Runtime Error when use shared lib in python

[ananan]

Hey Guys,

I got error when using enry as shared lib in python, it looks like below:

here is the way i built it:

here is the way i used it:

even tried in cffi:

can anyone tell me what't wrong?
thx...

[creachadair]

It's a little difficult to tell exactly what's happening from the screencaps, but I would be very surprised for this to work without more explicit type annotations. The Go types of the arguments and results are generated as structures, and the FFI library is unlikely to map correctly from str and bytes values without help.

I was able to make the following work as of f28fc12.

Setup:

git clone [email protected]:src-d/enry.git
cd enry
go generate
go build -buildmode=c-shared -o enry.so shared/enry.go

Test:

import ctypes

lib = ctypes.CDLL('enry.so')

with file('common.go', 'rb') as fp:
    data = fp.read()

class GoString (ctypes.Structure):
    _fields_ = [
        ('p', ctypes.c_char_p),
        ('n', ctypes.c_long),
    ]

class GoSlice (ctypes.Structure):
    _fields_ = [
        ('data', ctypes.c_char_p),
        ('len', ctypes.c_int64),
        ('cap', ctypes.c_int64),
    ]

lib.GetLanguage.argtypes = (GoString, GoSlice)
lib.GetLanguage.restype = GoString

def GetLanguage(path, data):
    s = GoString(p=path, n=len(path))
    d = GoSlice(data=data, len=len(data), cap=len(data))
    res = lib.GetLanguage(s, d)
    if res.p is not None:
        return res.p[:res.n]

print GetLanguage('common.go', data)

I implemented the type wrappers by hand based on inspection of enry.h. I am not very familiar with the cffi package, but in theory it should be able to do something similar.

[bzz]

I think @creachadair is right.

And we have #154 open for a Adding CFFI-based python bindings for Enry, that I'm also hoping to find some time soon to grapple with.

[bzz]

If no objections, going to close this as the question seems to be answered, further work on bindings is planned and there is no further discussion.