Metadata consumers and processors would be similar executable documentation.
Also, for there are benefits for spelling the metadata format in
a standard, as opposed to relying on a particular scraper implementation
to be the standard.
Human error would still be possible in coding a scraper that scrapes
unstructured data. I don't know the details of how they're coded, but
it's conceivable they could miss some part of the scheme implementation
which says which srfi's that implementation supports, especially when
things change over the years.
Such a mistake will be much harder to make when one is consuming
well documented and standardized metadata, that was explicitly designed
to give you that information.
It is still possible for humans to make a mistake in populating the
metadata in the first place, however. So I see your point.
I guess this is a tradeoff one has to decide on between errors by
humans in populating and maintaining their scheme's metadata vs
errors in scrapers as the contents of tar files change.
By all means, it would be much better if the source information was
provided by Scheme implementations' authors in a standard format so we
could have only one scraper. We are only using the tailor-made scrapers
because we don't have anything better :)
That makes sense to me. As long as it's structured data, explicitly
intended to furnish the desired metadata.
+1. Also, unlike many data formats, S-expressions are easy to extend in
the future without making a mess. This is important for long-term evolution.
