From 4c7e1e6858613913494fbba1b49a0bbe80ff95a0 Mon Sep 17 00:00:00 2001
From: Mikael Nordin <kano0049@su.se>
Date: Thu, 27 Oct 2016 14:59:21 +0200
Subject: [PATCH] Some comments on implementation

---
 cellaut.pl | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/cellaut.pl b/cellaut.pl
index 6eb6a50..dcfe69e 100755
--- a/cellaut.pl
+++ b/cellaut.pl
@@ -1,24 +1,31 @@
 #!/usr/bin/env perl
 use strict;
 use warnings;
-use Data::Dumper;
 
+# Get arguments
 my $gens = $ARGV[0];
 my $width = $ARGV[1];
 my $rule = $ARGV[2]; 
 
 # Set up all possible rules 0 - 255
+# 0   = 00000000
+# 1   = 00000001
+# ...
+# 254 = 11111110
+# 255 = 11111111
 my @rules;
 for (my $index = 255; $index >=0; $index--) {
 	push @rules, [get_bin($index, 8)];
 }
 
+# extract the correct binary number for this position and this rule
 sub get_val_at_pos {
 	my ($binstr) = @_;
 	my $pos = sprintf ('%d', $binstr);
 	return $rules[$rule][$pos];
 }
 
+# Get the binary representation of a number as an array of 1's and 0's
 sub get_bin{
 	my ($dec, $padding) = @_;
 	my $bin = sprintf('%0' . $padding .'b',$dec); 
@@ -26,6 +33,7 @@ sub get_bin{
 	return @binarr;
 }
 
+# Set up the initial condition to be all 1's except fo one 0 in the middle
 sub set_up_init {
 	my @init;
 	my $half = $width / 2;
@@ -43,20 +51,26 @@ sub set_up_init {
 	
 }
 
+# Print usage
 sub usage {
 	print "$0 <number of generations> <width> <rule number (0-255)>\n";
 }
 
+# Some error handling
 if (scalar @ARGV < 3 or $rule > 255) {
 	usage;
 	exit 1;
 
 }
 
+# Get the initial condition and print it out
 my @initial = set_up_init;
 print @initial;
 print "\n";
+
+# Now loop through all the generations
 for (my $gen = 0; $gen < $gens; $gen++) {
+	# This is the next evoultion of the the automation
 	my @next;
 	for (my $elem = 0; $elem < $width ; $elem++) {
 		# Boundary conditions
@@ -65,12 +79,18 @@ for (my $gen = 0; $gen < $gens; $gen++) {
 			$state = $initial[$width -1] . $initial[$elem] . $initial[$elem +1 ] ;
 		} elsif ($elem  == $width -1 ) {
 			$state = $initial[$elem-1] . $initial[$elem] . $initial[0];
+		# Normal, we are not on the boundary
 		} else {
 			$state =  $initial[$elem - 1] . $initial[$elem] . $initial[$elem +1];
 		}
+		# Get the corresponding value for this state
 		$next[$elem] = get_val_at_pos oct("0b".$state);
 	}
+	# The next state is now the new initial
 	@initial = @next;
+	# Print it out
 	print @initial;
 	print "\n";
 }
+
+exit 0