Declarative properties

[Diez B. Roggisch]

Dan Stromberg schrieb:
> On Thu, 11 Oct 2007 18:42:16 +0000, Marc 'BlackJack' Rintsch wrote:
> 
> 
>>> The "baggage" of possibly fixing (AKA "generalizing") how your attributes
>>> are accessed is something you lug around while your deadline looms.
>> Sorry I don't get it.  If I want to customize the access to a "normal"
>> attribute I simply turn it into a property.
> 
> You're right, properties are an intersting language feature.  I wasn't
> aware of them until today.
> 
> I'm not sure I believe they are better than disallowing public attributes
> and requiring setters and getters, but they do appear to address the same
> issue: the needless change in API when your internal representation
> needs to change.

This belief is most probably nurtured by Java. Or am I wrong here? 
Matter of factly, the whole getter/setter-mamboo-jamboo is nothing but a 
pathetic attempt to overcome the lack of attribute-access-hooks, as they 
are e.g. provided by python or C#.

By forcing this convention upon the programmer (and supporting it using 
e.g. BeanInfo and other introspection-based mechanisms), Java allows for 
the implementation of delegation, lazyness and so forth without all that 
forcing major interface changes upon the user. Talking of interfaces - 
they do lack properties as well... so you _can't_ possibly provide an 
interface with attributes.


But I really don't think one can argue over a more aesthetic & 
expressive syntax like

a.foo = b.bar * c.baz

compared to

a.setFoo(b.getBar() * c.getBaz())


Diez