CODEWITHSUNDEEP
scala
Adair
Adair

Reputation: 1845

Scala type mismatch with generics ArraySeq[T] instead of Array[T]

I have this method:

  private def doSomeStringProcessing[T](input: String, typeConverter: String => T): Array[T] = {
   cleanTheString(input)
            .split(",").map(typeConverter)
  }

which gives the error:

error: type mismatch;
[INFO]  found   : scala.collection.mutable.ArraySeq[T]
[INFO]  required: Array[T]

Per some googling, found posts saying to use the ClassManifest. Tried that and it was deprecated. So it pointed me to ClassTag. Googled that and found this resource which I'm trying to follow: https://docs.scala-lang.org/overviews/reflection/typetags-manifests.html#via-the-methods-typetag-classtag-or-weaktypetag

So I tried doing below:

  private def doSomeStringProcessing[T: TypeTag](input: String, typeConverter: String => T): Array[T] = {
   cleanTheString(input)
            .split(",").map(typeConverter)
  }

Which gives the exact same error. I want generics to make my code cleaner/easier to read, not convoluted, so I don't want to do any of the complicated solutions. What's the quickest way to fix this?

Upvotes: 0

Views: 297

Answers (1)

Adair
Adair

Reputation: 1845

This does work with ClassTag (I got confused because IntelliJ imported and/or code-completed it wrong, so including the correct import below):

import scala.reflect.ClassTag

 private def doSomeStringProcessing[T: ClassTag](input: String, typeConverter: String => T): Array[T] = {
   cleanTheString(input)
            .split(",").map(typeConverter)
  }

Upvotes: 4

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