root/trunk/x42view.net/Helpers.TokenParser.cs

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

namespace x42view
{
        partial class Helpers
        {
                /// <summary>
                /// Parses Quake 3 style ParseExt-based scripts.
                /// </summary>
                public sealed class TokenParser : IEnumerable<string>
                {
                        private static Regex rxCommentStripper = new Regex( @"(?://.*)|(?:/\*(?:(?:.|\r\n|\n)*?)\*/)", RegexOptions.Multiline | RegexOptions.Compiled );
                        private static Regex rxTokenParser = new Regex( @"[\s\r\n]*((?:""(?'2'.*?)(?:""|\Z))|(?:(?'3'[^\s\r\n]+?)(?:[\x00-\x20]|\Z)))", RegexOptions.Multiline | RegexOptions.Compiled );

                        private string text;

                        public TokenParser( string text )
                        {
                                if( text == null )
                                        throw new ArgumentNullException( "text" );

                                this.text = StripComments( text );
                        }

                        public static string StripComments( string text )
                        {
                                if( text == null )
                                        throw new ArgumentNullException( "text" );

                                return rxCommentStripper.Replace( text, "" );
                        }

                        #region IEnumerable<string> Members

                        public IEnumerator<string> GetEnumerator()
                        {
                                for( Match m = rxTokenParser.Match( text );
                                        m.Success; m = m.NextMatch() )
                                {
                                        string s;

                                        if( m.Groups[2].Value != string.Empty )
                                                s = m.Groups[2].Value;
                                        else
                                                s = m.Groups[3].Value;

                                        if( s[0] == '\0' )
                                                yield break;

                                        yield return s;
                                }
                        }

                        #endregion

                        #region IEnumerable Members

                        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
                        {
                                return GetEnumerator();
                        }

                        #endregion
                }
        }
}