Experimental lens like library in Python
Goals:
- reusability and composition of lenses
- typesafe
- easy syntax
Example of a composed lens using the overloaded >> operator
data = {"x": {"y": 42}}
lens_x = DictLens[dict](key="x")
lens_y = DictLens[int](key="y")
error, result = data >> lens_x >> lens_y
assert result == 42