Perl Weekly Challenge 027

Audit.pm

package Audit{
    use Data::Dump q/pp/;
    use Filter::Simple;

    our %Log;

    sub audit{
        my($name, $value) = @_; 
        $value = "undef" if !defined($value); 
        if($Log{$name}){
            push @{$Log{$name}}, $value;
        }
        else{
            $Log{$name} = [$value]; 
        } 
    }  

    sub clear_log{
        %Log = (); 
    } 

    sub print_log{
        for my $key (keys %Log){
            print "$key: " . join(", ", @{$Log{$key}}) . "\n";  
        } 
    } 
    
    sub pretty_print_log{
        for my $key (keys %Log){
            print "$key: " . join(", ", map{ pp $_ } @{$Log{$key}}) . "\n";  
        } 
    } 

    FILTER_ONLY code => sub{
       s|((\$[[:alnum:]_]*).*;)|$1 Audit::audit('$2', $2);|g;
    }  
}

ch-1.pl

use strict;
use warnings;
##
# Write a script to find the intersection of two straight lines.
# The co-ordinates of the two lines should be provided as command line parameters.
##
MAIN:{
    my @endpoints_line_0 = @ARGV[0, 1]; 
    my @endpoints_line_1 = @ARGV[2, 3]; 
    @endpoints_line_0 = map { $_=~tr/()//d; [split(/,/, $_)];} @endpoints_line_0;  
    @endpoints_line_1 = map { $_=~tr/()//d; [split(/,/, $_)];} @endpoints_line_1;  
    my($a, $b, $c, $d, $p, $q, $r, $s) = (
        $endpoints_line_0[0]->[0],
        $endpoints_line_0[0]->[1],
        $endpoints_line_0[1]->[0],
        $endpoints_line_0[1]->[1],
        $endpoints_line_1[0]->[0],
        $endpoints_line_1[0]->[1],
        $endpoints_line_1[1]->[0],
        $endpoints_line_1[1]->[1]
    ); 
    my $denominator = ($c - $a) * ($s - $q) - ($r - $p) * ($c - $b);  
    
    my $x0 = ($c * $b - $a * $d) * ($r - $p) - ($r * $q - $p * $s) * ($c - $a);  
    my $y0 = ($c * $b - $a * $d) * ($s - $q) - ($r * $q - $p * $s) * ($d - $b);  

    my $x = $x0/$denominator;
    my $y = $y0/$denominator;

    print "($a, $b)--($c, $d) and ($p, $q)--($r, $s) intersect at ($x, $y)\n";
} 

ch-2.pl

use strict;
use warnings;
##
# Write a script that allows you to capture/display historical data. 
# It could be an object or a scalar.
## 
use Audit; 
use Class::Hash; 

my $test0;
$test0 = 2;
$test0 = 3;

Audit::print_log(); 
Audit::clear_log(); 

my $test1 = new Class::Hash(A => "B");
$test1 = new Class::Hash(B => "C");
$test1 = new Class::Hash(C => "D");
Audit::pretty_print_log();