[comp.text.sgml] Entity end

enag@ifi.uio.no (Erik Naggum) (11/29/90)

Can some kind soul please enlighten me as to the purpose of the
"Entity end" (out-of-band) "signal" and it's use in SGML documents?  I
got so far as to understand how you would represent it (ASCII NUL or
DEL seem to fit the description very nicely), but as to the rationale
for its existence, I'm at a complete loss.

If you think this is narrow interest, mail me.  If I get enough
replies like this, I'll summarize.  Would prefer to use the group,
though.

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ath@prosys.se (Anders Thulin) (11/30/90)

In article <ENAG.90Nov29020830@hild.ifi.uio.no> enag@ifi.uio.no (Erik Naggum) writes:
>Can some kind soul please enlighten me as to the purpose of the
>"Entity end" (out-of-band) "signal" and it's use in SGML documents? 

As far as I can see, it is used in the same was as EOF is in C: it
signals 'end of file' for all entities, also those that are internal.

I'm not certain what you mean with 'out-of-band' though.

>I got so far as to understand how you would represent it (ASCII NUL or
>DEL seem to fit the description very nicely),

Perhaps you are right. Given the rather bewildering possibilities of
mapping characters to and fro in SGML I'd be inclined to think that no
byte value in *any* code table can be used as a universal EE. But
perhaps I'm bewildered beyond what's required ... :-).

> but as to the rationale for its existence, I'm at a complete loss.

I don't know about this. I'm inclined to suspect that it's something
to do with preventing markup inside entities to propagate outside.

	<!ENTITY foo	"<p>some random text">

and

	<p>This is &foo; as an example</p>

The <p> in foo isn't permitted to last beyond the EE of foo. 
I don't have the standard handy to check this out, so I may be off
track here.


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