def ask(self, prompt: str, default: Literal['y', 'n'],
do: ZIOMonad[System, NoReturn]) -> ZIO[System, NoReturn, bool]:
default_str = 'Y/n' if default == 'y' else 'y/N'
choice = do << self.get_input_from_console(
prompt=f"{prompt} [{default_str}]: ",
parse_value=(ZIO.from_callable(str).map(str.lower).require(
lambda s: s in {'y', 'n'},
lambda s: s).either().to_callable()),
default_value=default)
return ZIO.succeed(choice == 'y')
def prog(
do: ZIOMonad[ConsoleSystemEnvironment, NoReturn]
) -> ZIO[ConsoleSystemEnvironment, NoReturn, int]:
age = do << console.get_input_from_console(
prompt="How old are you?\n",
parse_value=ZIO.from_callable(str).map(int).catch(
ValueError).either().to_callable(),
default_value=21)
do << console.print(f"You are {age} years old.")
return ZIO.succeed(age)
def input(
self,
prompt: Optional[str] = None
) -> ZIO[object, Union[EOFError, KeyboardInterrupt], str]:
user_input = self._user_input.pop(0)
self._effects.append(console_effect.Input(prompt, user_input))
if isinstance(user_input, str):
return ZIO.succeed(user_input)
else:
result: Union[EOFError, KeyboardInterrupt] = user_input
return ZIO.fail(result)
def test_zio_flatten_1() -> None:
count = 0
def _impure_function(x: int) -> ZIO[object, NoReturn, int]:
nonlocal count
count += 1
return ZIO.succeed(x + 1)
assert (ZIO.succeed(100).flat_map(_impure_function).flat_map(
_impure_function).flat_map(_impure_function).map(
lambda x: ZIO.succeed(f"The result is: {x}")).flatten()._run(
())) == Right("The result is: 103")
assert count == 3
def test_from_callable() -> None:
def _f(arg_1: int, arg_2: str, *, arg_3: float) -> str:
return f"{arg_1} {arg_2} {arg_3}"
program = ZIO.from_callable(_f)
assert unsafe_run(program.provide(FunctionArguments(
42, "foo", arg_3=3.14))) == "42 foo 3.14"
def test_zio_flatten_2() -> None:
count = 0
def _impure_function(x: int) -> ZIO[object, NoReturn, int]:
nonlocal count
count += 1
return ZIO.succeed(x + 1)
def _kaboom(x: int) -> ZIO[object, NoReturn, int]:
raise Bippy
assert (ZIO.succeed(100).flat_map(_impure_function).flat_map(
_kaboom).flat_map(_impure_function).flat_map(_impure_function).map(
lambda x: ZIO.succeed(f"The result is: {x}")).catch(
Bippy).flatten()._run(())) == Left(Bippy())
assert count == 1
def test_zio_catch_3() -> None:
def _impure_function() -> int:
raise Bippy
program = ZIO.effect_total(_impure_function).catch(NotBippy)
with pytest.raises(Bippy):
program._run(())
def test_zio_effect_catch_3() -> None:
def _impure_function() -> None:
raise Bippy
program = ZIO.effect_catch(_impure_function, NotBippy)
with pytest.raises(Bippy):
program._run(())
def test_get_input_from_console_eof_error() -> None:
program = console.get_input_from_console(
prompt="How much wood would a woodchuck chuck?",
parse_value=ZIO.from_callable(str).map(int).catch(
ValueError).either().to_callable(),
default_value=None)
exception = EOFError()
mock_console = MockConsole(["bad", "input", exception])
mock_system = MockSystem()
with pytest.raises(SystemExit):
unsafe_run(
program.provide(
ConsoleSystemEnvironment(console=mock_console,
system=mock_system)))
assert mock_console.effects == [
console_effect.Input("How much wood would a woodchuck chuck?", "bad"),
console_effect.Input("How much wood would a woodchuck chuck?",
"input"),
console_effect.Input("How much wood would a woodchuck chuck?",
exception),
console_effect.Print("")
]
assert mock_console.user_input == []
assert mock_system.effects == [system_effect.Exit(None)]
def input(
self,
prompt: Optional[str] = None
) -> ZIO[object, Union[EOFError, KeyboardInterrupt], str]:
return (ZIO.effect_catch(
lambda: builtins.input(prompt)
if prompt is not None else builtins.input(),
EOFError).catch(KeyboardInterrupt))
def program(
do: ZIOMonad[Console, Union[EOFError, KeyboardInterrupt]]
) -> ZIO[Console, Union[EOFError, KeyboardInterrupt], str]:
con = do << Environment()
do << con.print("Hello, what is your name?")
