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9/25/2002 2:31:41 PM, Jonathan Robie <firstname.lastname@example.org> wrote:
>A substantial implementation is evidence of implementability, even if it is
>not written to the letter of the spec during the Working Draft phase.
I hesitate to get into this issue (having very divided loyalties on
the subject of XQuery!) but I think we need to clarify one point:
"implementability" is one thing, but INTEROPERABLE implementations
are another thing entirely. The XML community is still struggling with
what the namespaces spec "really means" 4 years after its release (and it's
only 20 pages long!). The XML mailing lists are full of questions and
comments that make it clear that the W3C XML Schema spec is not interpreted
the same way by all implementers. Even the DOM Level 1 HTML spec (which was
written by MS and Netscape to reflect what they actually did) is not
consistently implemented by the current versions of those browsers.
This is not to cast aspersions on anyone -- this is intrinsic to the
nature of the enterprise here -- just to request that people be VERY
careful about assertions that a spec is implementable because it has
been (partially) implemented.
>I don't understand what you are suggesting here. The language document
>(www.w3.org/tr/xquery) is pretty precise even without the formal semantics,
So is SQL (various versions) EVEN WITH the "formal semantics" of E. F. Codd
(accepting the conventional wisdom that SQL is indeed an implementation of
the relational model). Still, non-trivial SQL is clearly not interoperable
across RDBMS implementations without an awful lot of work.
XQuery is approximately at the level of complexity of SQL 3, which is not
even REMOTELY useful as the basis of interoperable code at this time
(to the best of my knowledge, speaking as a non-practicioner of SQL!).
Perhaps Dare is suggesting that the XQuery folks pay very careful
attention to the Dutch proverb that Brooks cites in the MYTHICAL
MAN MONTH "Een schip op het strand is een baken in zee."
(A ship on the beach is a lighthouse on the sea.). There are a lot
of wrecks on the beach that XQuery is navigating towards,
and extreme caution is warranted.