package com.jesusbornd.samuel2;
import java.util.Optional;

public class Samuel2_07_Chapter_Lv1 {
    record Covenant(String party, String promise, Optional<String> expiry) {
        boolean isEternal() { return expiry.isEmpty(); }
    }
    public static void main(String[] args) {
        var covenant = new Covenant("다윗", "왕위가 영원히 견고하리라", Optional.empty());
        System.out.printf("[%s] 약속: %s%n", covenant.party(), covenant.promise());
        System.out.println("유효 기간: " + (covenant.isEternal() ? "♾️  영구" : covenant.expiry().get()));
    }
}

from dataclasses import dataclass
from typing import Optional

@dataclass
class Covenant:
    party: str
    promise: str
    expiry: Optional[str] = None

    def is_eternal(self) -> bool:
        return self.expiry is None

c = Covenant("다윗", "왕위가 영원히 견고하리라")
print(f"[{c.party}] 약속: {c.promise}")
print(f"유효 기간: {'♾️  영구' if c.is_eternal() else c.expiry}")