name = do << con.input()
do << con.print(f"Your name is: {name}")
x = do << ZIO.succeed(1)
while x < 20:
x = do << (
ZIO.succeed(x).map(lambda p: p + 1).flat_map(lambda q: ZIO.succeed(
q - 1)).flat_map(lambda r: ZIO.succeed(r + 1)))
do << con.print(f"The value of x is: {x}")
return ZIO.succeed(f"Hello, {name}!")
def get_input_from_console(
self, prompt: str, parse_value: Callable[[str], Either[E, A]],
default_value: Optional[A],
do: ZIOMonad[System, NoReturn]) -> ZIO[System, NoReturn, A]:
while True:
keyboard_input = do << (
self.input(prompt).either().map(lambda e: e.to_union()))
if isinstance(keyboard_input, (EOFError, KeyboardInterrupt)):
do << self.print("")
system = do << Environment()
return system.exit()
if keyboard_input == '' and default_value is not None:
return ZIO.succeed(default_value)
parse_result = parse_value(keyboard_input)
if isinstance(parse_result, Right):
return ZIO.succeed(parse_result.value)
def test_zio_effect_catch_1() -> None:
x: Optional[int] = None
def _impure_function() -> int:
nonlocal x
x = 100
return 42
program = ZIO.effect_catch(_impure_function, Bippy)
assert x is None
assert program._run(()) == Right(42)
assert x == 100
def test_zio_map_1() -> None:
count = 0
def _impure_function(x: int) -> int:
nonlocal count
count += 1
return x + 1
assert (ZIO.succeed(100).map(_impure_function).map(_impure_function).map(
_impure_function).map(lambda x: f"The result is: {x}")._run(
())) == Right("The result is: 103")
assert count == 3
def test_from_to_callable_1() -> None:
class Cat:
def meow(self, *, volume: int) -> str:
if volume < 10:
return "meow"
else:
return "MEOW!"
meow_to_callable = (Environment[Cat]().map(lambda cat: ZIO.from_callable(
cat.meow)).swap_environments().to_callable())
assert unsafe_run(meow_to_callable(volume=11).provide(Cat())) == "MEOW!"
def test_zio_effect_success() -> None:
x: Optional[int] = None
def _impure_function() -> None:
nonlocal x
x = 42
program = ZIO.effect(_impure_function)
assert x is None
program._run(())
assert x == 42
def test_zio_map_error_1() -> None:
count = 0
def _impure_function(x: int) -> int:
nonlocal count
count += 1
return x + 1
assert (ZIO.fail(100).map_error(_impure_function).map_error(
_impure_function).map_error(_impure_function).map_error(
lambda x: f"The result is: {x}")._run(
())) == Left("The result is: 103")
assert count == 3
def test_zio_lshift_2() -> None:
def _kaboom(x: object) -> Either[NoReturn, int]:
raise Bippy
assert ((ZIO.succeed(100) << ZIO.succeed(1) << ZIO.succeed(2) <<
ZIO(_kaboom) << ZIO.succeed(3)).flat_map(lambda x: ZIO.succeed(
f"The result is: {x}")).catch(Bippy))._run(
()) == Left(Bippy())
def test_from_to_callable_2() -> None:
@dataclass(frozen=True)
class SomeException(Exception):
message: str
class SomeAPI:
def thing_that_may_fail(self, *, bippy: str) -> int:
raise SomeException("Murphy's Law")
safer_thing = (Environment[SomeAPI]().map(
lambda api: (ZIO.from_callable(api.thing_that_may_fail).catch(
SomeException).either())).swap_environments().to_callable())
assert unsafe_run(safer_thing(bippy="bippy").provide(SomeAPI())) == Left(
SomeException("Murphy's Law"))
def test_zio_map_error_2() -> None:
count = 0
def _impure_function(x: int) -> int:
nonlocal count
count += 1
return x + 1
def _kaboom(x: int) -> int:
raise Bippy
assert (ZIO.fail(100).map_error(_impure_function).map_error(_kaboom).
