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Re: LANGUAGE/COMPARATOR review




Cyrus Daboo wrote:
Hi Ken,

--On November 16, 2006 8:48:29 AM -0500 Ken Murchison <murch@xxxxxxxxxxxxxx> wrote:

- Section 4, fourth paragraph AND Section 4.1, third paragraph:  The
THREAD=REFERENCES algorithm also sorts by subject, so this needs to be
accounted for in the text.  It doesn't matter to me whether both
THREADing algorithms are listed, or if the text just mentions THREAD in
general.

Not quite: THREAD=REFERENCES actually "groups" by subject. i.e. it does a comparison operation on the subject, not a collation operation.

True.  Use of "sort" was a poor choice on my part.

So, SORT/THREAD use a minimum of two collations, and upto three in the case of ORDEREDSUBJECT. The question is whether these will ever need to be specified separately. I think it may be prudent to at least define two COMPARATORs, not one. One would be the active collation for comparisons, the other the active collation for ordering operations.

I can see arguments for using one collation throughout, or having two separate collations. I don't have a string opinion either way.

Cyrus, do you have a suggestion for how a second comparator would be selected? Would this be an addition to COMPARATOR or an addition to SORT/THREAD?


--
Kenneth Murchison
Systems Programmer
Project Cyrus Developer/Maintainer
Carnegie Mellon University