3.2 Choosing URIs

The Mozart system fully embraces the idea of modular programming: applications are assembled from ``components'' or ``modules'' which are loaded lazily when needed.

Furthermore, Mozart takes the idea of a world-wide, or universal, component library seriously: modules are referenced through URIs¹ and may be dowloaded from the net automatically when necessary. The essential idea is that every module should be uniquely identified by a URI. It's the same everywhere and it never changes. This means that other developers can reliably use these URIs to import these modules.

So what URI should you pick? You have 2 choices:

• You can pick a ``real'' url, like:

  http://random.com/people/quux/mogul/CL.ozf

  This has the advantage that if a copy of your module has not been installed into the user's cache, then it will be automatically downloaded from your site (assuming it is really available from there).

• You can pick an ``abstract'' uri, like:

  x-ozlib://quux/CL.ozf

  This has the advantage of making it a little more independent of physical location. Typically users would then either install your package into their local cache, or point the ``resolver'' to an appropriate cache by setting the OZ_SEARCH_PATH variable.

Which you choose is of course up to you, but we encourage you to choose an abstract uri.