How do I add a column, preserving the existing columns, without listing them all?

I want to add a new column to an alias, preserving all the existing ones.

A = foreach A generate
  A.id as id, 
  A.date as date, 
  A.foo as foo, 
  A.bar as bar, 
  A.foo / A.bar as foobar;

Can I do that without listing all of them explicitly?