Consider using pybind for seamless operability between C++11 and python

[paniash]

Hi Dan!

Now that pyqrack has been made with the intention of providing python bindings for qrack, might I suggest using the pybind library made specifically for this purpose. This will reduce a lot of work writing these bindings from scratch. :-)

[WrathfulSpatula]

@paniash Thank you for the suggestion, and I'll consider it. I'm not really a Python programmer, first, and I wasn't aware that pybind might do the job more easily.

However, notice that, beyond Qrack itself, we have 0 dependencies; this is literally pure Python, at least. Qrack itself, when compiled without OpenCL, is pure C++11, also no linker or package dependencies, beyond std namespace. This is part of the core philosophy of Qrack, to absolutely minimize attack surface and any potential points of failure or deprecation in dependencies.

If this project grows, I'll definitely keep pybind in mind, (because this was honestly mind-numbing to code, last night). However, I'm sure you see the reasoning behind dependency-free pure Python, if the Qrack shared library interface doesn't change rapidly.

[paniash]

@WrathfulSpatula Sure! I'm always in favour of lesser dependencies! Just thought I'd let you know.

Thanks!

[paniash]

Found another one: https://cppyy.readthedocs.io/en/latest/

[WrathfulSpatula]

I'd certainly be open to alternative implementations, perhaps particularly less verbose ones, but I think, in basically one night's work, at least we also have a dependency-free shared library wrapper, now, alongside any others, whether it was slightly short-sighted in the "design phase." 😃

[WrathfulSpatula]

@paniash Thank you for the suggestion. My first impulse, with Qrack, is always to first resort to pure language standard. However, after a little time testing the pure ctypes implementation, we lack exception handling that PyQrack needs. Specifically, when the OpenCL API returns errors, (hopefully intermittently,) our best recourse in C++ is to throw exception, but Python user code can't easily handle these low-level exceptions without a wrapper like via pybind11 to convert these C++ exceptions into ones that Python can handle.

I'm already looking into this, and it's going in for the next release. However, it'd be great if you had input or wanted to contribute code. Perhaps you could review the PR. (Thanks in advance!)

[paniash]

@WrathfulSpatula Hi! I'll be happy to contribute when I find some time from my work. Thanks!

[WrathfulSpatula]

I went ahead and actually wrote manual exception handling in the shared library C interface itself, a while ago, so error handling is no longer something we lack. I realized, while Python can handle exceptions in a shared library, this was the right choice for the shared library C interface as a self-standing piece of software in itself, as C++ exceptions don't exist in C, and so they should be handled before the layer at which we expose a C interface. Hence, if a shared library C interface will be reused, exception handling with a Python dependency is kind of moot, though it's a great feature to offer if a *.dll/*.so only exists to serve a single Python package!

So, this was a great suggestion that's still on my mind, but we already did the hard work, to avoid the dependency. I'm open to further discussion, but I think we can consider the issue ticket closed, for now.