Summary:
This is a central abstraction for coming future unknown nullability support.
# Context
Annot.ml is a low-level module:
- it contains lists of raw (string) annotations
- no algebraic datatypes for annotations
- it mixes annotations that Nullsafe should be aware of with all sorts of other annotations
- some annotations make sense for return values, some make sense for params, and some make sense for methods.
But, most importantly, it does not contain information about source of an annotation, making it hard to distinct things like "Nonnull as default" vs "Nonnull as explicitly annotated" vs "Nonnull as modelled". Ditto for nullable.
Because of this, it is tricky to introduce unknown nullability in an elegant way.
Let's get rid of using Annot.Item.t in nullsafe code in the following way:
- Move nullability information associated with the Java type to a dedicated algebraic DT.
- Split other annotations that are important for nullsafe into param flags, ret value flags, and method flags, and introduce corresponding datatypes.
# This diff
This diff introduces NullsafeType and adds this to AnnotatedSignature.
It is not used yet, hence the diff is a no-op.
In future diffs, we are going to (see also TODOs in the code):
- actually use this information instead of accessing Annot.item
- add more information to AnnotatedSignature
- remove Annot.item from AnnnotatedSignature
- when this is done, introduce notion of unknown nullability.
Reviewed By: ngorogiannis
Differential Revision: D17420595
fbshipit-source-id: b30706d9b
Mitya Lyubarskiy
633186c41e