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.simple2.Simple2;
@ProcessRule(rule={
"<Statement> ::= if <Expression> then <Statements> end",
"<Statement> ::= if <Expression> then <Statements> else <Statements> end"
})
/**
* Rule handler for the If-Then-Else rules.
*
* if <condition> then
* <statement(s)>
* end
*
* if <condition> then
* <statement(s)>
* else
* <statement(s)>
* end
*
* if <condition> then
* <statements(s)>
* else if <condition> then
* <statements(s)>
* else if ...
* <statement(s)>
* else
* <statement(s)>
* end end end ..
*
* @author Ralph Iden (http://www.creativewidgetworks.com)
* @version 5.0.0
*/
public class IfThenElse extends Reduction {
private Reduction conditional;
private Reduction thenStatements;
private Reduction elseStatements;
public IfThenElse(GOLDParser parser) {
Reduction reduction = parser.getCurrentReduction();
if (reduction != null) {
if (reduction.size() == 5) {
// if x then y end
conditional = reduction.get(1).asReduction();
thenStatements = reduction.get(3).asReduction();
} else if (reduction.size() == 7) {
// if x then y else z end
conditional = reduction.get(1).asReduction();
thenStatements = reduction.get(3).asReduction();
elseStatements = reduction.get(5).asReduction();
} else {
if (reduction.size() < 5) {
// if x then y form
parser.raiseParserException(Simple2.formatMessage("error.param_count", "5", String.valueOf(reduction.size())));
}
// if x then y else z end form
parser.raiseParserException(Simple2.formatMessage("error.param_count", "7", String.valueOf(reduction.size())));
}
} else {
parser.raiseParserException(Simple2.formatMessage("error.no_reduction"));
}
}
@Override
public void execute() throws ParserException {
if (conditional.getValue().asBool()) {
thenStatements.execute();
} else if (elseStatements != null) {
elseStatements.execute();
}
}
}