Add Scope features

[orekyuu]

refs: #641

Before

Until now there has been a need to write code that is not DRY.

example:

static Consumer<WhereDeclaration> onlyAdult(PropertyMetamodel<Integer> ageProp) {
  return w -> { w.gt(ageProp, 18) };
}

Entityql entityql;
UserEntity_ e;

// select * from users where age> 18;
entityql.from(e).where(onlyAdult(e.age));

// select * from users where age> 18 and role = 'customer';
entityql.from(e).where(onlyAdult(e.age).andThen(w -> { w.eq(e.role, 'customer') }));

After

Extend metamodel annotations to prevent non-DRY code.

@Entity(metamodel = @Metamodel(scope = { UserScope.class }))
class UserEntity {
  Long id;
  int age;
  String role;
}

class UserScope {
  public Consumer<WhereDeclaration> onlyAdult(UserEntity_ e) {
    return w -> w.gt(e.age, 18);
  }

  public Consumer<WhereDeclaration> onlyCustomer(UserEntity_ e) {
    return w -> w.eq(e.role, 'customer');
  }
}

Entityql entityql;
UserEntity_ e;

// select * from users where age> 18 and role = 'customer';
entityql.from(e).where(e.onlyAdult().andThen(e.onlyCustomer()));

Scope Class specifications

• Requires default constructor.
• The method must meet the following conditions
  • Requires first method parameter is Metamodel.
  • Requires public.
  • Requires non static.
  • Requires return value that is not void.
  • Ignored if these are not met.

[orekyuu]

Here, type checking cannot be performed correctly because it is before the Metamodel is generated.
Do you have a good idea?

[nakamura-to]

I have no idea.
But I think it's OK.

[nakamura-to]

Thanks. I'll review your pull request this weekend.

By the way, your sample code in the "After" section looks wrong.
The first parameter must be a Metamodel, right?

class UserScope {
  public Consumer<WhereDeclaration> onlyAdult(UserEntity_ e) {
    return w -> w.gt(e.age, 18);
  }

  public Consumer<WhereDeclaration> onlyCustomer(UserEntity_ e) {
    return w -> { w.eq(e.role, "customer");
  }
}

[orekyuu]

By the way, your sample code in the "After" section looks wrong.

Exactly. I'll fix it.

[orekyuu]

@nakamura-to Please review.

[nakamura-to]

Hi, I will review this weekend.

[nakamura-to]

@orekyuu Thanks for your changes!