question on parsing postgres sql queries

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