content: /*******************************************************************************
   * Copyright (c) 2009 IBM Corporation and others.
   *
   * This program and the accompanying materials are made
   * available under the terms of the Eclipse Public License 2.0
   * which is available at https://www.eclipse.org/legal/epl-2.0/
   *
   * SPDX-License-Identifier: EPL-2.0
   * 
   * Contributors:
   *     IBM Corporation - initial API and implementation
   *     Zend Technologies
   *******************************************************************************/
  package org.eclipse.php.core.ast.nodes;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import org.eclipse.php.core.PHPVersion;
  import org.eclipse.php.core.ast.match.ASTMatcher;
  import org.eclipse.php.core.ast.visitor.Visitor;
  
  /**
   * Represent a echo statement.
   * 
   * <pre>
   * e.g.
   * 
   * echo "hello", echo "hello", "world"
   * </pre>
   */
  public class EchoStatement extends Statement {
  
  	private ASTNode.NodeList<Expression> expressions = new ASTNode.NodeList<>(EXPRESSIONS_PROPERTY);
  
  	/**
  	 * The "expressions" structural property of this node type.
  	 */
  	public static final ChildListPropertyDescriptor EXPRESSIONS_PROPERTY = new ChildListPropertyDescriptor(
  			EchoStatement.class, "expressions", Expression.class, CYCLE_RISK); //$NON-NLS-1$
  
  	/**
  	 * A list of property descriptors (element type:
  	 * {@link StructuralPropertyDescriptor}), or null if uninitialized.
  	 */
  	private static final List<StructuralPropertyDescriptor> PROPERTY_DESCRIPTORS;
  
  	static {
  		List<StructuralPropertyDescriptor> properyList = new ArrayList<>(2);
  		properyList.add(EXPRESSIONS_PROPERTY);
  		PROPERTY_DESCRIPTORS = Collections.unmodifiableList(properyList);
  	}
  
  	public EchoStatement(int start, int end, AST ast, List<Expression> expressions) {
  		super(start, end, ast);
  		if (expressions == null) {
  			throw new IllegalArgumentException();
  		}
  
  		this.expressions.addAll(expressions);
  	}
  
  	public EchoStatement(AST ast) {
  		super(ast);
  	}
  
  	@Override
  	public void accept0(Visitor visitor) {
  		final boolean visit = visitor.visit(this);
  		if (visit) {
  			childrenAccept(visitor);
  		}
  		visitor.endVisit(this);
  	}
  
  	@Override
  	public void childrenAccept(Visitor visitor) {
  		for (ASTNode node : this.expressions) {
  			node.accept(visitor);
  		}
  	}
  
  	@Override
  	public void traverseTopDown(Visitor visitor) {
  		accept(visitor);
  		for (ASTNode node : this.expressions) {
  			node.traverseTopDown(visitor);
  		}
  	}
  
  	@Override
  	public void traverseBottomUp(Visitor visitor) {
  		for (ASTNode node : this.expressions) {
  			node.traverseBottomUp(visitor);
  		}
  		accept(visitor);
  	}
  
  	@Override
  	public void toString(StringBuilder buffer, String tab) {
  		buffer.append(tab).append("<EchoStatement"); //$NON-NLS-1$
  		appendInterval(buffer);
  		buffer.append(">\n"); //$NON-NLS-1$
  		for (ASTNode node : this.expressions) {
  			node.toString(buffer, TAB + tab);
  			buffer.append("\n"); //$NON-NLS-1$
  		}
  		buffer.append(tab).append("</EchoStatement>"); //$NON-NLS-1$
  	}
  
  	@Override
  	public int getType() {
  		return ASTNode.ECHO_STATEMENT;
  	}
  
  	/**
  	 * @return expression list of the echo statement
  	 */
  	public List<Expression> expressions() {
  		return this.expressions;
  	}
  
  	@Override
  	final List<? extends ASTNode> internalGetChildListProperty(ChildListPropertyDescriptor property) {
  		if (property == EXPRESSIONS_PROPERTY) {
  			return expressions();
  		}
  		// allow default implementation to flag the error
  		return super.internalGetChildListProperty(property);
  	}
  
  	/*
  	 * Method declared on ASTNode.
  	 */
  	@Override
  	public boolean subtreeMatch(ASTMatcher matcher, Object other) {
  		// dispatch to correct overloaded match method
  		return matcher.match(this, other);
  	}
  
  	@Override
  	ASTNode clone0(AST target) {
  		final List<Expression> expressions = ASTNode.copySubtrees(target, this.expressions());
  		return new EchoStatement(this.getStart(), this.getEnd(), target, expressions);
  	}
  
  	@Override
  	List<StructuralPropertyDescriptor> internalStructuralPropertiesForType(PHPVersion apiLevel) {
  		return PROPERTY_DESCRIPTORS;
  	}
  
  }
  