Re: Org-cite (oc-csl) tip: Filtering bibliography for language

[Christian Moe <mail@christianmoe.com>]

Denis Maier writes:

> Am 19.12.2022 um 23:20 schrieb András Simonyi:
>> ... I've forgotten to add that another (probably more user friendly)
>> option would be to design and implement some kind of  filtering DSL.
>> András
>> On Mon, 19 Dec 2022 at 23:05, András Simonyi
>> <andras.simonyi@gmail.com> wrote:
>>>
>>> Dear All,
>>>
>>> On Mon, 19 Dec 2022 at 15:49, Christian Moe <mail@christianmoe.com> wrote:
>>>
>>>> Refinements welcome. I'm especially wondering what would be an elegant
>>>> way to generalize this for more languages without defining a predicate
>>>> for each language (given that we cannot pass the language as an
>>>> additional argument in the print_bibliography line).
>>>
>>> Thanks for describing this usage! As for the problem of generalizing
>>> to more languages, one relatively simple solution would be to allow
>>> arbitrary sexps as filters. Then one could write something like
>>>
>>> #+print_bibliography: :filter (lambda (item) (bibitem-has-language item "en")))
>>>
>>> Would this type of extension be helpful? One (not necessarily
>>> important)  consequence would be that filters of this type would be
>>> obviously unusable with the biblatex exporter.
>>>
>>> best wishes,
>>> András
>
> I'd say both options are certainly useful. A filtering DSL is surely
> the more user friendly option, but allowing lambda expressions would
> probably be quicker to implement, and it would also allow for
> predicates not anticipated by DSL designers.
>
> Best,
> Denis

Arbitrary sexps would give us more flexibility. Alternately, one could
achieve more or less the same by letting :filter collect any additional
arguments and pass them as &rest to the user's predicate function,
something like:

  #+PRINT_BIBLIOGRAPHY: :filter bibitem-lang-p nb nn no :type article

(This perhaps makes for cleaner solutions. And it is perhaps slightly
better from a security viewpoint: I hope for a bright future of
collaborative authoring in Org, so I'm wary of proliferating ways to
execute arbitrary elisp that a user might not notice. But we do have
such ways already, and it's possible to abuse the above solution as
well, so I don't know.)

Alternatively, I think there is a case for adding a user-friendly
:language property to the print_bibliography keyword. On my bookshelf it
vies with primary/secondary sources as the most common criterion for
separate bibliographies.

I was going to say that this is the only extension I can think of that
is needed beside :(not)(csl)type and :(not)keyword, but of course people
are sooner or later going to want easy-to-use properties to filter by
author, publication date ranges, and probably other criteria I cannot
think of right now, so it's a strategic decision for the maintainer(s)
if you want to go that way. :-)

Yours,
Christian