Re: Implicit Globals - A compile time solution.

[David Given <dg@...>]

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John Hind wrote:
[...]
> In your example, "n" would now be a local at the outer lexical scope, so all 
> the inner references would see it and would therefore *not* create new, more 
> local, variables. If you *wanted* to create a more local "n" you'd still have 
> to use the local keyword. "global" still refers to the global environment 
> table - you can be "more local" but you cannot be "more global", you can only 
> be "global".

Oh, I see. You're right, I'd misunderstood you.

However, this still means we end up with the following situation:

a = 1
...56192 lines of code snipped...
function foo()
  for b = 1, 10 do ... end
end

foo() has it's own local b. Now I change the first line to:

b = 1

...and now foo() is modifying the outer-scope version. In other words,
making a keyword at the beginning of the file causes a semantic change
in the meaning of some code 56193 lines later --- not ideal if you want
robust code.

Give that your original suggestion was that global-by-default causes
pollution of the global namespace if you forget to declare a variable,
I'd suggest that this approach to local-by-default causes pollution of
the local namespace instead --- which I think is exactly the same problem!

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