On 05.02.22 00:55, Chapman Flack wrote:
I'm thinking plhandler.sgml is the only place that really needs to be said; readers looking up CREATE TRANSFORM and using an existing PL that supports it don't need to know how the sausage is made. (Maybe it is worth mentioning there, though, that it isn't possible to develop transforms for an arbitrary PL unless that PL applies transforms.)
makes sense
I noticed the CREATE TRANSFORM docs show the argument list as (argument_type [, ...]) even though check_transform_function will reject any argument list of length other than 1 or with type other than internal. Is that an overly-generic way to show the syntax, or is that a style with precedent elsewhere in the docs?
That could be corrected.
As long as a PL handler has the sole responsibility for invoking its transforms, I wonder if it would make sense to allow a PL to define what its transforms should look like, maybe replacing check_transform_function with a transform_validator for the PL. I'm not proposing such a patch here, but I am willing to prepare one for plhandler.sgml and maybe pltemplate.c documenting the current situation, if nobody tells me I'm wrong about something here.
Maybe. This kind of thing would mostly be driven what a PL wants in actual practice, and then how that could be generalized to many/all PLs.
