使用SWIG在C上创建面向对象的API

Question

I am using SWIG to create wrappers for a C library. The C library interface has a natural mapping to an object-oriented API (which I'd like to expose in the target language), but a straightforward usage of SWIG to produce wrappers will generate a single object in the target language with all of the interfaces of the C library.

I see a few options:

• Create a C++ interface to the C library, then wrap C++ with SWIG
• Build a custom classes in each target language that use the simple, non-OO SWIG output internally

I'd prefer bullet point 2, but my question is, is this an OK approach? It is attractive because I'd like to have full control over the interface in the target language with minimal amount of reliance on advanced SWIG features.

Answer 1

I do also prefer option 2 ("Build a custom classes in each target language that use the simple, non-OO SWIG output internally").

My reasons are:

1. You have to mantain "less code". The complex part is the C library + SWIG wrappers, so the better is to keep that as small as possible. Creating another C++ wrap would complicate this part a lot.

2. It is normally easier to create the interface classes in Python (or Java?), just because it is of a higher level of abstraction.

3. You can apply the adapter pattern, which fits very well to this case. http://en.wikipedia.org/wiki/Adapter_pattern

Answer 2

have you had a look at ctypes and / or cython ? both options should be much simpler than using SWIG; moreover ctypes is in the standard library and it will not necessitate recompilation on python version upgrade (and i think it will work across platforms, too).