System.Net.Http.Headers.Lexer.TryGetNumericValue C# (CSharp) Method

		public bool TryGetNumericValue (Token token, out int value)
		{
			return int.TryParse (GetStringValue (token), NumberStyles.None, CultureInfo.InvariantCulture, out value);
		}

		public static bool TryParse (string input, out RangeHeaderValue parsedValue)
		{
			parsedValue = null;

			var lexer = new Lexer (input);
			var t = lexer.Scan ();
			if (t != Token.Type.Token)
				return false;

			var value = new RangeHeaderValue ();
			value.unit = lexer.GetStringValue (t);

			t = lexer.Scan ();
			if (t != Token.Type.SeparatorEqual)
				return false;

			bool token_read;
			do {
				int? from = null, to = null;
				int number;
				token_read = false;

				t = lexer.Scan ();
				switch (t.Kind) {
				case Token.Type.SeparatorDash:
					t = lexer.Scan ();
					if (!lexer.TryGetNumericValue (t, out number))
						return false;

					to = number;
					break;
				case Token.Type.Token:
					string s = lexer.GetStringValue (t);
					var values = s.Split (new [] { '-' }, StringSplitOptions.RemoveEmptyEntries);
					if (!int.TryParse (values[0], out number))
						return false;

					switch (values.Length) {
					case 1:
						t = lexer.Scan ();
						switch (t.Kind) {
						case Token.Type.SeparatorDash:
							from = number;

							t = lexer.Scan ();
							if (t != Token.Type.Token) {
								token_read = true;
								break;
							}

							if (!lexer.TryGetNumericValue (t, out number))
								return false;

							to = number;
							if (to < from)
								return false;

							break;
						default:
							return false;
						}
						break;
					case 2:
						from = number;

						if (!int.TryParse (values[1], out number))
							return false;

						to = number;
						if (to < from)
							return false;

						break;
					default:
						return false;
					}

					break;
				default:
					return false;
				}

				value.Ranges.Add (new RangeItemHeaderValue (from, to));
				if (!token_read)
					t = lexer.Scan ();

			} while (t == Token.Type.SeparatorComma);

			if (t != Token.Type.End)
				return false;

			parsedValue = value;
			return true;
		}