- From: Martin J. Duerst <mduerst@ifi.unizh.ch>
- Date: Mon, 24 Feb 1997 18:22:21 +0100 (MET)
- To: "Gregory J. Woodhouse" <gjw@wnetc.com>
- Cc: "Roy T. Fielding" <fielding@kiwi.ICS.UCI.EDU>, URI mailing list <uri@bunyip.com>
Hello Gregory, On Thu, 20 Feb 1997, you wrote: > I believe Roy's comments are right on the mark here. URLs are resource > identifiers which have the added convenience of being easily transcribable > and can be chosen to have some mnemonic value, but it is not their function > to implement a directory service. It's definitely not the function of URLs to implement a directory service. URLs hit or fail, (most) directory services give you a possibly long list of alternatives. There are other problems when trying to solve the internationalization problem with directories above URLs. Many of them are general problems of not having internationalization available for URLs, such as the problems with the query part, the problem with the display of URLs in various places in the browser, and so on. Here are two more, specific to directory services: - There are a lot of different proposals for directory services, some of them caring about internationalization, but most of them not yet addressing this point. However, there is no one directory service that is in full use, and it's very difficult to know when there will be one. - Directory services themselves will create the need for schemes to access them with URLs. The dog bites it's own tail. The last one in particular is a serious knockout :-). > To use a worn out example, URLs are to > the web as i-nodes are to the Unix filesystem. Just as directories give us > meaningful file names under Unix (and not just i-node numbers), directory > services on the Internet are the right way to introduce names which are > meaningful in local character sets. If URLs were like i-number and internet addresses (and port numbers), you would see a lot more of things such as 21://130.60.48.8/210900 instead of ftp://ftp.ifi.unizh.ch/pub/multilingual/FontComposition.ps.Z In the first, using port number for scheme, and i-number for path/resource name is not possible (but the later could be simulated), and using the internet address is rarely done. No we can either say that URLs, file names, and domain names are low-level directory services, or we can say that URLs, file names, and domain names are not directory services, and that for example the unix "find" command would be a (crude) directory service for a file system, and a search engine would be a directory service for domain names or URLs. Which way we take to solve the terminology problem, it remains that URLs, file names, and domain names all are identifiers that are frequently used by human beings. And where this is possible, many human beings prefer to use these identifiers in their local script. Countless filenames on countless computers all over the world are a strong testimony. The (not fully guaranteed but in many case working) use of URLs in native encoding in HTML documents is another strong testimony. For domain names, we don't have such a testimony, but I know that where this is possible (e.g. NT), users like to give their machines names they can understand and that are written in a familliar script. > An advantage of directory services is > that it is possible to have multiple directory services for the same file > system (as a simple example think of long filenames and 8.3 filenames under > Windows 95). The same web could easily support Directory services for > English and Japanese. You can have multiple filenames without having a different directory service. Links do the job. You of course can have multiple URLs for one and the same resoure (apart from terminology problems :-). > It may sound a bit strange for me to say this now as I have objected in the > past to the idea that certain URI schemes should use what are in essence > binary strings. That URLs are transcribable and easily remembered is a > considerable convenience, and this feature of the URL mechanism is a great > asset. However, this should not obscure the fact tht URLs are not meant to > implement a directory service. We don't want URLs to become a high-level directory service. But we want URLs to provide the same convenience for users around the world. Every US user is free to choose an URL with numbers only, very few are doing it, not even those that vehemently claim that URLs should be without meaning. Yet people who don't use the Latin script, and to a lesser extent people that use the Latin script with extensions, are constantly forced to use URLs that are for them rather meaningless and arbitrary. Regards, Martin.
Received on Monday, 24 February 1997 12:22:21 UTC