*** empty log message ***

18 files changed, 56 insertions, 290 deletions

diff --git a/sources/meta/scala/MetaFunction.java b/sources/meta/scala/MetaFunction.java
index 3bcf4cc4c6..4f8c441e72 100644
--- a/sources/meta/scala/MetaFunction.java
+++ b/sources/meta/scala/MetaFunction.java
@@ -38,7 +38,7 @@ public class MetaFunction extends AbstractJavaExpander {
     public void printClassScalaTParams() {
         for (int i = 0; i < arity; i++)
             writer.print("?A").print(i).print(", ");
-        writer.print("?R");
+        writer.print("+ ?R");
     }
 
     public void printApplyScalaSignature() {
diff --git a/sources/meta/scalac/ast/Tree.java b/sources/meta/scalac/ast/Tree.java
index 02bb466d08..d596549522 100644
--- a/sources/meta/scalac/ast/Tree.java
+++ b/sources/meta/scalac/ast/Tree.java
@@ -100,8 +100,7 @@ public class Tree {
         n_SelectFromType = node("SelectFromType", Type, HasSym),
         n_FunType        = node("FunType"       , Type, NoSym),
         n_CompoundType   = node("CompoundType"  , Type, NoSym),
-        n_AppliedType    = node("AppliedType"   , Type, NoSym),
-        n_CovariantType  = node("CovariantType" , Type, NoSym);
+        n_AppliedType    = node("AppliedType"   , Type, NoSym);
 
     public final TreeNode[] nodes;
     public int arrays;
@@ -323,11 +322,6 @@ public class Tree {
             addField(t_TypeTree, "tpe").
             addField(t_TypeTrees, "args");
 
-        n_CovariantType.
-            setDescription("Covariant type").
-            setRange(Phase.PARSER, Phase.ANALYZER).
-            addField(t_TypeTree, "tpe");
-
     }
 
     //########################################################################
diff --git a/sources/scala/PartialFunction.scala b/sources/scala/PartialFunction.scala
index 9d8f8adbad..58e797b3f4 100644
--- a/sources/scala/PartialFunction.scala
+++ b/sources/scala/PartialFunction.scala
@@ -9,7 +9,7 @@
 // $Id$
 
 package scala {
-  trait PartialFunction[A, B] {
+  trait PartialFunction[A, +B] {
     def apply(x: A): B;
     def isDefinedAt(x: A): scala.Boolean;
   }
diff --git a/sources/scalac/ast/parser/Parser.java b/sources/scalac/ast/parser/Parser.java
index 589d33c31c..de959552dd 100644
--- a/sources/scalac/ast/parser/Parser.java
+++ b/sources/scalac/ast/parser/Parser.java
@@ -616,7 +616,7 @@ public class Parser implements Tokens {
 	    if (s.token == HASH)
 		t = make.SelectFromType(s.skipToken(), t, ident().toTypeName());
 	    else if (s.token == LBRACKET)
-		t = make.AppliedType(pos, t, varTypeArgs());//todo: change to typeArgs
+		t = make.AppliedType(pos, t, typeArgs());
 	    else break;
 	}
 	return t;
@@ -631,30 +631,6 @@ public class Parser implements Tokens {
 	return ts;
     }
 
-    /**  VarTypeArgs ::= `[' VarType {`,' VarType} `]'
-     */
-    Tree[] varTypeArgs() {
-        int pos = accept(LBRACKET);
-        TreeList ts = new TreeList();
-	ts.append(varType());
-        while (s.token == COMMA) {
-	    s.nextToken();
-	    ts.append(varType());
-	}
-	accept(RBRACKET);
-	return ts.toArray();
-    }
-
-    /** VarType ::= [`+'] Type
-     */
-    Tree varType() {
-	int pos = s.pos;
-	if (s.token == IDENTIFIER && s.name == PLUS)
-	    return make.CovariantType(s.skipToken(), type());
- 	else
-	    return type();
-    }
-
 //////// EXPRESSIONS ////////////////////////////////////////////////////////
 
     /** EqualsExpr ::= `=' Expr
diff --git a/sources/scalac/ast/printer/TextTreePrinter.java b/sources/scalac/ast/printer/TextTreePrinter.java
index 54f2764dab..5c6e04ddc9 100644
--- a/sources/scalac/ast/printer/TextTreePrinter.java
+++ b/sources/scalac/ast/printer/TextTreePrinter.java
@@ -527,11 +527,6 @@ public class TextTreePrinter implements TreePrinter {
 	    print(TXT_RIGHT_BRACKET);
             break;
 
