Discussion List Archives

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [ddlm-group] Use of elides in strings

Hi Joe: the eliding technique you suggest can easily be described and
handled at the dictionary level, and is unambiguous.  Do you therefore
agree with the proposition that there is no need to describe any
eliding mechanism in the CIF2 syntax?

When we (eventually) get on to discussing the DDL attributes that will
go into DDLm, we can discuss whether or not we want to define a
particular string type which would behave as you suggest.

As far as triple quotes are concerned, they provide alternative ways
of avoiding the need for any elision, and allow multiline strings to
start on the same line (as Herbert has pointed out).  If you would
like to take up the issue of triple quotes, can I ask you to start a
new thread or add to the previous one on that topic?

On Wed, Nov 25, 2009 at 10:38 AM, Joe Krahn <krahn@niehs.nih.gov> wrote:
> Nick Spadaccini wrote:
>> It appears to me that we have spent far too long on a syntactic issue which
>> can be avoided 99.9999% of the time. Quite simply given the 5 ways to
>> delimit strings, it is next to impossible to get a situation where you
>> cannot choose one of those to make the problem go away.
>> I think the RCSB systematically avoid it by choosing
>> "ab'cd"
>> 'ab"cd'
>> ;ab'"cd
>> ;
> IMHO, it would be cleaner to have an consistent elide mechanism that
> works 100% of the time, rather than add yet more quote mechanisms, and
> not bother to add triple quoting to the CIF syntax.
> If the semicolon-delimited quotes were updated to require an elided
> leading space on all quoted lines, the reverse-solidus elide sequence
> can also be avoided. It can also contain an entire CIF file, which can
> be valuable, even if some people think it is "silly".
> Herbert's line-folding example:
> ;\
> ;\
> ;
> would then be written as
> ;\
>  ;\
> ;
> The disadvantage is that it is not fully compatible with CIF1.1, but
> RCSB already indents intervening lines to match the first line, which is
> shifted by the beginning semicolon. For example (with ellipses added to
> avoid email folding):
> ;              The collection of x, y, and z ...
>                with reference to a Cartesian ...
>                system.
> ;
> Even without changing the current syntax, you can put CIF within CIF by
> indenting the multi-line string at the application/dictionary side.
> Joe Krahn
> _______________________________________________
> ddlm-group mailing list
> ddlm-group@iucr.org
> http://scripts.iucr.org/mailman/listinfo/ddlm-group

T +61 (02) 9717 9907
F +61 (02) 9717 3145
M +61 (04) 0249 4148
ddlm-group mailing list

Reply to: [list | sender only]
International Union of Crystallography

Scientific Union Member of the International Science Council (admitted 1947). Member of CODATA, the ISC Committee on Data. Partner with UNESCO, the United Nations Educational, Scientific and Cultural Organization in the International Year of Crystallography 2014.

International Science Council Scientific Freedom Policy

The IUCr observes the basic policy of non-discrimination and affirms the right and freedom of scientists to associate in international scientific activity without regard to such factors as ethnic origin, religion, citizenship, language, political stance, gender, sex or age, in accordance with the Statutes of the International Council for Science.