Scope of variables in a delegate

Question

I found the following rather strange. Then again, I have mostly used closures in dynamic languages which shouldn't be suspectable to the same "bug". The following makes the compiler unhappy:

VoidFunction t = delegate { int i = 0; };

int i = 1;

It says:

A local variable named 'i' cannot be declared in this scope because it would give a different meaning to 'i', which is already used in a 'child' scope to denote something else

So this basically means that variables declared inside a delegate will have the scope of the function declared in. Not exactly what I would have expected. I havn't even tried to call the function. At least Common Lisp has a feature where you say that a variable should have a dynamic name, if you really want it to be local. This is particularly important when creating macros that do not leak, but something like that would be helpful here as well.

So I'm wondering what other people do to work around this issue?

To clarify I'm looking for a solution where the variables I declare in the delegete doesn't interfere with variables declared after the delegate. And I want to still be able to capture variables declared before the delegate.

Answer 1

It has to be that way to allow anonymous methods (and lambdas) to use local variables and parameters scoped in the containing method.

The workarounds are to either use different names for the variable, or create an ordinary method.