functional_programming/CHANGELOG.md

Changelog of the functional-programming course

2025-03-11

• Demo version of notebook 05_functors.py

2025-03-13

• 0.1.0 version of notebook 05_functors

Thank Akshay and Haleshot for reviewing

2025-03-16

• Use uppercased letters for Generic types, e.g. A = TypeVar("A")

• Refactor the Functor class, changing fmap and utility methods to classmethod

  For example:

  @dataclass
  class Wrapper(Functor, Generic[A]):
      value: A
  
      @classmethod
      def fmap(cls, f: Callable[[A], B], a: "Wrapper[A]") -> "Wrapper[B]":
          return Wrapper(f(a.value))
  
  >>> Wrapper.fmap(lambda x: x + 1, wrapper)
  Wrapper(value=2)
  

• Move the check_functor_law method from Functor class to a standard function

• Rename ListWrapper to List for simplicity
• Remove the Just class

• Rewrite proofs