Python binding

[moskupols]

This is a cython-based python binding of PIRE. Mako template engine is used heavily to address repetitiveness of similar interfaces.

What is not wrapped:

• It is impossible yet to subclass Features and Scanners in python and pass the extension back to C++;
• Most low-level operations with Fsm;
• mmap- and Action-related methods and functions;
• Run for pair of scanners;
• Feature and Encoding classes.

Interface of the binding is similar to the original one. Differences:

• All C++-space global template functions are wrapped as python instance methods.
• Fsm::operator * () is wrapped as Fsm.Iterated().
• All scanners' states are represented as classes similar to Pire::RunHelper.
• Encoding, Feature and Option abstractions are replaced with single Options abstraction, which is used to tweak Lexer behavior. Options can be either parsed from string such as "aiyu" or composed of predefined constants such as I and UTF8.
• Instead of lexer::AddFeature(Capture(42)) you use lexer.AddCapturing(42).
• An OverflowError is raised on unsuccessful glue operation instead of returning empty scanner.

[moskupols]

#47