Is there a way to rename methods in Scala (or Java) at runtime?

Given the following:

case class Num(value: Double) {
  def plus(rhs: Num) = Num(value + rhs.value)
  def times(rhs: Num) = Num(value * rhs.value)
}

object TestApp exten开发者_如何学Gods App {
  // ** maybe do something here
  val one = Num(1)
  val two = Num(2)
  val three = Num(3)
  val result = three plus one times two
}

Is there a way to rename the plus method/function in Num to +plus and the times method to *times at runtime such that result = three +- one *- two?

It's very important that this happens at runtime. I'd like to avoid compiler plugins if possible. Also, I'm not against java examples, if applicable.

The reason I'd like to do this is because the default operator precedence in Scala for three plus one times two results in 8 while three +- one *- two results in 5.

---

You're assuming operator precedence will work by naming things the way you want, and that's not gonna work. The quickest way I can think of to make this work is with a pimp, as @Dave Griffith suggested:

case class Num(value: Double)

object Main {
  implicit def toDouble(v: Num) = v.value
  implicit def toNum(v: Double) = Num(v)
  def main(args: Array[String]) {
    val one = Num(1)
    val two = Num(2)
    val three = Num(3)
    val result: Num = three + one * two
    println(result)
  }
}

What's more is that you can't do this at "runtime". How would you expect to make the call to a function whose name doesn't exist at compile time? i.e. Num.+plus where Num has no +plus method? The compiler is going to tell you to get lost. And, as was already stated, +plus isn't valid anyway.

EDIT: I was looking at this again today and I'm not sure what I was smoking. A much better Pimp is:

class NumMath(u: Num) {
  def +(v: Num) = Num(u.value + v.value)
  def *(v: Num) = Num(u.value * v.value)
}

object Num {
  implicit def toNumMath(v: Num) = new NumMath(v)
}
case class Num(value: Double)

object Main {
  import Num._
  def main(args: Array[String]) {
    val one = Num(1)
    val two = Num(2)
    val three = Num(3)
    val result = three + one * two
    println(result)
  }
}

---

+plus and *times aren't valid Scala names. Names that start with non-alphabetic characters (other than _ and $) must include only non-alphabetic characters.

Other than that, the semantics you want could be done easily with an implicit conversion.