/******************************************************************************* | |
* Copyright (c) 2001 International Business Machines Corp. and others. | |
* All rights reserved. This program and the accompanying materials | |
* are made available under the terms of the Common Public License v0.5 | |
* which accompanies this distribution, and is available at | |
* http://www.eclipse.org/legal/cpl-v05.html | |
* | |
* Contributors: | |
* IBM Corporation - initial API and implementation | |
******************************************************************************/ | |
package org.eclipse.jdt.core.dom; | |
import java.util.HashMap; | |
import java.util.Map; | |
/** | |
* Postfix expression AST node type. | |
* | |
* <pre> | |
* PostfixExpression: | |
* Expression PostfixOperator | |
* </pre> | |
* | |
* @since 2.0 | |
*/ | |
public class PostfixExpression extends Expression { | |
/** | |
* Postfix operators (typesafe enumeration). | |
* <pre> | |
* PostfixOperator: | |
* <b><code>++</code></p> <code>INCREMENT</code> | |
* <b><code>--</code></p> <code>DECREMENT</code> | |
* </pre> | |
*/ | |
public static class Operator { | |
/** | |
* The token for the operator. | |
*/ | |
private String token; | |
/** | |
* Creates a new postfix operator with the given token. | |
* <p> | |
* Note: this constructor is private. The only instances | |
* ever created are the ones for the standard operators. | |
* </p> | |
* | |
* @param token the character sequence for the operator | |
*/ | |
private Operator(String token) { | |
this.token = token; | |
} | |
/** | |
* Returns the character sequence for the operator. | |
* | |
* @return the character sequence for the operator | |
*/ | |
public String toString() { | |
return token; | |
} | |
/** Postfix increment "++" operator. */ | |
public static final Operator INCREMENT = new Operator("++");//$NON-NLS-1$ | |
/** Postfix decrement "--" operator. */ | |
public static final Operator DECREMENT = new Operator("--");//$NON-NLS-1$ | |
/** | |
* Map from token to operator (key type: <code>String</code>; | |
* value type: <code>Operator</code>). | |
*/ | |
private static final Map CODES; | |
static { | |
CODES = new HashMap(20); | |
Operator[] ops = { | |
INCREMENT, | |
DECREMENT, | |
}; | |
for (int i = 0; i < ops.length; i++) { | |
CODES.put(ops[i].toString(), ops[i]); | |
} | |
} | |
/** | |
* Returns the postfix operator corresponding to the given string, | |
* or <code>null</code> if none. | |
* <p> | |
* <code>toOperator</code> is the converse of <code>toString</code>: | |
* that is, <code>Operator.toOperator(op.toString()) == op</code> for | |
* all operators <code>op</code>. | |
* </p> | |
* | |
* @param token the character sequence for the operator | |
* @return the postfix operator, or <code>null</code> if none | |
*/ | |
public static Operator toOperator(String token) { | |
return (Operator) CODES.get(token); | |
} | |
} | |
/** | |
* The operator; defaults to an unspecified postfix operator. | |
*/ | |
private PostfixExpression.Operator operator = | |
PostfixExpression.Operator.INCREMENT; | |
/** | |
* The operand; lazily initialized; defaults to an unspecified, | |
* but legal, simple name. | |
*/ | |
private Expression operand = null; | |
/** | |
* Creates a new AST node for an postfix expression owned by the given | |
* AST. By default, the node has unspecified (but legal) operator and | |
* operand. | |
* | |
* @param ast the AST that is to own this node | |
*/ | |
PostfixExpression(AST ast) { | |
super(ast); | |
} | |
/* (omit javadoc for this method) | |
* Method declared on ASTNode. | |
*/ | |
ASTNode clone(AST target) { | |
PostfixExpression result = new PostfixExpression(target); | |
result.setOperator(getOperator()); | |
result.setOperand((Expression) getOperand().clone(target)); | |
return result; | |
} | |
/* (omit javadoc for this method) | |
* Method declared on ASTNode. | |
*/ | |
boolean equalSubtrees(Object other) { | |
if (!(other instanceof PostfixExpression)) { | |
return false; | |
} | |
PostfixExpression o = (PostfixExpression) other; | |
return | |
(getOperator().equals(o.getOperator()) | |
&& ASTNode.equalNodes(getOperand(), o.getOperand())); | |
} | |
/* (omit javadoc for this method) | |
* Method declared on ASTNode. | |
*/ | |
void accept0(ASTVisitor visitor) { | |
boolean visitChildren = visitor.visit(this); | |
if (visitChildren) { | |
acceptChild(visitor, getOperand()); | |
} | |
visitor.endVisit(this); | |
} | |
/** | |
* Returns the operator of this postfix expression. | |
* | |
* @return the operator | |
*/ | |
public PostfixExpression.Operator getOperator() { | |
return operator; | |
} | |
/** | |
* Sets the operator of this postfix expression. | |
* | |
* @param operator the operator | |
* @exception $precondition-violation:invalid-argument$ | |
*/ | |
public void setOperator(PostfixExpression.Operator operator) { | |
if (operator == null) { | |
throw new IllegalArgumentException(); | |
} | |
modifying(); | |
this.operator = operator; | |
} | |
/** | |
* Returns the operand of this postfix expression. | |
* | |
* @return the operand expression node | |
*/ | |
public Expression getOperand() { | |
if (operand == null) { | |
// lazy initialize - use setter to ensure parent link set too | |
setOperand(new SimpleName(getAST())); | |
} | |
return operand; | |
} | |
/** | |
* Sets the operand of this postfix expression. | |
* | |
* @param expression the operand expression node | |
* @exception $precondition-violation:different-ast$ | |
* @exception $precondition-violation:not-unparented$ | |
* @exception $postcondition-violation:ast-cycle$ | |
*/ | |
public void setOperand(Expression expression) { | |
if (expression == null) { | |
throw new IllegalArgumentException(); | |
} | |
// a PostfixExpression may occur inside a Expression - must check cycles | |
replaceChild(this.operand, expression, true); | |
this.operand = expression; | |
} | |
/* (omit javadoc for this method) | |
* Method declared on ASTNode. | |
*/ | |
int memSize() { | |
// treat Operator as free | |
return BASE_NODE_SIZE + 2 * 4; | |
} | |
/* (omit javadoc for this method) | |
* Method declared on ASTNode. | |
*/ | |
int treeSize() { | |
return | |
memSize() | |
+ (operand == null ? 0 : getOperand().treeSize()); | |
} | |
} |