Function test_replacements

scripts/test_stringzilla.cpp:4234–4257

* Evaluates the correctness of look-up table transforms using random lookup tables. * * @param lookup_tables_to_try The number of random lookup tables to try. * @param slices_per_table The number of random inputs to test per lookup table. */

 *  @param slices_per_table The number of random inputs to test per lookup table.
 */
void test_replacements(std::size_t lookup_tables_to_try = 32, std::size_t slices_per_table = 16) {

    std::string body, transformed;
    body.resize(1024 * 1024); // 1MB
    transformed.resize(1024 * 1024);
    std::generate(body.begin(), body.end(), []() { return (char)(std::rand() % 256); });

    for (std::size_t lookup_table_variation = 0; lookup_table_variation != lookup_tables_to_try;
         ++lookup_table_variation) {
        sz::look_up_table lut;
        for (std::size_t i = 0; i < 256; ++i) lut[(char)i] = (char)(std::rand() % 256);

        for (std::size_t slice_idx = 0; slice_idx != slices_per_table; ++slice_idx) {
            std::size_t slice_offset = std::rand() % (body.length());
            std::size_t slice_length = std::rand() % (body.length() - slice_offset);

            sz::lookup<char>(sz::string_view(body.data() + slice_offset, slice_length), lut,
                             const_cast<char *>(transformed.data()) + slice_offset);
            for (std::size_t i = 0; i != slice_length; ++i) {
                assert(transformed[slice_offset + i] == lut[body[slice_offset + i]]);
            }
        }
    }
}

/**
 *  @brief  Tests array sorting functionality, such as `argsort`, `sort`, and `sorted`.