[xquery-talk] How do different XQuery products implement modules?
christian.gruen at gmail.com
Thu Oct 16 02:00:27 PDT 2008
some comments regarding the module implementation in BaseX:
> 1. Is the module URI just an arbitrary character string, or does it have
> any semantics?
..the module URI is handled as a simple URI instance without special
semantics (non-empty, differing from the XML namespace, ..)
> 2. Do you allow several different modules in the same query to have the
> same module URI?
> 2a. if so, can different "import module" declarations import different
> subsets of these?
> 3. Can users import a module without specifying a location URI? If so,
> how is the module located?
..no; only coders accessing can do so.
> 4. If import module specifies a location URI, is it used, and if so how?
..similar to the doc(..) function.
> 5. If import module specifies more than one location URI, how are they
..they are all sequentially parsed.
> 5b. If multiple location URIs are allowed, what happens if
> import module specifies the same location URI more than once?
..the known location URIs are skipped.
> 6. What happens when two modules A and B both import module URI M
> 6a. specifying the same location URI
..again, the known location URIs are skipped.
> 6b. specifying different location URIs
..if the resulting modules have different contents, everything
works fine - see 2) - otherwise, an error will be thrown because
of duplicate function/variable declarations.
> 6c. without specifying a location URI
..an error will be thrown - see 3)
> 7. Is it possible (by means of multiple imports) to create two different
> "instances" of the same module in a query, with distinct values of global
> variables, or do all imports get the same instance with a common set of
..all imports share the same instance.
Hope this helps,
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