wishlist: support for shorter pointers

Rafał Pietrak embedded@ztk-rp.eu
Tue Jul 4 14:20:28 GMT 2023



W dniu 3.07.2023 o 18:29, Rafał Pietrak pisze:
> Hi David,
> 
[--------------]
>> 4. It is worth taking a step back, and thinking about how you would 
>> like to use these pointers.  It is likely that you would be better 
>> thinking in terms of an array, rather than pointers - after all, you 
>> don't want to be using dynamically allocated memory here if you can 
>> avoid it, and certainly not generic malloc().  If you can use an 
>> array, then your index type can be as small as you like - maybe 
>> uint8_t is enough.
> 
> I did that trip ... some time ago. May be I discarded the idea 
> prematurely, but I dropped it because I was afraid of cost of 

I remember now what was my main problem with indexes implementation: 
inability to express/write chain "references" with them. Table/index 
semantic of:
	t[a][b][c][d].
is a "multidimentional table" which is completely different from 
"pointer semantic" of:
	*t->a->b->c->d

It is quite legit to do a full circle around a circular list this way, 
while table semantics doesn't allow that.

Indexes are off the table.

-R


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