System.Net.Policy.ClientAccessPolicy.ParsePorts C# (CSharp) Method

		static long ParsePorts (string ports)
		{
			long mask = 0;
			int sep = ports.IndexOf ('-');
			if (sep >= 0) {
				// range
				ushort from = ParsePort (ports.Substring (0, sep));
				ushort to = ParsePort (ports.Substring (sep + 1));
				for (int port = from; port <= to; port++)
					mask |= (long) (1ul << (port - AccessPolicy.MinPort));
			} else {
				// single
				ushort port = ParsePort (ports);
				mask |= (long) (1ul << (port - AccessPolicy.MinPort));
			}
			return mask;
		}