编写Scalaz 7验证

我想编写返回Scalaz 7

Validation

s的检查。我做了一个简单的例子，解析一系列单词并从中构造Person对象。解析可能在许多步骤中失败，在这种情况下，我们失败得很快，错误消息是失败的原因。下面的例子完全是捏造出来的，虽然很愚蠢，但它尽可能接近我想要实现的目标

看看我下面的理解，似乎有更好的方法来编写验证

初始顺序更改了几次，从

seq

到

seq2

再到

seq3

。例如调用

lastnamevalization

时，需要使用

seq2

显式调用它，即使它在

seq2=onlyShort（seq）

之后调用

我读过关于克莱斯利箭头组合的书，当人们可以组合

A=>M[B]

和

B=>M[C]

得到一个箭头

A=>M[C]

（其中

M

是单子）。然而，我在这里并不总是以这样一种方式编写东西，即下一步将重用上一步的计算。我无法让克莱斯利·阿罗用Scalaz 7创作作品 代码：

导入scalaz.\uz，scalaz_
案例类别地址（streetName:String，streetNumber:Int）
案例类人员（姓名：String，姓氏：String，年龄：Int，地址：address）
def namevalization（seq:List[String]）=seq.find（Set（“John”、“Carol”、“Susan”）。contains（)）。toSuccess（“未找到名称”）
def lastNameValidation（seq:List[String]）=seq.find（Set（“Kennedy”、“Hardy”、“Taplin”）。包含（））.toSuccess（“未找到姓氏”）
def lengthValidation（lastName:String）=lastName.size.success[String]
def dyValidation（lastName:String）=如果（！lastName.contains（“dy”））失败（“非此人”）否则成功（123）
def streetNumberValidation（seq:List[String]）=seq.find（u.forall（u.isDigit））.map（u.toInt）.toSuccess（“无法提取街道号”）
def streetValidation（seq:List[String]）=seq.find（Set（“布什街”、“松树街”、“市场街”）。包含（））.toSuccess（“未找到街道”）
def onlyShort（seq:List[String]）=seq.filter（u.size<15）
def omit垃圾（seq:List[String]）=seq.filter（！=“垃圾”）
def createPerson（seq:List[String]）=for{
列出两条快速注释。首先，如果您不想累积失败，请使用
\/
（或者使用普通的
或
）第二，从一大串字符串中挖掘值本质上是混乱的，如果你不能将问题分解成更小的阶段，我想这就和你将要得到的一样清晰了。
或者
都不是单子，所以我无法很好地用它来理解（我需要调用
.right
以获得正确的投影）默认情况下，
Validation
是右倾的，因此可以很好地将其组合在一起以便于理解。另一件事是，交错
Validation
也不是单子，关于它是否应该使用
flatMap
方法来生成
for
理解语法，存在一些争论可能。
\/
是一个单子，本质上只是一个右偏的
或
，带有一些方便的附加操作。
import scalaz._, Scalaz._

case class Address(streetName: String, streetNumber: Int)
case class Person(name: String, lastName: String, age: Int, address: Address)

def nameValidation(seq: List[String]) = seq.find(Set("John", "Carol", "Susan").contains(_)).toSuccess("Name not found")
def lastNameValidation(seq: List[String]) = seq.find(Set("Kennedy", "Hardy", "Taplin").contains(_)).toSuccess("Last name not found")
def lengthValidation(lastName: String) = lastName.size.success[String]
def dyValidation(lastName: String) = if (!lastName.contains("dy")) Failure("Not the person") else Success(123)
def streetNumberValidation(seq: List[String]) = seq.find(_.forall(_.isDigit)).map(_.toInt).toSuccess("Could not extract street number")
def streetValidation(seq: List[String]) = seq.find(Set("Bush Street", "Pine Street", "Market Street").contains(_)).toSuccess("Street not found")

def onlyShort(seq: List[String]) = seq.filter(_.size < 15)
def omitGarbage(seq: List[String]) = seq.filter(_ != "garbage")

def createPerson(seq: List[String]) = for {
  name <- nameValidation(seq)
  seq2 = onlyShort(seq)
  lastName <- lastNameValidation(seq2)
  length <- lengthValidation(lastName)
  dy <- dyValidation(lastName)
  seq3 = omitGarbage(seq2)
  streetNumber <- streetNumberValidation(seq3)
  street <- streetValidation(seq3)
} yield Person(name, lastName, 80, Address(street, streetNumber))

createPerson(List("255", "a very long string", "Bush Street", "Hardy", "San Francisco", "John", "garbage"))

createPerson(List("a very long string", "Bush Street", "Hardy", "San Francisco", "John", "garbage"))

scala> import scalaz._, Scalaz._
import scalaz._
import Scalaz._

scala> case class Address(streetName: String, streetNumber: Int)
defined class Address

scala> case class Person(name: String, lastName: String, age: Int, address: Address)
defined class Person

scala> def nameValidation(seq: List[String]) = seq.find(Set("John", "Carol", "Susan").contains(_)).toSuccess("Name not found")
nameValidation: (seq: List[String])scalaz.Validation[java.lang.String,String]

scala> def lastNameValidation(seq: List[String]) = seq.find(Set("Kennedy", "Hardy", "Taplin").contains(_)).toSuccess("Last name not found")
lastNameValidation: (seq: List[String])scalaz.Validation[java.lang.String,String]

scala> def lengthValidation(lastName: String) = lastName.size.success[String]
lengthValidation: (lastName: String)scalaz.Validation[String,Int]

scala> def dyValidation(lastName: String) = if (!lastName.contains("dy")) Failure("Not the person") else Success(123)
dyValidation: (lastName: String)Product with Serializable with scalaz.Validation[java.lang.String,Int]

scala> def streetNumberValidation(seq: List[String]) = seq.find(_.forall(_.isDigit)).map(_.toInt).toSuccess("Could not extract street number")
streetNumberValidation: (seq: List[String])scalaz.Validation[java.lang.String,Int]

scala> def streetValidation(seq: List[String]) = seq.find(Set("Bush Street", "Pine Street", "Market Street").contains(_)).toSuccess("Street not found")
streetValidation: (seq: List[String])scalaz.Validation[java.lang.String,String]

scala> def onlyShort(seq: List[String]) = seq.filter(_.size < 15)
onlyShort: (seq: List[String])List[String]

scala> def omitGarbage(seq: List[String]) = seq.filter(_ != "garbage")
omitGarbage: (seq: List[String])List[String]

scala> def createPerson(seq: List[String]) = for {
     |   name <- nameValidation(seq)
     |   seq2 = onlyShort(seq)
     |   lastName <- lastNameValidation(seq2)
     |   length <- lengthValidation(lastName)
     |   dy <- dyValidation(lastName)
     |   seq3 = omitGarbage(seq2)
     |   streetNumber <- streetNumberValidation(seq3)
     |   street <- streetValidation(seq3)
     | } yield Person(name, lastName, 80, Address(street, streetNumber))
createPerson: (seq: List[String])scalaz.Validation[java.lang.String,Person]

scala> createPerson(List("255", "a very long string", "Bush Street", "Hardy", "San Francisco", "John", "garbage"))
res19: scalaz.Validation[java.lang.String,Person] = Success(Person(John,Hardy,80,Address(Bush Street,255)))

scala> createPerson(List("a very long string", "Bush Street", "Hardy", "San Francisco", "John", "garbage"))
res20: scalaz.Validation[java.lang.String,Person] = Failure(Could not extract street number)