(j3.2006) [Third thoughts about DIM arguments]

[Malcolm Cohen]

Robert Corbett wrote:
> As I noted
> in my second e-mail, we need to decide whether or not "absent" means
> the same thing as "not present,"

We already decided (and so did English).

> and whatever we decide needs to be
> applied consistently in the specifications of the intrinsic functions.

I agree that consistent wording is good.  The standard is full of wording 
inconsistencies though.  We (i.e. not just me) have been trying to straighten 
out some of the most egregious ones, but ones that are stylistic differences 
have not been considered so important at this time.

> I shall suggest that if we decide "absent" maens "not present," we
> say "not present" instead of "absent."

I resist this suggestion.  "absent" and "present" are fine antonyms.  All of the 
occurrences of "absent" in the standard seem to be ok to me - they are all about 
optional dummy arguments.  I think we caught all the (many) uses of "present" 
that were not about optional dummy arguments and changed them (usually to 
"appears", sometimes to "is specified", etc.).  We didn't look for "omitted" - 
in hindsight, an omission.

However, in the context of optional dummy arguments, "omitted" absolutely has to 
mean "not present".  It would be a serious violation of the design principles of 
optional dummy arguments to draw a distinction between textually not present and 
textually present but runtimely not present.  I agree that "omitted" is a poor 
choice of word though since it is more often used to mean "does not appear" 
syntactically.

Cheers,
-- 
................................Malcolm Cohen, Nihon NAG, Tokyo.