-        case CovariantType(Tree tpe):
-	    print(TXT_PLUS);
-	    print(tpe);
-            break;
-
         case Template(Tree[] parents, Tree[] body):
             Debug.abort("unexpected case", tree);
             break;
diff --git a/sources/scalac/backend/jvm/GenJVM.java b/sources/scalac/backend/jvm/GenJVM.java
index c4b4909e75..ed8d40023e 100644
--- a/sources/scalac/backend/jvm/GenJVM.java
+++ b/sources/scalac/backend/jvm/GenJVM.java
@@ -462,7 +462,6 @@ class GenJVM {
         case TypeApply(_, _):
         case FunType(_, _):
         case CompoundType(_, _):
-        case CovariantType(_):
         case AppliedType(_,_):
             break;
 
diff --git a/sources/scalac/symtab/Definitions.java b/sources/scalac/symtab/Definitions.java
index 5f2bf4735c..b2dc7ac8ae 100644
--- a/sources/scalac/symtab/Definitions.java
+++ b/sources/scalac/symtab/Definitions.java
@@ -424,7 +424,7 @@ public class Definitions {
     public Type functionType(Type[] argtps, Type restp) {
 	Type[] argtps1 = new Type[argtps.length + 1];
 	System.arraycopy(argtps, 0, argtps1, 0, argtps.length);
-	argtps1[argtps.length] = Type.covarType(restp);
+	argtps1[argtps.length] = restp;
 	return Type.appliedType(
 	    getType(Name.fromString("scala.Function" + argtps.length)),
 	    argtps1);
@@ -433,7 +433,7 @@ public class Definitions {
     public Type partialFunctionType(Type argtpe, Type restpe) {
 	Type[] argtps1 = new Type[2];
 	argtps1[0] = argtpe;
-	argtps1[1] = Type.covarType(restpe);
+	argtps1[1] = restpe;
 	return Type.appliedType(PARTIALFUNCTION_CLASS.typeConstructor(), argtps1);
     }
 
diff --git a/sources/scalac/symtab/SymbolMapApplier.java b/sources/scalac/symtab/SymbolMapApplier.java
index b8f0b6978f..56d01ff9e6 100644
--- a/sources/scalac/symtab/SymbolMapApplier.java
+++ b/sources/scalac/symtab/SymbolMapApplier.java
@@ -71,9 +71,6 @@ public class SymbolMapApplier {
         case OverloadedType(Symbol[] alts, Type[] alttypes):
             return new Type.OverloadedType(apply(alts), apply(alttypes));
 
-	case CovarType(Type result):
-	    return Type.CovarType(apply(result));
-
         default:
             throw new ApplicationError("unknown type " + type);
         }
diff --git a/sources/scalac/symtab/Type.java b/sources/scalac/symtab/Type.java
index f61720c44d..ae0f830304 100644
--- a/sources/scalac/symtab/Type.java
+++ b/sources/scalac/symtab/Type.java
@@ -41,12 +41,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
     public case PolyType(Symbol[] tparams, Type result);
     public case OverloadedType(Symbol[] alts, Type[] alttypes);
 
-    /** Type such as +T. Only used as type arguments.
-     */
-    public case CovarType(Type tp) {
-	assert !(tp instanceof CovarType);
-    }
-
     /** Hidden case to implement delayed evaluation of types.
      *  No need to pattern match on this type; it will never come up.
      */
@@ -100,11 +94,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	}
     }
 
-    public static CovarType covarType(Type tp) {
-	if (tp instanceof CovarType) return (CovarType)tp;
-	else return CovarType(tp);
-    }
-
     public static CompoundType compoundType(Type[] parts, Scope members,
 					    Symbol clazz) {
 	ExtCompoundType res = new ExtCompoundType(parts, members);
@@ -445,19 +434,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	return this;
     }
 
-    /** If this is a covariant type, its underlying type, otherwise the type itself.
-     */
-    public Type dropVariance() {
-	switch (this) {
-	case CovarType(Type tp): return tp;
-	default: return this;
-	}
-    }
-
-    public static Map dropVarianceMap = new Map() {
-	public Type apply(Type t) { return t.dropVariance(); }
-    };
-
 // Tests --------------------------------------------------------------------
 
     /** Is this type a this type or singleton type?
@@ -504,17 +480,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	}
     }
 
