use strict;
use warnings;

print join "\n", myBigSub (1 .. 10);

sub myBigSub {
    my @params = &myLittleSub1;
    @params = myLittleSub4 (myLittleSub3 (myLittleSub2 (@params)));
    @params = myLittleSub5 (@params);
    return @params;
}


sub myLittleSub1 {
    my (@params) = @_;
    return reverse @params;
}


sub myLittleSub2 {
    return map {$_ * 3} @_;
}


sub myLittleSub3 {
    my @params = grep {$_ % 6} @_;
    return @params;
}


sub myLittleSub4 {
    my @params = @_;
    return @params[1, 2, 4];
}


sub myLittleSub5 {
    my (@params) = @_;

    $_ = 'x' x $_ for @params;
    return @params;
}
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Prints:

xxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxx
xxx
[download]