diff --git a/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithAllVisits.java b/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithAllVisits.java
index 43f47aa..5bc8ad8 100644
--- a/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithAllVisits.java
+++ b/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithAllVisits.java
@@ -27,7 +27,6 @@
 import com.google.gwt.dev.js.ast.JsContinue;
 import com.google.gwt.dev.js.ast.JsDecimalLiteral;
 import com.google.gwt.dev.js.ast.JsDefault;
-import com.google.gwt.dev.js.ast.JsDelete;
 import com.google.gwt.dev.js.ast.JsDoWhile;
 import com.google.gwt.dev.js.ast.JsEmpty;
 import com.google.gwt.dev.js.ast.JsExprStmt;
@@ -101,9 +100,6 @@
   public void endVisit(JsDefault x) {
   }
 
-  public void endVisit(JsDelete x) {
-  }
-
   public void endVisit(JsDoWhile while1) {
   }
 
@@ -239,10 +235,6 @@
     return true;
   }
 
-  public boolean visit(JsDelete x) {
-    return true;
-  }
-
   public boolean visit(JsDoWhile x) {
     return true;
   }
diff --git a/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithEndVisits.java b/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithEndVisits.java
index ca7a5fa..abf78e5 100644
--- a/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithEndVisits.java
+++ b/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithEndVisits.java
@@ -27,7 +27,6 @@
 import com.google.gwt.dev.js.ast.JsContinue;
 import com.google.gwt.dev.js.ast.JsDecimalLiteral;
 import com.google.gwt.dev.js.ast.JsDefault;
-import com.google.gwt.dev.js.ast.JsDelete;
 import com.google.gwt.dev.js.ast.JsDoWhile;
 import com.google.gwt.dev.js.ast.JsEmpty;
 import com.google.gwt.dev.js.ast.JsExprStmt;
@@ -100,9 +99,6 @@
   public void endVisit(JsDefault x) {
   }
 
-  public void endVisit(JsDelete x) {
-  }
-
   public void endVisit(JsDoWhile while1) {
   }
 
diff --git a/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithVisits.java b/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithVisits.java
index 543e3dd..4fd389d 100644
--- a/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithVisits.java
+++ b/dev/core/src/com/google/gwt/dev/js/JsAbstractVisitorWithVisits.java
@@ -27,7 +27,6 @@
 import com.google.gwt.dev.js.ast.JsContinue;
 import com.google.gwt.dev.js.ast.JsDecimalLiteral;
 import com.google.gwt.dev.js.ast.JsDefault;
-import com.google.gwt.dev.js.ast.JsDelete;
 import com.google.gwt.dev.js.ast.JsDoWhile;
 import com.google.gwt.dev.js.ast.JsEmpty;
 import com.google.gwt.dev.js.ast.JsExprStmt;
@@ -112,10 +111,6 @@
     return true;
   }
 
-  public boolean visit(JsDelete x) {
-    return true;
-  }
-
   public boolean visit(JsDoWhile x) {
     return true;
   }
diff --git a/dev/core/src/com/google/gwt/dev/js/JsParser.java b/dev/core/src/com/google/gwt/dev/js/JsParser.java
index a33ae9d..be3fcfb 100644
--- a/dev/core/src/com/google/gwt/dev/js/JsParser.java
+++ b/dev/core/src/com/google/gwt/dev/js/JsParser.java
@@ -27,7 +27,6 @@
 import com.google.gwt.dev.js.ast.JsConditional;
 import com.google.gwt.dev.js.ast.JsContinue;
 import com.google.gwt.dev.js.ast.JsDefault;
-import com.google.gwt.dev.js.ast.JsDelete;
 import com.google.gwt.dev.js.ast.JsDoWhile;
 import com.google.gwt.dev.js.ast.JsExpression;
 import com.google.gwt.dev.js.ast.JsExpressions;
@@ -468,17 +467,15 @@
   private JsNode mapDeleteProp(Node node) throws JsParserException {
     Node from = node.getFirstChild();
     JsExpression to = mapExpression(from);
-    JsDelete toDelete = new JsDelete();
     if (to instanceof JsNameRef) {
-      toDelete.setExpr((JsNameRef) to);
+      return new JsPrefixOperation(JsUnaryOperator.DELETE, to);
     } else if (to instanceof JsArrayAccess) {
-      toDelete.setExpr((JsArrayAccess) to);
+      return new JsPrefixOperation(JsUnaryOperator.DELETE, to);
     } else {
       throw createParserException(
           "'delete' can only operate on property names and array elements",
           from);
     }
-    return toDelete;
   }
 
