Shed Skin restricted-Python-to-C++ compiler 0.9.9

I have just released version 0.9.9 of Shed Skin, a restricted-Python-to-C++ compiler. It comes with many changes under the hood to improve the code base. For example, Shakeeb has started adding type annotations to Shed Skin itself, whereas I have fixed many C++ compiler warnings. We have also replaced the old CPython-based dict and set implementations with STL unordered_map and unordered_set. While this may cost some performance for especially small toy programs, it really helps with maintainability.

There was also a type inference improvement, which hasn't happened in a while since it wasn't needed. It was however needed to add a cool new example called "pycsg", which shows how one can perform CSG (constructive solid geometry) using binary space partitioning (BSP). After some investigation I decided to make the type inference slightly less "optimistic", which should make it scale a lot better, at the cost of being slower overall. In the end this new example runs about 15 times faster after compilation on my system (not 15%.. 15 times!).

Most notably on the outside, Shed Skin now comes with --floatXX/--intXXX options, which allow you to specify the desired float/int precision. Unfortunately under windows, --int128 does not yet work, since C++ has not yet standardized 128-bit integers.. The relatively new othello2 and collatz examples now require --int64 and --int128, respectively, to function properly.

For the full list of changes, please see the release notes.

I would like to take this opportunity to (once again) invite others to help out in Shed Skin development. There is always enough to do, also low-hanging fruit, on both the Python and the C++ side of things. I at least think it is rather fun to work on.. :) Let me know if you'd like to contribute but aren't sure what you could bring to the table.

Of course just sending in feedback or new example programs (especially if they fail!) can be very motivating as well to keep improving things.

Fast DOOM WAD renderer in 999 lines of Python

For the longest time, I've wanted to re-implement the original DOOM engine in Python, and compile it with Shedskin to get reasonable performance. So when I finally ran across a pretty small engine written in Java, by Leonardo Ono, I decided to convert his version to Python.

I left out some optimizations (most notably "visplanes"), for readability and in order to keep everything under 1000 lines of code (while following PEP8). So it could run quite a bit faster still. This is including a WAD loader and interactive Pygame wrapper, that makes it almost feel like you are playing DOOM.

It's interesting how using Python (using just CPython) seems to be about as fast as using assembler back in the day.

This video shows the day-and-night difference in FPS after compilation using Shedskin.

The source code can be found in the Shedskin examples directory.

I may revisit the code now and then, to try and improve readability by adding comments and/or refactoring parts. Patches in this direction very much welcome of course.

In general, we are also always looking to receive more feedback and contributions from the community! While not the 'final' solution to Python performance, Shed Skin is great fun to hack on. See some potential issues for the next release to start looking into.