Extensible predicates about honeysql

[seancorfield]

@hlship In MySQL, I'd expect DATE_SUB( NOW(), INTERVAL ? SECONDS ) so I was curious about the quote in the PostgreSQL version: can you write now() - interval '? seconds' and still have a parameter there?

(I'm considering a new reader literal that is halfway between raw and regular constructed SQL so parameters would work -- but I'm not sure how parameter lifting would work if you have them inside SQL strings)

[seancorfield]

I think this might be partly addressed by #219 because once that's done you should be able to write:

[:< :expired_at (raw ["now() - interval '" seconds " seconds'"])]

[seancorfield]

This has been implemented as part of #219 and the README now includes this particular example.

I'm not convinced that named abstractions/functions should be supported in the DSL (yet) so I'm going to close this out. Feel free to add comments to #219 for other use cases that are not yet supported by this.