package com.creativewidgetworks.goldparser.simple2.rulehandlers;
import com.creativewidgetworks.goldparser.engine.ParserException;
import com.creativewidgetworks.goldparser.engine.Reduction;
import com.creativewidgetworks.goldparser.parser.GOLDParser;
import com.creativewidgetworks.goldparser.parser.ProcessRule;
import com.creativewidgetworks.goldparser.parser.SystemConsole;
import com.creativewidgetworks.goldparser.parser.Variable;
import com.creativewidgetworks.goldparser.simple2.Simple2;
import com.creativewidgetworks.goldparser.util.ConsoleDriver;
@ProcessRule(rule={
"<Statement> ::= display <Expression>",
"<Statement> ::= display <Expression> read Id"
})
/**
* Rule handler for the display rules.
*
* @author Ralph Iden (http://www.creativewidgetworks.com)
* @version 5.0.0
*/
public class Display extends Reduction {
private GOLDParser theParser;
private Reduction dataToPrint;
private String variableName;
// These is made static and public so tests or applications can set the
// end of line sequence or reroute the console IO to another location.
public static String EOLN = "\r\n";
public static ConsoleDriver ioDriver = new SystemConsole();
public Display(GOLDParser parser) {
theParser = parser;
Reduction reduction = parser.getCurrentReduction();
if (reduction != null) {
if (reduction.size() == 2) {
dataToPrint = reduction.get(1).asReduction();
variableName = null;
} else if (reduction.size() == 4) {
dataToPrint = reduction.get(1).asReduction();
variableName = reduction.get(3).asString();
} else {
if (reduction.size() < 3) {
// print x form
parser.raiseParserException(Simple2.formatMessage("error.param_count", "2", String.valueOf(reduction.size())));
}
// print x read y form
parser.raiseParserException(Simple2.formatMessage("error.param_count", "4", String.valueOf(reduction.size())));
}
} else {
parser.raiseParserException(Simple2.formatMessage("error.no_reduction"));
}
}
@Override
public void execute() throws ParserException {
// Write the data to the console
ioDriver.write(dataToPrint.getValue().asObject().toString());
if (variableName != null) {
// Read console input from the user (assuming that EOLN is not echoed to console)
StringBuilder sb = new StringBuilder(ioDriver.read());
theParser.setProgramVariable(variableName, new Variable(sb.toString()));
}
ioDriver.write(EOLN);
}
}