simplify AST

src/com/google/dart/compiler/backend/js/ast/CanBooleanEval.java

@@ -1,13 +0,0 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-package com.google.dart.compiler.backend.js.ast;
-
-/**
- * An interface that describes the boolean evaluation of an expression.
- */
-public interface CanBooleanEval {
-    boolean isBooleanFalse();
-    boolean isBooleanTrue();
-}

src/com/google/dart/compiler/backend/js/ast/ChameleonJsExpression.java

@@ -14,21 +14,6 @@ public class ChameleonJsExpression implements JsExpression {
         this.expression = expression;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        return expression.hasSideEffects();
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return expression.isDefinitelyNotNull();
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return expression.isDefinitelyNull();
-    }
-
     @Override
     public boolean isLeaf() {
         return expression.isLeaf();

src/com/google/dart/compiler/backend/js/ast/JsArrayAccess.java

@@ -28,21 +28,6 @@ public final class JsArrayAccess extends JsExpressionImpl {
         return indexExpression;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        return arrayExpression.hasSideEffects() || indexExpression.hasSideEffects();
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return false;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return false;
-    }
-
     public void setArrayExpression(JsExpression arrayExpression) {
         this.arrayExpression = arrayExpression;
     }

src/com/google/dart/compiler/backend/js/ast/JsArrayLiteral.java

@@ -26,36 +26,6 @@ public final class JsArrayLiteral extends JsLiteral {
         return expressions;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        for (JsExpression expr : expressions) {
-            if (expr.hasSideEffects()) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    @Override
-    public boolean isBooleanFalse() {
-        return false;
-    }
-
-    @Override
-    public boolean isBooleanTrue() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return false;
-    }
-
     @Override
     public void accept(JsVisitor v, JsContext context) {
         v.visitArray(this, context);

src/com/google/dart/compiler/backend/js/ast/JsBinaryOperation.java

@@ -33,38 +33,6 @@ public final class JsBinaryOperation extends JsExpressionImpl {
         return op;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        return op.isAssignment() || arg1.hasSideEffects() || arg2.hasSideEffects();
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        // Precarious coding, but none of these can have null results.
-        if (op.getPrecedence() > 5) {
-            return true;
-        }
-        if (op == JsBinaryOperator.OR) {
-            if (arg1 instanceof CanBooleanEval) {
-                if (((CanBooleanEval) arg1).isBooleanTrue()) {
-                    assert arg1.isDefinitelyNotNull();
-                    return true;
-                }
-            }
-        }
-        // AND and OR can return nulls
-        if (op.isAssignment()) {
-            return op != JsBinaryOperator.ASG || arg2.isDefinitelyNotNull();
-        }
-
-        return op == JsBinaryOperator.COMMA && arg2.isDefinitelyNotNull();
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return op == JsBinaryOperator.AND && arg1.isDefinitelyNull();
-    }
-
     @Override
     public void accept(JsVisitor v, JsContext context) {
         v.visitBinaryExpression(this, context);

src/com/google/dart/compiler/backend/js/ast/JsConditional.java

@@ -30,21 +30,6 @@ public final class JsConditional extends JsExpressionImpl {
         return thenExpression;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        return testExpression.hasSideEffects() || thenExpression.hasSideEffects() || elseExpression.hasSideEffects();
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return thenExpression.isDefinitelyNotNull() && elseExpression.isDefinitelyNotNull();
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return thenExpression.isDefinitelyNull() && elseExpression.isDefinitelyNull();
-    }
-
     public void setElseExpression(JsExpression elseExpression) {
         this.elseExpression = elseExpression;
     }

src/com/google/dart/compiler/backend/js/ast/JsDocComment.java

@@ -26,19 +26,4 @@ public class JsDocComment extends JsExpressionImpl {
     public void accept(JsVisitor v, JsContext context) {
         v.visitDocComment(this, context);
     }
-
-    @Override
-    public boolean hasSideEffects() {
-        return false;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return false;
-    }
 }

src/com/google/dart/compiler/backend/js/ast/JsExpression.java

@@ -3,21 +3,6 @@ package com.google.dart.compiler.backend.js.ast;
 import com.google.dart.compiler.common.HasSourceInfo;
 
 public interface JsExpression extends JsNode, HasSourceInfo {
-    /**
-     * Determines whether the expression can cause side effects.
-     */
-    boolean hasSideEffects();
-
-    /**
-     * True if the target expression is definitely not null.
-     */
-    boolean isDefinitelyNotNull();
-
-    /**
-     * True if the target expression is definitely null.
-     */
-    boolean isDefinitelyNull();
-
     boolean isLeaf();
 
