- From: Jonathan Robie <jonathan.robie@softwareag.com>
- Date: Wed, 23 Jan 2002 13:11:03 -0500
- To: Shawn Vincent <svincent@exalt.com>, XQuery Comments <www-xml-query-comments@w3.org>
Hi Shawn, I like your suggestion, and will add text along these lines to the next Working Draft. Jonathan At 10:38 AM 1/14/2002 -0500, Shawn Vincent wrote: >Summary: Please add verbiage to the spec clarifying important points > about sequences. > >It is clear that a lot of thought and effort went into creating a >model for sequences that is usable and yet supports its XML legacy. > >In particular: > > 1. An item is IDENTICAL to a sequence of length 1 containing that > item. > > That is, 1 is the same as (1). > > 2. There are no nested sequences. > > That is, (1, (2, 3), ()) is the same as (1, 2, 3) > > 3. The empty sequence is often used as a nil/null value. > >These points (and especially the first two) are vital to understanding >and using XQuery. > >However, it took me a long time to understand these points, as they >are not clearly and explicitly stated, and this sequence model is >different from most other languages (it has similarities to APL, >perhaps). > >I'd propose adding some verbiage to the spec calling out these points >explicitly. This would ideally be done in the section that defines >sequences, singleton sequences, etc. > >Thank you for your time. > > -Shawn. > > >-- >Shawn Vincent, svincent@exalt.com >Exalt Inc.
Received on Wednesday, 23 January 2002 13:11:36 UTC