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, 99 insertions, 0 deletions

diff --git a/src/repl/scala/tools/nsc/interpreter/ExprTyper.scala b/src/repl/scala/tools/nsc/interpreter/ExprTyper.scala
new file mode 100644
index 0000000000..9edd54b939
--- /dev/null
+++ b/src/repl/scala/tools/nsc/interpreter/ExprTyper.scala
@@ -0,0 +1,99 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2013 LAMP/EPFL
+ * @author  Paul Phillips
+ */
+
+package scala.tools.nsc
+package interpreter
+
+import scala.tools.nsc.ast.parser.Tokens.EOF
+
+trait ExprTyper {
+  val repl: IMain
+
+  import repl._
+  import global.{ reporter => _, Import => _, _ }
+  import definitions._
+  import syntaxAnalyzer.UnitParser
+  import naming.freshInternalVarName
+
+  object codeParser {
+    val global: repl.global.type = repl.global
+    def applyRule[T](code: String, rule: UnitParser => T): T = {
+      reporter.reset()
+      val scanner = newUnitParser(code)
+      val result  = rule(scanner)
+
+      if (!reporter.hasErrors)
+        scanner.accept(EOF)
+
+      result
+    }
+    def stmts(code: String) = applyRule(code, _.templateStats())
+  }
+
+  /** Parse a line into a sequence of trees. Returns None if the input is incomplete. */
+  def parse(line: String): Option[List[Tree]] = debugging(s"""parse("$line")""")  {
+    var isIncomplete = false
+    reporter.withIncompleteHandler((_, _) => isIncomplete = true) {
+      val trees = codeParser.stmts(line)
+      if (reporter.hasErrors) Some(Nil)
+      else if (isIncomplete) None
+      else Some(trees)
+    }
+  }
+
+  def symbolOfLine(code: String): Symbol = {
+    def asExpr(): Symbol = {
+      val name  = freshInternalVarName()
+      // Typing it with a lazy val would give us the right type, but runs
+      // into compiler bugs with things like existentials, so we compile it
+      // behind a def and strip the NullaryMethodType which wraps the expr.
+      val line = "def " + name + " = " + code
+
+      interpretSynthetic(line) match {
+        case IR.Success =>
+          val sym0 = symbolOfTerm(name)
+          // drop NullaryMethodType
+          sym0.cloneSymbol setInfo exitingTyper(sym0.info.finalResultType)
+        case _          => NoSymbol
+      }
+    }
+    def asDefn(): Symbol = {
+      val old = repl.definedSymbolList.toSet
+
+      interpretSynthetic(code) match {
+        case IR.Success =>
+          repl.definedSymbolList filterNot old match {
+            case Nil        => NoSymbol
+            case sym :: Nil => sym
+            case syms       => NoSymbol.newOverloaded(NoPrefix, syms)
+          }
+        case _ => NoSymbol
+      }
+    }
+    def asError(): Symbol = {
+      interpretSynthetic(code)
+      NoSymbol
+    }
+    beSilentDuring(asExpr()) orElse beSilentDuring(asDefn()) orElse asError()
+  }
+
+  private var typeOfExpressionDepth = 0
+  def typeOfExpression(expr: String, silent: Boolean = true): Type = {
+    if (typeOfExpressionDepth > 2) {
+      repldbg("Terminating typeOfExpression recursion for expression: " + expr)
+      return NoType
+    }
+    typeOfExpressionDepth += 1
+    // Don't presently have a good way to suppress undesirable success output
+    // while letting errors through, so it is first trying it silently: if there
+    // is an error, and errors are desired, then it re-evaluates non-silently
+    // to induce the error message.
+    try beSilentDuring(symbolOfLine(expr).tpe) match {
+      case NoType if !silent => symbolOfLine(expr).tpe // generate error
+      case tpe               => tpe
+    }
+    finally typeOfExpressionDepth -= 1
+  }
+}