     JsStatement makeStmt();

src/com/google/dart/compiler/backend/js/ast/JsFunction.java

@@ -55,32 +55,6 @@ public final class JsFunction extends JsLiteral implements HasName {
         return scope;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        // If there's a name, the name is assigned to.
-        return name != null;
-    }
-
-    @Override
-    public boolean isBooleanFalse() {
-        return false;
-    }
-
-    @Override
-    public boolean isBooleanTrue() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return false;
-    }
-
     public void setBody(JsBlock body) {
         this.body = body;
     }

src/com/google/dart/compiler/backend/js/ast/JsInvocation.java

@@ -47,21 +47,6 @@ public final class JsInvocation extends JsExpressionImpl.JsExpressionHasArgument
         return qualifier;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return false;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return false;
-    }
-
     public void setQualifier(JsExpression qualifier) {
         this.qualifier = qualifier;
     }

src/com/google/dart/compiler/backend/js/ast/JsLiteral.java

@@ -4,7 +4,7 @@
 
 package com.google.dart.compiler.backend.js.ast;
 
-public abstract class JsLiteral extends JsExpressionImpl implements CanBooleanEval {
+public abstract class JsLiteral extends JsExpressionImpl {
     public static final JsValueLiteral THIS = new JsThisRef();
     public static final JsNameRef UNDEFINED = new JsNameRef("undefined");
 
@@ -22,26 +22,6 @@ public abstract class JsLiteral extends JsExpressionImpl implements CanBooleanEv
             super();
         }
 
-        @Override
-        public boolean isBooleanFalse() {
-            return false;
-        }
-
-        @Override
-        public boolean isBooleanTrue() {
-            return true;
-        }
-
-        @Override
-        public boolean isDefinitelyNotNull() {
-            return true;
-        }
-
-        @Override
-        public boolean isDefinitelyNull() {
-            return false;
-        }
-
         @Override
         public void accept(JsVisitor v, JsContext context) {
             v.visitThis(this, context);
@@ -60,26 +40,6 @@ public abstract class JsLiteral extends JsExpressionImpl implements CanBooleanEv
         return value;
       }
 
-      @Override
-      public boolean isBooleanFalse() {
-        return !value;
-      }
-
-      @Override
-      public boolean isBooleanTrue() {
-        return value;
-      }
-
-      @Override
-      public boolean isDefinitelyNotNull() {
-        return true;
-      }
-
-      @Override
-      public boolean isDefinitelyNull() {
-        return false;
-      }
-
       @Override
       public void accept(JsVisitor v, JsContext context) {
         v.visitBoolean(this, context);
@@ -93,11 +53,6 @@ public abstract class JsLiteral extends JsExpressionImpl implements CanBooleanEv
         protected JsValueLiteral() {
         }
 
-        @Override
-        public final boolean hasSideEffects() {
-            return false;
-        }
-
         @Override
         public final boolean isLeaf() {
             return true;

src/com/google/dart/compiler/backend/js/ast/JsNameRef.java

@@ -9,7 +9,7 @@ import com.google.dart.compiler.common.Symbol;
 /**
  * Represents a JavaScript expression that references a name.
  */
-public final class JsNameRef extends JsExpressionImpl implements CanBooleanEval, HasName {
+public final class JsNameRef extends JsExpressionImpl implements HasName {
     private String ident;
     private JsName name;
     private JsExpression qualifier;
@@ -54,31 +54,6 @@ public final class JsNameRef extends JsExpressionImpl implements CanBooleanEval,
         return qualifier;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        return qualifier != null && (!qualifier.isDefinitelyNotNull() || qualifier.hasSideEffects());
-    }
-
-    @Override
-    public boolean isBooleanFalse() {
-        return isDefinitelyNull();
-    }
-
-    @Override
-    public boolean isBooleanTrue() {
-        return false;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return false;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return name != null && (JsLiteral.UNDEFINED.getName() == name);
-    }
-
     @Override
     public boolean isLeaf() {
         return qualifier == null;

