/*
***** BEGIN LICENSE BLOCK *****
* Version: CPL 1.0/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Common Public
* License Version 1.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.eclipse.org/legal/cpl-v10.html
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Copyright (C) 2001-2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
* Copyright (C) 2001-2002 Benoit Cerrina <b.cerrina@wanadoo.fr>
* Copyright (C) 2002 Anders Bengtsson <ndrsbngtssn@yahoo.se>
* Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the CPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the CPL, the GPL or the LGPL.
***** END LICENSE BLOCK *****/
package org.jruby.ast;
import java.util.List;
import org.jruby.Ruby;
import org.jruby.RubyArray;
import org.jruby.ast.visitor.NodeVisitor;
import org.jruby.evaluator.ASTInterpreter;
import org.jruby.evaluator.Instruction;
import org.jruby.javasupport.util.RuntimeHelpers;
import org.jruby.lexer.yacc.ISourcePosition;
import org.jruby.runtime.Block;
import org.jruby.runtime.RubyEvent;
import org.jruby.runtime.MethodIndex;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
/**
* A Case statement. Represents a complete case statement, including the body with its
* when statements.
*/
public class CaseNode extends Node {
/**
* the case expression.
**/
private final Node caseNode;
/**
* the body of the case.
*/
private final Node caseBody;
public CaseNode(ISourcePosition position, Node caseNode, Node caseBody) {
super(position, NodeType.CASENODE);
assert caseBody != null : "caseBody is not null";
// TODO: Rewriter and compiler assume case when empty expression. In MRI this is just
// a when.
// assert caseNode != null : "caseNode is not null";
this.caseNode = caseNode;
this.caseBody = caseBody;
}
/**
* Accept for the visitor pattern.
* @param iVisitor the visitor
**/
public Instruction accept(NodeVisitor iVisitor) {
return iVisitor.visitCaseNode(this);
}
/**
* Gets the caseNode.
* caseNode is the case expression
* @return caseNode
*/
public Node getCaseNode() {
return caseNode;
}
/**
* Gets the first whenNode.
* the body of the case statement, the first of a list of WhenNodes
* @return whenNode
*/
public Node getFirstWhenNode() {
return caseBody;
}
public List<Node> childNodes() {
return Node.createList(caseNode, caseBody);
}
@Override
public IRubyObject interpret(Ruby runtime, ThreadContext context, IRubyObject self, Block aBlock) {
IRubyObject value = caseNode == null ? null : caseNode.interpret(runtime, context, self, aBlock);
context.pollThreadEvents();
for (Node current = caseBody; current != null; current = ((WhenNode) current).getNextCase()) {
if (!(current instanceof WhenNode)) return current.interpret(runtime, context, self, aBlock);
IRubyObject result = interpretExpressions((WhenNode) current, value, context, runtime, self, aBlock);
if (result != null) return result;
context.pollThreadEvents();
}
return runtime.getNil();
}
private static IRubyObject interpretExpressions(WhenNode whenNode, IRubyObject value,
ThreadContext context, Ruby runtime, IRubyObject self, Block aBlock) {
assert whenIsArray(whenNode);
for (Node expression: ((ArrayNode) whenNode.getExpressionNodes()).childNodes()) {
ISourcePosition position = expression.getPosition();
context.setFileAndLine(position.getFile(), position.getStartLine());
if (runtime.hasEventHooks()) ASTInterpreter.callTraceFunction(runtime, context, RubyEvent.LINE);
IRubyObject result = expression.when(whenNode, value, context, runtime, self, aBlock);
if (result != null) return result;
}
return null;
}
private static boolean whenIsArray(WhenNode whenNode) {
return whenNode.getExpressionNodes() instanceof ArrayNode;
}
}