/******************************************************************************* * Copyright (c) 2000, 2008 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package net.sourceforge.phpdt.core.dom; import java.util.ArrayList; import java.util.List; /** * If statement AST node type. *
* IfStatement: * if ( Expression ) Statement [ else Statement] ** * @since 2.0 * @noinstantiate This class is not intended to be instantiated by clients. */ public class IfStatement extends Statement { /** * The "expression" structural property of this node type. * @since 3.0 */ public static final ChildPropertyDescriptor EXPRESSION_PROPERTY = new ChildPropertyDescriptor(IfStatement.class, "expression", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$ /** * The "thenStatement" structural property of this node type. * @since 3.0 */ public static final ChildPropertyDescriptor THEN_STATEMENT_PROPERTY = new ChildPropertyDescriptor(IfStatement.class, "thenStatement", Statement.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$ /** * The "elseStatement" structural property of this node type. * @since 3.0 */ public static final ChildPropertyDescriptor ELSE_STATEMENT_PROPERTY = new ChildPropertyDescriptor(IfStatement.class, "elseStatement", Statement.class, OPTIONAL, CYCLE_RISK); //$NON-NLS-1$ /** * A list of property descriptors (element type: * {@link StructuralPropertyDescriptor}), * or null if uninitialized. */ private static final List PROPERTY_DESCRIPTORS; static { List properyList = new ArrayList(4); createPropertyList(IfStatement.class, properyList); addProperty(EXPRESSION_PROPERTY, properyList); addProperty(THEN_STATEMENT_PROPERTY, properyList); addProperty(ELSE_STATEMENT_PROPERTY, properyList); PROPERTY_DESCRIPTORS = reapPropertyList(properyList); } /** * Returns a list of structural property descriptors for this node type. * Clients must not modify the result. * * @param apiLevel the API level; one of the *
AST.JLS*
constants
* @return a list of property descriptors (element type:
* {@link StructuralPropertyDescriptor})
* @since 3.0
*/
public static List propertyDescriptors(int apiLevel) {
return PROPERTY_DESCRIPTORS;
}
/**
* The expression; lazily initialized; defaults to an unspecified, but
* legal, expression.
*/
private Expression expression = null;
/**
* The then statement; lazily initialized; defaults to an unspecified, but
* legal, statement.
*/
private Statement thenStatement = null;
/**
* The else statement; null
for none; defaults to none.
*/
private Statement optionalElseStatement = null;
/**
* Creates a new unparented if statement node owned by the given
* AST. By default, the expresssion is unspecified,
* but legal, the then statement is an empty block, and there is no else
* statement.
* * N.B. This constructor is package-private. *
* * @param ast the AST that is to own this node */ IfStatement(AST ast) { super(ast); } /* (omit javadoc for this method) * Method declared on ASTNode. */ final List internalStructuralPropertiesForType(int apiLevel) { return propertyDescriptors(apiLevel); } /* (omit javadoc for this method) * Method declared on ASTNode. */ final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) { if (property == EXPRESSION_PROPERTY) { if (get) { return getExpression(); } else { setExpression((Expression) child); return null; } } if (property == THEN_STATEMENT_PROPERTY) { if (get) { return getThenStatement(); } else { setThenStatement((Statement) child); return null; } } if (property == ELSE_STATEMENT_PROPERTY) { if (get) { return getElseStatement(); } else { setElseStatement((Statement) child); return null; } } // allow default implementation to flag the error return super.internalGetSetChildProperty(property, get, child); } /* (omit javadoc for this method) * Method declared on ASTNode. */ final int getNodeType0() { return IF_STATEMENT; } /* (omit javadoc for this method) * Method declared on ASTNode. */ ASTNode clone0(AST target) { IfStatement result = new IfStatement(target); result.setSourceRange(this.getStartPosition(), this.getLength()); result.copyLeadingComment(this); result.setExpression((Expression) getExpression().clone(target)); result.setThenStatement( (Statement) getThenStatement().clone(target)); result.setElseStatement( (Statement) ASTNode.copySubtree(target, getElseStatement())); return result; } /* (omit javadoc for this method) * Method declared on ASTNode. */ final boolean subtreeMatch0(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, getExpression()); acceptChild(visitor, getThenStatement()); acceptChild(visitor, getElseStatement()); } visitor.endVisit(this); } /** * Returns the expression of this if statement. * * @return the expression node */ public Expression getExpression() { if (this.expression == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.expression == null) { preLazyInit(); this.expression = new SimpleName(this.ast); postLazyInit(this.expression, EXPRESSION_PROPERTY); } } } return this.expression; } /** * Sets the condition of this if statement. * * @param expression the expression node * @exception IllegalArgumentException if: *
* Special note: The Java language does not allow a local variable declaration
* to appear as the "then" part of an if statement (they may only appear within a
* block). However, the AST will allow a VariableDeclarationStatement
* as the thenStatement of a IfStatement
. To get something that will
* compile, be sure to embed the VariableDeclarationStatement
* inside a Block
.
*
null
if
* this if statement has no "else" part.
* * Note that there is a subtle difference between having no else * statement and having an empty statement ("{}") or null statement (";"). *
* * @return the "else" statement node, ornull
if none
*/
public Statement getElseStatement() {
return this.optionalElseStatement;
}
/**
* Sets or clears the "else" part of this if statement.
*
* Note that there is a subtle difference between having no else part
* (as in "if(true){}"
) and having an empty block (as in
* "if(true){}else{}") or null statement (as in "if(true){}else;").
*
* Special note: The Java language does not allow a local variable declaration
* to appear as the "else" part of an if statement (they may only appear within a
* block). However, the AST will allow a VariableDeclarationStatement
* as the elseStatement of a IfStatement
. To get something that will
* compile, be sure to embed the VariableDeclarationStatement
* inside a Block
.
*
null
if
* there is none
* @exception IllegalArgumentException if:
*