Re^2: Operate with bits

http://qs321.pair.com?node_id=11114129

in reply to Re: Operate with bits
in thread Operate with bits

1.) would be correct for characters (or hex digits), but OP wants bits, so you would have to do split(//, sprintf("%b", $address))
2.) additionally, for substr to count its offset from right, you have to use negative, so substr((sprintf "%b", $address), -6, 1)

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Re^3: Operate with bits by rizzo (Curate) on Mar 12, 2020 at 04:18 UTC
Yep. Thanks for the correction.	[reply]
Re^3: Operate with bits by syedasadali95 (Acolyte) on Mar 12, 2020 at 06:18 UTC
Thanks rizzo & soonix. Actually substr((sprintf "%b", $address), -7, 1) is serving my need as we are starting from right side of the bit stream (LSB) and starting to count from bit 0 to bit 5, so total of six bits and keeping -7 in the substr func as index makes us catch the 6th bit from the bit stream. Thanks again for the help guys	[reply]
Re^4: Operate with bits by AnomalousMonk (Archbishop) on Mar 12, 2020 at 07:24 UTC
I don't understand why GrandFather's solution (bitwise-anding) would not give you the same result with a lot less wasted motion. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l]
Re^5: Operate with bits by soonix (Canon) on Mar 12, 2020 at 10:08 UTC
I assume that for most humans it is easier to see the "finding bit X" problem as one of dealing with strings, than as one of calculating (although, of course, the latter is much easier for the computer). In other words: sprintf '%b' converts to a string of bits, then I can take the 7th char from the right is easier to understand (for most humans) than If I have it as a number, I simply "AND" it with 2⁶ Of course, it all depends: if there are millions of lines, the inefficiency will add up and become noticeable.	[reply]
Re^6: Operate with bits by AnomalousMonk (Archbishop) on Mar 12, 2020 at 10:32 UTC
Re^7: Operate with bits by soonix (Canon) on Mar 12, 2020 at 10:40 UTC
Re^5: Operate with bits by GrandFather (Saint) on Mar 12, 2020 at 07:29 UTC
Maybe because syedasadali95 is actually dealing with hex digits (nibbles), not with bits as assumed by my post and stated by every one of syedasadali95's posts up until the reply to soonix. Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply]
Re^6: Operate with bits by AnomalousMonk (Archbishop) on Mar 12, 2020 at 08:07 UTC

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