scala分隔的continuations类型

我仍在弄清楚这里涉及的确切打字规则/含义

如果示例中的类型“足够简单”到“适合”，这似乎很容易，但与tiark rompf给出的类型相比（至少对我而言），情况变得更加复杂/困难：

|- e: A@cpsParam[B,C]; {[|r|]}: U
-----------------------------------------------------
[|val x: A = e; r|] = [|e|].map( (x: A) => {[|r|]} )

因此，

[|e |].map（（x:A）=>{[|r |]}）的结果将具有类型
Shift[U，B，C]
，根据蒂亚克论文中给出的map定义

这里U不一定与B相同

到目前为止，我还不明白为什么在没有类似U的东西的情况下，U可以与B不同我又看了一眼，想看看选择性cps变换在这两种情况下会产生什么结果

U
{shift{（k:Int=>Depp）=>k（7）}；sepp.asInstanceOf[Float]}
根据如下规则键入：
Float@cpsParam[Depp，Depp]
。您看到的类型错误是因为
reset
expected
Float@cpsParam[Float，Depp]
并且重置的参数类型不正确时失败。
package sample

import scala.util.continuations._

class Depp {
  override def toString = "DEPP"
}

class Sepp extends Depp {
  override def toString = "DEPP->SEPP"
}

object Sample extends Application {
  val depp = new Depp
  val sepp = new Sepp
  val res = reset {
    shift {
      (k: Int => Depp) => k(7)
    }
    val z = sepp
    z
  }
  println("Result = "+ res)
}

private[this] val res: sample.Depp = scala.util.continuations.package.reset[sample.Sepp, sample.Depp]({
   package.this.shiftR[Int, sample.Depp, sample.Depp](((k: (Int) => sample.Depp) => k.apply(7))).map[sample.Sepp]
     tmp1;
     val z: sample.Sepp = Sample.this.sepp;
     z
   }))

Sample.scala:16: error: type mismatch;
 found   : Float @scala.util.continuations.cpsParam[sample.Depp,sample.Depp] @scala.util.continuations.cpsSynth
 required: Float @scala.util.continuations.cpsParam[Float,sample.Depp]
  val res = reset {
                  ^
Float @scala.util.continuations.cpsParam[sample.Depp,sample.Depp] @scala.util.continuations.cpsSynth <: Float @scala.util.continuations.cpsParam[Float,sample.Depp]?
  scala.util.continuations.cpsParam[sample.Depp,sample.Depp] <: scala.util.continuations.cpsParam[Float,sample.Depp]?
    Float <: sample.Depp?
      <notype> <: sample.Depp?
      false
    false
  false
false
one error found

e: A@cpsParam[B,C]  {[|r|]}: U  U <: B
-----------------------------------------------------
[|val x: A = e; r|] = [|e|].map( (x: A) => {[|r|]} )