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Re: [ddlm-group] Finalizing DDLm

I would favor treating a looped presentation of a single row of items as
valid in all cases, and treating the presentation as individual tags
and value as equally valid and equivalent.  I also like David's suggestion
of allowing a individual tag and value to be distributed over a loop
for the same category.  This would start to put us into a parallel position
to the handling of XML attributes.


At 10:35 AM -0500 3/11/10, David Brown wrote:
>Dear Colleagues,
>
>I assume that we are essentially finished in resolving syntax 
>problems, but in that discussion some items were identified as being 
>related to DDLm rather than syntax, so before we settle into serious 
>dictionary writing we need to understand the DDLm rules.
>
>One item that I believe was raised under this heading was whether, 
>if a loop contained a single set of items, it was necessary to 
>formally include this in a loop structure.  If this is deemed to be 
>necessary, then there has to be some way of identifying the items 
>that must appear in a loop.  The presence in the dictionary of a 
>_category_key.* item would seem to flag this, but it is applied at 
>the level of the category rather than at the level of an individual 
>item.  If the requirement that the loop structure must always be 
>used, then all the items in the category must be loopable, i.e., the 
>category cannot include items that would not normally be included in 
>the loop, items for example that apply equally to all the listed 
>items such as a scale factor that is the same for all the structure 
>factors in a loop.  This seems to be workable, but I am not sure how 
>the legacy CIFs would fit in, since categories may include some 
>listable item and some non-listable items, and I am sure the 
>listable items do not always appear in a loop if there is only one 
>set of such items reported in the CIF.
>
>Is this something that can be clarified fairly easily?  It has an 
>important bearing on how the CIF dictionaries are written.
>
>David
>
>Attachment converted: Macintosh HD:idbrown 55.vcf (TEXT/ttxt) (0046DFC7)
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