question on parsing postgres sql queries

Hello,

I am doing some research on postgres sql query parsing.

I have found the https://github.com/lfittl/libpg_query project which
manages to re-use the native postgres server parser. For using this, you
need to accept an external dependency on a lib compiled out of the postgres
source.

I was wondering what people think of the conformance with regards to the
real parser of the documentations on
- https://www.postgresql.org/docs/current/static/sql-select.html
- https://www.postgresql.org/docs/current/static/sql-copy.html
... and more generally sgmls in
https://github.com/postgres/postgres/tree/master/doc/src/sgml/ref

Would it make sense to use these sgml synopsis as some kind of source of
truth, parse them, and automatically generate a parser for a specifc
language ?

This could enable the creation of parsers for different languages using
parser generators based on the synopsis.

I feel like the conformance level of the documentation is high and that the
sgml synopis seem to be nearly programmatically sufficient to create
parsers.

what do you think ?

Could the parser commiters share some lights on how the documentation
process interacts with the parser commits ?

Thanks,
Jerome