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Re: Draft JSON specification for CIF

In reply to Bob:

(1) CIF2 header: Sorry, my mistake, there should be a CIF2 header for the example CIF file (it is required).  I have corrected the draft at Github.
(2) ["dataname.a"] vs "dataname.a" . I don't understand why JSON would require that a string containing a period should be put inside square brackets
(3) Substituting "_" for ".". The proposed standard simply preserves the dataname as it appears in the CIF file (whether it contains "." or not). Strictly speaking, any equivalence between datanames can only be determined by consulting a CIF dictionary.  Although COMCIFS naming policy leads to some useful shortcuts, they are not part of the CIF syntax standard so should not be included in the JSON standard.
(4) Agree that a test implementation that can digest a range of valid CIF files would be necessary before acceptance.  Once we have some consensus I'm happy to produce something in Python (although one using the CIFAPI would be great as well).

all the best,

On 12 April 2017 at 21:36, Robert Hanson <hansonr@stolaf.edu> wrote:
I'd like to see an actual CIF or mmCIF file turned into JSON by this spec before judging.
But I'm pretty sure this is exactly what Jmol does already.

My first reaction is that "dataname.a" is problematic. The presence of the period demands that ["dataname.a"] syntax be used. And it suggest poor parsing of the data labels. But it might be the  simplest option.

An important aspect it seems to me is how to parse data names that include "." vs. "_". Jmol ignores this difference completely,  partially because mmCIF and CIF seem to differ some on this. (I can't remember what the IUCr spec says on "." vs. "_".)

The CIF file as shown is invalid. I presume there is an implied CIF2 header?

I would recommend REQUIRING a CIF2 header.

Bob Hanson

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