Cats Validated example 1

cats-validated-example-1.scala

import cats.data._
import cats.implicits._

//Left side is better as non empty list
type MyValidation[A] = Validated[Vector[String], A]

case class Person(name: String, age: Int)

def validateName(name: String): MyValidation[String] =
  if (name.isEmpty) {
    Validated.invalid(Vector("Name must not be empty"))
  } else {
    Validated.valid(name)
  }

def validateAge(age: Int): MyValidation[Int] =
  if (age < 0) {
    Validated.invalid(Vector("Age must be greater than zero"))
  } else {
    Validated.valid(age)
  }

def validateAndCreatePerson(name: String, age: Int): Either[Vector[String], Person] =
  (
    validateName(name),
    validateAge(age)
  ).mapN(Person.apply).toEither

validateAndCreatePerson("", -1)
//res0: Either[Vector[String],Person] = Left(Vector(Name must not be empty, Age must be greater than zero))

validateAndCreatePerson("Julian", 20)
// Either[Vector[String],Person] = Right(Person(Julian,20))