-    /** Is this type a covariant type?
-     */
-    public boolean isCovarType() {
-	switch (this) {
-	case CovarType(_):
-	    return true;
-	default:
-	    return false;
-	}
-    }
-
     /** Is this type of the form scala.FunctionN[T_1, ..., T_n, +T] or
      *  scala.Object with scala.FunctionN[T_1, ..., T_n, +T]?
      */
@@ -522,9 +487,7 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	switch (this) {
 	case TypeRef(Type pre, Symbol sym, Type[] args):
 	    if (sym.fullName().startsWith(Names.scala_Function)) {
-		for (int i = 0; i < args.length - 1; i++)
-		    if (args[i].isCovarType()) return false;
-		return args.length > 0; // !!! && args[args.length - 1].isCovarType();
+		return args.length > 0;
 	    }
 	    break;
 	case CompoundType(Type[] parents, Scope members):
@@ -626,8 +589,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
      */
     public abstract static class Map {
 
-	boolean covariantOK = true;
-
 	public abstract Type apply(Type t);
 
 	/** Apply map to all top-level components of this type.
@@ -677,16 +638,12 @@ public class Type implements Modifiers, Kinds, TypeTags {
 		}
 
 	    case MethodType(Symbol[] vparams, Type result):
-		covariantOK = false;
 		Symbol[] vparams1 = map(vparams);
-		covariantOK = true;
 		Type result1 = apply(result);
 		if (vparams1 == vparams && result1 == result) return tp;
 		else return MethodType(vparams1, result1);
 	    case PolyType(Symbol[] tparams, Type result):
-		covariantOK = false;
 		Symbol[] tparams1 = map(tparams);
-		covariantOK = true;
 		Type result1 = apply(result);
 		if (tparams1 != tparams) result1 = result1.subst(tparams, tparams1);
 		if (tparams1 == tparams && result1 == result) return tp;
@@ -695,10 +652,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 		Type[] alttypes1 = map(alttypes);
 		if (alttypes1 == alttypes) return tp;
 		else return OverloadedType(alts, alttypes1);
-	    case CovarType(Type t):
-		Type t1 = apply(t);
-		if (t1 == t) return tp;
-		else return covarType(t1);
 	    case UnboxedArrayType(Type elemtp):
 		Type elemtp1 = apply(elemtp);
 		if (elemtp1 == elemtp) return tp;
@@ -831,8 +784,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 
 	private Type pre;
 	private Symbol clazz;
-	private Type illegalType = NoType;
-	private boolean typeArg = false;
 
 	AsSeenFromMap(Type pre, Symbol clazz) {
 	    this.pre = pre; this.clazz = clazz;
@@ -858,24 +809,13 @@ public class Type implements Modifiers, Kinds, TypeTags {
 		    assert sym.kind == TYPE;
 		    Type t1 = t.toInstance(pre, clazz);
 		    //System.out.println(t + ".toInstance(" + pre + "," + clazz + ") = " + t1);//DEBUG
-		    switch (t1) {
-		    case CovarType(Type tp):
-			if (!covariantOK) {
-			    if (illegalType == NoType) illegalType = t1;
-			} else if (!typeArg) {
-			    t1 = tp;
-			}
-		    }
 		    return t1;
 		} else {
 		    //Type prefix1 = prefix.toPrefix(pre, clazz);
 		    Type prefix1 = apply(prefix);
 		    Symbol sym1 = (prefix1 == prefix || (sym.flags & MODUL) != 0)
 			? sym : prefix1.rebind(sym);
-		    boolean prevTypeArg = typeArg;
-		    typeArg = true;
 		    Type[] args1 = map(args);
-		    typeArg = prevTypeArg;
 		    if (prefix1 == prefix && args1 == args) return t;
 		    else return typeRef(prefix1, sym1, args1);
 		}
@@ -893,14 +833,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 		return map(t);
 	    }
 	}
-
-	void checkLegal(Type tp) {
-	    if (illegalType != NoType) {
-		throw new ApplicationError(
-		    "malformed type: " + tp + "; " +
-		    illegalType + " does not occur in covariant position");
-	    }
-	}
     }
     //where
         Type toInstance(Type pre, Symbol clazz) {
@@ -944,20 +876,13 @@ public class Type implements Modifiers, Kinds, TypeTags {
      */
     public Type asSeenFrom(Type pre, Symbol clazz) {
 	//System.out.println("computing asseenfrom of " + this + " with " + pre + "," + clazz);//DEBUG
-	AsSeenFromMap f = new AsSeenFromMap(pre, clazz);
-	Type t = f.apply(this);
-	f.checkLegal(t);
-	return t;
+	return new AsSeenFromMap(pre, clazz).apply(this);
     }
 
     /** Types `these' as seen from prefix `pre' and class `clazz'.
      */
     public static Type[] asSeenFrom(Type[] these, Type pre, Symbol clazz) {
-	AsSeenFromMap f = new AsSeenFromMap(pre, clazz);
-	Type[] these1 = f.map(these);
-	for (int i = 0; i < these1.length; i++)
-	    f.checkLegal(these1[i]);
-	return these1;
+	return new AsSeenFromMap(pre, clazz).map(these);
     }
 
