goose.py

"""
Goose implements Goose Typing (tm), a set of shims which allows the st3m
codebase to use both Python type annotations, Abstract Base Classes and run
under Micropython.
"""

# Detect whether we're in MyPy or just executing.
try:
    from typing import TYPE_CHECKING
except:
    TYPE_CHECKING = False

if TYPE_CHECKING:
    # We're in MyPy.
    from abc import ABCMeta, abstractmethod

    class ABCBase(metaclass=ABCMeta):
        pass

    from typing import (
        List,
        Optional,
        Tuple,
        Dict,
        Any,
        Callable,
        Iterator,
        Generator,
        Union,
    )
    from enum import Enum
else:
    # We're in CPython or Micropython.
    class ABCBase:
        pass

    def abstractmethod(f):
        def _fail():
            raise Exception("abstract method call")

        return _fail

    try:
        from typing import (
            List,
            Optional,
            Tuple,
            Dict,
            Any,
            Callable,
            Iterator,
            Generator,
            Union,
        )
        from enum import Enum
    except ImportError:
        # We're in Micropython.
        List = None
        Optional = None
        Tuple = None
        Dict = None
        Any = None
        Callable = None
        Iterator = None
        Generator = None
        Union = None

        class Enum:
            pass


__all__ = [
    "TYPE_CHECKING",
    "ABCBase",
    "abstractmethod",
    "List",
    "Optional",
    "Enum",
    "Tuple",
    "Dict",
    "Any",
    "Callable",
    "Iterator",
    "Generator",
    "Union",
]