mys 0.5.0

Strongly typed Python to C++ transpiler.

Mys

🚧 🚧 🚧 🚧 🚧 Under construction - DO NOT USE 🚧 🚧 🚧 🚧 🚧

Strongly typed Python to C++17 transpiler.

Project homepage: https://github.com/eerimoq/mys

🚧 🚧 🚧 🚧 🚧 Under construction - DO NOT USE 🚧 🚧 🚧 🚧 🚧

Installation

$ pip install mys

Tutorial

First of all, create a package and enter it. This package is used in the examples below.

$ mys new foo
$ cd foo

The package template creates a hello world appliaction.

def main():
    print('Hello, world!')

Build and run it with mys run.

$ mys run
Hello, world!

Now, replace the src/main.mys contents with the code below.

def foo(a: s32) -> Tuple[s32, str]:
     return 2 * a, 'Bar'

def main(args: List[str]):
    print(foo(s32(args[1])))

Build and run it.

$ mys run
(10, 'Bar')

Goals

• Blazingly fast programs written in Python.

• Small statically linked binary.

• No GIL, mainly to allow threads to run in parallel. However, data races will occur when multiple threads uses a variable at the same time, which will likely make the program crash.

Limitations

• All elements in a list must have the same type.

• All items in a dict must have the same key and value types. Key and value may be different types.

• All items in a set must have the same type.

• Max 64 bits integers.

• 32 and 64 bits floats.

• No decorators.

• No dynamic properties (getattr, setattr, eval, …).

• No async.

• …

Types

Using types defined in the standard library typing module where possible.

Variables may all be set to None if declared as Optional.

C++ auto is used in the generated code if the type is omitted.

Python Type	Mys Type
int	u8, u16, u32, u64
int	s8, s16, s32, s64
float	f32, f64
str	str
bytes	bytes
bytearray	bytearray
tuple	Tuple
list	List
dict	Dict
set	Set

Performance

ToDo.

Resources

https://github.com/python/mypy/blob/master/test-data/unit/pythoneval.test

https://medium.com/@konchunas/monkeytype-type-inference-for-transpiling-python-to-rust-64fa5a9eb966

http://blog.madhukaraphatak.com/functional-programming-in-c++/

https://github.com/Instagram/MonkeyType

Similar projects

https://github.com/konchunas/pyrs

https://github.com/lukasmartinelli/py14

https://github.com/shedskin/shedskin

https://github.com/pradyun/Py2C

https://github.com/mbdevpl/transpyle

http://numba.pydata.org/

https://github.com/Nuitka/Nuitka

https://github.com/QQuick/Transcrypt

https://github.com/pyjs/pyjs