Method dispatch doesn't respect privacy

[Wh1teDuke]

Code

==> Foo.nim <==
type Foo* = ref object of RootObj
type Bar* = ref object of Foo
method test*(this: Foo) = echo "Foo"
==> BarA.nim <==
import Foo
method test(this: Bar) = echo "Bar A"
==> BarB.nim <==
import Foo
method test(this: Bar) = echo "Bar B"
==> Main.nim <==
import Foo, BarA, BarB
test(Bar())

Expected Foo

Got Bar B

I'm more concerned about the fact that it resolves to BarB.test and I think the compiler should complain.

---

>nim -v
Nim Compiler Version 2.1.9 [Linux: amd64]
Compiled at 2024-07-31
Copyright (c) 2006-2024 by Andreas Rumpf

git hash: cb156648d69fd0c21ee5d041a98ddc69294eaa96
active boot switches: -d:release

[litlighilit]

I think its doing so is fine.

If using C++/java's class[^cls] as reference, maybe we shall enforce subclass's method must be also exported if its parent does.

However, such a change may break some existing code, but such a break that turns potential pitfalls to compile-error shall be called as improvement.

[^cls]: As in Nim there is just no concept like public/private in C++ or Java. There is just module-level isolation in Nim, which in turn C++ doesn't have (at least before C++23).