building failed for BitField with dynamic length about construct HOT 7 CLOSED

what's the exception?

from construct.

Full backtrack:

Traceback (most recent call last):
File "/home/erenlii/.local/lib/python2.7/site-packages/construct/core.py", line 211, in build
self.build_stream(obj, stream)
File "/home/erenlii/.local/lib/python2.7/site-packages/construct/core.py", line 218, in build_stream
self._build(obj, stream, Container())
File "/home/erenlii/.local/lib/python2.7/site-packages/construct/core.py", line 682, in _build
sc._build(subobj, stream, context)
File "/home/erenlii/.local/lib/python2.7/site-packages/construct/core.py", line 1133, in _build
self.subcon._build(obj, stream2, context)
File "/home/erenlii/.local/lib/python2.7/site-packages/construct/core.py", line 272, in _build
self.subcon._build(obj, stream, context)
File "/home/erenlii/.local/lib/python2.7/site-packages/construct/core.py", line 682, in _build
sc._build(subobj, stream, context)
File "/home/erenlii/.local/lib/python2.7/site-packages/construct/core.py", line 289, in _build
self.subcon._build(self._encode(obj, context), stream, context)
File "/home/erenlii/.local/lib/python2.7/site-packages/construct/adapters.py", line 51, in _encode
obj2 = int_to_bin(obj, width = self.width)
File "/home/erenlii/.local/lib/python2.7/site-packages/construct/lib/binary.py", line 116, in int_to_bin
i = width - 1
TypeError: unsupported operand type(s) for -: 'function' and 'int'

Here, width is the lambda from MetaField.

from construct.

For a quick fix, I added

        if callable(self.width):
            width = self.width(context)
        else:
            width = self.width

before file "/home/erenlii/.local/lib/python2.7/site-packages/construct/adapters.py", line 51, in _encode
obj2 = int_to_bin(obj, width = self.width)

from construct.

great! you can even make it shorter with obj2 = int_to_bin(obj, width = self.width(context) if callable(self.width) else self.width). could you test it and submit a pull request?

from construct.

Sure, i break it to pass pep8 check.
And is it the right place to fix? i'm not sure it can fix all problems with the same type.

from construct.

yeah, i think it's the right place. thanks!

Tomer Filiba
tomerfiliba.com http://www.facebook.com/tomerfiliba
http://il.linkedin.com/in/tomerfiliba

On Fri, Mar 28, 2014 at 4:24 AM, tdsparrow [email protected] wrote:

Sure, i break it to pass pep8 check.
And is it the right place to fix? i'm not sure it can fix all problems
with the same type.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/39#issuecomment-38880455
.

from construct.

This seems to have been patched a long time ago. Added regression test in a4eb053.

from construct.