map_error(_impure_function).map_error(_impure_function).map_error(
lambda x: f"The result is: {x}").catch(Bippy)._run(
())) == Left(Bippy())
assert count == 1
def test_get_input_from_console_1() -> None:
program = console.get_input_from_console(
prompt="How much wood would a woodchuck chuck?",
parse_value=ZIO.from_callable(str).map(int).catch(
ValueError).either().to_callable(),
default_value=None)
mock_console = MockConsole(["42"])
mock_system = MockSystem()
output = unsafe_run(
program.provide(
ConsoleSystemEnvironment(console=mock_console,
system=mock_system)))
assert output == 42
assert mock_console.effects == [
console_effect.Input("How much wood would a woodchuck chuck?", "42")
]
assert mock_console.user_input == []
def exit(
self,
exit_code: Optional[int] = None
) -> ZIO[object, NoReturn, NoReturn]:
self._effects.append(system_effect.Exit(exit_code))
return ZIO.fail(SystemExit(exit_code)).or_die()
def exit(
self,
exit_code: Optional[int] = None
) -> ZIO[object, NoReturn, NoReturn]:
return ZIO.effect_total(lambda: sys.exit(exit_code)) # type: ignore
def print(self, line: str) -> ZIO[object, NoReturn, None]:
self._effects.append(console_effect.Print(line))
return ZIO.succeed(None)
def test_zio_fail() -> None:
assert ZIO.fail(42)._run(()) == Left(42)
def print(self, line: str) -> ZIO[object, NoReturn, None]:
return ZIO.effect_total(lambda: builtins.print(line))
def test_to_callable() -> None:
def _f(arg_1: int, arg_2: str, *, arg_3: float) -> str:
return f"{arg_1} {arg_2} {arg_3}"
g = ZIO.from_callable(_f).to_callable()
assert g(42, "foo", arg_3=3.14) == "42 foo 3.14"
def test_zio_effect_failure() -> None:
def _impure_function() -> None:
raise Bippy
program = ZIO.effect(_impure_function)
assert program._run(()) == Left(Bippy())
def effects(
self) -> List[Union[console_effect.Print, console_effect.Input]]:
return self._effects
@property
def user_input(self) -> List[Union[EOFError, KeyboardInterrupt, str]]:
return self._user_input
class HasConsole(Protocol):
@property
def console(self) -> Console:
pass # pragma: nocover
print = (Environment[HasConsole]().map(lambda env: ZIO.from_callable(
env.console.print).flatten()).swap_environments().to_callable())
input = (Environment[HasConsole]().map(lambda env: ZIO.from_callable(
env.console.input).flatten()).swap_environments().to_callable())
class HasConsoleSystem(HasConsole, HasSystem, Protocol):
pass
def get_input_from_console(
prompt: str, parse_value: Callable[[str], Either[E, A]],
default_value: Optional[A]) -> ZIO[HasConsoleSystem, NoReturn, A]:
return (Environment[HasConsoleSystem]
().flat_map(lambda env: env.console.get_input_from_console(
prompt, parse_value, default_value).provide(env.system)))
def test_zio_effect_catch_2() -> None:
def _impure_function() -> None:
raise Bippy
program = ZIO.effect_catch(_impure_function, Bippy)
assert program._run(()) == Left(Bippy())