src/com/google/dart/compiler/backend/js/ast/JsNew.java

@@ -24,23 +24,6 @@ public final class JsNew extends JsExpressionImpl.JsExpressionHasArguments {
         return constructorExpression;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        // Sadly, in JS it can be!
-        // TODO: analysis could probably determine most instances cannot be null.
-        return false;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return false;
-    }
-
     @Override
     public void accept(JsVisitor v, JsContext context) {
         v.visitNew(this, context);

src/com/google/dart/compiler/backend/js/ast/JsNullLiteral.java

@@ -8,26 +8,6 @@ public final class JsNullLiteral extends JsLiteral.JsValueLiteral {
     JsNullLiteral() {
     }
 
-    @Override
-    public boolean isBooleanFalse() {
-        return true;
-    }
-
-    @Override
-    public boolean isBooleanTrue() {
-        return false;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return false;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return true;
-    }
-
     @Override
     public void accept(JsVisitor v, JsContext context) {
         v.visitNull(this, context);

src/com/google/dart/compiler/backend/js/ast/JsNumberLiteral.java

@@ -5,16 +5,6 @@
 package com.google.dart.compiler.backend.js.ast;
 
 public abstract class JsNumberLiteral extends JsLiteral.JsValueLiteral {
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return false;
-    }
-
     public static final class JsDoubleLiteral extends JsNumberLiteral {
         public final double value;
 
@@ -22,16 +12,6 @@ public abstract class JsNumberLiteral extends JsLiteral.JsValueLiteral {
             this.value = value;
         }
 
-        @Override
-        public boolean isBooleanFalse() {
-            return value == 0.0;
-        }
-
-        @Override
-        public boolean isBooleanTrue() {
-            return value != 0.0;
-        }
-
         @Override
         public void accept(JsVisitor v, JsContext context) {
             v.visitDouble(this, context);
@@ -49,16 +29,6 @@ public abstract class JsNumberLiteral extends JsLiteral.JsValueLiteral {
             this.value = value;
         }
 
-        @Override
-        public boolean isBooleanFalse() {
-            return value == 0;
-        }
-
-        @Override
-        public boolean isBooleanTrue() {
-            return value != 0;
-        }
-
         @Override
         public void accept(JsVisitor v, JsContext context) {
             v.visitInt(this, context);

src/com/google/dart/compiler/backend/js/ast/JsObjectLiteral.java

@@ -38,36 +38,6 @@ public final class JsObjectLiteral extends JsLiteral {
         return properties;
     }
 
-    @Override
-    public boolean hasSideEffects() {
-        for (JsPropertyInitializer prop : properties) {
-            if (prop.hasSideEffects()) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    @Override
-    public boolean isBooleanFalse() {
-        return false;
-    }
-
-    @Override
-    public boolean isBooleanTrue() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return false;
-    }
-
     @Override
     public void accept(JsVisitor v, JsContext context) {
         v.visitObjectLiteral(this, context);

src/com/google/dart/compiler/backend/js/ast/JsPostfixOperation.java

@@ -13,16 +13,6 @@ public final class JsPostfixOperation extends JsUnaryOperation {
     super(op, arg);
   }
 
-  @Override
-  public boolean isDefinitelyNotNull() {
-    return true;
-  }
-
-  @Override
-  public boolean isDefinitelyNull() {
-    return false;
-  }
-
   @Override
   public void accept(JsVisitor v, JsContext context) {
     v.visitPostfixOperation(this, context);

src/com/google/dart/compiler/backend/js/ast/JsPrefixOperation.java

@@ -4,8 +4,7 @@
 
 package com.google.dart.compiler.backend.js.ast;
 