   private JsStatement mapDoOrWhileStatement(boolean isWhile, Node ifNode)
diff --git a/dev/core/src/com/google/gwt/dev/js/JsPrecedenceVisitor.java b/dev/core/src/com/google/gwt/dev/js/JsPrecedenceVisitor.java
index 5ed8182..1f41312 100644
--- a/dev/core/src/com/google/gwt/dev/js/JsPrecedenceVisitor.java
+++ b/dev/core/src/com/google/gwt/dev/js/JsPrecedenceVisitor.java
@@ -15,7 +15,6 @@
  */
 package com.google.gwt.dev.js;
 
-import com.google.gwt.dev.js.ast.JsAbstractVisitorWithEndVisits;
 import com.google.gwt.dev.js.ast.JsArrayAccess;
 import com.google.gwt.dev.js.ast.JsArrayLiteral;
 import com.google.gwt.dev.js.ast.JsBinaryOperation;
@@ -28,7 +27,6 @@
 import com.google.gwt.dev.js.ast.JsContinue;
 import com.google.gwt.dev.js.ast.JsDecimalLiteral;
 import com.google.gwt.dev.js.ast.JsDefault;
-import com.google.gwt.dev.js.ast.JsDelete;
 import com.google.gwt.dev.js.ast.JsDoWhile;
 import com.google.gwt.dev.js.ast.JsEmpty;
 import com.google.gwt.dev.js.ast.JsExprStmt;
@@ -149,11 +147,6 @@
     throw new RuntimeException("Only expressions have precedence.");
   }
 
-  public boolean visit(JsDelete x) {
-    answer = 14; // not modeled as an operator
-    return false;
-  }
-
   public boolean visit(JsDoWhile x) {
     throw new RuntimeException("Only expressions have precedence.");
   }
diff --git a/dev/core/src/com/google/gwt/dev/js/JsToStringGenerationVisitor.java b/dev/core/src/com/google/gwt/dev/js/JsToStringGenerationVisitor.java
index 9624bf6..b7ad13e 100644
--- a/dev/core/src/com/google/gwt/dev/js/JsToStringGenerationVisitor.java
+++ b/dev/core/src/com/google/gwt/dev/js/JsToStringGenerationVisitor.java
@@ -29,7 +29,6 @@
 import com.google.gwt.dev.js.ast.JsContinue;
 import com.google.gwt.dev.js.ast.JsDecimalLiteral;
 import com.google.gwt.dev.js.ast.JsDefault;
-import com.google.gwt.dev.js.ast.JsDelete;
 import com.google.gwt.dev.js.ast.JsDoWhile;
 import com.google.gwt.dev.js.ast.JsEmpty;
 import com.google.gwt.dev.js.ast.JsExprStmt;
@@ -142,10 +141,20 @@
     JsExpression arg1 = x.getArg1();
     _parenPush(x, arg1, !op.isLeftAssociative());
     arg1.traverse(this);
-    _parenPopOrSpace(x, arg1, !op.isLeftAssociative());
+    boolean needSpace = op.isKeyword() || arg1 instanceof JsPostfixOperation;
+    if (needSpace) {
+      _parenPopOrSpace(x, arg1, !op.isLeftAssociative());
+    } else {
+      _parenPop(x, arg1, !op.isLeftAssociative());
+    }
     p.print(op.getSymbol());
     JsExpression arg2 = x.getArg2();
-    _parenPushOrSpace(x, arg2, op.isLeftAssociative());
+    needSpace = op.isKeyword() || arg2 instanceof JsPrefixOperation;
+    if (needSpace) {
+      _parenPushOrSpace(x, arg2, op.isLeftAssociative());
+    } else {
+      _parenPush(x, arg2, op.isLeftAssociative());
+    }
     arg2.traverse(this);
     _parenPop(x, arg2, op.isLeftAssociative());
     return false;
@@ -297,14 +306,11 @@
 
   public boolean visit(JsDecimalLiteral x) {
     String s = x.getValue();
-    boolean needParens = s.startsWith("-");
-    if (needParens) {
-      _lparen();
+    // TODO: optimize this to only the cases that need it
+    if (s.startsWith("-")) {
+      _space();
     }
     p.print(s);
-    if (needParens) {
-      _rparen();
-    }
     return false;
   }
 
