RegexMatcher.cs :  » Development » Vici-Parser » Vici » Core » Parser » C# / CSharp Open Source

#region License
//=============================================================================
// Vici Core - Productivity Library for .NET 3.5 
//
// Copyright (c) 2008-2010 Philippe Leybaert
//
// Permission is hereby granted, free of charge, to any person obtaining a copy 
// of this software and associated documentation files (the "Software"), to deal 
// in the Software without restriction, including without limitation the rights 
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
// copies of the Software, and to permit persons to whom the Software is 
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in 
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//=============================================================================
#endregion

using System;
using System.Text.RegularExpressions;

namespace Vici.Core.Parser{
    public class RegexMatcher : ITokenMatcher, ITokenProcessor
    {
        private readonly Regex _regex;
        private readonly Regex _regexComplete;

        private string _buffer;
        private bool _seen;

        public ITokenProcessor CreateTokenProcessor()
        {
            return new RegexMatcher(_regex, _regexComplete);
        }

        private RegexMatcher(Regex regex, Regex regexComplete)
        {
            _regex = regex;
            _regexComplete = regexComplete;
        }

        public RegexMatcher(string regex, string regexComplete)
        {
            if (!regex.StartsWith("^"))
                regex = "^" + regex;

            if (!regex.EndsWith("$"))
                regex += "$";

            if (!regexComplete.StartsWith("^"))
                regexComplete = "^" + regexComplete;

            if (!regexComplete.EndsWith("$"))
                regexComplete += "$";

            _regex = new Regex(regex, RegexOptions.Singleline);
            _regexComplete = new Regex(regexComplete, RegexOptions.Singleline);
        }

        public void ResetState()
        {
            _buffer = "";
            _seen = false;
        }

        public TokenizerState ProcessChar(char c, string fullExpression, int currentIndex)
        {
            _buffer += c;

            bool isMatch = _regex.IsMatch(_buffer);

            if (isMatch)
            {
                if (_regexComplete.IsMatch(_buffer))
                    _seen = true;

                return TokenizerState.Valid;
            }

            if (_seen)
                return TokenizerState.Success;
            else
                return TokenizerState.Fail;
        }

        public string TranslateToken(string originalToken, ITokenProcessor tokenProcessor)
        {
            return originalToken;
        }
    }
}