     /** The info of `sym', seen as a member of this type.
@@ -1337,7 +1262,7 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	    //todo: should we test for equality with origin?
 	    if (constr.inst != NoType) {
 		return this.isSubType(constr.inst);
-	    } else if (!this.isCovarType()) {
+	    } else {
 		constr.lobounds = new List(this, constr.lobounds);
 		return true;
 	    }
@@ -1358,8 +1283,7 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	    if (constr.inst != NoType) {
 		return constr.inst.isSubType(that);
 	    } else {
-		constr.hibounds = new List(that.dropVariance(), constr.hibounds);
-		assert that.dropVariance().symbol() != Global.instance.definitions.ALL_CLASS;//debug
+		constr.hibounds = new List(that, constr.hibounds);
 		return true;
 	    }
 
@@ -1412,23 +1336,12 @@ public class Type implements Modifiers, Kinds, TypeTags {
     static boolean isSubArgs(Type[] these, Type[] those, Symbol[] tparams) {
 	if (these.length != those.length) return false;
 	for (int i = 0; i < these.length; i++) {
-	    switch (those[i]) {
-	    case CovarType(Type tp1):
-		switch (these[i]) {
-		case CovarType(Type tp):
-		    if (!tp.isSubType(tp1)) return false;
-		    break;
-		default:
-		    if (!these[i].isSubType(tp1)) return false;
-		}
-		break;
-	    default:
-		if (these[i].isCovarType()) return false;
-		if ((tparams[i].flags & COVARIANT) != 0) {
-		    if (!these[i].isSubType(those[i])) return false;
-		} else {
-		    if (!these[i].isSameAs(those[i])) return false;
-		}
+	    if ((tparams[i].flags & COVARIANT) != 0) {
+		if (!these[i].isSubType(those[i])) return false;
+	    } else if ((tparams[i].flags & CONTRAVARIANT) != 0) {
+		if (!those[i].isSubType(these[i])) return false;
+	    } else {
+		if (!these[i].isSameAs(those[i])) return false;
 	    }
 	}
 	return true;
@@ -1539,7 +1452,7 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	case TypeRef(Type pre, Symbol sym, Type[] args):
 	    switch (that) {
 	    case TypeRef(Type pre1, Symbol sym1, Type[] args1):
-		if (sym == sym1 && pre.isSameAs(pre1) && isSameArgs(args, args1))
+		if (sym == sym1 && pre.isSameAs(pre1) && isSameAs(args, args1))
 		    return true;
 	    }
 	    break;
@@ -1610,23 +1523,19 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	case NoType:
 	    return false;
 	case TypeVar(Type origin, Constraint constr):
-	    if (constr.inst != NoType)
-		return constr.inst.isSameAs(this);
-	    else if (!this.isCovarType())
-		return constr.instantiate(this.any2typevar());
+	    if (constr.inst != NoType) return constr.inst.isSameAs(this);
+	    else return constr.instantiate(this.any2typevar());
 	}
 
 	switch (this) {
 	case NoType:
 	    return false;
-	case TypeVar(Type origin, Constraint constr):
-	    if (constr.inst != NoType)
-		return constr.inst.isSameAs(that);
-	    else if (!that.isCovarType())
-		return constr.instantiate(that.any2typevar());
-	    break;
 	case TypeRef(_, Symbol sym, _):
 	    if (sym.kind == ALIAS) return this.unalias().isSameAs(that);
+	    break;
+	case TypeVar(Type origin, Constraint constr):
+	    if (constr.inst != NoType) return constr.inst.isSameAs(that);
+	    else return constr.instantiate(that.any2typevar());
 	}
 
 	switch (that) {
@@ -1637,19 +1546,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	return false;
     }
 
-    /** Is this type argument that same as `that'?
-     */
-    public boolean isSameArg(Type that) {
-	switch (this) {
-	case CovarType(Type tp):
-	    switch (that) {
-	    case CovarType(Type tp1):
-		return tp.isSameAs(tp1);
-	    }
-	}
-	return this.isSameAs(that);
-    }
-
     /** Are types `these' the same as corresponding types `those'?
      */
     public static boolean isSameAs(Type[] these, Type[] those) {
@@ -1660,16 +1556,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	return true;
     }
 
