From 5d4d8b21cec21fe23490e66182a9b4890e15a9d1 Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Sat, 7 Jan 2006 18:55:52 +0000
Subject:

---
 .../scala/tools/nsc/CompilationUnits.scala         |   2 +-
 src/compiler/scala/tools/nsc/Global.scala          |   2 +
 src/compiler/scala/tools/nsc/Settings.scala        |   2 +-
 src/compiler/scala/tools/nsc/ast/Trees.scala       |   2 +-
 .../scala/tools/nsc/ast/parser/MarkupParsers.scala |   2 +-
 .../scala/tools/nsc/ast/parser/Parsers.scala       | 102 ++++++++++++++++-----
 .../scala/tools/nsc/ast/parser/Scanners.scala      |  20 +++-
 .../tools/nsc/backend/icode/BasicBlocks.scala      |   2 +-
 .../nsc/backend/icode/ExceptionHandlers.scala      |   2 +-
 .../tools/nsc/backend/icode/Linearizers.scala      |   2 +-
 .../scala/tools/nsc/backend/icode/Members.scala    |   2 +-
 .../scala/tools/nsc/backend/icode/Opcodes.scala    |   2 +-
 .../scala/tools/nsc/backend/icode/Primitives.scala |   2 +-
 .../scala/tools/nsc/backend/icode/TypeKinds.scala  |   2 +-
 .../scala/tools/nsc/backend/icode/TypeStacks.scala |   2 +-
 .../tools/nsc/matching/AlgebraicMatchers.scala     |   2 +-
 src/compiler/scala/tools/nsc/matching/Autom2.scala |   2 +-
 .../scala/tools/nsc/matching/BerrySethis.scala     |   2 +-
 .../scala/tools/nsc/matching/CodeFactory.scala     |   2 +-
 .../scala/tools/nsc/matching/DetWordAutoms.scala   |   2 +-
 .../scala/tools/nsc/matching/LeftTracers.scala     |   2 +-
 .../scala/tools/nsc/matching/MatcherLabels.scala   |   2 +-
 .../tools/nsc/matching/NondetWordAutoms.scala      |   2 +-
 .../scala/tools/nsc/matching/PatternMatchers.scala |   2 +-
 .../tools/nsc/matching/PatternNodeCreator.scala    |   2 +-
 .../scala/tools/nsc/matching/PatternNodes.scala    |   2 +-
 .../scala/tools/nsc/matching/RightTracers.scala    |   2 +-
 .../tools/nsc/matching/SequenceMatchers.scala      |   2 +-
 .../scala/tools/nsc/matching/WordAutoms.scala      |   2 +-
 .../scala/tools/nsc/symtab/Constants.scala         |   6 +-
 .../scala/tools/nsc/symtab/Definitions.scala       |   2 +-
 .../scala/tools/nsc/symtab/InfoTransformers.scala  |   2 +-
 src/compiler/scala/tools/nsc/symtab/Scopes.scala   |   2 +-
 src/compiler/scala/tools/nsc/symtab/StdNames.scala |   2 +-
 src/compiler/scala/tools/nsc/symtab/Symbols.scala  |   2 +-
 src/compiler/scala/tools/nsc/symtab/Types.scala    |   4 +-
 .../nsc/symtab/classfile/ClassfileParser.scala     |  23 ++++-
 .../scala/tools/nsc/typechecker/Analyzer.scala     |   2 +-
 .../scala/tools/nsc/typechecker/Codification.scala |   2 +-
 .../scala/tools/nsc/typechecker/Contexts.scala     |   2 +-
 .../scala/tools/nsc/typechecker/EtaExpansion.scala |   2 +-
 .../scala/tools/nsc/typechecker/Infer.scala        |   2 +-
 .../scala/tools/nsc/typechecker/Namers.scala       |   2 +-
 .../tools/nsc/typechecker/SyntheticMethods.scala   |   2 +-
 .../scala/tools/nsc/typechecker/Typers.scala       |  10 +-
 .../scala/tools/nsc/typechecker/Variances.scala    |   2 +-
 46 files changed, 168 insertions(+), 77 deletions(-)

(limited to 'src/compiler')

diff --git a/src/compiler/scala/tools/nsc/CompilationUnits.scala b/src/compiler/scala/tools/nsc/CompilationUnits.scala
index 0c39d99c16..30a4e77064 100644
--- a/src/compiler/scala/tools/nsc/CompilationUnits.scala
+++ b/src/compiler/scala/tools/nsc/CompilationUnits.scala
@@ -10,7 +10,7 @@ import scala.tools.nsc.util.FreshNameCreator;
 import scala.tools.util.AbstractFile;
 import scala.collection.mutable.HashSet;
 
-[_trait_] abstract class CompilationUnits: Global {
+mixin class CompilationUnits requires Global {
 
   class CompilationUnit(val source: SourceFile, val mixinOnly: boolean) {
 
diff --git a/src/compiler/scala/tools/nsc/Global.scala b/src/compiler/scala/tools/nsc/Global.scala
index e8d72fb88d..3e1ce5bf50 100644
--- a/src/compiler/scala/tools/nsc/Global.scala
+++ b/src/compiler/scala/tools/nsc/Global.scala
@@ -150,6 +150,8 @@ class Global(val settings: Settings, val reporter: Reporter) extends SymbolTable
 
   def rootLoader: LazyType = new loaders.PackageLoader(classPath.getRoot());
 
