The overall approach looks architecturally correctly. Just two cosmetic
nits:
1. In `mcv_can_cap()`, the early-exit branch uses braces around `return
false`. This would normally be written without braces.
2. The doc comment above `mcv_can_cap()` says condition requires the
clause to be either an equality operator, or a bare boolean Var, but
implementation actually handles one more cases - `NOT var`
3. Apply pgindent into diff.
--
Best regards,
Ilia Evdokimov,
Tantor Labs LLC,
https://tantorlabs.com/
