EXPath Archive: updated specification: Editor's draft 12 May 2014

An updated editor's draft of this specification (12 May 2014) is 
available from:

    http://expath.org/spec/archive/editor

(A diff version from the previous (3 December 2013) version is available 
but not yet on the website). The major changes are:

  * Shifting to a fully serialization-like structured entry description,
    e.g. <arch:entry><arch:name value="picture.jpg"/>.....
  * Map-based functions are an optional interface, in the same namespace
    as the element-based versions and with '-map' suffix to the name.
  * Map-based functions can use 'position' properties to report on and
    control archive order.
  * All map-based functions use single maps, rather than map sequences,
    as arguments.
  * A new function arch:entry-names() just yields the names of all the
    entries in sequence (simpler than the structured one, and useful
    when using maps.)
  * Two convenience functions arch:text() and arch:xml() are defined, to
    generate xs:base64Binary for archive content sequences.

Issue(s) arising:

  * I have not yet used structured entry descriptions in arch:create()
    and arch:update() - to do so would require polymorphism (i.e. type
    detection) on the arguments, as the arity would probably remain the
    same between structured entry and string versions. To create with
    different compressions on a per-entry basis (as might be needed for
    EPUB) would require something like this. The alternative is to use
    different function names for the two versions. [On the other hand
    you could be modern and use maps, where you can do this as easily as
    falling off a log....]

Further work:

  * Some of the examples need further alteration; minor formatting changes
  * I have not yet started changing the qt3 tests on GitHub (or indeed
    our Saxon implementation) until the shift to structured entry
    descriptions is pretty clear.

Reactions would be welcome. I hope that with the specification as now 
altered, we can move to some reasonably quick convergence and actually 
get this specification completed.



John Lumley
-- 
*John Lumley* MA PhD CEng FIEE
john@saxonica.com <mailto:john@saxonica.com>
on behalf of Saxonica Ltd