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[REBOL] Re: bitset help

From: brett:codeconscious at: 28-Sep-2002 13:01

Hi Gregg, Romano,
> I ask myself if you learned all from that RT doc, i did not understand > anything from it!
I'd heard that some DBs nowadays incorporate bit vector indexes - not sure what the term is and after RT made those notes I figured it was time to find out what bitset! could be used for. So I searched the internet for examples and experimented with various series functions. So no, I didn't get it from the docs :^)
> > On my machine and with this version a bitset seems to have a maximum
size of
> > 2040.
I need to correct this - after seeing your post. I'm not sure what the maximum is now - could be as much as OS is willing to provide perhaps. For example this works, but I can here my disk starting to work heavily. r: make bitset! 1024 * 1024 * 768 == make bitset! #{ 0000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000... But 1024 * 1024 * 1024 causes a crash. My comment about multiples of 8 could be wrong too, not sure what the actual constraint is.
> >Here's a little function to represent the bits of a bitset: > > stringbits: func [bitset [bitset!]][ > > enbase/base head reverse to-string load find/tail/last form bitset
{ }
> 2 > > ] > > Very useful. Cannot be removed that to-string?
Probably, it evolved :^)
> That reverse will not fail on different system? (big-endian/little endian)
Another good point. I'm using Win NT 4.0 on Intel. What happens on other systems? Thanks for the info on REMOVE as well. Regards, Brett.