Re: Making Lua lexically scoped (was: Re: Proper tail recursion)

["John Belmonte" <jvb@...>]

John D. Ramsdell wrote:
> By the way, the more I think about the suspected Python
> method for making that language lexically scoped, the more
> I like it.  That is, I like the idea that a language is lexically
> scoped, but as sacrifice to allow efficient implementations,
> variables become immutable whenever they are referenced
> by a closure.  This language design is in the spirit of Lua's
> simplicity, and would allow the complexities of upvalues
> to be purged from the language.

If you read the Python lexical scoping PEP, it states that the rebinding
limitation is due to Python's default local semantics (that is, its lack of
variable declarations).  It doesn't seem to have been for performance
reasons.