System.Web.Routing.PatternParser.MatchSegment C# (CSharp) Method

		bool MatchSegment (int segIndex, int argsCount, string[] argSegs, List <PatternToken> tokens, RouteValueDictionary ret)
		{
			string pathSegment = argSegs [segIndex];
			int pathSegmentLength = pathSegment != null ? pathSegment.Length : -1;
			int startIndex = pathSegmentLength - 1;
			PatternTokenType tokenType;
			int tokensCount = tokens.Count;
			PatternToken token;
			string tokenName;

			for (int tokenIndex = tokensCount - 1; tokenIndex > -1; tokenIndex--) {
				token = tokens [tokenIndex];
				if (startIndex < 0)
					return false;

				tokenType = token.Type;
				tokenName = token.Name;

				if (segIndex > segmentCount - 1 || tokenType == PatternTokenType.CatchAll) {
					var sb = new StringBuilder ();

					for (int j = segIndex; j < argsCount; j++) {
						if (j > segIndex)
							sb.Append ('/');
						sb.Append (argSegs [j]);
					}
						
					ret.Add (tokenName, sb.ToString ());
					break;
				}

				int scanIndex;
				if (token.Type == PatternTokenType.Literal) {
					int nameLen = tokenName.Length;
					if (startIndex + 1 < nameLen)
						return false;
					scanIndex = startIndex - nameLen + 1;
					if (String.Compare (pathSegment, scanIndex, tokenName, 0, nameLen, StringComparison.OrdinalIgnoreCase) != 0)
						return false;
					startIndex = scanIndex - 1;
					continue;
				}

				// Standard token
				int nextTokenIndex = tokenIndex - 1;
				if (nextTokenIndex < 0) {
					// First token
					ret.Add (tokenName, pathSegment.Substring (0, startIndex + 1));
					continue;
				}

				if (startIndex == 0)
					return false;
				
				var nextToken = tokens [nextTokenIndex];
				string nextTokenName = nextToken.Name;

				// Skip one char, since there can be no empty segments and if the
				// current token's value happens to be the same as preceeding
				// literal text, we'll save some time and complexity.
				scanIndex = startIndex - 1;
				int lastIndex = pathSegment.LastIndexOf (nextTokenName, scanIndex, StringComparison.OrdinalIgnoreCase);
				if (lastIndex == -1)
					return false;

				lastIndex += nextTokenName.Length - 1;
						
				string sectionValue = pathSegment.Substring (lastIndex + 1, startIndex - lastIndex);
				if (String.IsNullOrEmpty (sectionValue))
					return false;

				ret.Add (tokenName, sectionValue);
				startIndex = lastIndex;
			}
			
			return true;
		}