Re: PATCH: Explicitly show how let works on global-variables

[Phil Sainty]

On 2022-10-04 20:59, tomas@tuxteam.de wrote:
> I think this is technically wrong and potentially confusing.
>
> I'd tend to say that a new binding is created which shadows the
> global binding. The `system-time-locale' in your let-bound scope
> is a different variable from the global one, although it has the
> same name.
>
> More importantly, nothing gets "restored": it's just the compiler
> which sees a different variable depending on scope. This is even
> "more true" (I know, I know) with lexical variables.

I think this is technically wrong and potentially confusing :)

(info "(elisp)Dynamic Binding") explains it pretty clearly:

   "Dynamic binding is implemented in Emacs Lisp in a simple way.  Each
symbol has a value cell, which specifies its current dynamic value (or
absence of value).  *Note Symbol Components::.  When a symbol is given a
dynamic local binding, Emacs records the contents of the value cell (or
absence thereof) in a stack, and stores the new local value in the value
cell.  When the binding construct finishes executing, Emacs pops the old
value off the stack, and puts it in the value cell."