Application: gvSIG desktop

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

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class BitGetFunction extends AbstractFunction {

    public BitGetFunction() {

        super(

            "Numeric", "BITGET", Range.is(2),

            "Returns true if and only if the first parameter has a bit set "

                + "in the position specified by the second parameter. "

                + "This method returns a boolean. "

                + "The second parameter is zero-indexed; the least significant "

                + "bit has position 0",

            "BITGET({{bits}}, nbit)",

            new String[]{

                "bits - a bit set",

                "nbit - bit to check"

            },

            "Boolean"

        );

    }

    @Override

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

        Object value = args[0];

        int bit = getInt(args, 1);

        if( value instanceof Integer ) {

            int mask = 1<<bit;

            boolean r = (((Number) value).intValue() & mask) == mask;

            return r;

        } 

        if( value instanceof Number ) {

            int mask = 1<<bit;

            boolean r = (((Number) value).longValue() & mask) == mask;

            return r;

        } 

        throw new IllegalArgumentException("Types not allowed in '"+name()+"' function.");

    }

}