Re: Searching for an object

[tmoran@bix.com]

I presume you couldn't do
  Lastname : array(1 .. N) of String(1 .. 10);
  Firstname : array(1 .. N) of String(1 .. 10);

and have separate Find_xxx routines for the different fields

Find_Lastname("Matthias  "); -- not found
Find_Lastname("Teege     "); -- found

thus making the caller of Find_xxx make the "which field" decision.

If a single Find routine needs to make a decision based on the
particular desired field, then at some level you really do need what
amounts to a set of "if"s or a "case" statement.  If you can use a
subscript and index, then the hardware that decides which RAM address
you're accessing can make the decision, eg

type fields is (lastname, firstname);
subtype names is string(1 .. 10);
type name_parts is array(fields) of names;

type Customer is
   record
        name_part : name_parts;
        other_info: other_types;
   end record

Cust : Customer;

Cust.name_part(lastname) = "Teege     ";
Cust.name_part(firstname)= "Matthias  ";

Find(lastname, "Matthias  "); -- not found
Find(lastname, "Teege     "); -- found

If you can't do that, you could get the compiler to generate an
implicit "case" by using tagged types and dispatching to a particular
Find depending on the field, but that might be overkill.