((x, y) => Select(x, y)),
+      ImportSelector.wildList
+    )
+    tree setSymbol sym
+    new ImportHandler(tree)
+  }
+
+  /** Symbols whose contents are language-defined to be imported. */
+  def languageWildcardSyms: List[Symbol] = List(JavaLangPackage, ScalaPackage, PredefModule)
+  def languageWildcardHandlers = languageWildcardSyms map makeWildcardImportHandler
+
+  def allImportedNames = importHandlers flatMap (_.importedNames)
+
+  /** Types which have been wildcard imported, such as:
+   *    val x = "abc" ; import x._  // type java.lang.String
+   *    import java.lang.String._   // object java.lang.String
+   *
+   *  Used by tab completion.
+   *
+   *  XXX right now this gets import x._ and import java.lang.String._,
+   *  but doesn't figure out import String._.  There's a lot of ad hoc
+   *  scope twiddling which should be swept away in favor of digging
+   *  into the compiler scopes.
+   */
+  def sessionWildcards: List[Type] = {
+    importHandlers filter (_.importsWildcard) map (_.targetType) distinct
+  }
+
+  def languageSymbols        = languageWildcardSyms flatMap membersAtPickler
+  def sessionImportedSymbols = importHandlers flatMap (_.importedSymbols)
+  def importedSymbols        = languageSymbols ++ sessionImportedSymbols
+  def importedTermSymbols    = importedSymbols collect { case x: TermSymbol => x }
+
+  /** Tuples of (source, imported symbols) in the order they were imported.
+   */
+  def importedSymbolsBySource: List[(Symbol, List[Symbol])] = {
+    val lang    = languageWildcardSyms map (sym => (sym, membersAtPickler(sym)))
+    val session = importHandlers filter (_.targetType != NoType) map { mh =>
+      (mh.targetType.typeSymbol, mh.importedSymbols)
+    }
+
+    lang ++ session
+  }
+  def implicitSymbolsBySource: List[(Symbol, List[Symbol])] = {
+    importedSymbolsBySource map {
+      case (k, vs) => (k, vs filter (_.isImplicit))
+    } filterNot (_._2.isEmpty)
+  }
+
+  /** Compute imports that allow definitions from previous
+   *  requests to be visible in a new request.  Returns
+   *  three pieces of related code:
+   *
+   *  1. An initial code fragment that should go before
+   *  the code of the new request.
+   *
+   *  2. A code fragment that should go after the code
+   *  of the new request.
+   *
+   *  3. An access path which can be traversed to access
+   *  any bindings inside code wrapped by #1 and #2 .
+   *
+   * The argument is a set of Names that need to be imported.
+   *
+   * Limitations: This method is not as precise as it could be.
+   * (1) It does not process wildcard imports to see what exactly
+   * they import.
+   * (2) If it imports any names from a request, it imports all
+   * of them, which is not really necessary.
+   * (3) It imports multiple same-named implicits, but only the
+   * last one imported is actually usable.
+   */
+  case class ComputedImports(prepend: String, append: String, access: String)
+  protected def importsCode(wanted: Set[Name]): ComputedImports = {
+    /** Narrow down the list of requests from which imports
+     *  should be taken.  Removes requests which cannot contribute
+     *  useful imports for the specified set of wanted names.
+     */
+    case class ReqAndHandler(req: Request, handler: MemberHandler) { }
+
+    def reqsToUse: List[ReqAndHandler] = {
+      /** Loop through a list of MemberHandlers and select which ones to keep.
+        * 'wanted' is the set of names that need to be imported.
+       */
+      def select(reqs: List[ReqAndHandler], wanted: Set[Name]): List[ReqAndHandler] = {
+        // Single symbol imports might be implicits! See bug #1752.  Rather than
+        // try to finesse this, we will mimic all imports for now.
+        def keepHandler(handler: MemberHandler) = handler match {
+          case _: ImportHandler => true
+          case x                => x.definesImplicit || (x.definedNames exists wanted)
+        }
+
+        reqs match {
+          case Nil                                    => Nil
+          case rh :: rest if !keepHandler(rh.handler) => select(rest, wanted)
+          case rh :: rest                             =>
+            import rh.handler._
+            val newWanted = wanted ++ referencedNames -- definedNames -- importedNames
+            rh :: select(rest, newWanted)
+        }
+      }
+
+      /** Flatten the handlers out and pair each with the original request */
+      select(allReqAndHandlers reverseMap { case (r, h) => ReqAndHandler(r, h) }, wanted).reverse
+    }
+
+    val code, trailingBraces, accessPath = new StringBuilder
+    val currentImps = mutable.HashSet[Name]()
+
+    // add code for a new object to hold some imports
+    def addWrapper() {
+      val impname = nme.INTERPRETER_IMPORT_WRAPPER
+      code append "object %s {\n".format(impname)
+      trailingBraces append "}\n"
+      accessPath append ("." + impname)
+      currentImps.clear()
+    }
+    def maybeWrap(names: Name*) = if (names exists currentImps) addWrapper()
+    def wrapBeforeAndAfter[T](op: => T): T = {
+      addWrapper()
+      try op finally addWrapper()
+    }
+
+    // loop through previous requests, adding imports for each one
+    wrapBeforeAndAfter {
+      for (ReqAndHandler(req, handler) <- reqsToUse) {
+        handler match {
+          // If the user entered an import, then just use it; add an import wrapping
+          // level if the import might conflict with some other import
+          case x: ImportHandler if x.importsWildcard =>
+            wrapBeforeAndAfter(code append (x.member + "\n"))
+          case x: ImportHandler =>
+            maybeWrap(x.importedNames: _*)
+            code append (x.member + "\n")
+            currentImps ++= x.importedNames
+
+          // For other requests, import each defined name.
+          // import them explicitly instead of with _, so that
+          // ambiguity errors will not be generated. Also, quote
+          // the name of the variable, so that we don't need to
+          // handle quoting keywords separately.
+          case x =>
+            for (sym <- x.definedSymbols) {
+              maybeWrap(sym.name)
+              code append s"import ${x.path}\n"
+              currentImps += sym.name
+            }
+        }
+      }
+    }
+
+    ComputedImports(code.toString, trailingBraces.toString, accessPath.toString)
+  }
+
+  private def allReqAndHandlers =
+    prevRequestList flatMap (req => req.handlers map (req -> _))
+
+  private def membersAtPickler(sym: Symbol): List[Symbol] =
+    enteringPickler(sym.info.nonPrivateMembers.toList)
+}