/*
* Copyright (c) 1998-2010 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.quercus.expr;
import com.caucho.quercus.Location;
import com.caucho.quercus.env.ArrayValue;
import com.caucho.quercus.env.ArrayValueImpl;
import com.caucho.quercus.env.Env;
import com.caucho.quercus.env.NullValue;
import com.caucho.quercus.env.StringValue;
import com.caucho.quercus.env.Value;
import com.caucho.quercus.env.Var;
/**
* Represents a PHP variable expression.
*/
public class VarVarExpr extends AbstractVarExpr {
private static final NullValue NULL = NullValue.create();
protected final Expr _var;
public VarVarExpr(Location location, Expr var)
{
super(location);
_var = var;
}
public VarVarExpr(Expr var)
{
_var = var;
}
public Expr getExpr()
{
return _var;
}
/**
* Evaluates the expression.
*
* @param env the calling environment.
*
* @return the expression value.
*/
public Value eval(Env env)
{
StringValue varName = _var.evalStringValue(env);
Value value = env.getValue(varName);
if (value != null)
return value;
else
return NULL;
}
/**
* Evaluates the expression.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public Value evalAssignRef(Env env, Value value)
{
StringValue varName = _var.evalStringValue(env);
// php/0d63
env.setRef(varName, value);
return value;
}
/**
* Evaluates the expression.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public void evalUnset(Env env)
{
StringValue varName = _var.evalStringValue(env);
env.unsetVar(varName);
}
/**
* Evaluates the expression.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public Var evalVar(Env env)
{
StringValue varName = _var.evalStringValue(env);
return env.getVar(varName);
}
/**
* Evaluates the expression.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public Value evalArg(Env env, boolean isTop)
{
StringValue varName = _var.evalStringValue(env);
Value value = env.getVar(varName);
if (value != null)
return value;
else
return NULL;
}
/**
* Evaluates the expression, converting to an array if necessary.
*
* @param env the calling environment.
*
* @return the expression value.
*/
public Value evalArray(Env env)
{
StringValue varName = _var.evalStringValue(env);
Value value = env.getVar(varName);
if (value != null)
return value.getArray();
else {
ArrayValue array = new ArrayValueImpl();
env.setRef(varName, array);
return array;
}
}
public String toString()
{
return "$" + _var;
}
}