New Feature: Type checker now supports generators functions. If yield type isn't specified, the checker infers the type from yield clauses.
New Feature: Added support for type hints that use a combination of string and non-string tokens (e.g. Optional['Foo']).
New Feature: Added support for comment-based type hints for assignment statements, since these are used in some typeshed stub files.
New Feature: Added support for class decorators and added a configuration switch "reportUntypedClassDecorator" to allow these to be flagged by the type checker.
New Feature: Type checker now distinguishes between access, set, and delete operations when accessing members of an object and flags errors when that usage is not supported (e.g. writing to a property that has no defined setter).
Enhancement: Improved type checker's ability to track types within while and for loops.
Fixed bug with structural (protocol) type checking that generated false positives.
Deleted Python 2 typeshed fallback stub files since they are never used by Pyright. This reduced the package size by about 100K.