Final fixes

examples/rule_demo/main.orc

@@ -1 +1,12 @@
-expor main := foo bar baz
+export main := [foo, bar, baz, quz]
+
+[...$data] := (cons_start ...$data cons_carriage(none))
+
+[] := none
+
+, $item cons_carriage($tail) := cons_carriage(
+  (some (cons $item $tail))
+)
+
+cons_start $item cons_carriage($tail) := some (cons $item $tail)
+