/YieldProlog/Modules/FindallAnswers.cs

/*

 * Copyright (c) Contributors, http://aurora-sim.org/

 * See CONTRIBUTORS.TXT for a full list of copyright holders.

 *

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 * modification, are permitted provided that the following conditions are met:

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 *       derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

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 */



using System;

using System.Collections;

using System.Collections.Generic;



namespace OpenSim.Region.ScriptEngine.Shared.YieldProlog

{

    /// <summary>

    /// A FindallAnswers holds answers for findall.

    /// </summary>

    public class FindallAnswers

    {

        private object _template;

        private List<object> _bagArray;



        public FindallAnswers(object Template)

        {

            _template = Template;

            _bagArray = new List<object>();

        }



        public void add()

        {

            _bagArray.Add(YP.makeCopy(_template, new Variable.CopyStore()));

        }



        public List<object> resultArray()

        {

            return _bagArray;

        }



        /// <summary>

        /// Unify Bag with the result. This frees the internal answers, so you can only call this once.

        /// </summary>

        /// <param name="Bag"></param>

        /// <returns></returns>

        public IEnumerable<bool> result(object Bag)

        {

            object result = ListPair.make(_bagArray);

            // Try to free the memory.

            _bagArray = null;

            return YP.unify(Bag, result);

        }



        // disable warning on l1, don't see how we can

        // code this differently

        #pragma warning disable 0168, 0219



        /// <summary>

        /// This is a simplified findall when the goal is a single call.

        /// </summary>

        /// <param name="Template"></param>

        /// <param name="goal"></param>

        /// <param name="Bag"></param>

        /// <returns></returns>

        public static IEnumerable<bool> findall(object Template, IEnumerable<bool> goal, object Bag)

        {

            FindallAnswers findallAnswers = new FindallAnswers(Template);

            foreach (bool l1 in goal)

                findallAnswers.add();

            return findallAnswers.result(Bag);

        }



        /// <summary>

        /// Like findall, except return an array of the results.

        /// </summary>

        /// <param name="template"></param>

        /// <param name="goal"></param>

        /// <returns></returns>

        public static List<object> findallArray(object Template, IEnumerable<bool> goal)

        {

            FindallAnswers findallAnswers = new FindallAnswers(Template);

            foreach (bool l1 in goal)

                findallAnswers.add();

            return findallAnswers.resultArray();

        }

        #pragma warning restore 0168, 0219

    }

}