langs a-z

Task/Caesar-cipher/Perl-6/caesar-cipher.pl6

@@ -0,0 +1,15 @@
+my @alpha = 'A' .. 'Z';
+sub encrypt ( $key where 1..25, $plaintext ) {
+    $plaintext.trans( @alpha Z=> @alpha.rotate($key) );
+}
+sub decrypt ( $key where 1..25, $cyphertext ) {
+    $cyphertext.trans( @alpha.rotate($key) Z=> @alpha );
+}
+
+my $original = 'THE FIVE BOXING WIZARDS JUMP QUICKLY';
+my $en = encrypt( 13, $original );
+my $de = decrypt( 13, $en );
+
+.say for $original, $en, $de;
+
+say 'OK' if $original eq all( map { .&decrypt(.&encrypt($original)) }, 1..25 );