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Re: [ddlm-group] Role of separators in CIF

Dear Colleagues,

   I am also concerned about Nick's statement.  I believe that it has set 
this group off in an unfortunate direction.   I would like to suggest
that each of us, including Nick, simply express what they individually
believe will produce the most useful and coherent CIF2 specification
with whatever technical reasons are behind it and not adopt rigid
"non-negotiable" positions.

   I do not see how allowing the quote and double quote in non-delimited
strings after the first character impedes the creation of recursive
data structures any more than the apperance of single quote in a
double quoted string or a double quote in a single quoted string
would impede the creation of recursive data structures.


  Herbert J. Bernstein, Professor of Computer Science
    Dowling College, Kramer Science Center, KSC 121
         Idle Hour Blvd, Oakdale, NY, 11769


On Tue, 1 Dec 2009, Brian McMahon wrote:

> I want to vote "For" on this proposition, but I'm concerned by Nick's
> assertion of 9 October
> http://www.iucr.org/__data/iucr/lists/ddlm-group/msg00038.html
>     (1) restricting the character set of non-delimited strings is
>     NON-NEGOTIABLE. If we don't restrict it, then we can't build
>     recursive data structures and exploit DDLm.
> I understood this to be definitely ruling out the embedding of the
> quote characters in non-delimited strings, but I've lost track of the
> details of the subsequent discussions.
> Regards
> Brian
> On Tue, Dec 01, 2009 at 04:56:52PM +1100, James Hester wrote:
>> Simon: From reading your previous emails, I'm guessing that the source of
>> your concern is that the possible characterset of non-delimited strings
>> appears more restrictive than is strictly necessary.  In particular, you're
>> not sure why we have excluded quote and double quote from non-delimited
>> strings.
>> You are correct that the other CIF2 syntax does not require that quote or
>> double quote are excluded from non-delimited strings (apart from the first
>> character, of course).  The exclusion of the quote/double quote was on
>> general principle of keeping all characters that serve as delimiters out of
>> non-delimited strings, even if those characters could never cause confusion.
>> It also has the benefit of allowing some syntax errors to be picked up.
>> Nick is with me in Sydney, and we have decided that this is the sort of
>> issue that we just have to vote on, as the arguments either way are not
>> conclusive.
>> I would therefore call everybody to vote on the following proposition:
>> "That <quote> and <double quote> may appear in non-delimited strings, as
>> long as they are not the first character"
>> Voting so far:
>> Against: Nick
>> For: James
>> Agnostic: ?
>> --
>> T +61 (02) 9717 9907
>> F +61 (02) 9717 3145
>> M +61 (04) 0249 4148
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