/******************************************************************************* | |
* 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; | |
/** | |
* Prefix expression AST node type. | |
* | |
* <pre> | |
* PrefixExpression: | |
* PrefixOperator Expression | |
* </pre> | |
* | |
* @since 2.0 | |
*/ | |
public class PrefixExpression extends Expression { | |
/** | |
* Prefix operators (typesafe enumeration). | |
* <pre> | |
* PrefixOperator: | |
* <b><code>++</code></p> <code>INCREMENT</code> | |
* <b><code>--</code></p> <code>DECREMENT</code> | |
* <b><code>+</code></p> <code>PLUS</code> | |
* <b><code>-</code></p> <code>MINUS</code> | |
* <b><code>~</code></p> <code>COMPLEMENT</code> | |
* <b><code>!</code></p> <code>NOT</code> | |
* </pre> | |
*/ | |
public static class Operator { | |
/** | |
* The token for the operator. | |
*/ | |
private String token; | |
/** | |
* Creates a new prefix 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; | |
} | |
/** Prefix increment "++" operator. */ | |
public static final Operator INCREMENT = new Operator("++");//$NON-NLS-1$ | |
/** Prefix decrement "--" operator. */ | |
public static final Operator DECREMENT = new Operator("--");//$NON-NLS-1$ | |
/** Unary plus "+" operator. */ | |
public static final Operator PLUS = new Operator("+");//$NON-NLS-1$ | |
/** Unary minus "-" operator. */ | |
public static final Operator MINUS = new Operator("-");//$NON-NLS-1$ | |
/** Bitwise complement "~" operator. */ | |
public static final Operator COMPLEMENT = new Operator("~");//$NON-NLS-1$ | |
/** Logical complement complement "!" operator. */ | |
public static final Operator NOT = 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, | |
PLUS, | |
MINUS, | |
COMPLEMENT, | |
NOT, | |
}; | |
for (int i = 0; i < ops.length; i++) { | |
CODES.put(ops[i].toString(), ops[i]); | |
} | |
} | |
/** | |
* Returns the prefix 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 prefix operator, or <code>null</code> if none | |
*/ | |
public static Operator toOperator(String token) { | |
return (Operator) CODES.get(token); | |
} | |
} | |
/** | |
* The operator; defaults to an unspecified prefix operator. | |
*/ | |
private PrefixExpression.Operator operator = | |
PrefixExpression.Operator.PLUS; | |
/** | |
* The operand; lazily initialized; defaults to an unspecified, | |
* but legal, simple name. | |
*/ | |
private Expression operand = null; | |
/** | |
* Creates a new AST node for an prefix 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 | |
*/ | |
PrefixExpression(AST ast) { | |
super(ast); | |
} | |
/* (omit javadoc for this method) | |
* Method declared on ASTNode. | |
*/ | |
public int getNodeType() { | |
return PREFIX_EXPRESSION; | |
} | |
/* (omit javadoc for this method) | |
* Method declared on ASTNode. | |
*/ | |
ASTNode clone(AST target) { | |
PrefixExpression result = new PrefixExpression(target); | |
result.setOperator(getOperator()); | |
result.setOperand((Expression) getOperand().clone(target)); | |
return result; | |
} | |
/* (omit javadoc for this method) | |
* Method declared on ASTNode. | |
*/ | |
public boolean subtreeMatch(ASTMatcher matcher, Object other) { | |
// dispatch to correct overloaded match method | |
return matcher.match(this, other); | |
} | |
/* (omit javadoc for this method) | |
* Method declared on ASTNode. | |
*/ | |
void accept0(ASTVisitor visitor) { | |
boolean visitChildren = visitor.visit(this); | |
if (visitChildren) { | |
// visit children in normal left to right reading order | |
acceptChild(visitor, getOperand()); | |
} | |
visitor.endVisit(this); | |
} | |
/** | |
* Returns the operator of this prefix expression. | |
* | |
* @return the operator | |
*/ | |
public PrefixExpression.Operator getOperator() { | |
return operator; | |
} | |
/** | |
* Sets the operator of this prefix expression. | |
* | |
* @param operator the operator | |
* @exception IllegalArgumentException if the argument is incorrect | |
*/ | |
public void setOperator(PrefixExpression.Operator operator) { | |
if (operator == null) { | |
throw new IllegalArgumentException(); | |
} | |
modifying(); | |
this.operator = operator; | |
} | |
/** | |
* Returns the operand of this prefix 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 prefix expression. | |
* | |
* @param expression the operand expression node | |
* @exception IllegalArgumentException if the node belongs to a different AST | |
* @exception IllegalArgumentException if the node already has a parent | |
* @exception IllegalArgumentException if a cycle in would be created | |
*/ | |
public void setOperand(Expression expression) { | |
if (expression == null) { | |
throw new IllegalArgumentException(); | |
} | |
// a PrefixExpression 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()); | |
} | |
} | |