[Python-Dev] PEP for Better Control of Nested Lexical Scopes (original) (raw)

Greg Ewing greg.ewing at canterbury.ac.nz
Thu Feb 23 05:27:21 CET 2006

Almann T. Goo wrote:

(although rebinding a name in the global scope from a local scope is really just a specific case of that).

That's what rankles people about this, I think -- there doesn't seem to be a good reason for treating the global scope so specially, given that all scopes could be treated uniformly if only there were an 'outer' statement. All the arguments I've seen in favour of the status quo seem like rationalisations after the fact.

Since there were no nested lexical scopes back then, there was no need to have a construct for arbitrary enclosing scopes.

However, if nested scopes had existed back then, I rather suspect we would have had an 'outer' statement from the beginning, or else 'global' would have been given the semantics we are now considering for 'outer'.

Of all the suggestions so far, it seems to me that 'outer' is the least radical and most consistent with what we already have. How about we bung it in and see how it goes? We can always yank it out in 3.0 if it turns out to be a horrid mistake and we get swamped with a terabyte of grievously abusive nested scope code. :-)

-- Greg Ewing, Computer Science Dept, +--------------------------------------+ University of Canterbury, | Carpe post meridiam! | Christchurch, New Zealand | (I'm not a morning person.) | greg.ewing at canterbury.ac.nz +--------------------------------------+

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