5509 2008-02-28 19:02:20 +0000 [FT] Semantics of distance wrt overlapping tokens at same starting position is unclear 2008-04-04 15:53:30 +0000 1 1 1 Unclassified XPath / XQuery / XSLT Full Text 1.0 Working drafts PC Windows NT CLOSED FIXED P2 normal --- 1 holstege holstege public-qt-comments oldest_to_newest 19217 0 holstege 2008-02-28 19:02:20 +0000 FT semantics defines distance by ordering tokens by their starting positions. However, if tokens overlap and have different ending positions but the same starting positions, the results will be indeterminate. 19218 1 holstege 2008-02-28 19:14:35 +0000 Proposal: (1) Change the semantics functions to order by startPos, endPos This still leads to some non-determinism when the startPos and endPos are identical. However, for the purposes of distance calculations, this is irrelevant. (2) In addition, and this relates to #4715 more than this bug, we could in section 2 say something like: "Tokens are ordered by their starting positions and, if necessary, their ending positions." I will go ahead with (1) as we agree this is the right thing to do. Comments on #2? 19219 2 jim.melton 2008-02-28 19:28:55 +0000 Thanks, Mary. Your change to (1) is OK with me, and I agree that it is basically what we agreed on the call. I'm OK with (2) as well. On (1), you said "This still leads to some non-determinism when the startPos and endPos are identical". True, that's irrelevant for distance calculations. Can you identify a place in the language or document where it is relevant? 19220 3 holstege 2008-02-28 19:34:21 +0000 It can come into play when we talk about phrases, I think -- a phrase being an ordered sequence of tokens. However, I believe that non-determinism doesn't matter in practice, because phrase matching is implementation-dependent anyhow, and we want to allow implementations to come to their own conclusions about matching overlapping tokens in such cases (cf the Dampfschiffmumble example) 19507 4 holstege 2008-03-17 19:40:06 +0000 Bug was fixed as part of other work.