Make dur a property?

[Jacob Carlborg]

On 2013-01-25 20:27, Nick Sabalausky wrote:

> I agree in principle, but unfortunately "return zis variable" getters
> are often needed because no major language (that I know of) offers any
> other way to create data that's privately-writable and
> publicly-read-only - a very common need.
>
> Ie, that's the "something" that "is wrong already": the lack of a
> simple built-in "The public can only read this, but I can R/W it." to
> obviate an extremely common idiom.

In Ruby one would do:

class Foo
   attr_reader :foo
end

This would create a getter and an instance variable. Internally one can 
write directly do the instance variable, or create a setter:

class Foo
   attr_reader :foo

private

   def foo= (value)
     # code
   end
end

The equal sign indicates the method is a property. Not that 
"attr_reader" is not a language feature, it's implemented in the core 
library. There are also functions available for getter and both getter 
and setter.

In D, I would like to see something like this:

@property(get, set) int a;
@property(get) int b;
@property(set) int c;
@property int d; // same as "a"

This would create a getter and/or setter and an instance variable. One 
could also experiment with the protection attributes like this:

public @property(get, protected set) int a;

One way could affect the instance variable, the other way to affect the 
getter/setter implementation.

-- 
/Jacob Carlborg