Encoding of an algebraic list type in Java

gistfile1.java

public static abstract class List<a> {
    private static final class $Nil<a> extends List<a> {
        private $Nil() {
        }

        public <M> M match(final M $ifNil, final $F<a, $F<List<a>, M>> $ifCons) {
            return $ifNil;
        }
    }

    private static final class $Cons<a> extends List<a> {
        private final a $1;
        private final List<a> $2;

        private $Cons(final a $1, final List<a> $2) {
            this.$1 = $1;
            this.$2 = $2;
        }

        public <M> M match(final M $ifNil, final $F<a, $F<List<a>, M>> $ifCons) {
            return $ifCons.$apply($1).$apply($2);
        }
    }

    public abstract <M> M match(final M $ifNil, final $F<a, $F<List<a>, M>> $ifCons);
}