+template <typename Type_>
+static Type_ *CYmemrchr(Type_ *data, Type_ value, size_t size) {
+ while (size != 0)
+ if (data[--size] == value)
+ return data + size;
+ return NULL;
+}
+
+static int CYConsoleKeyUp(int count, int key) {
+ char *after(CYmemrchr(rl_line_buffer, '\n', rl_point));
+ if (after == NULL) {
+ if (int value = rl_get_previous_history(count, key))
+ return value;
+ return 0;
+ }
+
+ char *before(CYmemrchr(rl_line_buffer, '\n', after - rl_line_buffer));
+ if (before == NULL)
+ before = rl_line_buffer - 1;
+
+ ptrdiff_t offset(rl_line_buffer + rl_point - after);
+ if (offset > after - before)
+ rl_point = after - 1 - rl_line_buffer;
+ else
+ rl_point = before + offset - rl_line_buffer;
+
+ return 0;
+}
+
+static int CYConsoleKeyDown(int count, int key) {
+ char *after(static_cast<char *>(memchr(rl_line_buffer + rl_point, '\n', rl_end - rl_point)));
+ if (after == NULL) {
+ if (int value = rl_get_next_history(count, key))
+ return value;
+ rl_point = 0;
+ return 0;
+ }
+
+ char *before(CYmemrchr(rl_line_buffer, '\n', rl_point));
+ if (before == NULL)
+ before = rl_line_buffer - 1;
+
+ ptrdiff_t offset(rl_line_buffer + rl_point - before);
+ if (offset > rl_line_buffer + rl_end - after)
+ rl_point = rl_end;
+ else
+ rl_point = after + offset - rl_line_buffer;
+
+ return 0;
+}
+