lorenzo-pasa / voc

A transpiler that converts Python bytecode into Java bytecode.

VOC

A transpiler that converts Python bytecode into Java bytecode.

This is experimental code. If it breaks, you get to keep all the shiny pieces.

What it does:

• Provides an API to let you programmatically create Java class files.
• Compiles a Python 3.4 source file into a Java class file in a nominated package. Supports the conversion of:
  • Class definition and construction
  • Class instantiation
  • Method definition and invocation
  • Some mathematical operations
  • Exception handling
  • for/while/if constructs
  • Identification of mainline entry points
  • Static initialization of modules.
  • List comprehensions

It doesn't currently support:

• Keyword arguments
• Generators
• Import statements
• exec()/eval()

These things should all be possible - it's just a matter of time and development effort.

Quickstart

Using Python 3.4, install voc, then run the example script:

$ pip install voc
$ python -m voc tests/example.py org.pybee
Creating class 'example'...
Writing example.class...
Done.

This will produce an example.class, in the org.pybee namespace, that you can run on any Java 1.7+ VM.

Next step - you need to compile the Python support libraries:

$ make

This will compile python.jar. You will need to make sure that the python.jar support file is in your classpath:

$ java -XX:-UseSplitVerifier -classpath python.jar:. example
Hello, World

The -CC:-UseSplitVerifier argument is necessary to turn off stack map verification in Java 7. This could be addressed by computing stack maps for generated code.

Documentation

Documentation for VOC can be found on Read The Docs.

Why "VOC"?

The Vereenigde Oostindische Compagnie (VOC), or Dutch East India Company, is often considered the be the world's first multinational corporation. It was also the first company to issue shares, and facilitate the trading of those shares. It was granted a 21 year monopoly to carry out trade activities in Asia, primarily the Spice Islands - the Dutch East Indies. They established a major trading port at Batavia - now Jakarta, on the island of Java (now part of Indonesia). As a result of their monopoly, the VOC became an incredibly valuable company, issuing an 18% annual dividend for almost 200 years.

VOC was... the world's first Enterprise using Java. (rimshot!)

VOC is also a backronym for "Vestigial Output Compiler". Or "Vexing Obtuse Compiler". Or "Valuable Obscure Compiler". Or "Varigated Ocelot Calibrator". It's your choice.

Community

VOC is part of the BeeWare suite. You can talk to the community through:

• @pybeeware on Twitter
• The BeeWare Users Mailing list, for questions about how to use the BeeWare suite.
• The BeeWare Developers Mailing list, for discussing the development of new features in the BeeWare suite, and ideas for new tools for the suite.

Contributing

If you experience problems with VOC, log them on GitHub. If you want to contribute code, please fork the code and submit a pull request.