+  val migrateMsg = "migration problem when moving from Scala version 1.0 to version 2.0:\n";
+
 // Phases ------------------------------------------------------------
 
   var globalPhase: Phase = NoPhase;
diff --git a/src/compiler/scala/tools/nsc/Settings.scala b/src/compiler/scala/tools/nsc/Settings.scala
index 9cb74fd726..f7c58d7749 100644
--- a/src/compiler/scala/tools/nsc/Settings.scala
+++ b/src/compiler/scala/tools/nsc/Settings.scala
@@ -61,8 +61,8 @@ class Settings(error: String => unit) {
   val extdirs       = StringSetting ("-extdirs", "dirs", "Override location of installed extensions", extdirsDefault)
   val outdir        = StringSetting ("-d", "directory", "Specify where to place generated class files", "")
   val encoding      = StringSetting ("-encoding", "encoding", "Specify character encoding used by source files", "ISO-8859-1")
-  val separate      = ChoiceSetting ("-separate", "Read symbol files for separate compilation", List("yes","no"), "default")
   val target        = ChoiceSetting ("-target", "Specify which backend to use",  List("jvm", "msil"), "jvm")
+  val migrate       = BooleanSetting("-migrate", "Assist in migrating from Scala version 1.0")
   val debug         = BooleanSetting("-debug", "Output debugging messages")
   val statistics    = BooleanSetting("-statistics", "Print compiler statistics")
   val explaintypes  = BooleanSetting("-explaintypes", "Explain type errors in more detail")
diff --git a/src/compiler/scala/tools/nsc/ast/Trees.scala b/src/compiler/scala/tools/nsc/ast/Trees.scala
index 48f6cbbd7b..bd853d3f93 100644
--- a/src/compiler/scala/tools/nsc/ast/Trees.scala
+++ b/src/compiler/scala/tools/nsc/ast/Trees.scala
@@ -11,7 +11,7 @@ import java.io.PrintWriter;
 import scala.tools.nsc.util.{Position,SourceFile};
 import symtab.Flags._;
 
-[_trait_] abstract class Trees: Global {
+mixin class Trees requires Global {
 
   //statistics
   var nodeCount = 0;
diff --git a/src/compiler/scala/tools/nsc/ast/parser/MarkupParsers.scala b/src/compiler/scala/tools/nsc/ast/parser/MarkupParsers.scala
index cf4244cb3f..b6293cd50c 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/MarkupParsers.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/MarkupParsers.scala
@@ -20,7 +20,7 @@ import scala.tools.nsc.util.Position;
 import scala.xml.{Text,TextBuffer};
 
 
-trait MarkupParsers: SyntaxAnalyzer {
+trait MarkupParsers requires SyntaxAnalyzer {
 
   import global._ ;
   import posAssigner.atPos;
diff --git a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
index 5d548cbf4c..0e51f1ab8d 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
@@ -38,7 +38,7 @@ import Tokens._;
  *  (4) Wraps naked case definitions in a match as follows:
  *        { cases }   ==>   (x => x.match {cases}), except when already argument to match
  */
-[_trait_] abstract class Parsers: SyntaxAnalyzer {
+mixin class Parsers requires SyntaxAnalyzer {
 
   import global._;
   import posAssigner.atPos;
@@ -106,9 +106,22 @@ import Tokens._;
 	unit.error(pos, msg);
 	in.errpos = pos;
       }
-      if (skipIt) skip();
+      if (skipIt) {
+        in.skipping = true;
+        skip();
+        in.skipping = false;
+      }
     }
 
+    def syntaxErrorMigrate(msg: String) =
+      syntaxError(in.currentPos, migrateMsg + msg, false);
+
+    def warning(msg: String) =
+      if (in.currentPos != in.errpos) {
+        unit.warning(in.currentPos, msg);
+	in.errpos = in.currentPos;
+      }
+
     def accept(token: int): int = {
       val pos = in.currentPos;
       if (in.token != token)
@@ -311,10 +324,19 @@ import Tokens._;
 	in.nextToken();
 	name
       } else {
+        if (settings.migrate.value &&
+            in.token == REQUIRES || in.token == IMPLICIT || in.token == MIXIN)
+          syntaxErrorMigrate(""+in+" is now a reserved word; cannot be used as identifier");
 	accept(IDENTIFIER);
 	nme.ERROR
       }
 
+    def selector(t: Tree) = {
+      if (in.token == MATCH && settings.migrate.value)
+        syntaxErrorMigrate("Period should be omitted before `match'")
+      Select(t, ident())
+    }
+
     /** StableRef  ::= StableId
      *              |  [Ident `.'] this
      *  SimpleType ::=  StableRef [`.' type]
@@ -329,7 +351,7 @@ import Tokens._;
 	t = atPos(in.skipToken()) {
 	  Super(nme.EMPTY.toTypeName, mixinQualifierOpt())
 	}
-	t = atPos(accept(DOT)) { Select(t, ident()) }
+	t = atPos(accept(DOT)) { selector(t) }
 	if (in.token == DOT)
 	  t = { selectors(t, typeOK, in.skipToken()) }
       } else {
@@ -345,7 +367,7 @@ import Tokens._;
 	  } else if (in.token == SUPER) {
 	    in.nextToken();
 	    t = atPos(i.pos) { Super(i.name.toTypeName, mixinQualifierOpt()) }
-	    t = atPos(accept(DOT)) { Select(t, ident())}
+	    t = atPos(accept(DOT)) { selector(t)}
 	    if (in.token == DOT)
 	      t = { selectors(t, typeOK, in.skipToken()) }
 	  } else {
@@ -361,7 +383,7 @@ import Tokens._;
 	in.nextToken();
 	atPos(pos) { SingletonTypeTree(t) }
       } else {
-	val t1 = atPos(pos) { Select(t, ident()); }
+	val t1 = atPos(pos) { selector(t); }
 	if (in.token == DOT) { selectors(t1, typeOK, in.skipToken()) }
 	else t1
       }
@@ -439,7 +461,14 @@ import Tokens._;
       }
     }
 
-    def newLineOpt(): unit = if (in.token == NEWLINE) in.nextToken();
+    def newLineOpt(): unit =
+      if (in.token == NEWLINE) {
+        if (settings.migrate.value) in.newNewLine = false;
+        in.nextToken();
+      }
+
+    def newLineOptWhenFollowedBy(token: int): unit =
+      if (in.token == NEWLINE && in.next.token == token) newLineOpt();
 
 //////// TYPES ///////////////////////////////////////////////////////////////
 
@@ -452,7 +481,11 @@ import Tokens._;
     /** RequiresTypedOpt ::= [`:' SimpleType | requires SimpleType]
     */
     def requiresTypeOpt(): Tree =
-      if (in.token == COLON | in.token == REQUIRES) { in.nextToken(); simpleType() }
+      if (in.token == COLON | in.token == REQUIRES) {
+        if (in.token == COLON)
+          warning("`:' has been deprecated; use `requires' instead");
+        in.nextToken(); simpleType()
+      }
       else TypeTree();
 
