Discussion on: Implementing a Ternary Operator in Scala

[Kane Ong]

Just for comparison, compare this

object Main {
  def main(args: Array[String]): Unit = {

    val n = 0

    if (n == 0) 
      println(s"$n == 0 is true")
    else 
      println(s"${3/n}") 

  }
}

with this

import Implicits._

object Main {
  def main(args: Array[String]): Unit = {

    val n = 0

    ((n == 0) ? true |: n) match {
      case Left(v) => println(s"$n == 0 is $v")
      case Right(v) => println(s"${3/v}") 
    } 

  }
}

The conciseness is obvious.

[Andrew (he/him)]

Fair enough! So what you're saying is you'd have the ifTrue and ifFalse themselves return Eithers, if necessary, like

(3 < 2) ? Left(42) |: Right("forty-two")

Is that right?

I wonder if there's an implicit conversion that would let us do away with the Left() and Right()...

[Kane Ong]

That is a good example to ensure type consistency with minimal effort, you don't need |: and &: at the same time and achieve the same result (Option[Either[T, F]]).

One of my main point here is do not over obsess with data type generalization and construct unnecessary structures.