-public final class JsPrefixOperation extends JsUnaryOperation implements CanBooleanEval {
+public final class JsPrefixOperation extends JsUnaryOperation {
-
     public JsPrefixOperation(JsUnaryOperator op) {
         this(op, null);
     }
@@ -14,37 +13,6 @@ public final class JsPrefixOperation extends JsUnaryOperation implements CanBool
         super(op, arg);
     }
 
-    @Override
-    public boolean isBooleanFalse() {
-        if (getOperator() == JsUnaryOperator.VOID) {
-            return true;
-        }
-        if (getOperator() == JsUnaryOperator.NOT && getArg() instanceof CanBooleanEval) {
-            CanBooleanEval eval = (CanBooleanEval) getArg();
-            return eval.isBooleanTrue();
-        }
-        return false;
-    }
-
-    @Override
-    public boolean isBooleanTrue() {
-        if (getOperator() == JsUnaryOperator.NOT && getArg() instanceof CanBooleanEval) {
-            CanBooleanEval eval = (CanBooleanEval) getArg();
-            return eval.isBooleanFalse();
-        }
-        return getOperator() == JsUnaryOperator.TYPEOF;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return getOperator() == JsUnaryOperator.TYPEOF || getOperator() != JsUnaryOperator.VOID;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return getOperator() == JsUnaryOperator.VOID;
-    }
-
     @Override
     public void accept(JsVisitor v, JsContext context) {
         v.visitPrefixOperation(this, context);

src/com/google/dart/compiler/backend/js/ast/JsPropertyInitializer.java

@@ -30,10 +30,6 @@ public class JsPropertyInitializer extends SourceInfoAwareJsNode {
         return valueExpr;
     }
 
-    public boolean hasSideEffects() {
-        return labelExpr.hasSideEffects() || valueExpr.hasSideEffects();
-    }
-
     public void setValueExpr(@NotNull JsExpression valueExpr) {
         this.valueExpr = valueExpr;
     }

src/com/google/dart/compiler/backend/js/ast/JsRegExp.java

@@ -22,26 +22,6 @@ public final class JsRegExp extends JsLiteral.JsValueLiteral {
         return pattern;
     }
 
-    @Override
-    public boolean isBooleanFalse() {
-        return false;
-    }
-
-    @Override
-    public boolean isBooleanTrue() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNotNull() {
-        return true;
-    }
-
-    @Override
-    public boolean isDefinitelyNull() {
-        return false;
-    }
-
     public void setFlags(String suffix) {
         flags = suffix;
     }

src/com/google/dart/compiler/backend/js/ast/JsStringLiteral.java

@@ -4,9 +4,6 @@
 
 package com.google.dart.compiler.backend.js.ast;
 
-/**
- * A JavaScript string literal expression.
- */
 public final class JsStringLiteral extends JsLiteral.JsValueLiteral {
 
   private final String value;
@@ -20,26 +17,6 @@ public final class JsStringLiteral extends JsLiteral.JsValueLiteral {
     return value;
   }
 
-  @Override
-  public boolean isBooleanFalse() {
-    return value.length() == 0;
-  }
-
-  @Override
-  public boolean isBooleanTrue() {
-    return value.length() != 0;
-  }
-
-  @Override
-  public boolean isDefinitelyNotNull() {
-    return true;
-  }
-
-  @Override
-  public boolean isDefinitelyNull() {
-    return false;
-  }
-
   @Override
   public void accept(JsVisitor v, JsContext context) {
     v.visitString(this, context);

src/com/google/dart/compiler/backend/js/ast/JsUnaryOperation.java

@@ -28,11 +28,6 @@ public abstract class JsUnaryOperation extends JsExpressionImpl {
         return op;
     }
 
-    @Override
-    public final boolean hasSideEffects() {
-        return op.isModifying() || arg.hasSideEffects();
-    }
-
     public void setArg(JsExpression arg) {
         this.arg = arg;
     }