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Re: [ddlm-group] Space as a list item separator>

My low-weighted vote is for a uniform delimiter for all series of 
values. If #1 is deemed to be a better list delimiter, then it should be 
used to separate all adjacent values, not just bracketed lists.

The backwards-compatibility argument that a comma-delimited list can be 
an opaque CIF1.1 string is somewhat valuable, but it would not apply to 
lists containing any string with spaces, and is only a short-term benefit.

If commas are allowed, care needs to be taken in defining syntax rules. 
What happens if you mix commas and spaces in a single list? Is [1 2,3,4] 
the same as [1,2,3,4] or ["1 2",3,4], or a syntax error?

If some people rally want commas, is it possible to define two list 
forms, where braces contain commas, and brackets do not? For example, 
{1,2,3,4} is equivalent to [1 2 3 4]? I think this idea relates to an 
earlier discussion of multiple list types, but this idea is to allow two 
syntax forms of the same common list type. I don't like the extra 
complexity, but maybe this is a useful compromise. Even if it is not 
used in actual CIF files, the bracket+comma notation could be a standard 
conversion syntax when you want to represent a list as a single string item.

Joe Krahn


Herbert J. Bernstein wrote:
> First amending the arguments
> 
> To summarise the arguments:
> 
> 1. In favour of both space and comma
>    - comma is used in some other non-CIF contexts as a list delimiter
>     - comma allows a large subset of lists and arrays to be carried
> opaquely in CIF 1 and CIF 1.1 documents.
> 
> 2. Against comma:
>    - A single type of separator makes the grammar simpler
>    - Space is used everywhere else in CIF as a separator (consistency)
>    - Comma can then be used in non-delimited strings
> 
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