PatternMatchingShow.java

    public static String show(final Json json) {
        return json.match(
                seq -> seq.getElems().stream()
                        .map(j -> show(j))
                        .collect(Collectors.joining(",", "[", "]")),
                jobject -> jobject.getMembers().entrySet().stream()
                        .map(kv -> "\"" + kv.getKey() + "\":" + show(kv.getValue()))
                        .collect(Collectors.joining(",", "{", "}")),
                jnumber -> jnumber.getNum().toString(),
                jstring -> "\"" + jstring.getStr() + "\"",
                jboolean -> jboolean.getB().toString(),
                jNull -> "null"
        );
    }