| namespace strata::program::logits_selection { | |
| // Storage selection only: callers must still condition on every input token. | |
| // Positive decimal int64, with no sign, whitespace, suffix or overflow. | |
| inline bool parse_stride(std::string_view text, int64_t& result) { | |
| if (text.empty() || text.front() < '0' || text.front() > '9') return false; | |
| int64_t value = 0; | |
| const auto parsed = std::from_chars(text.data(), text.data() + text.size(), value); | |
| if (parsed.ec != std::errc{} || parsed.ptr != text.data() + text.size() || value <= 0) return false; | |
| result = value; | |
| return true; | |
| } | |
| // Zero-based multiples of stride, followed by the final input position once. | |
| inline constexpr bool selected(int64_t position, int64_t total, int64_t stride) { | |
| return total > 0 && stride > 0 && position >= 0 && position < total && | |
| (position % stride == 0 || position == total - 1); | |
| } | |
| inline constexpr int64_t row_count(int64_t total, int64_t stride) { | |
| return total > 0 && stride > 0 ? (total - 1) / stride + 1 + ((total - 1) % stride != 0) : 0; | |
| } | |
| } // namespace strata::program::logits_selection | |