Objects in Python

[Steven D'Aprano]

On Sun, 26 Aug 2012 16:22:05 +1000, Chris Angelico wrote:

> On Sun, Aug 26, 2012 at 3:45 PM, Evan Driscoll <driscoll at cs.wisc.edu>
> wrote:
>> Third, and more wackily, you could technically create a C
>> implementation that works like Python, where it stores variables (whose
>> addresses aren't taken) in a dict keyed by name, and generates code
>> that on a variable access looks up the value by accessing that dict
>> using the name of the variable.
> 
> That would be a reasonable way to build a C interactive interpreter.

No it wouldn't. Without fixed addresses, the language wouldn't be able to 
implement pointers. C without pointers isn't C, it is something else. 
Possibly called Python :)

I suppose you could get pointers in Namespace-C if you somehow mapped 
names to addresses, and vice versa, but why would you do that? You end up 
with a hybrid system that doesn't give you any advantage over C but has a 
much more complicated implementation (and therefore many more new and 
exciting bugs).

But if you want me to agree that you could implement C using name 
binding, plus some weird scheme to track memory addresses, then yes, I 
suppose you could. Then the parts of C that don't rely on fixed memory 
addresses could use the name bindings (with the corresponding loss of 
performance), and the parts of C which do require them could continue to 
do so, and we'll have one more language with a confusing, unclear and 
unclean execution model. Everybody wins! For some definition of win.



-- 
Steven