Deconstruction a speciality. Rather than explain extensively
I have gone for the plain perl recoding approach to make it
blindingly obvious how this works. I like this JAPH.

cheers

tachyon

#!/usr/bin/perl -w
use strict;
# this string identifies the key  encoding features basically the
# length, but also the . and , The ) is meaningless other than
# not meaning something! The final full stop does nix.         
$_="xxxx xxxxxxxxxx xxxxxxx xxxxx xxxxxxx xxx xxxxxxx xxxx xx,
xxxxxx x xxxxxx xxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxx xxxxxxx xxxx
xxxxxx xxxxxxxx xxxxxx xxxxx xxxxxxx xx xx. xxxxx, xxxxxx xxxxx
xxxxxxx xx xxxxxx xxxxxxxxxxxx xx. xxxxxx xxxxxxxx xxxxxx x) xxxxxx
xxx xxxxxx xxxxxxxxxxx xxxxxx xxxxx xxxxxxx xx.";
# this loop replaces the map
for (m/x+|[\.,]/g) {
    push @a, eval'(/[\.,]/) ? 0 : length $_';
}
# net result of map step is:
# @a = qw(4 10 7 5 7 3 7 4 2 0 6 1 6 14 6 15 7 4 6 8 6 5 7 2 2 0 5 0 6
+ 5 7 2 6 12 2 0 6 8 6 1 6 3 6 11 6 5 7 2 0); 

# this breaks down the second line into self evident steps
while ($foo = shift @a) {
    $hex_code1 = sprintf "%x", $foo;
    $hex_code2 = sprintf "%x", shift @a;
    $hex = $hex_code1.$hex_code2;
    $dec = hex $hex;
    $ascii = chr $dec;
    print $ascii;
} 

# Notes $$ is the $PID, I substitute $foo just because
# %x is unsigned integer in hex so sprintf %x, $foo converts $foo
# to hex. 
# The '%x'x2 is the same as "%x%x" 
# sprint "%x%x", $a ,$b; shoves both $a and $b into hex format
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