/*
***** 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) 2002 Benoit Cerrina <b.cerrina@wanadoo.fr>
* Copyright (C) 2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
* Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
* Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
* Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
*
* 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.RubyBoolean;
import org.jruby.ast.visitor.NodeVisitor;
import org.jruby.evaluator.Instruction;
import org.jruby.lexer.yacc.ISourcePosition;
import org.jruby.runtime.Block;
import org.jruby.runtime.DynamicScope;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
/**
* A Range in a boolean expression (named after a FlipFlop component in electronic?).
*/
public class FlipNode extends Node {
private final Node beginNode;
private final Node endNode;
private final boolean exclusive;
// A scoped location of this variable (high 16 bits is how many scopes down and low 16 bits
// is what index in the right scope to set the value.
private final int location;
public FlipNode(ISourcePosition position, Node beginNode, Node endNode, boolean exclusive, int location) {
super(position, NodeType.FLIPNODE);
assert beginNode != null : "beginNode is not null";
assert endNode != null : "endNode is not null";
this.beginNode = beginNode;
this.endNode = endNode;
this.exclusive = exclusive;
this.location = location;
}
/**
* Accept for the visitor pattern.
* @param iVisitor the visitor
**/
public Instruction accept(NodeVisitor iVisitor) {
return iVisitor.visitFlipNode(this);
}
/**
* Gets the beginNode.
* beginNode will set the FlipFlop the first time it is true
* @return Returns a Node
*/
public Node getBeginNode() {
return beginNode;
}
/**
* Gets the endNode.
* endNode will reset the FlipFlop when it is true while the FlipFlop is set.
* @return Returns a Node
*/
public Node getEndNode() {
return endNode;
}
/**
* Gets the exclusive.
* if the range is a 2 dot range it is false if it is a three dot it is true
* @return Returns a boolean
*/
public boolean isExclusive() {
return exclusive;
}
/**
* How many scopes should we burrow down to until we need to set the block variable value.
*
* @return 0 for current scope, 1 for one down, ...
*/
public int getDepth() {
return location >> 16;
}
/**
* Gets the index within the scope construct that actually holds the eval'd value
* of this local variable
*
* @return Returns an int offset into storage structure
*/
public int getIndex() {
return location & 0xffff;
}
public List<Node> childNodes() {
return Node.createList(beginNode, endNode);
}
@Override
public IRubyObject interpret(Ruby runtime, ThreadContext context, IRubyObject self, Block aBlock) {
DynamicScope scope = context.getCurrentScope();
IRubyObject nil = runtime.getNil();
int index = getIndex();
// Make sure the appropriate scope has proper size. See JRUBY-2046.
DynamicScope flipScope = scope.getFlipScope();
flipScope.growIfNeeded();
IRubyObject result = flipScope.getValueDepthZeroOrNil(index, nil);
if (exclusive) {
if (result == null || !result.isTrue()) {
result = trueIfTrue(runtime, beginNode.interpret(runtime, context, self, aBlock));
flipScope.setValueDepthZero(result, index);
return result;
} else {
if (endNode.interpret(runtime, context, self, aBlock).isTrue()) {
flipScope.setValueDepthZero(runtime.getFalse(), index);
}
return runtime.getTrue();
}
} else {
if (result == null || !result.isTrue()) {
if (beginNode.interpret(runtime, context, self, aBlock).isTrue()) {
flipScope.setValueDepthZero(falseIfTrue(runtime, endNode.interpret(runtime, context, self, aBlock)), index);
return runtime.getTrue();
}
return runtime.getFalse();
} else {
if (endNode.interpret(runtime, context, self, aBlock).isTrue()) {
flipScope.setValueDepthZero(runtime.getFalse(), index);
}
return runtime.getTrue();
}
}
}
private static RubyBoolean trueIfTrue(Ruby runtime, IRubyObject truish) {
return truish.isTrue() ? runtime.getTrue() : runtime.getFalse();
}
private static RubyBoolean falseIfTrue(Ruby runtime, IRubyObject truish) {
return truish.isTrue() ? runtime.getFalse() : runtime.getTrue();
}
}