Python's garbage collection was Re: Python reliability

[Diez B. Roggisch]

Delaney, Timothy (Tim) wrote:
> Tom Anderson wrote:
> 
> 
>>Except that in smalltalk, this isn't true: in ST, every variable
>>*appears* to contain a reference to an object, but implementations
>>may not actually work like that. In particular, SmallTalk 80 (and
>>some earlier smalltalks, and all subsequent smalltalks, i think)
>>handles small integers (those that fit in wordsize-1 bits)
>>differently: all variables contain a word, whose bottom bit is a tag
>>bit; if it's one, the word is a genuine reference, and if it's zero,
>>the top bits of the word contain a signed integer.
> 
> 
> This type of implementation has been discussed on python-dev. IIRC it
> was decided by Guido that unless anyone wanted to implement it and show
> a significant performance advantage without any regressions on any
> platform, it wasn't worth it.

AFAIK some LISPs do a similar trick to carry int values on cons-cells. 
And by this tehy reduce integer precision to 28 bit or something. Surely 
_not_ going to pass a regression test suite :)

Diez