Re: Advantage of XML based GUI? (was Re: Ada-inspired OS/Language)

[Georg Bauhaus <sb463ba@l1-hrz.uni-duisburg.de>]

Warren W. Gay VE3WWG <ve3wwg@cogeco.ca> wrote:
:> I'm not convinced that calling a BNF like thing (and more)
:> mere convention is really appropriate.
: 
: I'm not sure why this is being raised.  The original point
: was calling an O/S something to do with XML, or to put
: "XML" in the name because of its present "hype".

I was reacting to the subject line and other issues that
have been raised, sorry if I'm beeing carried away.
However, BNF is being raised, because one standard isn't
like every other one, they differ in quality and extent;
an "industry standard" might be ``We'll send records,
3 to 5 lines each, where the firsts line is ...''.
Then let's hope that (as is my daily experience) there
is not a line break within one field etc.
According to Goldfarb's law, if there is a bug in some text
processing software, one has to do with line breaks (that is,
naively defined special case data formats :-).

: How do you define "explicit" that is different from
: any other data format?

Here (in this example) the explicitness comes in. Line breaks don't
matter unless you make them correspond to some (empty) element,
or better, forget about line breaks and just mark your fields and
records. In the format described (defined) above you cannot see
the line breaks, in a sense. And if one is missing, or if some
line break sneaks into field content... Likewise, you don't have
to infer where something starts or ends, as you would have to in a
Lisp based format that has recently been suggested. It's familiar:

procedure Rant is
begin
OT: begin
       Don'T("talk about XML in c.l.a");
    end OT;  -- this "named end" can be checked by the compiler!
end Rant;  -- same here

: But _any_ "data format" has a concept of "wellformedness".
: This is not unique to XML.

It isn't, but not any data format has a concept of validity.
And not every format can be checked by a standard toolset,
when there isn't one.

Here is some background, you may conclude why I think that
XML based data streams deserve some hype, no matter what
the marketing press prints. We have to process:
- an ancient video text stream as a news feed
- MS Word xml output (no Word style sheet) with no
  indication of structure but a mix of p-tags and several
  meaningless name spaces in it (job: extract pieces of relevant
  data into some RDB. It's doomed to fail again and again)
- CSV with no line breaks, only group length...

: I guess what I am saying is "not everyone is as
: hyped about XML as maybe you are."  Is that a fair
: statement to make?

I guess so, although I won't call it "hype". XML is roughly
as old as Ada (essentially; it used to be called SGML then).
Data streams are probably at least as old, as are the problems.
XML deserves to be praised, as does Ada when compared to
other options; I've heard that there used to be a lot of
"Ada hype" sometime in the past. The hype doesn't count,
though, does it?

As for operating systems' interfaces, I am rather fond of
Plan 9's, and I think that non-document centric windowsish
window fair grounds are but a big step backwards. Sells well,
though. :-) (Thus, there would be little need to specify the
properties of trappings. Mind you, they have reintroduced
the MDI, and cascading menus! Distructing jugglery, I say.)

:> As a side note, why are these standard lectures called
:> "algorithms _and_ data structures"? 
: 
: Where does the algorithm come in?  Maybe a poor choice
: in title?

Indeed I know of one such lecture that leaves algorithm
out of the title.

: Every program reacts to the input data it is given 
: [...]  So I fail
: to see how XML is "new" in this regard or in this role.
: It still just represents plain old data in a new
: wrapper.

The wrapper isn't new as SGML isn't new. But the wrapper is
the essential thing. Not a T-shirt with holes in it but a
universal jacket helpful in almost all sorts of situations :-)
And the data is not just plain old, it is even plain old text.

: It is still just a data format ;-)

So is BNF? ;-)

-- Georg
---
Microsoft Windows--a fresh perspective on information hiding