I have found myself writing a lot of little information transformation functions lately, for instance, we have a DB table that stores County names and state assigned County_ID's. So i have a function called county_name_by_id() that takes a db_handle, and a county_id as input, and returns the county name.

There are often occasions where i'd like to look up multiple county names from their ids at one time, so I allow the second param, county_id to be either a scalar (one county_id), or an arrayref of county_ids.

If called with one county id, it returns the name as a scalar, and if called with an arrayref, it returns a hashref where the keys are the county_id's and the values are the corresponding names.

This works fine, but I am determining the return context based on the input params, as opposed to using wantarray(). So this seems a bit paradoxical, because if i call the function with 1 county_id, I know I want 1 name back, and calling with multiple county_id's, I want multiple names back.

In any case, wantarray() wont tell me anything useful, becuase I'm returning either a string or a hashref, which get assigned to a scalar, so wantarray() will return defined but false in both cases if I call it with a proper return assignment: 

   my $name = county_name_by_id($dbh, 23);

   my $name_refs = county_name_by_id($dbh, [12, 25, 7, 13]);

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So, is this type of call / return pairing a normal thing to do, or am I smoking crack today?

In reply to function call / return philosophies by shemp

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