     /** Types ::= Type {`,' Type}
@@ -511,10 +544,10 @@ import Tokens._;
     }
 
     /** SimpleType ::= SimpleType TypeArgs
-     *              | SimpleType `#' Id
-     *              | StableId
-     *              | StableRef `.' type
-     *              | `(' Type `)'
+     *              |  SimpleType `#' Id
+     *              |  StableId
+     *              |  StableRef `.' type
+     *              |  `(' Type `)'
      */
     def simpleType(): Tree = {
       val pos = in.currentPos;
@@ -814,13 +847,19 @@ import Tokens._;
           }
 	  isNew = true
 	case _ =>
+          if (settings.migrate.value) {
+            if (in.token == MATCH)
+              syntaxErrorMigrate("`match' must be preceded by a selector expression")
+            else if (in.token == REQUIRES || in.token == IMPLICIT || in.token == MIXIN)
+              syntaxErrorMigrate(""+in+" is now a reserved word; cannot be used as identifier");
+          }
 	  syntaxError("illegal start of simple expression", true);
 	  t = errorTermTree
       }
       while (true) {
 	in.token match {
 	  case DOT =>
-	    t = atPos(in.skipToken()) { Select(t, ident()) }
+	    t = atPos(in.skipToken()) { selector(t) }
 	  case LBRACKET =>
 	    t match {
 	      case Ident(_) | Select(_, _) =>
@@ -1054,6 +1093,9 @@ import Tokens._;
         //Console.println("successfully parsed xml pattern "+r); DEBUG
         r
       case _ =>
+        if (settings.migrate.value &&
+            in.token == REQUIRES || in.token == IMPLICIT || in.token == MIXIN)
+          syntaxErrorMigrate(""+in+" is now a reserved word; cannot be used as identifier");
 	syntaxError("illegal start of simple pattern", true);
 	errorPatternTree
     }
@@ -1128,11 +1170,11 @@ import Tokens._;
 
 //////// PARAMETERS //////////////////////////////////////////////////////////
 
-    /** ParamClauses ::= {`(' [Param {`,' Param}] ')'}
-     *                   [`(' implicit Param {`,' Param} `)']
+    /** ParamClauses ::= {[NL] `(' [Param {`,' Param}] ')'}
+     *                   [[NL] `(' implicit Param {`,' Param} `)']
      *  Param ::= Id `:' ParamType
-     *  ClassParamClauses ::= {`(' [ClassParam {`' ClassParam}] ')'}
-     *                        [`(' implicit ClassParam {`,' ClassParam} `)']
+     *  ClassParamClauses ::= {[NL] `(' [ClassParam {`' ClassParam}] ')'}
+     *                        [[NL] [`(' implicit ClassParam {`,' ClassParam} `)']
      *  ClassParam ::= [[modifiers] (val | var)] Param
      */
     def paramClauses(owner: Name, implicitViews: List[Tree], ofCaseClass: boolean): List[List[ValDef]] = {
@@ -1178,11 +1220,13 @@ import Tokens._;
       }
       val vds = new ListBuffer[List[ValDef]];
       val pos = in.currentPos;
+      newLineOptWhenFollowedBy(LPAREN);
       while (implicitmod == 0 && in.token == LPAREN) {
 	in.nextToken();
 	vds += paramClause();
 	accept(RPAREN);
-	caseParam = false
+	caseParam = false;
+        newLineOptWhenFollowedBy(LPAREN);
       }
       val result = vds.toList;
       if (owner == nme.CONSTRUCTOR &&
@@ -1214,7 +1258,7 @@ import Tokens._;
         } else t
       }
 
-    /** TypeParamClauseOpt ::= [`[' TypeParam {`,' TypeParam} `]']
+    /** TypeParamClauseOpt ::= [[NL] `[' TypeParam {`,' TypeParam} `]']
      *  TypeParam    ::= [`+' | `-'] FunTypeParam
      *  FunTypeParamClauseOpt ::= [`[' FunTypeParam {`,' FunTypeParam} `]']
      *  FunTypeParam ::= Id TypeBounds
@@ -1240,6 +1284,7 @@ import Tokens._;
         param
       }
       val params = new ListBuffer[AbsTypeDef];
+      newLineOptWhenFollowedBy(LBRACKET);
       if (in.token == LBRACKET) {
         in.nextToken();
         params += typeParam();
@@ -1285,7 +1330,7 @@ import Tokens._;
         var pos = 0;
         if (in.token == THIS) {
           t = atPos(in.currentPos) { This(nme.EMPTY.toTypeName) }
-          t = atPos(accept(DOT)) { Select(t, ident()) }
+          t = atPos(accept(DOT)) { selector(t) }
           pos = accept(DOT);
         } else {
           val i = atPos(in.currentPos) { Ident(ident()) }
@@ -1293,7 +1338,7 @@ import Tokens._;
           if (in.token == THIS) {
             in.nextToken();
             t = atPos(i.pos) { This(i.name.toTypeName) }
-            t = atPos(accept(DOT)) { Select(t, ident()) }
+            t = atPos(accept(DOT)) { selector(t) }
             pos = accept(DOT);
           } else {
             t = i;
@@ -1478,8 +1523,9 @@ import Tokens._;
           val statlist = new ListBuffer[Tree];
 	  statlist += selfInvocation();
           val stats =
-            if (in.token == SEMI || in.token == NEWLINE) { in.nextToken(); blockStatSeq(statlist) }
-            else statlist.toList;
+            if (in.token == SEMI || in.token == NEWLINE) {
+              in.nextToken(); blockStatSeq(statlist)
+            } else statlist.toList;
           accept(RBRACE);
           makeBlock(stats)
         }
@@ -1566,9 +1612,13 @@ import Tokens._;
      */
     def classTemplate(mods: Modifiers, name: Name, vparamss: List[List[ValDef]]): Template =
       atPos(in.currentPos) {
-        def acceptEmptyTemplateBody(msg: String): unit =
-          if (!(in.token == SEMI || in.token == NEWLINE || in.token == COMMA || in.token == RBRACE))
+        def acceptEmptyTemplateBody(msg: String): unit = {
+          if (in.token == LPAREN && settings.migrate.value)
+            syntaxErrorMigrate("mixin classes may not have parameters");
+          if (!(in.token == SEMI || in.token == NEWLINE ||
+                in.token == COMMA || in.token == RBRACE))
             syntaxError(msg, true);
+        }
         val parents = new ListBuffer[Tree];
         val argss = new ListBuffer[List[Tree]];
         if (in.token == EXTENDS) {
@@ -1584,6 +1634,8 @@ import Tokens._;
 	    parents += simpleType()
           }
         } else {
+          if (in.token == WITH && settings.migrate.value)
+            syntaxErrorMigrate("`extends' needed before `with'")
           if (in.token != LBRACE) acceptEmptyTemplateBody("`extends' or `{' expected");
           argss += List()
         }
@@ -1591,7 +1643,7 @@ import Tokens._;
           parents += scalaScalaObjectConstr;
 	if (mods.hasFlag(Flags.CASE)) parents += caseClassConstr;
         val ps = parents.toList;
-        if (in.token == NEWLINE && in.next.token == LBRACE) in.nextToken();
+        newLineOptWhenFollowedBy(LBRACE);
 	var body =
 	  if (in.token == LBRACE) templateBody()
 	  else { acceptEmptyTemplateBody("`{' expected"); List() }
diff --git a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
index 717d4fd23a..1266252ffd 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Scanners.scala
@@ -10,7 +10,7 @@ import scala.tools.nsc.util.{Position, SourceFile}
 import SourceFile.{LF, FF, CR, SU}
 import scala.tools.nsc.util.CharArrayReader
 
