是否有更好的方法来提升Scala中的PartialFunction？

问题描述

偶尔遇到下面的模式，我基本上有一个 PartialFunction [SomeType，AnotherType] ，并且想把它当作一个 Function [SomeType，Option [AnotherType] ，例如：

  def f（s：SomeType）：Option [AnotherType] = s match {
 case s1：SubType1 => Some（AnotherType（s1.whatever））
 case s2：SubType2 => Some（AnotherType（s2.whatever））
 case _ =>无
} 
  

有没有办法以避免默认情况下，并将结果包装在 Some 中它的定义位置？到目前为止我所得到的最好的是这样的：
$ b $ pre $ def f（s：SomeType）：Option [AnotherType] = pf.lift（s）
def pf：PartialFunction [SomeType，AnotherType] = {
case s1：SubType1 => AnotherType（s1.whatever）
case s2：SubType2 => AnotherType（s2.whatever）
}


有没有办法在没有定义中间功能？我已经尝试了以下各种方法，但还没有任何东西可以编译：

  def f ：函数[SomeType，Option [AnotherType]] = {
 case s1：SubType1 => AnotherType（s1.whatever）
 case s2：SubType2 => AnotherType（s2.whatever）
} .lift 
  

解决方案

condOpt 在对象scala.PartialFunction中。从scaladoc：

pre $ def onlyInt（v：Any）：Option [Int] = condOpt（v）{case x：Int => x}


I occasionally come across the following pattern, where I essentially have a PartialFunction[SomeType,AnotherType], and want to treat it as a Function[SomeType,Option[AnotherType], eg:

def f(s:SomeType):Option[AnotherType] = s match {
  case s1:SubType1 => Some(AnotherType(s1.whatever))
  case s2:SubType2 => Some(AnotherType(s2.whatever))
  case _ => None
}

Is there a way to write the above function in a way that avoids the default case and wrapping the result in Some where it's defined? The best I've come up with so far is this:

def f(s:SomeType):Option[AnotherType] = pf.lift(s)
def pf:PartialFunction[SomeType,AnotherType] = {
  case s1:SubType1 => AnotherType(s1.whatever)
  case s2:SubType2 => AnotherType(s2.whatever)
}

Is there a way to do it without defining an intermediate function? I've already tried various things along the lines of the following, but haven't got anything to compile yet:

def f:Function[SomeType,Option[AnotherType]] = {
  case s1:SubType1 => AnotherType(s1.whatever)
  case s2:SubType2 => AnotherType(s2.whatever)
}.lift

解决方案

condOpt in object scala.PartialFunction. From the scaladoc:

def onlyInt(v: Any): Option[Int] = condOpt(v) { case x: Int => x }

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