3 ms·

You cannot do these things easily currently since the assignment operator cannot be overloaded. There are ways around it, you can "fix" the broken builtin assig

• beagle3 12y ago
  How about doing something like: type refCounted[T] = val: T refs: int proc `v=`(var x:refCounted[T], var y:refCounted[T]) = inc(y.refs) dec(x.refs) if x.refs <= 0: destroy(x.val) x.val = y.val # use let so x and y cannot be assigned let x, y = refCounted[string] # instead use x.v to assign and manage refs properly. x.v = y using "let" would make sure all assignments happen through a blessed method (such as the ".v" assignment I defined above). But to actually make it work, I would need to decrease reference on going-out-of-scope (as there a way to do that? maybe a python "with" style enter exit macro?). And to make it easy to work with, there would need to be a way to pre- "incref" an argument before it is passed as an argument, and "decref" it after the function call return. I can probably write a macro that rewrites every function call with a refCounted arg so that it increfs() on the way in, decrefs() on the way out; or maybe have that macro on the callees instead. Guess I'll have to try the different approaches and see what works and how efficiently.
  • def- 12y ago
    I think that should be type refCounted[T] = object val: T refs: int You could try a destructor for the object: http://nim-lang.org/manual.html#destructors http://nim-lang.org/manual.html#destructors