From: SASADA Koichi <ko1@...>
Date: 2012-07-10T03:56:44+09:00
Subject: [ruby-core:46282] Re: [ruby-trunk - Feature #6710] new special binding specifier :isolated

Hi,

(2012/07/09 23:19), jballanc (Joshua Ballanco) wrote:
> I like this idea, but I have one question: why make this a special argument to `eval` and not to `Binding.new`?

Just a performance.  My proposal doesn't make any binding object.
It is similar that `nil' specifier (means current binding).

> I've wanted `Binding` to become better specified and more refined for some time now, and I think this would be a good step in the right direction. I think at some point it would be good to think about all of the things that can happen in a binding (e.g. specify locals, shadow locals, function defs, shadow defs, new classes, reopening classes, etc.), and give an API to tell bindings what they can and cannot do.
> 
> So, in this case, ISOLATED_BINDING would be something like
>     b = Binding.new(TOPLEVEL_BINDING) # New binding "inherits" from Top Level (but not same as class inheritance)
>     b.live_locals = false             # This binding will not propagate locals to its "parent" binding (TOPLEVEL_BINDING, in this case)
>     eval('def foo; end; a = 10', b)   # method foo is now available, but local "a" is not
> 
> This, obviously, requires a lot more thought and work, but for now we could maybe at least have `Binding.new(isolated: true)` as shorthand for the case described above? 

This is another feature.  Make another ticket for it if you want.
I agree that we need more and more thought to introduce your proposal.

-- 
// SASADA Koichi at atdot dot net