Re: What does "persist" really mean ?
On Thu, 31 Jul 2008, Lew wrote:
Lew wrote:
XML has many benefits as an serialization format, not least that it is
semantically void.
Tom Anderson wrote:
"Semantically void"?
XML formats do not depend on nor impinge on the meaning of the content.
Put another way, XML (like ASN.1 from what you've told us) is
self-describing, so one need not refer to an external source to
interpret the contents.
Right, got it.
The meaning is entirely at the endpoints of an XML document's use, not
internal to the document. With other formats, for example positional
layouts where a field belongs to a certain position on a line, the
semantics are part of the format.
Yes. XML is more of a format architecture than a format per se, and it's
the formats you define with XML that impose meaning.
Although one could argue that XML does impose some meaning, in that it's
hierarchical: it doesn't have a natural way to describe directed acyclic
graphs, or matrices. The ID/IDREF mechanism does give you quite a good way
to do DAGs, but it's not quite as natural as the way XML deals with
hierarchies.
tom
--
Faith in chaos.