Pass an entire row to SQLite custom function

I am trying to create a SQLite custom function that will accept the entire row as its argument. An example query would be:

SELECT * FROM some_table ORDER BY custom_rank_function(<entire row>)

However, I'm unsure for the syntax to pass in the entire row. I tried using * but this passes each column value as a separate argument, which results in many arguments as my table has 15 fields. Is there any way to pass some kind of "row pointer" and then pull field values from this row pointer?

Thanks.