Re^2: Bit manipulation of a bit stream to generate different elements of an array with each nibble taking either 0 or 1 in perl

You don't need to have the intermediate 'a' and 'b' chars, you could either turn 0s and 1s into the corresponding nibble explicitly:

$stream =~ s/0/0000 /g;
$stream =~ s/1/1111 /g;
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(perl only searches in the part of the string that wasn't already modified, so the 0s in "0000 " aren't turned again).

Or you could use the power of regexes:

$stream =~ s/(.)/$1$1$1$1 /g; # could be rewritten using /e and x 4
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Or, if you're fine with hex representation, turn the 1s into F:

$stream =~ tr/1/F/;
print "0x$stream\n";
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0x0000
0x000F
0x00F0
0x00FF
0x0F00
0x0F0F
0x0FF0
0x0FFF
0xF000
0xF00F
0xF0F0
0xF0FF
0xFF00
0xFF0F
0xFFF0
0xFFFF
[download]

++ for your solution nevertheless :)

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Re^3: Bit manipulation of a bit stream to generate different elements of an array with each nibble taking either 0 or 1 in perl by bliako (Abbot) on Nov 16, 2018 at 10:31 UTC
good to know thanks.i like `$1$1$1$1`.	[reply] [d/l]
Re^4: Bit manipulation of a bit stream to generate different elements of an array with each nibble taking either 0 or 1 in perl by Eily (Monsignor) on Nov 16, 2018 at 10:45 UTC
I find it kind of hard to read. The /e alternative I mentioned would be something like: `$stream =~ s/(.)/$1 x 4/eg; # Without extra space $stream =~ s/(.)/($1 x 4).' '/eg; # With extra space` [download] I didn't include the first one on my post because it felt it would be too many advanced features for a beginner (s/// operator, regex, capture, eval, /g modifier, x operator). But now that I've actually written it down, I find it better than $1$1$1$1: it's actually more intuitive when you read it, and looks less like line noise.	[reply] [d/l]