On 11/12/2003 10:16, Mark Davis wrote:
Mark, don't patronise me. I'm not talking about levels of enlightenment.
I'm not talking about levels in the sense you just used when you
mentioned "higher-level issues". I'm talking about the well-known
concept of levels or layers of programming and of communication protocols.
My apologies; I had intended a lighter tone, not patronization.
Apology accepted. I should have recognised the "enlightenment" of the tone.
...
One could, of course, design a programming language that always indexed and
counted by some other entity, say, default grapheme clusters. Such a language
would be be unable to deal with pieces that didn't constitute a complete
cluster, or and have to deal with the issues such as that the number of entities
in the concatenation of two strings is not the same as the same as the sum of
number of numbers of entities in each of the strings, so indexing gets pretty
tricky. I don't know of any programming language that has tried to do this, and
I don't think it would be of particular value -- and would be exceedlingly slow.
This is I suppose what I was thinking of. I see the problem if partial
clusters are permitted, but they could be forbidden from this type. Is
there ever a case where a concatenation of n DGCs and m DGCs is not
equal to (n+m) DGCs? If so there is a small problem, but one which is
surmountable if it is made clear that concatenation does not always
imply addition of string length. I do think this would be a useful thing
to do, and Benjamin, who seems to agree, suggests that .NET does it at
least to some extent. I am sure that some tricks could be found to
simplify the indexing if necessary, e.g. using PUA or non-character code
points indexed into a special table to replace DGCs which cannot be
represented as a single character. (There are plenty of non-characters
available as you need to use UTF-32 here to avoid exactly the same
problems with surrogates.)
--
Peter Kirk
[EMAIL PROTECTED] (personal)
[EMAIL PROTECTED] (work)
http://www.qaya.org/
