static ImmutableTreeVector<T> slice(ImmutableTreeVector<T>& in, boost::python::slice s) { int32_t start = boost::python::extract<int32_t>(s.start()); if (start < 0) start = in.size() - start; int32_t stop = boost::python::extract<int32_t>(s.stop()); if (stop < 0) stop = in.size() - stop; return in.slice(start, stop); }
static boost::python::list getSlice( Set &s, boost::python::slice sl ) { Py_ssize_t start, stop, step, length; if( PySlice_GetIndicesEx( (PySliceObject *)sl.ptr(), s.size(), &start, &stop, &step, &length ) ) { boost::python::throw_error_already_set(); } boost::python::list result; for( Py_ssize_t i = start; i < stop; i++ ) { result.append( Set::MemberPtr( s.member( i ) ) ); } return result; }
adapted_slice::adapted_slice(boost::python::slice const& sl, std::size_t sz) : step(1), size(0) { static const boost::python::slice_nil slice_nil = boost::python::slice_nil(); long signed_sz = static_cast<long>(sz); if (sl.step() != slice_nil) { step = boost::python::extract<long>(sl.step()); } if (sl.start() == slice_nil) { start = step < 0 ? signed_sz-1 : 0; } else { start = boost::python::extract<long>(sl.start()); if (start < 0) start += signed_sz; } if (sl.stop() == slice_nil) { stop = step < 0 ? -1 : signed_sz; } else { stop = boost::python::extract<long>(sl.stop()); if (stop < 0) stop += signed_sz; } if (start > signed_sz-1) start = signed_sz; if (start < 0) start = 0; if (stop < -1) stop = -1; else if (stop > signed_sz) stop = signed_sz; SCITBX_ASSERT(step != 0 || stop == start); long signed_size = stop - start + step; if (step < 0) signed_size++; else if (step > 0) signed_size--; else { signed_size = 0; step = 1; } signed_size /= step; if (signed_size < 0) signed_size = 0; size = static_cast<std::size_t>(signed_size); stop = start + step * size; }