Re^2: Splitting a string to chunks

in reply to Re: Splitting a string to chunks
in thread Splitting a string to chunks

thx for pointing out. what about

'regexpad' => sub 
{
  # padding the string 
  my $padding = 8 - length($str%8) if length($str%8); #has to be 8 - m
+odulo not modulo, thx johngg
  $str .= "x" x $padding;

  # dividing the string in parts of 8 chars
  my @arr = $str =~ /(........)/g;

  #remove padding
  $arr[-1] = substr($arr[-1],-$padding);
}
[download]

although its a bit slower than the other 2 regex solutions

               Rate split_pos grep_split substr_map regexpad regexo re
+gex substr_loop unpack
split_pos    5841/s        --       -64%       -70%     -75%   -76%  -
+76%        -79%   -80%
grep_split  16129/s      176%         --       -17%     -30%   -33%  -
+34%        -42%   -45%
substr_map  19531/s      234%        21%         --     -15%   -19%  -
+20%        -30%   -33%
regexpad    22936/s      293%        42%        17%       --    -5%   
+-6%        -17%   -22%
regexo      24038/s      312%        49%        23%       5%     --   
+-1%        -13%   -18%
regex       24272/s      316%        50%        24%       6%     1%   
+ --        -13%   -17%
substr_loop 27778/s      376%        72%        42%      21%    16%   
+14%          --    -5%
unpack      29240/s      401%        81%        50%      27%    22%   
+20%          5%     --
[download]

Edit: corrected padding

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-- Terry Pratchett, "Reaper Man"

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Re^3: Splitting a string to chunks by johngg (Canon) on Nov 29, 2006 at 23:25 UTC
I think your "padding" algorith might be a bit wonky. Given a string of length, say, 19 characters you would arrive at a `$padding` value of 3, thus padding your `$str` with three "x"s to end up with a length of 22, not 24 as I think you wanted. This should work (not tested) `my $padding = 8 - ($str % 8);` [download] The remove padding part would be something like (again, not tested) `substr $arr[-1], -$padding, $padding, q{} if $padding;` [download] Cheers, JohnGG Update: I must have been half-asleep; where's the `length` call? Line should be `my $padding = 8 - (length($str) % 8);` [download] You can't do modulo on a string :) `$ perl -le '$str = q{abc}; $pad = $str % 8; print $pad;' 0 $ perl -le '$str = q{abcdefghijkl}; $pad = $str % 8; print $pad;' 0 $` [download]	[reply] [d/l] [select]

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Re^3: Splitting a string to chunks
by johngg (Canon) on Nov 29, 2006 at 23:25 UTC

$padding

$str

my $padding = 8 - ($str % 8);
[download]

The remove padding part would be something like (again, not tested)

substr $arr[-1], -$padding, $padding, q{} if $padding;
[download]

Cheers,

JohnGG

Update: I must have been half-asleep; where's the length call? Line should be

my $padding = 8 - (length($str) % 8);
[download]

You can't do modulo on a string :)

$ perl -le '$str = q{abc}; $pad = $str % 8; print $pad;'
0
$ perl -le '$str = q{abcdefghijkl}; $pad = $str % 8; print $pad;'
0
$
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