-    /** Are type arguments `these' the same as corresponding types `those'?
-     */
-    public static boolean isSameArgs(Type[] these, Type[] those) {
-	if (these.length != those.length) return false;
-	for (int i = 0; i < these.length; i++) {
-	    if (!these[i].isSameArg(those[i])) return false;
-	}
-	return true;
-    }
-
     /** Do scopes `s1' and `s2' define he same symbols with the same kinds and infos?
      */
     public boolean isSameAs(Scope s1, Scope s2) {
@@ -1852,14 +1738,10 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	    }
 	}
 	for (int j = 0; j < args.length; j++) {
-	    if ((tparams[j].flags & COVARIANT) != 0) {
-		args[j] = commonType(argss[j]);
-		if (args[j] == NoType)
-		    args[j] = lub(argss[j]);
-	    } else { //todo: test if all same, return notype otherwise.
-		args[j] = commonType(argss[j]);
-		if (args[j] == NoType)
-		    args[j] = CovarType(lub(argss[j]));
+	    args[j] = commonType(argss[j]);
+	    if (args[j] == NoType) {
+		if ((tparams[j].flags & COVARIANT) != 0) args[j] = lub(argss[j]);
+		else return NoType;
 	    }
 	}
 	return typeRef(pre, sym, args);
@@ -2139,8 +2021,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	case CompoundType(Type[] parents, _):
 	    if (parents.length > 0) return parents[0].erasure();
 	    else return this;
-	case CovarType(Type tp):
-	    return tp.erasure();  // note: needed because of UnboxedArrayType
 	case MethodType(Symbol[] params, Type tp):
 	    Symbol[] params1 = erasureMap.map(params);
 	    Type tp1 = tp.fullErasure();
@@ -2198,7 +2078,7 @@ public class Type implements Modifiers, Kinds, TypeTags {
 		    Type[] params = new Type[args.length - 1];
 		    System.arraycopy(args, 0, params, 0, params.length);
 		    return ArrayApply.toString(params, "(", ",", ") => ") +
-			args[params.length].dropVariance();
+			args[params.length];
 		} else if (sym.isAnonymousClass()) {
 		    return "<template: " +
 			ArrayApply.toString(
@@ -2245,8 +2125,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	case PolyType(Symbol[] tparams, Type result):
 	    return ArrayApply.toString(Symbol.defString(tparams), "[", ",", "]") +
 		result;
-	case CovarType(Type tp):
-	    return "+" + tp;
 	case OverloadedType(Symbol[] alts, Type[] alttypes):
 	    return ArrayApply.toString(alttypes, "", " <and> ", "");
 	case TypeVar(Type origin, Constraint constr):
@@ -2344,9 +2222,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 	    return POLYtpe
 		^ (hashCode(tparams) * 41)
 		^ (result.hashCode() * (41 * 41));
-	case CovarType(Type tp):
-	    return COVARtpe
-		^ (tp.hashCode() * (41));
 	case OverloadedType(Symbol[] alts, Type[] alttypes):
 	    return OVERLOADEDtpe
 		^ (hashCode(alts) * 41)
@@ -2428,12 +2303,6 @@ public class Type implements Modifiers, Kinds, TypeTags {
 		    return equals(tparams, tparams1) && result.equals(result1);
 		default: return false;
 		}
-	    case CovarType(Type tp):
-		switch (that) {
-		case CovarType(Type tp1):
-		    return tp.equals(tp1);
-		default: return false;
-		}
 	    case OverloadedType(Symbol[] alts, Type[] alttypes):
 		switch (that) {
 		case OverloadedType(Symbol[] alts1, Type[] alttypes1):
@@ -2559,6 +2428,5 @@ public class Type implements Modifiers, Kinds, TypeTags {
     case MethodType(Symbol[] vparams, Type result):
     case PolyType(Symbol[] tparams, Type result):
     case OverloadedType(Symbol[] alts, Type[] alttypes):
-    case CovarType(Type tp):
 */
 
