libs/python/test/slice.cpp
#include <boost/python.hpp>
#include <boost/python/slice.hpp>
#include <vector>
// Copyright (c) 2004 Jonathan Brandmeyer
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
using namespace boost::python;
// These checks are only valid under Python 2.3
// (rich slicing wasn't supported for builtins under Python 2.2)
bool check_string_rich_slice()
{
object s("hello, world");
// default slice
if (s[slice()] != "hello, world")
return false;
// simple reverse
if (s[slice(_,_,-1)] != "dlrow ,olleh")
return false;
// reverse with mixed-sign offsets
if (s[slice(-6,1,-1)] != " ,oll")
return false;
// all of the object.cpp check_string_slice() checks should work
// with the form that omits the step argument.
if (s[slice(_,-3)] != "hello, wo")
return false;
if (s[slice(-3,_)] != "rld")
return false;
if (", " != s[slice(5,7)])
return false;
return s[slice(2,-1)][slice(1,-1)] == "lo, wor";
}
// These tests work with Python 2.2, but you must have Numeric installed.
bool check_numeric_array_rich_slice()
{
using numeric::array;
array original = array( make_tuple( make_tuple( 11, 12, 13, 14),
make_tuple( 21, 22, 23, 24),
make_tuple( 31, 32, 33, 34),
make_tuple( 41, 42, 43, 44)));
array upper_left_quadrant = array( make_tuple( make_tuple( 11, 12),
make_tuple( 21, 22)));
array odd_cells = array( make_tuple( make_tuple( 11, 13),
make_tuple( 31, 33)));
array even_cells = array( make_tuple( make_tuple( 22, 24),
make_tuple( 42, 44)));
array lower_right_quadrant_reversed = array(
make_tuple( make_tuple(44, 43),
make_tuple(34, 33)));
// The following comments represent equivalent Python expressions used
// to validate the array behavior.
// original[::] == original
if (original[slice()] != original)
return false;
// original[:2,:2] == array( [[11, 12], [21, 22]])
if (original[make_tuple(slice(_,2), slice(_,2))] != upper_left_quadrant)
return false;
// original[::2,::2] == array( [[11, 13], [31, 33]])
if (original[make_tuple( slice(_,_,2), slice(_,_,2))] != odd_cells)
return false;
// original[1::2, 1::2] == array( [[22, 24], [42, 44]])
if (original[make_tuple( slice(1,_,2), slice(1,_,2))] != even_cells)
return false;
// original[:-3:-1, :-3,-1] == array( [[44, 43], [34, 33]])
if (original[make_tuple( slice(_,-3,-1), slice(_,-3,-1))] != lower_right_quadrant_reversed)
return false;
return true;
}
// Verify functions accepting a slice argument can be called
bool accept_slice( slice) { return true; }
#if BOOST_WORKAROUND( BOOST_MSVC, BOOST_TESTED_AT(1400)) \
|| BOOST_WORKAROUND( BOOST_INTEL_WIN, == 710)
int check_slice_get_indicies(slice index);
#endif
int check_slice_get_indicies(const slice index)
{
// A vector of integers from [-5, 5].
std::vector<int> coll(11);
typedef std::vector<int>::iterator coll_iterator;
for (coll_iterator i = coll.begin(); i != coll.end(); ++i) {
*i = i - coll.begin() - 5;
}
slice::range<std::vector<int>::iterator> bounds;
try {
bounds = index.get_indicies(coll.begin(), coll.end());
}
catch (std::invalid_argument) {
return 0;
}
int sum = 0;
while (bounds.start != bounds.stop) {
sum += *bounds.start;
std::advance( bounds.start, bounds.step);
}
sum += *bounds.start;
return sum;
}
BOOST_PYTHON_MODULE(slice_ext)
{
def( "accept_slice", accept_slice);
def( "check_numeric_array_rich_slice", check_numeric_array_rich_slice);
def( "check_string_rich_slice", check_string_rich_slice);
def( "check_slice_get_indicies", check_slice_get_indicies);
}