Re: Making two 8-bit numbers from indices of set bits

Perhaps this

$ perl -le '
> vec($str, $_, 1) = 1 for 1, 8, 9;
> $high = unpack q{xc}, $str;
> $low = unpack q{c}, $str;
> print qq{$high - $low};'
3 - 2
$
[download]

Cheers,

JohnGG

Comment on Re: Making two 8-bit numbers from indices of set bits Download Code

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Re^2: Making two 8-bit numbers from indices of set bits by carcassonne (Pilgrim) on Feb 20, 2007 at 02:44 UTC
Works fine. Thanks. When unselecting the only selection of the multiple choice list, ncurses will return an empty array that cannot go through, so I've added a condition: `# (inside ncurses listbox callback) my $listbox = shift; my @sel = $listbox->id; $byte2 = 0; $byte1 = 0; if (@sel) { my $code; $code \|= 1 << $_ for @sel; $byte2 = $code >> 8; $byte1 = $code & 0xFF; }` [download] I've taken that solution although the unpack and pack is interesting. Thanks again ! Cheers. Al	[reply] [d/l]

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Re^2: Making two 8-bit numbers from indices of set bits
by carcassonne (Pilgrim) on Feb 20, 2007 at 02:44 UTC

Works fine. Thanks. When unselecting the only selection of the multiple choice list, ncurses will return an empty array that cannot go through, so I've added a condition:

# (inside ncurses listbox callback)

my $listbox = shift;
my @sel = $listbox->id;

$byte2 = 0;
$byte1 = 0;

if (@sel) {
  my $code;
  $code |= 1 << $_ for @sel;
  $byte2 = $code >> 8;
  $byte1 = $code & 0xFF;
}
[download]

I've taken that solution although the unpack and pack is interesting. Thanks again !

Cheers.

[reply]
[d/l]