Re: Empty IA5String

[Hallvard B Furuseth <h.b.furuseth@usit.uio.no>]

John McMeeking writes:
> On a personal note, I've always found the notion of an zero-length
> value hard to digest.  I could really use a real world example (not in
> the drafts, just to help me accept the concept) where a zero-length
> value has a different meaning than no value.

I can give you what might have become a real-world example at our site
if Directory Strings could be zero-length:  A 'vacation message'
attribute which the mail system would check.  If the attribute was
present, the mail system would send a vacation message in response to
incoming messages, with a standard initial text + the optional
user-supplied message.

As it is, we ended up another boolean attribute which means 'there is an
active vacation message', and only use the vacation attribute if the
boolean is TRUE.

Except for that, I have no problem with empty attributes in general.
The presence of a value - or of an attribute - is information.  Its
contents is some other information, and its format depends on the
application.  Empty strings are rare, but not useless.  Think of an
empty DN, for example.  (Yes, I know that does not have string syntax.)

-- 
Hallvard