PyHaskell

Rewriting Haskell modules and libraries in Python.

We care about the function signatures, not the implementation. For example, consider a function in Haskell that operates on what is semantically a list, taking other arguments, and then returns a list.

We don't care how Haskell did it. We'll do the correct semantic thing for Python.

Let's start with Prelude!

Reference the builtins from the builtins module:

import builtins

def all(fn, a) -> bool:
    """all :: Foldable t => (a -> Bool) -> t a -> Bool
    """
    return builtins.all(fn(i) for i in a)

Let's keep them in order that we get them from the following command:

Prelude> :browse Prelude

Functions that aren't legal python names (keywords or symbols) should get a name that uses a short nickname for it.

• bang means !
• hat means ^
• cash means $
• ampersand means & (unless we can get away with and)

For example:

def bangbang(list_of_a, integer) -> 'a':
    """(!!) :: [a] -> Int -> a
    """