The @fieldloop() function allows you to execute the same code over all the
fields starting with a given pattern.

@fieldloop( "1234", "a_", @print( "Field is %f, value is %v" ) )

The %f is replaced with the name of the field, and the %v is
replaced with what the field is set to (the "value").  This example
will execute the @print statement for each field of object #1234
that starts with the characters "a_".