I wasn't going to follow up but decided to do so since there is a small but
subtle bug in my original post.
I wouldn't want to mislead you Todd.
The \d has been changed to [0..9] as the expected input would only ever be
in that range. (\d includes Unicode Characters)
I've also included an alignment parameter (shadow'ing the sub written by
you Todd).
sub sbprint( Int $n, Int :$alignment = 8) {
my Int $padding = $alignment + $n.msb - ( $n.msb +& ( $alignment -
1 ) );
'0b' ~ "\%0{$padding}b".sprintf($n).comb(/<[0..9]> ** { $alignment
}/).join('_')
}
say sbprint 0x04F842;
say sbprint 0x04F842, :alignment(4);
# ./test.pl6
0b00000100_11111000_01000010
0b0100_1111_1000_0100_0010
I'm not suggesting you use my routine as I have no idea about what you're
requirements are but wanted to be sure my contribution to your problem was
sound.
Take Care.
On Wed, Feb 5, 2020 at 10:29 PM ToddAndMargo via perl6-users <
perl6-us...@perl.org> wrote:
> On 2020-02-03 13:51, ToddAndMargo via perl6-users wrote:
> > Hi All,
> >
> > Is ther a way to get
> >
> > $ p6 'my uint8 $u = 84; printf "\$u = <%08s>\n", $u;'
> > $u = <00000084>
> >
> > to print
> >
> > $u = <0000_0084>
> >
> > ?
> >
> >
> > Many thanks,
> > -T
>
> Hi All,
>
> Just to torment myself, I wrote a sub to do this:
>
> .......................................
> sub sbprint( UInt $b ) {
> my $bits = $b.UInt.msb + 1;
> my $bytes = $bits div 8;
> if ($bits % 8 ) > 0 { $bytes += 1 };
> # say "bits = $bits bytes = $bytes";
> my Str $bitstr = "";
>
> loop ( my $i = 0; $i < $bytes; $i += 1 ) {
> my $j = ( $b +> ( $i * 8 ) ) +& 0xFF;
> my $k = sprintf "_%08s", $j.base(2);
> # say "b = $b.base(2) i = $i j = $j.base(2) k = $k";
> $bitstr = $k ~ $bitstr;
> # say $bitstr;
> }
> $bitstr = "0b" ~ $bitstr;
> $bitstr ~~ s/ 0b_ /0b/;
> return $bitstr;
> }
>
> say sbprint 0x04F842;
> say 0x04F842.base(2);
> .......................................
>
> $ intTest.pl6
> 0b00000100_11111000_01000010
> 100 11111000 01000010 # spaces added by me
>
--
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