Script Engine Implemented by C# and Regular Expression

using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;

namespace Zadesoft.Library.Script
{
    public abstract class AbstractParseRout
    {
        private readonly List<WordTokenMap> _maps;

        private readonly IToken _startToken;

        public AbstractParseRout(IToken startToken)
        {
            if (startToken == null)
            {
                throw new ArgumentNullException("start token cannot be null");
            }

            _startToken = startToken;
            _maps = new List<WordTokenMap>();
        }

        public abstract int Priority { get; }

        public IToken StartToken
        {
            get
            {
                return _startToken;
            }
        }

        public IToken[] AvailableEndToken
        {
            get
            {
                List<IToken> tokens = new List<IToken>();

                foreach (WordTokenMap map in _maps)
                {
                    tokens.Add(map.Token);
                }

                return tokens.ToArray();
            }
        }

        public bool DoesMatchStartToken(IToken token)
        {
            if (token == null)
            {
                return false;
            }

            return _startToken.GetType().Equals(token.GetType());
        }

        public IToken Accept(string word)
        {
            foreach (WordTokenMap map in _maps)
            {
                if (map.DoesAnyWordMatch(word))
                {
                    return map.Token;
                }
            }

            return null;
        }

        internal class WordTokenMap
        {
            private List<string> _regexs;

            private IToken _token;

            public string[] Regexs
            {
                get
                {
                    return _regexs.ToArray();
                }
            }

            public IToken Token
            {
                get
                {
                    return _token;
                }
            }

            public WordTokenMap(IToken token)
            {
                if (_token == null)
                {
                    throw new ArgumentNullException("token cannot be null");
                }

                _token = token;
                _regexs = new List<string>();
            }

            public void AddWord(string regex)
            {
                if (!string.IsNullOrEmpty(regex))
                {
                    _regexs.Add(regex);
                }
            }

            public bool DoesAnyWordMatch(string str)
            {
                foreach (string regex in _regexs)
                {
                    if (Regex.IsMatch(str, regex))
                    {
                        return true;
                    }
                }

                return false;
            }
        }
    }
}