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.Function;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class WhileFunction extends AbstractFunction {

    public static final String NAME = "WHILE";

    public WhileFunction() {

        super(Function.GROUP_PROGRAMMING,

                NAME,

                Range.is(2),

                "The while() function evaluate expression while the condition is true.",

                "WHILE {{condition}} BEGIN\n  PASS;\nEND WHILE\n",

                null,

                "Object",

                false

        );

    }

    @Override

    public boolean isHidden() {

      return true;

    }

    @Override

    public boolean useArgumentsInsteadObjects() {

        return true;

    }

    @Override

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

        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

    }

    @Override

    public boolean allowConstantFolding() {

        return false;

    }

    @Override

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

        Object body = null;

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

        while( condition ) {

            body = getObject(interpreter, args, 1);

            condition = getBoolean(interpreter, args, 0);

        }

        return body;

    }

}