@@ -327,15 +333,6 @@
     return false;
   }
 
-  public boolean visit(JsDelete x) {
-    _delete();
-    JsExpression expr = x.getExpr();
-    _parenPushOrSpace(expr, x, true);
-    expr.traverse(this);
-    _parenPopOrSpace(expr, x, true);
-    return false;
-  }
-
   public boolean visit(JsDoWhile x) {
     _do();
     _nestedPush(x.getBody(), true);
@@ -621,6 +618,9 @@
   public boolean visit(JsPrefixOperation x) {
     JsUnaryOperator op = x.getOperator();
     p.print(op.getSymbol());
+    if (op.isKeyword()) {
+      _space();
+    }
     JsExpression arg = x.getArg();
     // unary operators always associate correctly (I think)
     _parenPush(x, arg, true);
@@ -654,9 +654,9 @@
 
   public boolean visit(JsReturn x) {
     _return();
-    _space();
     JsExpression expr = x.getExpr();
     if (expr != null) {
+      _space();
       expr.traverse(this);
     }
     return false;
@@ -930,7 +930,6 @@
     return doPop;
   }
 
-  // TODO(later): we often leave a space when we don't need to
   private boolean _parenPush(JsExpression parent, JsExpression child,
       boolean wrongAssoc) {
     boolean doPush = _parenCalc(parent, child, wrongAssoc);
@@ -957,6 +956,7 @@
     return doPush;
   }
 
