Thread

1. Re: Casting, again

   Peter Eisentraut <peter_e@gmx.net> — 2000-05-15T18:57:27Z

   Tom Lane writes:
   
   > I've noticed in other cases that it's willing to do implicit
   > conversion to text from practically anything.  That strikes me as a
   > bug, or at least pretty darn unintuitive.  Is this behavior
   > intentional, and if so what's the rationale?
   
   Well, I'm sure you know my stance on these things by now, but let me add
   one last thing: What I'm missing from the type system is a governing
   strategy. On the one hand there is strong typing, on the other hand
   implicit casting across the board, but not when you would actually want
   it. This is usually where programming language paradigms clash, but note
   that programming language design in the last two decades has clearly been
   moving to one of two things: either strong and strict typing or no typing
   at all. I'm not saying I like strict like Java were you can't pass a
   literal `5' as a `short int' argument without complaints but strict as in
   a string is a string, a date is a date, a point is a point, a number is a
   number.
   
   I would go as far as saying that if you try to insert a 5 in a text field
   then this should be an error, you must write '5'. Surely some might claim
   that this is an inconvenience. Indeed, this is inconveniencing me because
   possible errors in string processing or even system logic are silently
   dropped under the table. Nobody ever got carpal tunnel syndrome because of
   two extra quotes, and if the SQL is machine-generated then fixing the
   program is the best thing in the long run anyway.
   
   The previous paragraph agrees with SQL (see section 9.2).
   
   
   -- 
   Peter Eisentraut                  Sernanders väg 10:115
   peter_e@gmx.net                   75262 Uppsala
   http://yi.org/peter-e/            Sweden
   
   
   

2. Re: Casting, again

   Raul Chirea <raul@brahms.ro> — 2000-05-17T00:02:17Z

   Your pg_excelencies,
   
   Peter Eisentraut wrote:
   
   > I would go as far as saying that if you try to insert a 5 in a text field
   > then this should be an error, you must write '5'. Surely some might claim
   > that this is an inconvenience. Indeed, this is inconveniencing me because
   > possible errors in string processing or even system logic are silently
   > dropped under the table. Nobody ever got carpal tunnel syndrome because of
   > two extra quotes, and if the SQL is machine-generated then fixing the
   > program is the best thing in the long run anyway.
   
   Did you think to a system with some abstract types (like numeric, char, date,
   etc.) and fizical
   types within the abstract types (i.e. abstract numeric type holds physical
   integer type, physical
   float type, phisical numeric type), and the only implicit cast that parser
   does to be
   between phisical types whithin the same abstract type ?
   
   Raul.