On 2012-02-21 19:33, Juan Manuel Cabo wrote:
That because you can't (shouldn't) push up implementations specific to a given
subclass. Why don't we only have one
class, Object, and add a Variant[string] there.
Do you see how stupid that is.
As stupid as any database API which returns result items as Variant[string] or
string[string], but it works. (the sad part is that one has to rely a bit on
convention, but convention can be standardized (string constants) and measures
taken when deviated so that it is done gracefuly).
That's because we are limited by the database API. If you created a new
database from scratch, completely written in D, perhaps even object
oriented, you could return the correct object form the beginning.
Do you have an alternative solution that allows to extend an exception
object with extra information, while keeping it the same class?
No, but that's what subclasses are used for.
So if one removes the bad reasons to create new Exception types, then the
ones that DO get created are solid, standard, reusable, and can withstand
the test of time. Because they would be open for extension but closed for
source code modification.
--
/Jacob Carlborg
