This is a variation of the Python 3.9 version of lis.py, to demonstrate some features of Python 3.10.

The most important change is using pattern matching in evaluate(). Language processing is great to show why match/case is much more than a switch statement. To showcase nested list destructuring in case, I added support to the (define (fun parm...) body) special form.

Other Python 3.10 features used:

• union types written as A | B instead of Union[A, B];
• explicit type alias definitions with typing.TypeAlias.

LR

São Paulo, June 19, 2021