+  // TODO(later): we often leave a space when we don't need to
   private boolean _parenPushOrSpace(JsExpression parent, JsExpression child,
       boolean wrongAssoc) {
     boolean doPush = _parenCalc(parent, child, wrongAssoc);
@@ -1040,8 +1040,9 @@
   private void _while() {
     p.print(CHARS_WHILE);
   }
+
   // CHECKSTYLE_NAMING_ON
-  
+
   private void indent() {
     p.indentIn();
   }
diff --git a/dev/core/src/com/google/gwt/dev/js/ast/JsAbstractVisitorWithEndVisits.java b/dev/core/src/com/google/gwt/dev/js/ast/JsAbstractVisitorWithEndVisits.java
deleted file mode 100644
index 45a0000..0000000
--- a/dev/core/src/com/google/gwt/dev/js/ast/JsAbstractVisitorWithEndVisits.java
+++ /dev/null
@@ -1,148 +0,0 @@
-/*
- * Copyright 2006 Google Inc.
- * 
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not
- * use this file except in compliance with the License. You may obtain a copy of
- * the License at
- * 
- * http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations under
- * the License.
- */
-package com.google.gwt.dev.js.ast;
-
-/**
- * Implements stubs for the <code>endVisit()</code> interface methods.
- */
-public abstract class JsAbstractVisitorWithEndVisits implements JsVisitor {
-
-  public void endVisit(JsArrayAccess x) {
-  }
-
-  public void endVisit(JsArrayLiteral x) {
-  }
-
-  public void endVisit(JsBinaryOperation x) {
-  }
-
-  public void endVisit(JsBlock x) {
-  }
-
-  public void endVisit(JsBooleanLiteral x) {
-  }
-
-  public void endVisit(JsBreak x) {
-  }
-
-  public void endVisit(JsCase x) {
-  }
-
-  public void endVisit(JsCatch x) {
-  }
-
-  public void endVisit(JsConditional x) {
-  }
-
-  public void endVisit(JsContinue x) {
-  }
-
-  public void endVisit(JsDecimalLiteral x) {
-  }
-
-  public void endVisit(JsDefault x) {
-  }
-
-  public void endVisit(JsDelete x) {
-  }
-
-  public void endVisit(JsDoWhile while1) {
-  }
-
-  public void endVisit(JsEmpty x) {
-  }
-
-  public void endVisit(JsExprStmt x) {
-  }
-
-  public void endVisit(JsFor x) {
-  }
-
-  public void endVisit(JsForIn x) {
-  }
-
-  public void endVisit(JsFunction x) {
-  }
-
-  public void endVisit(JsIf x) {
-  }
-
-  public void endVisit(JsIntegralLiteral x) {
-  }
-
-  public void endVisit(JsInvocation x) {
-  }
-
-  public void endVisit(JsLabel x) {
-  }
-
-  public void endVisit(JsNameRef x) {
-  }
-
-  public void endVisit(JsNew x) {
-  }
-
-  public void endVisit(JsNullLiteral x) {
-  }
-
-  public void endVisit(JsObjectLiteral x) {
-  }
-
-  public void endVisit(JsParameter x) {
-  }
-
-  public void endVisit(JsParameters x) {
-  }
-
-  public void endVisit(JsPostfixOperation x) {
-  }
-
-  public void endVisit(JsPrefixOperation x) {
-  }
-
-  public void endVisit(JsProgram x) {
-  }
-
-  public void endVisit(JsPropertyInitializer x) {
-  }
-
-  public void endVisit(JsRegExp x) {
-  }
-
-  public void endVisit(JsReturn x) {
-  }
-
-  public void endVisit(JsStringLiteral x) {
-  }
-
-  public void endVisit(JsSwitch x) {
-  }
-
-  public void endVisit(JsThisRef x) {
-  }
-
-  public void endVisit(JsThrow x) {
-  }
-
-  public void endVisit(JsTry x) {
-  }
-
-  public void endVisit(JsVars x) {
-  }
-
-  public void endVisit(JsWhile x) {
-  }
-}
diff --git a/dev/core/src/com/google/gwt/dev/js/ast/JsBinaryOperator.java b/dev/core/src/com/google/gwt/dev/js/ast/JsBinaryOperator.java
index 2173aff..98453ce 100644
--- a/dev/core/src/com/google/gwt/dev/js/ast/JsBinaryOperator.java
+++ b/dev/core/src/com/google/gwt/dev/js/ast/JsBinaryOperator.java
@@ -46,7 +46,7 @@
   public static final JsBinaryOperator GT = create(">", 10, LEFT_INFIX);
   public static final JsBinaryOperator GTE = create(">=", 10, LEFT_INFIX);
   public static final JsBinaryOperator INSTANCEOF = create("instanceof", 10,
-    LEFT_INFIX);
+      LEFT_INFIX);
   public static final JsBinaryOperator INOP = create("in", 10, LEFT_INFIX);
 
   public static final JsBinaryOperator EQ = create("==", 9, LEFT_INFIX);
@@ -81,12 +81,18 @@
   public static final JsBinaryOperator ASG_BIT_XOR = create("^=", 2, INFIX);
 
   public static final JsBinaryOperator COMMA = create(",", 1, LEFT_INFIX);
-  
+
   private static JsBinaryOperator create(String symbol, int precedence, int mask) {
     JsBinaryOperator op = new JsBinaryOperator(symbol, precedence, mask);
     return op;
   }
+
   private JsBinaryOperator(String symbol, int precedence, int mask) {
     super(symbol, precedence, mask);
   }
+
+  public boolean isKeyword() {
+    return this == INSTANCEOF || this == INOP;
+  }
+
 }
diff --git a/dev/core/src/com/google/gwt/dev/js/ast/JsDelete.java b/dev/core/src/com/google/gwt/dev/js/ast/JsDelete.java
deleted file mode 100644
index 8390295..0000000
--- a/dev/core/src/com/google/gwt/dev/js/ast/JsDelete.java
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright 2006 Google Inc.
- * 
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not
- * use this file except in compliance with the License. You may obtain a copy of
- * the License at
- * 
- * http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations under
- * the License.
- */
-package com.google.gwt.dev.js.ast;
-
-/**
- * Represents the JavaScript delete statement.
- */
-public class JsDelete extends JsExpression {
-
-  private JsExpression toDelete;
-
-  public JsDelete() {
-  }
-
-  public JsExpression getExpr() {
-    return toDelete;
-  }
-
-  public void setExpr(JsArrayAccess arrayElem) {
-    this.toDelete = arrayElem;
-  }
-
-  public void setExpr(JsNameRef nameRef) {
-    this.toDelete = nameRef;
-  }
-
-  public void traverse(JsVisitor v) {
-    if (v.visit(this)) {
-      toDelete.traverse(v);
-    }
-    v.endVisit(this);
-  }
-}
diff --git a/dev/core/src/com/google/gwt/dev/js/ast/JsOperator.java b/dev/core/src/com/google/gwt/dev/js/ast/JsOperator.java
index 5fd7aac..dc04e21 100644
--- a/dev/core/src/com/google/gwt/dev/js/ast/JsOperator.java
+++ b/dev/core/src/com/google/gwt/dev/js/ast/JsOperator.java
@@ -18,7 +18,7 @@
 /**
  * A JavaScript operator.
  */
-public class JsOperator {
+public abstract class JsOperator {
 