diff --git a/sources/scalac/symtab/classfile/AttributeParser.java b/sources/scalac/symtab/classfile/AttributeParser.java
index dba5daa3de..0d585bf836 100644
--- a/sources/scalac/symtab/classfile/AttributeParser.java
+++ b/sources/scalac/symtab/classfile/AttributeParser.java
@@ -232,10 +232,19 @@ public class AttributeParser implements ClassfileConstants {
                     Vector syms = new Vector();
                     do {
                         nextToken();
+			int vflag = 0;
+			if (token.equals("+")) {
+			    nextToken();
+			    vflag = Modifiers.COVARIANT;
+			} else if (token.equals("-")) {
+			    nextToken();
+			    vflag = Modifiers.CONTRAVARIANT;
+			}
                         assert token.startsWith("?");
                         Symbol s = getTVar(token);
                         if (s == Symbol.NONE)
                             return defaultType;
+			s.flags |= vflag;
                         nextToken();
                         //System.out.println("new var " + s + ", " + token);//DEBUG
                         if (token.equals("<")) {
diff --git a/sources/scalac/transformer/AddInterfaces.java b/sources/scalac/transformer/AddInterfaces.java
index e3d93217d8..71a3a3db52 100644
--- a/sources/scalac/transformer/AddInterfaces.java
+++ b/sources/scalac/transformer/AddInterfaces.java
@@ -268,8 +268,6 @@ class AddInterfaces extends SubstTransformer {
                 return new Type.PolyType(tparams, apply(result));
             case OverloadedType(Symbol[] alts, Type[] alttypes):
                 return new Type.OverloadedType(alts, apply(alttypes));
-            case CovarType(Type t):
-                return new Type.CovarType(apply(t));
             case NoType:
                 return tp;
             default:
diff --git a/sources/scalac/transformer/Erasure.java b/sources/scalac/transformer/Erasure.java
index a890c37498..413dae1609 100644
--- a/sources/scalac/transformer/Erasure.java
+++ b/sources/scalac/transformer/Erasure.java
@@ -485,7 +485,6 @@ public class Erasure extends Transformer implements Modifiers {
         case FunType(_,_):
         case CompoundType(_,_):
         case AppliedType(_, _):
-        case CovariantType(_):
             throw Debug.abort("illegal case", tree);
 
 	default:
diff --git a/sources/scalac/transformer/PatternMatcher.java b/sources/scalac/transformer/PatternMatcher.java
index 1ab354301e..8d8a5922fa 100644
--- a/sources/scalac/transformer/PatternMatcher.java
+++ b/sources/scalac/transformer/PatternMatcher.java
@@ -509,7 +509,7 @@ public class PatternMatcher {
             if (casted.pos == Position.NOPOS) {
                 Symbol atSym = casted.type().lookup(AT_N);
                 //System.out.println("casted type = " + typeOf(casted));
-                Type seqType = casted.type().baseType(defs.SEQ_CLASS).typeArgs()[0].dropVariance();
+                Type seqType = casted.type().baseType(defs.SEQ_CLASS).typeArgs()[0];
                 Tree t = make.Select(
                             pat.pos,
                             make.Ident(pat.pos, casted.name)
diff --git a/sources/scalac/transformer/matching/PatternMatcher.java b/sources/scalac/transformer/matching/PatternMatcher.java
index 1ab354301e..8d8a5922fa 100644
--- a/sources/scalac/transformer/matching/PatternMatcher.java
+++ b/sources/scalac/transformer/matching/PatternMatcher.java
@@ -509,7 +509,7 @@ public class PatternMatcher {
             if (casted.pos == Position.NOPOS) {
                 Symbol atSym = casted.type().lookup(AT_N);
                 //System.out.println("casted type = " + typeOf(casted));
-                Type seqType = casted.type().baseType(defs.SEQ_CLASS).typeArgs()[0].dropVariance();
+                Type seqType = casted.type().baseType(defs.SEQ_CLASS).typeArgs()[0];
                 Tree t = make.Select(
                             pat.pos,
                             make.Ident(pat.pos, casted.name)
diff --git a/sources/scalac/typechecker/Analyzer.java b/sources/scalac/typechecker/Analyzer.java
index 63d1c31317..5190f2da97 100644
--- a/sources/scalac/typechecker/Analyzer.java
+++ b/sources/scalac/typechecker/Analyzer.java
@@ -743,9 +743,6 @@ public class Analyzer extends Transformer implements Modifiers, Kinds {
 	    break;
 	case OverloadedType(Symbol[] alts, Type[] alttypes):
 	    validateVariance(base, all, alttypes, variance);
-	    break;
-	case CovarType(Type tp1):
-	    validateVariance(base, all, tp1, CoVariance);
 	}
     }
 
@@ -1741,7 +1738,7 @@ public class Analyzer extends Transformer implements Modifiers, Kinds {
 		    }
 		} else if (clazz.isSubClass(definitions.SEQ_CLASS)) {
 		    // set type to instantiated sequence class constructor
-		    Type seqtp = dropVarArgs(pt.baseType(clazz));
+		    Type seqtp = pt.baseType(clazz);
 		    if (seqtp != Type.NoType) {
 			tree.type = seqConstructorType(seqtp, pt);
 		    } else {
@@ -1826,26 +1823,6 @@ public class Analyzer extends Transformer implements Modifiers, Kinds {
 	    }
 	}
 
