chkr_first_try

package chkr;

@FunctionalInterface
interface CheckedFunction<T, R> {
  R apply(T t) throws Exception;
}


-----------

package chkr;

import java.util.function.Function;

public class Extend {
  public CheckedFunction fn;

  Extend(){}
  Extend(CheckedFunction fn) {
    this.fn = fn;
  }

  @SuppressWarnings("unchecked")
  public Extend match(CheckedFunction check) {
    return new Extend(value -> {
      try {
        return check.apply(value);
      } catch (Exception e) {
        throw new Exception(e.getMessage());
      }
    });
  }

  @SuppressWarnings("unchecked")
  public Extend judge(Function<Object, Boolean> cond, String message) {
    return match(value -> {
      if (fn != null) fn.apply(value);
      if (cond.apply(value)) {
        return value;
      } else {
        throw new Exception(message);
      }
    });
  }

  @SuppressWarnings("unchecked")
  public Object check(Object value) throws Exception {
    return fn.apply(value);
  }
}
----------------

package chkr;

import java.util.Map;
import java.util.Objects;

public class T {

  public static Extend Null = new Extend().judge(Objects::isNull, "is not Null");

  public static Extend Any = new Extend().judge(Objects::nonNull, "is Null");

  public static Extend Num() throws Exception {
    return Any.judge(a -> {
      try {
        int b = (int) a;
        return true;
      } catch (Exception e){
        return false;
      }
    }, "is not Num");
  }

  public static Extend Str() {
    return Any.judge(a -> {
      try {
        String b = (String) a;
        return true;
      } catch (Exception e){
        return false;
      }
    }, "is not Str");
  }

  public static Extend Or(Extend... es) {
    return new Extend().match(value -> {
      boolean matchSome = false;
      for (Extend e : es) {
        try {
          e.check(value);
          matchSome = true;
          break;
        } catch (Exception exp) {

        }
      }
      if (matchSome) {
        return value;
      } else {
        throw new Exception("Or failed");
      }
    });
  }

  public static void main(String[] args) {
    try {
      System.out.println(Num().check(null)); // throw error
      System.out.println(Num().check(123)); // 123
      System.out.println(Num().check("abc")); // throw error

      System.out.println(Str().check(null)); // throw error
      System.out.println(Str().check("abc")); // abc
      System.out.println(Str().check(123)); // throw error

      System.out.println(Or(Str(), Num()).check(123)); // 123
      System.out.println(Or(Str(), Num()).check("abc")); // abc
      System.out.println(Or(Str(), Num()).check(true)); // throw error

      var typeCheck = Map.of(
        "userId", Num(),
        "userName", Str(),
        "phone", Str(),
        "IdCard", Or(Num(), Str())
      );

    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}