/* An actor that converts tokens into expressions.
@Copyright (c) 1998-2006 The Regents of the University of California.
All rights reserved.
Permission is hereby granted, without written agreement and without
license or royalty fees, to use, copy, modify, and distribute this
software and its documentation for any purpose, provided that the
above copyright notice and the following two paragraphs appear in all
copies of this software.
IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
ENHANCEMENTS, OR MODIFICATIONS.
PT_COPYRIGHT_VERSION 2
COPYRIGHTENDKEY
*/
package ptolemy.actor.lib.conversions;
import ptolemy.data.StringToken;
import ptolemy.data.type.BaseType;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
//////////////////////////////////////////////////////////////////////////
//// TokenToExpression
/**
This actor reads a token from the input port and outputs a string token
whose value is an expression that can be parsed to yield the input token.
For example, if the input is itself a string token, the output will be a
new string token whose value is the value of the input string token surrounded
by double quotation marks. The input data type is undeclared, so this actor
can accept any input. If the input known to be absent, this actor outputs
a string "absent".
@author Steve Neuendorffer, Haiyang Zheng
@version $Id$
@since Ptolemy II 2.1
@Pt.ProposedRating Yellow (neuendor)
@Pt.AcceptedRating Red (liuj)
*/
public class TokenToExpression extends Converter {
/** Construct an actor with the given container and name.
* @param container The container.
* @param name The name of this actor.
* @exception IllegalActionException If the actor cannot be contained
* by the proposed container.
* @exception NameDuplicationException If the container already has an
* actor with this name.
*/
public TokenToExpression(CompositeEntity container, String name)
throws IllegalActionException, NameDuplicationException {
super(container, name);
input.setTypeEquals(BaseType.UNKNOWN);
output.setTypeEquals(BaseType.STRING);
}
///////////////////////////////////////////////////////////////////
//// public methods ////
/** Output a string token whose value is an expression representing
* the value of the input token. If the input known to be absent,
* this actor outputs a string "absent".
* @exception IllegalActionException If there's no director.
*/
public void fire() throws IllegalActionException {
super.fire();
if (input.hasToken(0)) {
String string = input.get(0).toString();
output.broadcast(new StringToken(string));
} else {
output.broadcast(new StringToken("absent"));
}
}
}