Is it possible to provide an interface that includes some default methods such as "IN()" to indirectly enhance the SqlProvider

[WONGHONGMING]

The interface like this:

/** Actually, this is a bit like mapper.dtd */
public interface SQLEnhancer {

    default <E> String IN(Iterable<E> iterable, ForEachElementProvider<E> forEachElementProvider) {
        List<String> elementList = new ArrayList<>();
        int elementIndex = 0;
        for (E element : iterable) {
            elementList.add(forEachElementProvider.apply(element, elementIndex));
            elementIndex++;
        }
        return " IN (" + String.join(", ", elementList) + ")";
    }

    default <E> String VALUES(Iterable<E> iterable, ForEachElementProvider<E> forEachElementProvider) {
        ......
    }

    default String WHERE(String... sqlSlices) {
        ......
    }

    default String if(boolean condition, String sqlSlice) {
        ......
    }

    interface ForEachElementProvider<E> {

        String apply(E element, int elementIndex);
    }
}

Then the SqlProvider class implements the above interface:

 public class SqlProvider implements ProviderMethodResolver, SQLEnhancer {

        public String findAllByIds(@Param("idList") List<String> idList) {
            return "SELECT * FROM user WHERE id" + IN(idList, (e, i) -> "#{idList[" + i + "]}");
        }

        public String deleteAllByIds(@Param("idList") List<String> idList) {
            // can also be used in  SQL class
            return new SQL()
                    .DELETE_FROM("user")
                    .WHERE("id" + IN(idList, (e, i) -> "#{idList[" + i + "]}"))
                    .toString();
        }
}

Additionally, this can also be used for string templates (unfortunately, Java23 has temporarily removed string templates).