Quoting chiaro scuro <kiaroskuro@[...].com> :

>  I believe we can do without this style, because the rationale to
>  support it (without looking at the implementation details) is a
>  defensive programming argument.

But do we really want a situation where the names of local variables
become important to the external interface of a class?

If some mixin adds a method with the same name as a local variable
somewhere, we don't want things to suddenly break.

I think a better solution would be requiring explicit variable
declarations.  Let variables be unambiguously variables.

The implementation details would hairy too though.

-mental