0: # This function works like map, except it produces a single scalar
1: # output.  It hence maps an array into a scalar hence the (clumsy)
2: # name scalarmap
3: #
4: # It requires 3 parameters
5: # 1) A code block like map.  This will be passed $a and $b
6: #    $a will be the result and $b is the current element
7: #    it should return the new result
8: # 2)  An initial value
9: # 3) An array
10: 
11: sub scalarmap (&$@)
12: {
13:     my $code = shift;
14:     local ($a, $b) = ( shift );
15:     foreach $b (@_)
16:     {
17:         $a = &$code;
18:     }
19:     return $a;
20: }
21: 
22: # Here are some examples
23: 
24: my @array = 1..10;
25: 
26: my $sum = scalarmap {  $a + $b } 0, @array;
27: 
28: my $sum_of_even_numbers = scalarmap {  $b & 1 ? $a : $a + $b } 0, @array;
29: 
30: my $factorial = scalarmap {  $a * $b } 1, @array;
31: 
32: my $fancy_join = scalarmap {  $a . $b } "", 'a'..'z';
33: 
34: # I don't suppose this will be actually useful in real life but it
35: # amused me to make a twist an the all powerful map!
36: #
37: # This was inspired by a reference kudra made to subroutines and man
38: # perlsub.