/*
* Copyright (c) 1998-2011 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.Env;
import com.caucho.quercus.env.Value;
import com.caucho.quercus.env.Var;
import com.caucho.quercus.parser.QuercusParser;
import com.caucho.quercus.statement.Statement;
/**
* Represents an expression that is assignable
*/
abstract public class AbstractVarExpr extends Expr {
public AbstractVarExpr(Location location)
{
super(location);
}
public AbstractVarExpr()
{
}
/**
* Returns true if the expression is a var/left-hand-side.
*/
@Override
public boolean isVar()
{
return true;
}
/**
* Marks the value as assigned
*/
public void assign(QuercusParser parser)
{
// XXX: used by list, e.g. quercus/03l8. need further tests
}
/**
* Creates the assignment.
*/
@Override
public Expr createAssign(QuercusParser parser, Expr value)
{
return value.createAssignFrom(parser, this);
}
/**
* Creates the assignment.
*/
@Override
public Expr createAssignRef(QuercusParser parser,
Expr value)
{
return parser.getExprFactory().createAssignRef(this, value);
}
/**
* Creates the reference
* @param location
*/
@Override
public Expr createRef(QuercusParser parser)
{
return parser.getExprFactory().createRef(this);
}
/**
* Creates the copy.
* @param location
*/
@Override
public Expr createCopy(ExprFactory factory)
{
return factory.createCopy(this);
}
/**
* Creates the assignment.
*/
@Override
public Statement createUnset(ExprFactory factory, Location location)
{
return factory.createExpr(location, factory.createUnsetVar(this));
}
/**
* Evaluates the expression, returning a Value.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
abstract public Value eval(Env env);
/**
* Evaluates the expression as a reference (by RefExpr).
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
abstract public Var evalVar(Env env);
/**
* Evaluates the expression as a reference when possible.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public Value evalRef(Env env)
{
return evalVar(env);
}
/**
* Evaluates the expression as an argument.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public Value evalArg(Env env, boolean isTop)
{
return evalVar(env);
}
/**
* Evaluates the expression and copies the result for an assignment.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public Value evalCopy(Env env)
{
return eval(env).copy();
}
/**
* Evaluates the expression as an array.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public Value evalArray(Env env)
{
return evalVar(env).toAutoArray();
}
/**
* Evaluates the expression as an object.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public Value evalObject(Env env)
{
return evalVar(env).toObject(env);
}
/**
* Evaluates the expression as an argument.
*
* @param env the calling environment.
*
* @return the expression value.
*/
abstract public void evalUnset(Env env);
/**
* Evaluates the expression.
*
* @param env the calling environment.
*
* @return the expression value.
*/
@Override
public Value evalAssignValue(Env env, Value value)
{
return evalAssignRef(env, value);
}
/**
* Assign the variable with a new reference value.
*
* @param env the calling environment.
*
* @return the expression value.
*/
abstract public Value evalAssignRef(Env env, Value value);
}