-[_trait_] abstract class Scanners: SyntaxAnalyzer {
+mixin class Scanners requires SyntaxAnalyzer {
 
   import global._
 
@@ -94,6 +94,16 @@ import scala.tools.nsc.util.CharArrayReader
      */
     var sepRegions: List[int] = List()
 
+    /** A new line was inserted where in version 1.0 it would not be.
+     *  Only significant if settings.migrate.value is set
+     */
+    var newNewLine = false;
+
+    /** Parser is currently skipping ahead because of an error.
+     *  Only significant if settings.migrate.value is set
+     */
+    var skipping = false;
+
 // Get next token ------------------------------------------------------------
 
     /** read next token and return last position
@@ -123,6 +133,12 @@ import scala.tools.nsc.util.CharArrayReader
           sepRegions = sepRegions.tail
       }
 
+      if (newNewLine && !skipping) {
+        unit.warning(pos, migrateMsg + "new line will start a new statement here;\n"
+                     + "to suppress it, enclose expression in parentheses (...)")
+        newNewLine = false
+      }
+
       val lastToken = token
       if (next.token == EMPTY) {
         fetchToken()
@@ -157,7 +173,9 @@ import scala.tools.nsc.util.CharArrayReader
           (sepRegions.isEmpty || sepRegions.head == RBRACE)) {
         next.copyFrom(this)
         pos = in.lineStartPos
+        if (settings.migrate.value) newNewLine = lastToken != RBRACE && token != EOF;
         token = NEWLINE
+
 /*
       } else if (lastToken == RBRACE) {
         System.out.println("failing to insert NL after RBRACE: " + sepRegions + " " +
diff --git a/src/compiler/scala/tools/nsc/backend/icode/BasicBlocks.scala b/src/compiler/scala/tools/nsc/backend/icode/BasicBlocks.scala
index 6fdbe98c57..4fc5891be8 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/BasicBlocks.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/BasicBlocks.scala
@@ -11,7 +11,7 @@ import scala.tools.nsc.ast._;
 import scala.collection.mutable.Map;
 import scala.tools.nsc.util.Position;
 
-trait BasicBlocks: ICodes {
+mixin class BasicBlocks requires ICodes {
   import opcodes._;
 
   /** This class represents a basic block. Each
diff --git a/src/compiler/scala/tools/nsc/backend/icode/ExceptionHandlers.scala b/src/compiler/scala/tools/nsc/backend/icode/ExceptionHandlers.scala
index 126e20ebef..1e80d0eac0 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/ExceptionHandlers.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/ExceptionHandlers.scala
@@ -17,7 +17,7 @@ import scala.collection.mutable.HashSet;
  * all our handlers will catch `Throwable' and rely on proper ordering
  * in the generated code to preserve nesting.
  */
-trait ExceptionHandlers: ICodes {
+mixin class ExceptionHandlers requires ICodes {
   import global.{Symbol, NoSymbol};
 
   class ExceptionHandler(val method: IMethod, label: String, val cls: Symbol) {
diff --git a/src/compiler/scala/tools/nsc/backend/icode/Linearizers.scala b/src/compiler/scala/tools/nsc/backend/icode/Linearizers.scala
index 7a0b77f6fa..8a3ad0fe23 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/Linearizers.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/Linearizers.scala
@@ -10,7 +10,7 @@ package scala.tools.nsc.backend.icode;
 import scala.tools.nsc.ast._;
 import scala.collection.mutable.Stack;
 
-trait Linearizers: ICodes {
+mixin class Linearizers requires ICodes {
   import opcodes._;
 
   trait Linearizer {
diff --git a/src/compiler/scala/tools/nsc/backend/icode/Members.scala b/src/compiler/scala/tools/nsc/backend/icode/Members.scala
index f12c4ef62c..28826a5439 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/Members.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/Members.scala
@@ -13,7 +13,7 @@ import scala.{Symbol => scala_Symbol};
 
 import scala.tools.nsc.symtab.Flags;
 
-trait Members: ICodes {
+mixin class Members requires ICodes {
   import global._;
 
   /**
diff --git a/src/compiler/scala/tools/nsc/backend/icode/Opcodes.scala b/src/compiler/scala/tools/nsc/backend/icode/Opcodes.scala
index bb2b0c39eb..40e2e64639 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/Opcodes.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/Opcodes.scala
@@ -48,7 +48,7 @@ import scala.tools.nsc.util.Position;
  * erased types of Scala and references Symbols to refer named entities
  * in the source files.
  */
-[_trait_] abstract class Opcodes: ICodes {
+mixin class Opcodes requires ICodes {
   import global.{Symbol, NoSymbol, Type, Name, Constant};
 
