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Re: Numeric limits in 8th

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On 08/17/2015 09:54, Jan Coombs <Jan-54 wrote:
> As with Ilya's Forth this provides significant user benefit
> in usage simplification.

Hello, Jan -

Yes, I think so.

> For smaller systems it might be good to use a variable length
> representation of stack items. This would reduce the stack
> memory size, and required memory bandwidth, also remove the upper
> limit on data item size.

I think using variable-sized items on the stack would greatly complicate 
matters, and make the code bigger ultimately.  As it stands, each stack 
location contains exactly one-item, and no item requires more than one 
stack location.

The backing representation of the item - that is, what is pointed to by 
the stack item - can be most anything.  Of course there are advantages 
to keeping that small as well, though that's not always possible.

"Smaller systems" is a bit of an issue, as that's not within the design 
parameters of 8th.  We are venturing into the embedded arena, but only 
for larger systems (Raspberry Pi, for example, will be released very soon).


> It does require caching for the items near the stack top
> which need to be accessed or re-ordered, but these may be few.
>
> The Python engine only needs access to the top two or three
> stack items, how many does 8th require?

Generally not more than two.  The default stack is 2000 deep, but that 
can be controlled by an option on the command-line.

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Thread

Numeric limits in 8th Ron Aaron <rambamist@gmail.com> - 2015-08-16 07:35 +0300
  Re: Numeric limits in 8th Jan Coombs <Jan-54 <jenfhaomndgfwutc@murmic.plus.com>> - 2015-08-17 07:54 +0100
    Re: Numeric limits in 8th Ron Aaron <rambamist@gmail.com> - 2015-08-17 10:41 +0300
      Re: Numeric limits in 8th Jan Coombs <Jan-54 <jenfhaomndgfwutc@murmic.plus.com>> - 2015-08-21 22:59 +0100

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