Re: globals (_locals)

[Jean-Claude Wippler <jcw@...>]

[Tom]
>> More concretely, any variable that 
>> occurs anywhere on the left hand side of
>> ":=" anywhere in a function would be declared 
>> local to the function (not just local to the block).

[Markus]
>Oh no! :-(
>
>Please keep Lua as simple at it is. This is complicated stuff.

It's far worse than that.  The problem is identifier scope, not
assignment.  To make "a := b" affect other lines where "a = b" is used is
an extremely confusing way of overloading assignment.

Hmm... how about one of the following alternatives:
    - all local identifiers must start with an underscore ("_")
    - all global identifiers must start with an upper-case letter

The first would require going through all existing code, looking for the
"local" reserved word and altering names (it seems like that could be
automated 95%).

The second would break every Lua script currently in existence, because
all Lua library functions would have to be renamed.

I repeat that I do not consider the current scoping an issue.  The
"globals.lua" and "undefined.lua" scripts provide ample security IMO. 
But if it had to change, I'd vote for "_localname", and eventually
dropping the "local" reserved word.

-jcw