-	Type dropVarArgs(Type tp) {
-	    switch (tp) {
-	    case TypeRef(Type pre, Symbol sym, Type[] targs):
-		Type[] targs1 = targs;
-		for (int i = 0; i < targs.length; i++) {
-		    Type targ = targs[i];
-		    Type targ1 = targ.dropVariance();
-		    if (targ != targ1 && targs1 == targs) {
-			targs1 = new Type[targs.length];
-			System.arraycopy(targs, 0, targs1, 0, i);
-		    }
-		    targs1[i] = targ1;
-		}
-		if (targs1 == targs) return tp;
-		else return Type.TypeRef(pre, sym, targs1);
-	    default:
-		return tp;
-	    }
-	}
-
 	Type seqConstructorType(Type paramtp, Type resulttp) {
 	    Symbol constr = resulttp.symbol().constructor();
 	    Symbol param = new TermSymbol(
@@ -2019,8 +1996,7 @@ public class Analyzer extends Transformer implements Modifiers, Kinds {
 			Tree tree1 = transformVisitor(tree, pattpe, restpe);
 			if (!infer.isFullyDefined(restpe)) restpe = tree1.type;
 			return transform(
-			    desugarize.partialFunction(
-				tree, pattpe, restpe.dropVariance()));
+			    desugarize.partialFunction(tree, pattpe, restpe));
 		    } else {
 			return error(tree.pos, "expected pattern type of cases could not be determined");
 		    }
@@ -2139,8 +2115,7 @@ public class Analyzer extends Transformer implements Modifiers, Kinds {
 		if (!infer.isFullyDefined(restype)) restype = body1.type;
 		popContext();
 		Tree tree1 = copy.Function(tree, vparams, body1);
-		Tree tree2 = transform(desugarize.Function(tree1, restype));
-		return desugarize.postFunction(tree2);
+		return transform(desugarize.Function(tree1, restype));
 
 	    case TypeApply(Tree fn, Tree[] args):
 		Tree fn1 = transform(fn, EXPRmode | FUNmode, Type.AnyType);
@@ -2317,11 +2292,6 @@ public class Analyzer extends Transformer implements Modifiers, Kinds {
 		}
 		return make.TypeTerm(tree.pos).setType(owntype);
 
-	    case CovariantType(Tree tpe):
-		Tree tpe1 = transform(tpe, TYPEmode);
-		return make.TypeTerm(tree.pos)
-		    .setType(Type.covarType(tpe1.type));
-
 	    case FunType(_, _):
 		return transform(desugarize.FunType(tree));
 
diff --git a/sources/scalac/typechecker/DeSugarize.java b/sources/scalac/typechecker/DeSugarize.java
index 13e9ad4564..07c2e4a234 100644
--- a/sources/scalac/typechecker/DeSugarize.java
+++ b/sources/scalac/typechecker/DeSugarize.java
@@ -110,7 +110,7 @@ public class DeSugarize implements Kinds, Modifiers {
 	case FunType(Tree[] argtpes, Tree restpe):
 	    Tree[] types = new Tree[argtpes.length + 1];
 	    System.arraycopy(argtpes, 0, types, 0, argtpes.length);
-	    types[argtpes.length] = make.CovariantType(restpe.pos, restpe);
+	    types[argtpes.length] = restpe;
 	    return make.AppliedType(tree.pos,
 		make.Select(tree.pos,
 		    make.Ident(tree.pos, Names.scala),
@@ -151,7 +151,7 @@ public class DeSugarize implements Kinds, Modifiers {
 		ptargs.length == vparams.length + 1) {
 		for (int i = 0; i < vparams.length; i++)
 		    assignType(vparams[i], ptargs[i]);
-		return ptargs[vparams.length].dropVariance();
+		return ptargs[vparams.length];
 	    }
 	}
 	return Type.AnyType;
@@ -171,7 +171,6 @@ public class DeSugarize implements Kinds, Modifiers {
      *  T_i's might be missing in the original tree.
      */
     public Tree Function(Tree tree, Type restype) {
-	assert !restype.isCovarType();
 	switch (tree) {
 	case Function(ValDef[] vparams, Tree body):
 	    int length = vparams.length;
@@ -213,30 +212,11 @@ public class DeSugarize implements Kinds, Modifiers {
 	}
     }
 
