Application: gvSIG desktop

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

import java.util.List;

import java.util.Map;

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.ExpressionRuntimeException;

import org.gvsig.expressionevaluator.Function;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

import org.gvsig.tools.util.Size;

import org.gvsig.tools.util.Size64;

public class LenFunction extends AbstractFunction {

    public static final String NAME = "LEN";

    public LenFunction() {

        super(Function.GROUP_PROGRAMMING, 

            NAME, 

            Range.is(1),

            null,

            null,

            null,

            "Object",

            false

        );

    }

    @Override

    public boolean allowConstantFolding() {

        return false;

    }

    @Override

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

        Object value;

        Object obj = getObject(args, 0);

        if( obj == null ) {

            return 0;

        }        

        if( obj instanceof List ) {

            List l = ((List)obj);

            value = l.size();

        } else if( obj instanceof CharSequence ) {

            CharSequence s = (CharSequence)obj;

            value = s.length();

        } else if( obj instanceof Map ) {

            Map m = (Map)obj;

            value = m.size();

        } else if( obj instanceof Size ) {

            Size s = (Size)obj;

            value = s.size();

        } else if( obj instanceof Size64 ) {

            Size64 s = (Size64)obj;

            value = s.size64();

        } else {

            throw new ExpressionRuntimeException("The "+NAME+" function require a String, List, Map or Size and a received a '"+obj.getClass().getSimpleName()+"'.");

        }

        return value;

    }

}