On 11/02/2021 03:07, Ryan Joseph via fpc-pascal wrote:
We get the shared namespace
So basically, we get the compiler to automatically create forwarder
methods for us (or at least that behaviour). And that is all there is.
right?
In that case IIRC, it was said traits are not allowed constructors. Why?
Now a constructor would and should not have a forwarding method, but
that the compiler can skip.
Yet, in my code, in the constructor of the TMyClass, I could add
_traitA.Create
even
_traitA := TTraitA.Create; // if the trait was not an object, but
another class.
The compiler can with no doubt create the forwarder methods. And if I
understand right, then that is all the compiler should do?
(Not that I advertise a trait should be a class / IMHO better not)
procedure TMyClass.DoThis;
begin
// resolve the conflict by directly referencing the trait
traitA.DoThis;
end;
This we already can do. Write our own forwarder method.
I understand it is for conflict resolution only. But see my example =>
as soon as you need to repeat a trait with just a change in name, you
always need conflict resolution.
IMHO, there are many traits that a class could need more than once.
Also that only works, if a trait is included as a field.
There was at least one message in this mail-thread that suggested
TMyClass = class(TObject, TTraitA);
The solution is on
https://en.wikipedia.org/wiki/Trait_(computer_programming)
/alias/: an operation that creates a new trait by adding a new name
for an existing method
Doing that for all methods, means having 2 identical traits, but with
different names. => no conflict.
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