   /** This class represents an instruction of the intermediate code.
diff --git a/src/compiler/scala/tools/nsc/backend/icode/Primitives.scala b/src/compiler/scala/tools/nsc/backend/icode/Primitives.scala
index 5cebb0edaf..b134819853 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/Primitives.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/Primitives.scala
@@ -9,7 +9,7 @@ package scala.tools.nsc.backend.icode;
 
 import java.io.PrintWriter;
 
-[_trait_] abstract class Primitives: ICodes {
+mixin class Primitives requires ICodes {
 
   /** This class represents a primitive operation. */
   class Primitive {
diff --git a/src/compiler/scala/tools/nsc/backend/icode/TypeKinds.scala b/src/compiler/scala/tools/nsc/backend/icode/TypeKinds.scala
index c1f0c204c6..362aeb9100 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/TypeKinds.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/TypeKinds.scala
@@ -25,7 +25,7 @@ package scala.tools.nsc.backend.icode;
 
 import scala.collection.mutable.{Map, HashMap};
 
-[_trait_] abstract class TypeKinds: ICodes {
+mixin class TypeKinds requires ICodes {
   import global._;
 
   /** This class represents a type kind. Type kinds
diff --git a/src/compiler/scala/tools/nsc/backend/icode/TypeStacks.scala b/src/compiler/scala/tools/nsc/backend/icode/TypeStacks.scala
index 1f0f8b887c..69f1f34cb7 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/TypeStacks.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/TypeStacks.scala
@@ -9,7 +9,7 @@ package scala.tools.nsc.backend.icode;
 
 import scala.tools.nsc.backend.icode.Primitives;
 
-trait TypeStacks: ICodes {
+trait TypeStacks requires ICodes {
   import opcodes._;
   import global.{Symbol, Type, definitions};
 
diff --git a/src/compiler/scala/tools/nsc/matching/AlgebraicMatchers.scala b/src/compiler/scala/tools/nsc/matching/AlgebraicMatchers.scala
index 4137b128eb..a5ce51e472 100644
--- a/src/compiler/scala/tools/nsc/matching/AlgebraicMatchers.scala
+++ b/src/compiler/scala/tools/nsc/matching/AlgebraicMatchers.scala
@@ -9,7 +9,7 @@ package scala.tools.nsc.matching;
 /** the pattern matcher, tweaked to work with regular patterns
  *  @author Burak Emir
  */
-trait AlgebraicMatchers : TransMatcher {
+mixin class AlgebraicMatchers  requires TransMatcher {
 
   import global._;
 
diff --git a/src/compiler/scala/tools/nsc/matching/Autom2.scala b/src/compiler/scala/tools/nsc/matching/Autom2.scala
index b99db700b4..f455e1f619 100644
--- a/src/compiler/scala/tools/nsc/matching/Autom2.scala
+++ b/src/compiler/scala/tools/nsc/matching/Autom2.scala
@@ -4,7 +4,7 @@ package scala.tools.nsc.matching ;
 
 import scala.tools.nsc.util.Position;
 
-trait Autom2: TransMatcher {
+mixin class Autom2 requires TransMatcher {
 
   import global._;
 
diff --git a/src/compiler/scala/tools/nsc/matching/BerrySethis.scala b/src/compiler/scala/tools/nsc/matching/BerrySethis.scala
index 85638903b0..dad2e75f85 100644
--- a/src/compiler/scala/tools/nsc/matching/BerrySethis.scala
+++ b/src/compiler/scala/tools/nsc/matching/BerrySethis.scala
@@ -4,7 +4,7 @@ import java.util.{ HashSet, HashMap, TreeSet, TreeMap, Vector };
 
 //import scala.compiler.printer.XMLAutomPrinter;
 
-trait BerrySethis: TransMatcher {
+mixin class BerrySethis requires TransMatcher {
 
 import global._;
 /** a Berry-Sethi style construction for nfas.
diff --git a/src/compiler/scala/tools/nsc/matching/CodeFactory.scala b/src/compiler/scala/tools/nsc/matching/CodeFactory.scala
index d4678738ec..870ae1dfe5 100644
--- a/src/compiler/scala/tools/nsc/matching/CodeFactory.scala
+++ b/src/compiler/scala/tools/nsc/matching/CodeFactory.scala
@@ -5,7 +5,7 @@ package scala.tools.nsc.matching ;
 
 import scala.tools.nsc.util.Position;
 
-[_trait_] abstract class CodeFactory: TransMatcher  {
+mixin class CodeFactory requires TransMatcher  {
 
   import global._ ;
 
diff --git a/src/compiler/scala/tools/nsc/matching/DetWordAutoms.scala b/src/compiler/scala/tools/nsc/matching/DetWordAutoms.scala
index 8e4d2943be..545940f510 100644
--- a/src/compiler/scala/tools/nsc/matching/DetWordAutoms.scala
+++ b/src/compiler/scala/tools/nsc/matching/DetWordAutoms.scala
@@ -7,7 +7,7 @@ package scala.tools.nsc.matching ;
 
 import java.util._ ;
 
-trait DetWordAutoms: TransMatcher  {
+mixin class DetWordAutoms requires TransMatcher  {
 
 import global._;
 class DetWordAutom {
diff --git a/src/compiler/scala/tools/nsc/matching/LeftTracers.scala b/src/compiler/scala/tools/nsc/matching/LeftTracers.scala
index b58e11b4cb..0d77065d40 100644
--- a/src/compiler/scala/tools/nsc/matching/LeftTracers.scala
+++ b/src/compiler/scala/tools/nsc/matching/LeftTracers.scala
@@ -10,7 +10,7 @@ import java.util._ ;
 
 import scala.tools.nsc.util.Position;
 
-trait LeftTracers: TransMatcher {
+mixin class LeftTracers requires TransMatcher {
 
 import global._;
 
diff --git a/src/compiler/scala/tools/nsc/matching/MatcherLabels.scala b/src/compiler/scala/tools/nsc/matching/MatcherLabels.scala
index 06c8cd2baa..65ce90cb8c 100644
--- a/src/compiler/scala/tools/nsc/matching/MatcherLabels.scala
+++ b/src/compiler/scala/tools/nsc/matching/MatcherLabels.scala
@@ -1,6 +1,6 @@
 package scala.tools.nsc.matching ;
 
