Re: if oo programming is the roman numerals of computing why add it?

[Adam Beneschan <adam@irvine.com>]

On Tuesday, July 9, 2013 12:14:05 PM UTC-7, Georg Bauhaus wrote:

> Luca Cardelli's article, featured on the page, has many comments 
> in favor of O-O, provided a language gets it right. If you read the
> article, you will notice that Ada's style of O-O is very much like
> Cardelli suggests it should be.

I read "Pitfalls of Object-Oriented Programming" (linked on the page) yesterday, and it seems his argument delves into details like memory cacheing and branch prediction.  This was a big yawner for me.  My feeling has always been that if you take all the extra nanoseconds that good programming techniques sometimes cause, you can add up all the wasted time that occurs every time the program has been run, anywhere in the world, maybe millions of times, and it still won't nearly add up to the time that would be wasted trying to track down one difficult bug caused by bad programming practice.

Then again, the author was from Sony Entertainment, so I can understand why perhaps every nanosecond might be important.  Still, a good compilation system could, in theory, make up for the time wastage that O-O or other good programming techniques could cause.  The need to break programs up into smaller subroutines and modules has been recognized for 30 or 40 years, but this can lead to small inefficiencies when code has to contain CALL instructions instead of executing the subroutine inline.  I suspect that people back then objected to this important technique for that reason.  But compilers are now able to rearrange the code to eliminate the inefficiency.  I think similar optimizations can be done for O-O techniques.  If you have an abstract type A, but the compiler can determine that the only objects in A'Class (using Ada terminology, but I mean this to apply to any language) used in the entire program all have type B, then a compiler could, in theory, rearrange the code to avoid the overhead that a dispatching call on one of A's operations would entail.  That's just one possibility; there should be others.  Don't know if any existing compiler (for any language) goes this far.

                           -- Adam