langs a-z

Task/Evolutionary-algorithm/Perl-6/evolutionary-algorithm.pl6

@@ -0,0 +1,13 @@
+constant target = "METHINKS IT IS LIKE A WEASEL";
+constant mutate_chance = .08;
+constant alphabet = 'A'..'Z',' ';
+constant C = 100;
+
+sub mutate { $^string.comb.map({ rand < mutate_chance ?? alphabet.pick !! $_ }).join }
+sub fitness { [+] $^string.comb Zeq target.comb }
+
+loop (
+    my $parent = alphabet.roll(target.chars).join;
+    $parent ne target;
+    $parent = max :by(&fitness), mutate($parent) xx C
+) { printf "%6d: '%s' %2d\n", (state $)++, $parent, fitness $parent }