> @GuardedClass
> class Foo:
The functionality can be done using a meta-class, in a similarily
declarative way.
> @Transient
> a = 'a transient field, ignored when serializing'
>
> @Const
> PI = 22.0 / 7
>
> @TypeSafe(int)
> count = 10
These are tricky, as the implicitly change the nature of the values -
they become properties. And the decorator protocol has to change, as the
passed value is obviously not a callable, but a random value. So in the
end, you could simply do something like this:
@Const(3.24)
def PI(self):
pass
with Const basically ignoring its callable-argument and simply returning
a get-only-property. I have to admit that I was tempted to use such a
thingy just the other day. But it is not exactly nice, and using
PI = Const(3.14) as you suggested is even more pleasing.
Additionally, the first @Transient-decorator can't be done that way, as
the decorator protocol doesn't know about the _name_ a thing is bound to
later. And you'd need that to actually set up e.g. __getstate__ operate
properly.
And it doesn't mkae much sense anyway, as "a" is a class variable, not a
instance variable.
So - I'm not very much in favour of these enhancements.
> It would also be better if multiple decorators could be written on the
> same line. E.g.:
> @A @B(x, y) @C
> def foo(): ...
That one I like.
Diez
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