Application: gvSIG desktop

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

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.Function;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.MutableSymbolTable;

import org.gvsig.expressionevaluator.SymbolTable;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class LetFunction extends AbstractFunction {

    public LetFunction() {

        super(Function.GROUP_OTHER, "let", Range.is(2));

    }

    @Override

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

        String name = getStr(args,0);

        Object obj = getObject(args, 1);

        if( name == null ) {

            throw new NullPointerException("A string with a variable name was expected and a null was received");

        }

        SymbolTable symbolTable = interpreter.getSymbolTable();

        if( symbolTable instanceof MutableSymbolTable ) {

            ((MutableSymbolTable)symbolTable).setVar(name, obj);

        } else {

            throw new RuntimeException("A MutableSymbolTable is required for use let function.");

        }

        return obj;

    }

}