Bug report
Thank you for this project! I'm new to Python, so I apologize if I've overlooked something.
What's wrong
from collections.abc import Callable
from returns.pipeline import flow, pipe
from returns.pointfree import map_
from returns.result import Success
def get_data(data: str) -> str:
return "200" + data
def do_more(data: int) -> int:
return data - 300
def transform(s: str) -> str:
return f"transformed: {s}"
my_pipe: Callable[[str], str] = pipe(get_data, do_more, transform)
print(flow(Success("500"), map_(my_pipe)))Gives following runtime error while mypy doesn't complain:
(py-starter) python-boilerplate > python working.py
Traceback (most recent call last):
File "/Users/hoschi/repos/python-boilerplate/working.py", line 22, in <module>
print(flow(Success("500"), map_(my_pipe)))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Caskroom/miniconda/base/envs/py-starter/lib/python3.12/site-packages/returns/_internal/pipeline/flow.py", line 50, in flow
return reduce( # type: ignore
^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Caskroom/miniconda/base/envs/py-starter/lib/python3.12/site-packages/returns/_internal/pipeline/flow.py", line 51, in <lambda>
lambda composed, function: function(composed), # type: ignore
^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Caskroom/miniconda/base/envs/py-starter/lib/python3.12/site-packages/returns/pointfree/map.py", line 55, in factory
return container.map(function)
^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Caskroom/miniconda/base/envs/py-starter/lib/python3.12/site-packages/returns/result.py", line 426, in map
return Success(function(self._inner_value))
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Caskroom/miniconda/base/envs/py-starter/lib/python3.12/site-packages/returns/_internal/pipeline/pipe.py", line 34, in <lambda>
return lambda instance: flow(instance, *functions)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Caskroom/miniconda/base/envs/py-starter/lib/python3.12/site-packages/returns/_internal/pipeline/flow.py", line 50, in flow
return reduce( # type: ignore
^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/homebrew/Caskroom/miniconda/base/envs/py-starter/lib/python3.12/site-packages/returns/_internal/pipeline/flow.py", line 51, in <lambda>
lambda composed, function: function(composed), # type: ignore
^^^^^^^^^^^^^^^^^^
File "/Users/hoschi/repos/python-boilerplate/working.py", line 13, in do_more
return data - 300
~~~~~^~~~~
TypeError: unsupported operand type(s) for -: 'str' and 'int'
How is that should be
Mypy should detect the error. It can detect the error when the problem function is used at first arg: pipe(do_more, get_data, transform)
System information
-
python version: 3.12
-
returns version: returns = {extras = ["compatible-mypy"], version = "^0.26.0"}
-
mypy version: mypy = "^1.17.1"
-
hypothesis version (if any):
-
pytest version (if any):
Bug report
Thank you for this project! I'm new to Python, so I apologize if I've overlooked something.
What's wrong
Gives following runtime error while mypy doesn't complain:
How is that should be
Mypy should detect the error. It can detect the error when the problem function is used at first arg:
pipe(do_more, get_data, transform)System information
pythonversion: 3.12returnsversion:returns = {extras = ["compatible-mypy"], version = "^0.26.0"}mypyversion:mypy = "^1.17.1"hypothesisversion (if any):pytestversion (if any):