Swig support

[drewwells]

Since libsass's official plan is to bring Sass to many languages, has anyone successfully wrapped it for another language with Swig?

I'm getting a few fixable errors, then some more serious ones.

sass2scss.h:106: Warning 890: Ignoring 'sass2scss' due to Go name ('Sass2scss') conflict with 'sass2scss'

sass2scss is defined in multiple namespaces which is not allowed when converting to Go, probably other languages as well.

json.hpp:66: Warning 312: Nested union not currently supported (ignored).
prelexer.hpp:24: Warning 302: Identifier 'exactly' redefined (ignored),

Full build log: https://gist.github.com/drewwells/ea7063395959a9154172

[QuLogic]

I don't know about Swig, but aren't there already a few Go implementations?

[QuLogic]

Actually, scratch that; it appears you're swig'ing the entire code base, when all you need are the two or three .h headers.

[drewwells]

I already maintain a Go implementation that links to libsass: https://github.com/wellington/wellington/tree/master/context

I've been looking for a while to wrap/compile it better into Go, so that I don't have to build and link libsass separately anymore.

[QuLogic]

Ah, in that case, you should be aware that only the .h files are necessary to define the interface. Your swig warnings/errors are coming from the C++ files. I'm not sure how, but you'd need to configure swig to not attempt to parse them.

I'm not even sure whether the C++ side is guaranteed to be a public API; you'd have to check proper maintainers' thoughts on that one.

[drewwells]

I made a little more progress on this, swig is throwing errors processing what looks like c++11 syntax:

Swig error:

ast_factory.hpp:25:11: error: expected member name or ';' after declaration specifiers

The code causing the error:

Import<Function_Call*>* new_CSS_Import(string p, size_t l, Function_Call* loc);

[mgreter]

@drewwells the API has change slightly (Function_Call was renamed), please consult #1000

[saper]

Does it work now?

[drewwells]

No, the problems are going to be target language dependent ie. Go can't handle having multiple variables with the same names. So I'm closing this in favor of directly building/linking the C API that is already provided & documented.

[saper]

@drewwells Here's some very initial swig interface file that got me started with Python https://gist.github.com/49387732f25ad50f913f

[drewwells]

So how do you make use of it? Compile libsass, then use this to generate python native code from those C API headers?