   protected static final int LEFT = 0x01;
   protected static final int INFIX = 0x02;
@@ -45,6 +45,8 @@
     return symbol;
   }
 
+  public abstract boolean isKeyword();
+
   public boolean isLeftAssociative() {
     return (mask & LEFT) != 0;
   }
diff --git a/dev/core/src/com/google/gwt/dev/js/ast/JsUnaryOperator.java b/dev/core/src/com/google/gwt/dev/js/ast/JsUnaryOperator.java
index c5c0ea2..7c17de9 100644
--- a/dev/core/src/com/google/gwt/dev/js/ast/JsUnaryOperator.java
+++ b/dev/core/src/com/google/gwt/dev/js/ast/JsUnaryOperator.java
@@ -28,12 +28,9 @@
   public static final JsUnaryOperator NOT = create("!", 14, PREFIX);
   public static final JsUnaryOperator DEC = create("--", 14, POSTFIX | PREFIX);
   public static final JsUnaryOperator INC = create("++", 14, POSTFIX | PREFIX);
-// 'delete' is modeled as JsDelete
-//  public static final JsUnaryOperator DELETE = create("delete", 14, PREFIX);
-  // TODO(later): Keep the trailing space on "typeof" until jsgen is better
-  public static final JsUnaryOperator TYPEOF = create("typeof ", 14, PREFIX);
-  // TODO(later): Keep the trailing space on "void" until jsgen is better
-  public static final JsUnaryOperator VOID = create("void ", 14, PREFIX);
+  public static final JsUnaryOperator DELETE = create("delete", 14, PREFIX);
+  public static final JsUnaryOperator TYPEOF = create("typeof", 14, PREFIX);
+  public static final JsUnaryOperator VOID = create("void", 14, PREFIX);
 
   private static JsUnaryOperator create(String symbol, int precedence, int mask) {
     JsUnaryOperator op = new JsUnaryOperator(symbol, precedence, mask);
@@ -43,4 +40,8 @@
   private JsUnaryOperator(String symbol, int precedence, int mask) {
     super(symbol, precedence, mask);
   }
+
+  public boolean isKeyword() {
+    return this == DELETE || this == TYPEOF || this == VOID;
+  }
 }
diff --git a/dev/core/src/com/google/gwt/dev/js/ast/JsVisitor.java b/dev/core/src/com/google/gwt/dev/js/ast/JsVisitor.java
index c03ff52..df4ebee 100644
--- a/dev/core/src/com/google/gwt/dev/js/ast/JsVisitor.java
+++ b/dev/core/src/com/google/gwt/dev/js/ast/JsVisitor.java
@@ -44,8 +44,6 @@
 
   void endVisit(JsDefault x);
 
-  void endVisit(JsDelete x);
-
   void endVisit(JsDoWhile while1);
 
   void endVisit(JsEmpty x);
@@ -128,8 +126,6 @@
 
   boolean visit(JsDefault x);
 
-  boolean visit(JsDelete x);
-
   boolean visit(JsDoWhile x);
 
   boolean visit(JsEmpty x);