fun main(args:Array
     
      ):Unit{    val x = a{        aa{            +"01.01"            +"01.02"        }        aa{            +"02.01"            +"02.02"        }    }    print(x)}fun a(p:A.()->Unit):A {    val a = A()    a.p()    return a;}class A {    val children=arrayListOf
      
       ()    fun aa(p:AA.()->Unit){        val aa = AA();        aa.p();        children.add(aa);    }    override fun toString(): String {        val builder = StringBuilder("
       ")        children.forEach { builder.append(it.toString()) }        builder.append("\r\n")        return builder.toString();    }}class AA {    val children=arrayListOf
       
        ()    operator fun String.unaryPlus() {        children.add("\r\n\t\t
        
         ${this}
        ")    }    override fun toString(): String {        val builder = StringBuilder("\r\n\t
        
         ")        children.forEach { builder.append(it.toString()) }        builder.append("\r\n\t
        ")        return builder.toString();    }}
       
      
     

 执行结果

    
              
       
        01.01
               
       
        01.02
           
          
              
       
        02.01
               
       
        02.02
           
      

 

import java.util.*import List.Companion.listimport Map.Companion.mapfun main(args: Array
     
      ): Unit {    val x = list {        values("a", "b", "c")        list {            values("a", "b", "c")            map {                values("name" to "Fred")            }        }        map {            values(                    "name" to "Fred",                    "age" to "28",                    "fav" to list {                        values("java", "c++", "kotlin")                    }            )        }    }    val y = map {        values("languages" to list {            values("java", "c++", "perl")            values("scala","kotlin","ruby")        })    }    println(x)    println(y)}class List : ArrayList
      
       () {    companion object {        fun list(p: List.() -> Unit): List {            val l = List()            l.p()            return l        }    }    fun values(vararg x: Any) {        this.addAll(x)    }    fun list(p: List.() -> Unit) {        val l = List()        l.p()        this.add(l as Any)    }    fun map(p: Map.() -> Unit) {        val m = Map()        m.p()        this.add(m as Any)    }}class Map : HashMap
       
        () {    companion object {        fun map(p: Map.() -> Unit): Map {            val m = Map()            m.p()            return m        }    }    fun values(vararg x: Pair
        
         ) {        this.putAll(x)    }    fun list(p: List.() -> Unit): List {        val l = List()        l.p()        return l;    }    fun map(p: Map.() -> Unit): Map {        val m = Map()        m.p()        return m    }}
        
       
      
     

执行结果

[a, b, c, [a, b, c, {name=Fred}], {name=Fred, fav=[java, c++, kotlin], age=28}]

{languages=[java, c++, perl, scala, kotlin, ruby]}