On 12 April 2016 at 12:36, Arcadiy Ivanov <arca...@gmail.com> wrote:
> Is there any interest and/or tips to allow a pluggable parser or at least
> allow some syntactical pluggability by extensions?
> I think this may allow some projects to move towards becoming an extension
> as opposed to forking the project entirely.
How would you go about it?
PostgreSQL uses a parser generator that produces C code as its output.
Extensions can't just patch the grammar and regenerate the parser. So even
if it were desirable, a fully extensible parser would require a total
rewrite of the parser/lexer.
That doesn't mean there can't be extension points for SQL syntax, they just
need to be planned carefully, located where they won't create parsing
ambiguities, and somewhat limited.
Craig Ringer http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services