Application: gvSIG desktop

package org.gvsig.expressionevaluator.impl.function.programming;

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.Codes;

import org.gvsig.expressionevaluator.ExpressionBuilder;

import org.gvsig.expressionevaluator.Function;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class IFFunction extends AbstractFunction {

    public IFFunction() {

        super(Function.GROUP_BOOLEAN, 

                ExpressionBuilder.FUNCTION_IF, 

                Range.between(2,3),

                ExpressionBuilder.FUNCTION_IF+"() function tests a specified numeric expression and returns one of two values, based on whether the expression tested was true or false.",

                "IF {{condition}} THEN\n  PASS\nELSE\n  PASS;\nEND IF\n",

                null,

                "Object",

                true

        );

    }

    @Override

    public boolean useArgumentsInsteadObjects() {

        return true;

    }

    @Override

    public boolean allowConstantFolding() {

        return false;

    }

    @Override

    public Object call(Interpreter interpreter, Object[] args) throws Exception {

         throw new UnsupportedOperationException("Not supported yet."); 

    }

    @Override

    public Object call(Interpreter interpreter, Codes args) throws Exception {

        Object value;

        boolean condition = getBoolean(interpreter, args, 0);

        if( condition ) {

            value = getObject(interpreter, args, 1);

        } else {

            if( args.size()>2 && args.get(2)!=null ) {

                value = getObject(interpreter, args, 2);

            } else {

                value = null;

            }

        }

        return value;

    }

}