Added _metis.pyx and _api.pxd

[OrkoHunter]

This adds _metis.pyx and _api.pxd files.

[OrkoHunter]

@ysitu I think I am facing an ambiguous error. Earlier I said that renaming gklib.c into gklib.cc worked fine. But as of now, If I fetch and combine all the 4 branches from orkohunter/networkx-metis i.e. master, setup, wrapper and pyx-and-pxd and do $ python setup.py build_clib followed by $ python setup.py build_ext --inplace, then this error is generated.

test/ python                                                        
Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import metis
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "metis.py", line 19, in <module>
    from _metis import node_nd, part_graph, compute_vertex_separator
ImportError: ./_metis.so: undefined symbol: libmetis__rpqSeeTopVal

Can you please look at it sometime?

[ysitu]

See inline comments in #4.

[OrkoHunter]

@ysitu Thanks for the fix in setup.py. That helped building the .cc files. But, I've encountered another issue while building the library.

Related to gklib.cc, it seems that the declared datatypes are not being recognized. Here's a small gist

src/libmetis/gklib.cc:16:27: error: ‘ikv_t’ does not name a type
     bool operator()(const ikv_t &lhs, const ikv_t &rhs) const {
                           ^
src/libmetis/gklib.cc: In member function ‘bool ikvi_t_less::operator()(const int&, const int&) const’:
src/libmetis/gklib.cc:17:35: error: request for member ‘key’ in ‘lhs’, which is of non-class type ‘const int’
         return std::make_pair(lhs.key, lhs.val) < std::make_pair(rhs.key, rhs.val);
                                   ^
src/libmetis/gklib.cc: At global scope:
src/libmetis/gklib.cc:22:27: error: ‘uvw_t’ does not name a type
     bool operator()(const uvw_t &lhs, const uvw_t &rhs) const {
                           ^

and here's one example of the error in sort.cc

In file included from /usr/include/c++/4.8/bits/stl_algobase.h:67:0,
                 from /usr/include/c++/4.8/algorithm:61,
                 from src/GKlib/sort.cc:5:
/usr/include/c++/4.8/bits/stl_iterator.h:347:5: note: template<class _IteratorL, class _IteratorR> bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)
     operator<(const reverse_iterator<_IteratorL>& __x,
     ^
/usr/include/c++/4.8/bits/stl_iterator.h:347:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/algorithm:62:0,
                 from src/GKlib/sort.cc:5:
/usr/include/c++/4.8/bits/stl_algo.h:89:18: note:   ‘gk_fkv_t’ is not derived from ‘const std::reverse_iterator<_Iterator>’
    else if (*__a < *__c)
                  ^

Are we still missing something in setup.py?

[ysitu]

You probably need to move your C includes above the anonymous namespace.

[OrkoHunter]

The std::greater<>() also seems to have problem with these data types.

In file included from /usr/include/c++/4.8/algorithm:62:0,
                 from src/GKlib/sort.cc:5:
/usr/include/c++/4.8/bits/stl_algo.h: In instantiation of ‘void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator) [with _RandomAccessIterator = gk_ckv_t*]’:
/usr/include/c++/4.8/bits/stl_algo.h:2211:62:   required from ‘void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator) [with _RandomAccessIterator = gk_ckv_t*]’
/usr/include/c++/4.8/bits/stl_algo.h:5453:47:   required from ‘void std::sort(_RAIter, _RAIter) [with _RAIter = gk_ckv_t*]’
src/GKlib/sort.cc:176:27:   required from here
/usr/include/c++/4.8/bits/stl_algo.h:2137:13: error: no match for ‘operator<’ (operand types are ‘gk_ckv_t’ and ‘gk_ckv_t’)
    if (*__i < *__first)
             ^
/usr/include/c++/4.8/bits/stl_algo.h:2137:13: note: candidates are:
In file included from /usr/include/c++/4.8/utility:70:0,
                 from /usr/include/c++/4.8/algorithm:60,
                 from src/GKlib/sort.cc:5:
/usr/include/c++/4.8/bits/stl_pair.h:220:5: note: template<class _T1, class _T2> bool std::operator<(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)
     operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
     ^
/usr/include/c++/4.8/bits/stl_pair.h:220:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/4.8/algorithm:62:0,
                 from src/GKlib/sort.cc:5:
/usr/include/c++/4.8/bits/stl_algo.h:2137:13: note:   ‘gk_ckv_t’ is not derived from ‘const std::pair<_T1, _T2>’
    if (*__i < *__first)
             ^

[ysitu]

You need to define comparison functors similar to the ones you have in gklib.cc.

[OrkoHunter]

Yes I tried it. This leads to

src/GKlib/sort.cc: In member function ‘bool {anonymous}::gk_ikv_t_greater::operator()(const gk_ikv_t&, const gk_ikv_t&) const’:
src/GKlib/sort.cc:24:18: error: no match for ‘operator>’ (operand types are ‘const gk_ikv_t’ and ‘const gk_ikv_t’)
         return a > b;
                  ^

[ysitu]

You cannot just use >. That is never defined. You need to look at the original sort.c and replicate the comparison logic.