Opened 7 years ago
Last modified 5 years ago
#760 new enhancement
Use lemon %fallback?
| Reported by: | Olly Betts | Owned by: | Olly Betts |
|---|---|---|---|
| Priority: | normal | Milestone: | |
| Component: | QueryParser | Version: | git master |
| Severity: | normal | Keywords: | |
| Cc: | Blocked By: | ||
| Blocking: | Operating System: | All |
Description
Recent versions of the lemon parser generator have a %fallback directive:
https://www.sqlite.org/src/doc/trunk/doc/lemon.html#pfallback
This is potentially useful for handling parsing of operators like AND, OR, NEAR, etc while also allowing parsing of pasted text which might contain these operators as words (especially an issue when FLAG_BOOLEAN_ANY_CASE is used and and, or, near, etc are recognised as operators).
One wrinkle is that it would be useful to hook in and detect when this has happened so we can provide correction suggestions instead, or say the correction has been done but provide a way to undo it. Maybe that can be done by using an intermediate token as the target for %fallback which records the correction that was done?