-    /** e of type FunctionN[T_1,...,T_N, T] -->
-     *            (e: FunctionN[T_1,...,T_n, +T])
-     */
-    Tree postFunction(Tree tree) {
-	Type[] targs = tree.type.typeArgs();
-	if (targs.length >= 1) {
-	    Type[] targs1 = new Type[targs.length - 1];
-	    System.arraycopy(targs, 0, targs1, 0, targs1.length);
-	    Tree result = gen.Typed(
-		tree,
-		global.definitions.functionType(targs1, targs[targs1.length]));
-	    print(tree, "postfun", result);
-	    return result;
-	} else {
-	    print(tree, "postfun", tree);
-	    return tree;
-	}
-    }
-
     /** Cases, Argtpe, Restpe ==>
-     *     (new scala.PartialFunction[Argtpe, Restpe]() {
+     *     new scala.PartialFunction[Argtpe, Restpe]() {
      *        def apply(x: Argtpe): Restpe = x match {Cases}
      *        def isDefinedAt(x: Argtpe): scala.Boolean = x match {Cases'}
-     *      }: scala.PartialFunction[Argtpe, +Restpe])
+     *     }
      *  WHERE
      *    case P1 if G1 => E1, ..., Pn if Gn => En) = Cases
      *    Cases' = case P1 if G1 => True, ..., Pn if Gn => True, _ => False
@@ -278,10 +258,6 @@ public class DeSugarize implements Kinds, Modifiers {
 	    make.Template(
 		tree.pos, new Tree[]{constr}, new Tree[]{applyDef, isDefinedAtDef}));
 
-	//Tree result = make.Typed(tree.pos,
-	//    newTree,
-	//    gen.mkType(tree.pos,
-        //        global.definitions.partialFunctionType(targs[0], targs[1])));
 	print(tree, "partialfun", result);
 	return result;
     }
diff --git a/sources/scalac/typechecker/Infer.java b/sources/scalac/typechecker/Infer.java
index d6bfe57384..ab8c98e544 100644
--- a/sources/scalac/typechecker/Infer.java
+++ b/sources/scalac/typechecker/Infer.java
@@ -220,15 +220,7 @@ public class Infer implements Modifiers, Kinds {
     private boolean isWithinBounds(Symbol[] tparams, Type[] targs) {
 	// check that covariant types do not appear in F-bounds.
 	for (int i = 0; i < targs.length; i++) {
-	    if (targs[i].isCovarType()) {
-		for (int j = 0; j < tparams.length; j++)
-		    if (tparams[j].info().contains(tparams[i]))
-			return false;
-	    }
-	}
-	for (int i = 0; i < targs.length; i++) {
-	    if (!targs[i].dropVariance().isSubType(
-		    tparams[i].info().subst(tparams, targs)))
+	    if (!targs[i].isSubType(tparams[i].info().subst(tparams, targs)))
 		return false;
 	}
 	return true;
@@ -458,16 +450,15 @@ public class Infer implements Modifiers, Kinds {
 	return true;
     }
 
-    /** Does given `tparam' occur only covariantly in argument types?
+    /** Does given `tvar' occur only covariantly in argument types `tps' for formal
+     *  type parameetrs `tparams'?
      */
-    private boolean isCovariantArgs(Symbol tparam, Type[] tps) {
+    private boolean isCovariantArgs(Symbol tvar, Type[] tps, Symbol[] tparams) {
 	for (int i = 0; i < tps.length; i++) {
-	    switch (tps[i]) {
-	    case CovarType(Type t):
-		if (!isCovariant(tparam, t)) return false;
-		break;
-	    default:
-		if (tps[i].contains(tparam)) return false;
+	    if ((tparams[i].flags & COVARIANT) != 0) {
+		if (!isCovariant(tvar, tps[i])) return false;
+	    } else {
+		if (tps[i].contains(tvar)) return false;
 	    }
 	}
 	return true;
@@ -483,7 +474,7 @@ public class Infer implements Modifiers, Kinds {
 	case ThisType(Symbol sym):
 	    return true;
 	case TypeRef(Type pre, Symbol sym, Type[] args):
-	    return isCovariant(tparam, pre) && isCovariantArgs(tparam, args);
+	    return isCovariant(tparam, pre) && isCovariantArgs(tparam, args, sym.typeParams());
 	case SingleType(Type pre, Symbol sym):
 	    return !pre.contains(tparam);
 	case CompoundType(Type[] parts, Scope members):
diff --git a/sources/scalac/util/Debug.java b/sources/scalac/util/Debug.java
index 6bb2c75e52..24e087b3bc 100644
--- a/sources/scalac/util/Debug.java
+++ b/sources/scalac/util/Debug.java
@@ -385,12 +385,6 @@ public class DebugType extends DebugAbstractHandler {
             buffer.append(')');
             return;
 
-        case CovarType(Type tp):
-            buffer.append("CovarType(");
-            Debug.append(buffer, tp);
-            buffer.append(')');
-            return;
-
         case LazyType():
             buffer.append("LazyType()");
             return;