/*

***** 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) 2004-2006 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

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package org.jruby.ast;

import java.util.List;

import org.jruby.Ruby;

import org.jruby.ast.types.INameNode;

import org.jruby.ast.visitor.NodeVisitor;

import org.jruby.lexer.yacc.ISourcePosition;

import org.jruby.runtime.Block;

import org.jruby.runtime.ThreadContext;

import org.jruby.runtime.builtin.IRubyObject;

import org.jruby.util.ByteList;

/**

* Access a dynamic variable (e.g. block scope local variable).

*/

public class DVarNode extends Node implements INameNode {

// The name of the variable

private String name;

// 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 int location;

public DVarNode(ISourcePosition position, int location, String name) {

super(position);

this.location = location;

this.name = name;

}

public NodeType getNodeType() {

return NodeType.DVARNODE;

}

/**

* Accept for the visitor pattern.

* @param iVisitor the visitor

**/

public Object accept(NodeVisitor iVisitor) {

return iVisitor.visitDVarNode(this);

}

/**

* 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;

}

/**

* Gets the name.

* @return Returns a String

*/

public String getName() {

return name;

}

/**

* Sets the name of this variable (for refactoring support)

* @param name to set the variable to

*/

public void setName(String name) {

this.name = name;

}

public List<Node> childNodes() {

return EMPTY_LIST;

}

@Override

public IRubyObject interpret(Ruby runtime, ThreadContext context, IRubyObject self, Block aBlock) {

// System.out.println("DGetting: " + iVisited.getName() + " at index " + iVisited.getIndex() + " and at depth " + iVisited.getDepth());

IRubyObject obj = context.getCurrentScope().getValue(getIndex(), getDepth());

// FIXME: null check is removable once we figure out how to assign to unset named block args

return obj == null ? runtime.getNil() : obj;

}

@Override

public ByteList definition(Ruby runtime, ThreadContext context, IRubyObject self, Block aBlock) {

ByteList definition = LOCAL_VARIABLE_BYTELIST;

if (!context.getRuntime().is1_9()) {

definition = LOCAL_VARIABLE_IN_BLOCK_BYTELIST;

}

return definition;

}

}