-[_trait_] abstract class MatcherLabels: TransMatcher {
+mixin class MatcherLabels requires TransMatcher {
 
   import global._ ;
 
diff --git a/src/compiler/scala/tools/nsc/matching/NondetWordAutoms.scala b/src/compiler/scala/tools/nsc/matching/NondetWordAutoms.scala
index cd1d8b576e..3afa3d376d 100644
--- a/src/compiler/scala/tools/nsc/matching/NondetWordAutoms.scala
+++ b/src/compiler/scala/tools/nsc/matching/NondetWordAutoms.scala
@@ -1,7 +1,7 @@
 package scala.tools.nsc.matching ;
 import java.util._ ;
 
-trait NondetWordAutoms {
+mixin class NondetWordAutoms {
 /** a nondeterministic word automaton.
  *  states are represented (implicitly) as Integer objects.
  */
diff --git a/src/compiler/scala/tools/nsc/matching/PatternMatchers.scala b/src/compiler/scala/tools/nsc/matching/PatternMatchers.scala
index 7d4292e3ff..38febba140 100644
--- a/src/compiler/scala/tools/nsc/matching/PatternMatchers.scala
+++ b/src/compiler/scala/tools/nsc/matching/PatternMatchers.scala
@@ -8,7 +8,7 @@ package scala.tools.nsc.matching ;
 
 import scala.tools.nsc.util.Position;
 
-trait PatternMatchers: (TransMatcher with PatternNodes) extends AnyRef with PatternNodeCreator {
+mixin class PatternMatchers requires (TransMatcher with PatternNodes) extends AnyRef with PatternNodeCreator {
 
 
   import global._;
diff --git a/src/compiler/scala/tools/nsc/matching/PatternNodeCreator.scala b/src/compiler/scala/tools/nsc/matching/PatternNodeCreator.scala
index 79ba780469..703763f1a7 100644
--- a/src/compiler/scala/tools/nsc/matching/PatternNodeCreator.scala
+++ b/src/compiler/scala/tools/nsc/matching/PatternNodeCreator.scala
@@ -6,7 +6,7 @@ import scala.tools.nsc.util.Position;
  *  we inherit the globals from PatternTool.
  */
 
-trait PatternNodeCreator: (TransMatcher with PatternNodes) {
+mixin class PatternNodeCreator requires (TransMatcher with PatternNodes) {
 
   import global._;
 
diff --git a/src/compiler/scala/tools/nsc/matching/PatternNodes.scala b/src/compiler/scala/tools/nsc/matching/PatternNodes.scala
index 551d964c39..e13db74083 100644
--- a/src/compiler/scala/tools/nsc/matching/PatternNodes.scala
+++ b/src/compiler/scala/tools/nsc/matching/PatternNodes.scala
@@ -10,7 +10,7 @@ package scala.tools.nsc.matching ;
 
 import scala.tools.nsc.util.Position;
 
-trait PatternNodes: TransMatcher {
+mixin class PatternNodes requires TransMatcher {
 
   import global._;
 
diff --git a/src/compiler/scala/tools/nsc/matching/RightTracers.scala b/src/compiler/scala/tools/nsc/matching/RightTracers.scala
index f0daf20fed..754fd0bf1d 100644
--- a/src/compiler/scala/tools/nsc/matching/RightTracers.scala
+++ b/src/compiler/scala/tools/nsc/matching/RightTracers.scala
@@ -11,7 +11,7 @@ import java.util._ ;
 import scala.tools.nsc.util.Position;
 import scala.tools.nsc.symtab.Flags;
 
-trait RightTracers: TransMatcher {
+mixin class RightTracers requires TransMatcher {
 
   import global._ ;
   import java.util._ ;
diff --git a/src/compiler/scala/tools/nsc/matching/SequenceMatchers.scala b/src/compiler/scala/tools/nsc/matching/SequenceMatchers.scala
index d2d8aa7414..334b8273d0 100644
--- a/src/compiler/scala/tools/nsc/matching/SequenceMatchers.scala
+++ b/src/compiler/scala/tools/nsc/matching/SequenceMatchers.scala
@@ -14,7 +14,7 @@ import java.util._ ;
  *  is the "Builder" for "Director" class TransMatch.
  */
 
-trait SequenceMatchers: TransMatcher  {
+mixin class SequenceMatchers requires TransMatcher  {
 
   import global._;
 
diff --git a/src/compiler/scala/tools/nsc/matching/WordAutoms.scala b/src/compiler/scala/tools/nsc/matching/WordAutoms.scala
index de17fc6445..836253ca8e 100644
--- a/src/compiler/scala/tools/nsc/matching/WordAutoms.scala
+++ b/src/compiler/scala/tools/nsc/matching/WordAutoms.scala
@@ -10,7 +10,7 @@ import java.util._ ;
 
 import scala.tools.nsc.util.Position;
 
-trait WordAutoms: TransMatcher {
+mixin class WordAutoms requires TransMatcher {
 
   import global._ ;
   /** translates a recognizer to scala code
diff --git a/src/compiler/scala/tools/nsc/symtab/Constants.scala b/src/compiler/scala/tools/nsc/symtab/Constants.scala
index 3a6746cf61..8fcc383c2c 100644
--- a/src/compiler/scala/tools/nsc/symtab/Constants.scala
+++ b/src/compiler/scala/tools/nsc/symtab/Constants.scala
@@ -9,7 +9,7 @@ package scala.tools.nsc.symtab;
 
 import classfile.PickleFormat._;
 
-[_trait_] abstract class Constants: SymbolTable {
+mixin class Constants requires SymbolTable {
 
   import definitions._;
 
@@ -178,7 +178,9 @@ import classfile.PickleFormat._;
 	Constant(floatValue)
       else if (target == DoubleClass && ByteTag <= tag && tag <= DoubleTag)
 	Constant(doubleValue)
-      else null
+      else {
+        null
+      }
     }
 
     def stringValue: String =
diff --git a/src/compiler/scala/tools/nsc/symtab/Definitions.scala b/src/compiler/scala/tools/nsc/symtab/Definitions.scala
index af2f8e55d8..63f6b90706 100644
--- a/src/compiler/scala/tools/nsc/symtab/Definitions.scala
+++ b/src/compiler/scala/tools/nsc/symtab/Definitions.scala
@@ -9,7 +9,7 @@ import scala.tools.nsc.util.Position;
 import collection.mutable.HashMap;
 import Flags._;
 
