case-class

问题 I am trying to override a method of trait in my case class which want to display all the members of case class. I am using it for debugging purpose. trait A{ def myMethod(employee:Emp):Unit } case class Emp(id:String,name:String) extends A { override def myMethod(employee: Emp): Unit = emp.productIterator.toList.foreach(println) } other possible way to do this is emp.productIterator.toList.mkString("\n") to declare Emp("10","abc") . I am new to Scala , not sure how to call the override method

问题 I have a very complicated JSON file that looks like this: { "Animals": [ [ 100, "Mammals", [ 1, "Cat", 50, 45, 57, -1 ], [ 2, "Dog", 31, 44, 18, -1 ] ], [ 159, "Reptiles", [ 1, "Lizard", 11, 12, 9, -1 ] ] ] } I am attempting to parse this structure and somehow get scala objects out of it. Here was my attempt: case class Facts(number: Int, subTypeOfAnimal: String, data: List[Int]) case class Animaltype(value: Int, typeOfAnimal: String, characteristics: List[Facts]) case class Animal(rows: List

问题 How can I have the scala compiler automatically generate the case object? // Pizza class class Pizza (val crust_type: String) // companion object object Pizza { val crustType = "crust_type" } Desired properties for case object for each attribute in the case class generate an attribute in the case object set the value in of each corresponding case object to the string representation of the attribute name and change camelCase to snake_case for the object attribute name, keep snake_case for

问题 I would like to define a class hierarchy with about 100 case classes deriving from common base. The types are describing nodes in the AST hierarchy, like this one. I would like to do something along the lines of: trait Base { def doCopy: Base } trait CloneSelf[T <: CloneSelf[T]] extends Base { self: T => def copy(): T override def doCopy: T = copy() } case class CaseA(a: String) extends Base with CloneSelf[CaseA] case class CaseB(b: Int) extends Base with CloneSelf[CaseB] This gives an error,

问题 I have the following case class case class Something(val input : Array[Int], val output : Array[Int] = null, val remainder : Array[Int] = null, val next : Something = null) { override def equals(thatGeneric: scala.Any): Boolean = { if(!thatGeneric.isInstanceOf[Something]) return false val that = thatGeneric.asInstanceOf[Something] val thisInput = if(this.input == null) null else this.input.deep val thatInput = if(that.input == null) null else that.input.deep val thisOutput = if(this.output ==

问题 I want to group elements of different types into one. Following is one example trait Element case class ElementString(key:String,value:String) extends Element case class ElementDouble(key:String,value:Double) extends Element case class ElementInt(key:String,value:Int) extends Element Grp(ElementString("2","abc"),ElementDouble("3",100.20),ElementInt("4",10)) One possible way is to use varargs case class Grp(group:Element*) . Is there any other efficient way to achieve the above . Any possible

问题 This question already has an answer here : Encode an ADT / sealed trait hierarchy into Spark DataSet column (1 answer) Closed last year . Hi I have an RDD which is basically made after reading a CSV file. I have defined a method which basically maps the lines of rdd to different case classes based on input parameter. The RDD returned need to be converted to dataframe When I try to run the same I get below error. Method defined is case class Australiafile1(sectionName: String, profitCentre:

问题 sorry for asking a simple question. I want to pass a case class to a function argument and I want to use it further inside the function. Till now I have tried this with TypeTag and ClassTag but for some reason, I am unable to properly use it or may be I am not looking at the correct place. Use cases is something similar to this: case class infoData(colA:Int,colB:String) case class someOtherData(col1:String,col2:String,col3:Int) def readCsv[T:???](path:String,passedCaseClass:???): Dataset[???]

问题 So, I had a very simple case class: case class StreetSecondary1(designator: String, value: Option[String]) This was working just fine. However, I kept having places where I was parsing a single string into a tuple which was then used to build an instance of this case class: def parse1(values: String): StreetSecondary1 = { val index = values.indexOf(" ") StreetSecondary1.tupled( if (index > -1) //clip off string prior to space as designator and optionally use string after space as value

问题 I'm developing a simulation in Scala inside a game. I would like to use only immutable objects to define the game logic even if it's inefficient. Why? Because I can, so I will. Now I'm stressing a bit the main game loop with pushing the simulation with a huge load. Basically I have these nested case classes and I operate with .copy() to define the following state of a given entity inside the simulation. The problem is that all these operations generate a lot of unreferenced objects and so at