Scala 创建一组元素 [英] Scala create group of elements

问题描述

我想在消息中创建一组元素，如下图所示

I want to create a group of elements in a message as in below image

更新:

 case class Element(key:String;value:String)

消息可以像下面这样表示

Message can be represented something like below

 case class Msg(field1:Element,field2:Group)

Group->代表重复组 - 我需要帮助定义组和子团体

Group->represents the repeating group - I need help to define group and sub groups

元素定义了在组中重复的key=value组合

The element defines the key=value combination which is repeated in groups

以下几点

1. 是 FixMessage 的字段"属性吗?

1. Are the "fields" attributes of a FixMessage?

-是的，它们是 Fix Message 的属性，每个字段表示为case class Element(key:String;value:String)

-Yes they are attributes of a Fix Message and each field is represented as case class Element(key:String;value:String)

重复组它们是 Element 重复次数不

Repeating group they are Element repeating no of times

键和值都是字符串吗?

-暂时将它们视为字符串

-Consider them as string for now

字段 N(字段 1、字段 2 等)代表不同的类型?

Field N (Field 1, Field 2, etc) represent different types?

-是的，它们将其表示为不同的数据类型.但现在我们可以将它们视为相同的数据类型以使其简单.

-Yes they represent it as different data types.But for now we can take them as of same data type to make it simple.

输出:

key2=value2 ;key3=value3;key4=value=4;key3=value3;key4=value=4;key2=value‌e2;key3=value3;key‌ 4=value4;key3=value‌ 3;key4=value4

说明

组 key2=value2 重复了 2 次子组为key3=value3;key4=value=4;key3=value3;key4=value=4，每组增益重复2次(key2=value2) 分别

The group key2=value2 is repeating 2 times The sub group is key3=value3;key4=value=4;key3=value3;key4=value=4 which is gain repeating 2 times in each group (key2=value2) respectively

推荐答案

如果我正确理解域，这样的事情应该可行:

If I understand the domain correctly, something like this should work:

case class Message(entries: List[Entry])

case class Entry(name: String, value: Value)
trait Value
object Value {
  case class Single (v: String) extends Value
  case class Group (entries: List[List[Entry]]) extends Value
}

Message(
  Entry("Key 1", Value.Single("Value 1")),
  Entry("Key 2", Value.Group(
    List(
      List(
        Entry("Key 3", Value.Single("Value 3")),
        Entry("Key 4", Value.Single("Value 4"))
      ),
      List(
        Entry("Key 3", Value.Single("Value 5")),
        Entry("Key 4", Value.Single("Value 6"))
      )
    )
  ))
)

当然可以创建一些辅助函数来为它制作更好的 DSL.

Of course some helper functions could be created to make a nicer DSL for it.

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