Comment by lpghatguy
15 hours ago
When I was writing a bunch of Lua, I was a big fan of having a None sentinel value (Lua uses 'nil' for representing absence) and it was useful for a lot of things similar to Pydantic's MISSING.
This distinction is something that I think is actually handy about JavaScript, and distinguishing between 'null' and 'undefined' is sometimes useful for similar reasons.
I feel like faster exceptions would be a better solution for this sort of thing. Leave functions returning the happy path with excepted values. Exceptional things, like missing values being handled at the level where of abstraction that actually cares to catch it: