Completing myself.

> Though, you insist on being able to enter it as a number anyway,
> hoping ob-asymptote will do the magic behind. How could it, since the
> language can't itself?

Actually, the attached patch does that magic: if there's any string in
the table, every cell will be turned into a string and the array will be
of type string.

I still think a more general way would be better. I'll let Eric Schulte
decide what to do about it.

Regards,

-- 
Nicolas Goaziou