[Feature Request] Make inner functions access to all the variables defined outside.

[Withered-Flower-0422]

From my own perspective, I still strongly ask for the inner function can access all the variables defined outside, like other languages do.

WHY
One important reason we need an inner function is that we want to keep some variables defined inside a function private, unable to access form outside.
But if we cannot access them even from inside, these variables are likely to be "dead"(unable to access via any means in a deeper inner function). That's what we don't want to see.

HOW
If we don't want any magic, we can do like this:

1. Variables are looked up by isa chain. Default the scope of an inner function is a child of an outer one. (let the locals of function c isa the locals of function b)
2. outer(n=1) is a function that returns n-level-up's scope.

Or, we can make it easier with some magic?

See details on Discord.