[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Why not PIs for namespace declarations?
On Fri, 24 Dec 1999, james anderson wrote: > Arjun Ray wrote: > > On Thu, 23 Dec 1999, David Brownell wrote: > > The "requirement" that had to be met, apparently, was that the > > syntactic device announcing a "local" lexical scope had to be > > "locally" available itself (thus ruling out, e.g., stuff in the > > internal subset that would be indefinitely "far away".) > > I surmise that "stuff" here refers to a PI which would have preceeded > or followed the respective element tag. Not just a PI. ArchForms, for instance, work with attributes which have to be declared in <!ATTLIST...> declarations. (New-fangled PIs are one way of working around the fact that declarations can't appear within the instance.) The *general* idea - to use "special" attributes - can be considered well-accepted; the issue is how these special attributes are to be recognized. > > There are only two natural scoping constructs in XML: elements and > > marked sections. > As XML had, to that point in time, neither a storage nor a processing > model, any arguments regarding "natural" whould have been most > suspect. Natural in the syntactic sense: both "start" and "end" lexically separate and explicit. "Natural scoping constructs", not "natural scopes":) > A claim, for example, that the present encoding does not place the > encoding for the namespace binding "indefinitely far away" from the > encoding for the respective element type depends on the presumption of > a procesing structure akin to that proposed in the recent strawman > sax2. Namely one in which interning the type name is deferred until > the attributes have been read. A PI encoding with a lexical scope > covering the immediately succeeding element would not have made this > presumption. Yes. The inherent chicken-and-egg problem is normally solved by separating declaration and use (and sometimes the declaration can be "indefinitely far away" enough to have to be assumed - e.g. in some block-structured languages, a new block *mandates* a new lexical scope, so there's no need to "declare" this fact.) Arjun xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1 To unsubscribe, mailto:majordomo@i... the following message; unsubscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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