Open jml opened 7 years ago
Experience from Aeson shows that we want to be very clear about the difference between a missing field and null
. Maybe
can communicate both, but in JSON missing and null
are not the same (e.g. in JavaScript they get decoded to undefined
and null
on key lookup).
So IMO we should mark fields that can be null
and fields that are optional differently and clearly.
It's possibly a bit dodgy relying on
Maybe Foo
in a schema definition to mean "Foo
is nullable". I've forgotten why it's dodgy, but @teh can fill in.