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Re: [ddlm-group] Elide close quotes by doubling?

Judging by the difficulties we had that eventually led to agreeing
that there were enough alternative data value delimiters to avoid
the use of any eliding mechanism (and thus returning all values as raw),
I suspect that arguing for a different eliding mechanism will also be fruitless?

I understand your view (Joe) about CSV, but we have to respect the
legacy that is CIF, which is why we have a variety of delimiters.
Otherwise, it could probably be argued that only one type of delimiter is necessary
(say """")...



From: Joe Krahn <krahn@niehs.nih.gov>
To: Group finalising DDLm and associated dictionaries <ddlm-group@iucr.org>
Sent: Friday, 4 December, 2009 18:03:03
Subject: [ddlm-group] Elide close quotes by doubling?

The reverse solidus (aka backslash) elide was dropped because it really
does not work well to elide only the close quote. Now that close quotes
are invalid when not followed by white space, it provides the
opportunity to elide close quotes by a repeated close-quote sequence,
similar to Fortran and CSV format. It is free of most of the
repercussions of defining reverse-solidus as an escape character, and is
only making use of a character sequence that would otherwise just be a
syntax error.

The caveat is that it could misinterpret valid CIF1 values. However, at
least RCSB has done a good job of avoiding embedded quotes by picking
alternate quoting types.

There are workarounds for embedded quotes, even for CIF-within-CIF, so
elides are not essential. However, I think this should be easy to
implement, and free of the hassles generated by backslash escapes.

Joe Krahn
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