-[_trait_] abstract class Definitions: SymbolTable {
+mixin class Definitions requires SymbolTable {
 
   object definitions {
 
diff --git a/src/compiler/scala/tools/nsc/symtab/InfoTransformers.scala b/src/compiler/scala/tools/nsc/symtab/InfoTransformers.scala
index e1ff9bbac5..87f4ba7b12 100644
--- a/src/compiler/scala/tools/nsc/symtab/InfoTransformers.scala
+++ b/src/compiler/scala/tools/nsc/symtab/InfoTransformers.scala
@@ -5,7 +5,7 @@
 // $Id$
 package scala.tools.nsc.symtab;
 
-[_trait_] abstract class InfoTransformers: SymbolTable {
+mixin class InfoTransformers requires SymbolTable {
 
   abstract class InfoTransformer {
     var prev: InfoTransformer = this;
diff --git a/src/compiler/scala/tools/nsc/symtab/Scopes.scala b/src/compiler/scala/tools/nsc/symtab/Scopes.scala
index fe8ffaa47b..81c12dc177 100644
--- a/src/compiler/scala/tools/nsc/symtab/Scopes.scala
+++ b/src/compiler/scala/tools/nsc/symtab/Scopes.scala
@@ -5,7 +5,7 @@
 // $Id$
 package scala.tools.nsc.symtab;
 
-[_trait_] abstract class Scopes: SymbolTable {
+mixin class Scopes requires SymbolTable {
 
   class ScopeEntry(val sym: Symbol, val owner: Scope) {
 
diff --git a/src/compiler/scala/tools/nsc/symtab/StdNames.scala b/src/compiler/scala/tools/nsc/symtab/StdNames.scala
index a07933af4f..8a4cc204df 100644
--- a/src/compiler/scala/tools/nsc/symtab/StdNames.scala
+++ b/src/compiler/scala/tools/nsc/symtab/StdNames.scala
@@ -7,7 +7,7 @@ package scala.tools.nsc.symtab;
 
 import scala.tools.nsc.util.NameTransformer;
 
-[_trait_] abstract class StdNames: SymbolTable {
+mixin class StdNames requires SymbolTable {
 
   object nme {
 
diff --git a/src/compiler/scala/tools/nsc/symtab/Symbols.scala b/src/compiler/scala/tools/nsc/symtab/Symbols.scala
index e8fed63916..c4e7153809 100644
--- a/src/compiler/scala/tools/nsc/symtab/Symbols.scala
+++ b/src/compiler/scala/tools/nsc/symtab/Symbols.scala
@@ -9,7 +9,7 @@ import scala.tools.util.AbstractFile;
 import scala.tools.nsc.util.{Position, SourceFile};
 import Flags._;
 
-[_trait_] abstract class Symbols: SymbolTable {
+mixin class Symbols requires SymbolTable {
   import definitions._;
 
   private var ids = 0;
diff --git a/src/compiler/scala/tools/nsc/symtab/Types.scala b/src/compiler/scala/tools/nsc/symtab/Types.scala
index 58ef0187e1..7fda6f09ed 100644
--- a/src/compiler/scala/tools/nsc/symtab/Types.scala
+++ b/src/compiler/scala/tools/nsc/symtab/Types.scala
@@ -30,7 +30,7 @@ import Flags._;
   case TypeVar(_, _) =>
 */
 
-[_trait_] abstract class Types: SymbolTable {
+mixin class Types requires SymbolTable {
   import definitions._;
 
   //statistics
@@ -413,7 +413,7 @@ import Flags._;
 
 // Subclasses ------------------------------------------------------------
 
-  [_trait_] abstract class UniqueType {
+  mixin class UniqueType {
     private val hashcode = { val h = super.hashCode(); if (h < 0) -h else h }
     override def hashCode() = hashcode;
   }
diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
index e5803d18e5..ffd5add6f0 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
@@ -65,7 +65,8 @@ abstract class ClassfileParser {
       parseClass()
     } catch {
       case e: RuntimeException =>
-        if (settings.debug.value) e.printStackTrace();
+        e.printStackTrace();
+        if (settings.debug.value)
         throw new IOException("class file '" + in.file + "' is broken")
     }
     busy = false
@@ -249,6 +250,7 @@ abstract class ClassfileParser {
     parseAttributes(clazz, classInfo);
     if (!isScala) {
       clazz.setFlag(sflags);
+      setPrivateWithin(clazz, jflags);
       if (!hasMeta) {
 	clazz.setInfo(classInfo);
       }
@@ -281,6 +283,7 @@ abstract class ClassfileParser {
       val info = pool.getType(in.nextChar());
       val sym = getOwner(jflags)
         .newValue(Position.NOPOS, name).setFlag(sflags).setInfo(info);
+      setPrivateWithin(sym, jflags);
       parseAttributes(sym, info);
       getScope(jflags).enter(sym);
     }
@@ -303,12 +306,19 @@ abstract class ClassfileParser {
 	}
       val sym = getOwner(jflags)
         .newMethod(Position.NOPOS, name).setFlag(sflags).setInfo(info);
+      setPrivateWithin(sym, jflags);
       parseAttributes(sym, info);
       getScope(jflags).enter(sym);
     }
   }
 
   def parseAttributes(sym: Symbol, symtype: Type): unit = {
+    def convertTo(c: Constant, pt: Type): Constant = {
+      if (pt.symbol == definitions.BooleanClass && c.tag == IntTag)
+        Constant(if (c.value == 0) false else true)
+      else
+        c convertTo pt
+    }
     def parseAttribute(): unit = {
       val attrName = pool.getName(in.nextChar());
       val attrLen = in.nextInt();
@@ -324,8 +334,9 @@ abstract class ClassfileParser {
           in.skip(attrLen)
         case nme.ConstantValueATTR =>
           val c = pool.getConstant(in.nextChar());
-	  val c1 = c convertTo symtype;
-          sym.setInfo(ConstantType(c1));
+	  val c1 = convertTo(c, symtype);
+          if (c1 != null) sym.setInfo(ConstantType(c1));
+          else System.out.println("failure to convert "+c+" to "+symtype);//debug
         case nme.InnerClassesATTR =>
           parseInnerClasses()
         case nme.ScalaSignatureATTR =>
@@ -385,8 +396,6 @@ abstract class ClassfileParser {
       res = res | PRIVATE
     else if ((flags & JAVA_ACC_PROTECTED) != 0)
       res = res | PROTECTED
-    else if ((flags & JAVA_ACC_PUBLIC) == 0)
-      res = res | PRIVATE;
     if ((flags & JAVA_ACC_ABSTRACT) != 0)
       res = res | DEFERRED;
     if ((flags & JAVA_ACC_FINAL) != 0)
@@ -399,4 +408,8 @@ abstract class ClassfileParser {
       res = res | STATIC;
     res | JAVA;
   }
+
+  private def setPrivateWithin(sym: Symbol, jflags: int): unit =
+    if ((jflags & (JAVA_ACC_PRIVATE | JAVA_ACC_PROTECTED | JAVA_ACC_PUBLIC)) == 0)
+      sym.privateWithin = sym.toplevelClass.owner
 }
diff --git a/src/compiler/scala/tools/nsc/typechecker/Analyzer.scala b/src/compiler/scala/tools/nsc/typechecker/Analyzer.scala
index e895524915..0118dadbaf 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Analyzer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Analyzer.scala
@@ -7,7 +7,7 @@ package scala.tools.nsc.typechecker;
 
 /** The main attribution phase.
  */
-[_trait_] abstract class Analyzer
+mixin class Analyzer
 	 extends AnyRef
             with Contexts
     	    with Namers
diff --git a/src/compiler/scala/tools/nsc/typechecker/Codification.scala b/src/compiler/scala/tools/nsc/typechecker/Codification.scala
index 59ddca225a..2542f0d9f8 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Codification.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Codification.scala
@@ -10,7 +10,7 @@ import scala.collection.immutable.ListMap;
 import scala.collection.mutable.ListBuffer;
 import scala.tools.nsc.util.FreshNameCreator;
 
-[_trait_] abstract class Codification: Analyzer {
+mixin class Codification requires Analyzer {
 
   import global._;
 
diff --git a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
index d0cfa6f3a1..c6aa1d8c8e 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
@@ -8,7 +8,7 @@ package scala.tools.nsc.typechecker;
 import symtab.Flags._;
 import scala.tools.nsc.util.Position;
 
-[_trait_] abstract class Contexts: Analyzer {
+mixin class Contexts requires Analyzer {
   import global._;
 
   val NoContext = new Context {
diff --git a/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala b/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala
index 36dd960342..28bbff53c2 100644
--- a/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala
@@ -8,7 +8,7 @@ package scala.tools.nsc.typechecker;
 import scala.collection.mutable.ListBuffer;
 import symtab.Flags._;
 
-[_trait_] abstract class EtaExpansion: Analyzer {
+mixin class EtaExpansion requires Analyzer {
 
   import global._;
   import posAssigner.atPos;
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index d80f573029..9c9c969b39 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -8,7 +8,7 @@ package scala.tools.nsc.typechecker;
 import scala.collection.mutable.ListBuffer;
 import symtab.Flags._;
 
-[_trait_] abstract class Infer: Analyzer {
+mixin class Infer requires Analyzer {
   import global._;
   import definitions._;
   import posAssigner.atPos;
diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
index 739cb4935a..0c8937f1f9 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Namers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
@@ -10,7 +10,7 @@ import symtab.Flags;
 import symtab.Flags._;
 
 /** Methods to create symbols and to enter them into scopes. */
-trait Namers: Analyzer {
+trait Namers requires Analyzer {
   import global._;
   import definitions._;
 
diff --git a/src/compiler/scala/tools/nsc/typechecker/SyntheticMethods.scala b/src/compiler/scala/tools/nsc/typechecker/SyntheticMethods.scala
index ae4cdb2b58..71b21084a0 100644
--- a/src/compiler/scala/tools/nsc/typechecker/SyntheticMethods.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/SyntheticMethods.scala
@@ -18,7 +18,7 @@ import scala.collection.mutable.ListBuffer;
  *       unless they are defined in the class or a baseclass
  *       different from java.lang.Object
 */
-[_trait_] abstract class SyntheticMethods: Analyzer {
+mixin class SyntheticMethods requires Analyzer {
   import global._;                  // the global environment
   import definitions._;             // standard classes and methods
   import typer.{typed};             // methods to type trees
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 4179674f94..076ec2479a 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -11,7 +11,7 @@ import scala.tools.nsc.util.Position
 import scala.collection.mutable.{HashMap, ListBuffer}
 
 /** Methods to create symbols and to enter them into scopes. */
-[_trait_] abstract class Typers: Analyzer {
+mixin class Typers requires Analyzer {
   import global._
   import definitions._
   import posAssigner.atPos
@@ -354,8 +354,12 @@ import scala.collection.mutable.{HashMap, ListBuffer}
                    mt.paramTypes.isEmpty && isCompatible(mt.resultType, pt)) { // (4.3)
           typed(Apply(tree, List()) setPos tree.pos)
         } else {
-          if (context.reportGeneralErrors)
-            error(tree.pos, "missing arguments for "+tree.symbol)
+          if (context.reportGeneralErrors) {
+            if (settings.migrate.value && !tree.symbol.isConstructor && isCompatible(mt, pt))
+              error(tree.pos, migrateMsg + " method can be converted to function only if an expected function type is given");
+            else
+              error(tree.pos, "missing arguments for "+tree.symbol)
+          }
           setError(tree)
         }
       case _ =>
diff --git a/src/compiler/scala/tools/nsc/typechecker/Variances.scala b/src/compiler/scala/tools/nsc/typechecker/Variances.scala
index ca7c52d242..100230d70f 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Variances.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Variances.scala
@@ -9,7 +9,7 @@ import symtab.Flags._;
 
 /** Variances form a lattice, 0 <= COVARIANT <= Variances, 0 <= CONTRAVARIANT <= VARIANCES
  */
-[_trait_] abstract class Variances {
+mixin class Variances {
 
   val global: Global;
   import global._;
-- 
cgit v1.2.3