Questions tagged [unapply]
37 questions
0
votes
2 answers
Using unapply defined in traits
I have a trait
trait A {
def doSomething(a: Seq[Int]): Seq[String] = {
a.map {
case AA(s) => s // want to use unapply defined in trait (this(AA) not allowed)
case _ => "idc"
}
}
def unapply(a:…
CodeMan
- 45
- 6
0
votes
1 answer
Unable to resolve unapply
object micro extends App {
sealed trait FuncExpr
sealed trait FuncSpecialize
sealed case class Func(i:Int) extends FuncExpr
sealed case class Cube(b:Boolean) extends FuncSpecialize
object Cube {
def unapply(arg:Func) :…
Tilman Zuckmantel
- 643
- 1
- 6
- 18
0
votes
2 answers
scala uanpply without parameter
I am a student who studies Scala in korea. I am learning about pattern matching and unapply methods. The thing I am confused about is that Emergency object has a parameter in unapply method. I can't know the reason when I don't put the parameter in…
dogyhbin2
- 25
- 6
0
votes
3 answers
Scala: Workaround for unparameterizable extractor
Since extractors cannot take custom parameters (as answered in Stack Overflow: Can extractors be customized...), I try to find an alternative way of solving the following problem.
I have a lot of translations which can be combined. In my code…
ideaboxer
- 3,863
- 8
- 43
- 62
0
votes
1 answer
Playing with Nat without case classes
I just create a definition in scala for Naturals, and also a PLUS operation:
abstract class Nat {
def +(other:Nat):Nat = this match {
case Zero => other
case Succ(x) => x + Succ(other)
}
}
object Zero extends Nat {
override def…
Joselo
- 93
- 1
- 8
0
votes
2 answers
How do I inherit shared code in a Scala unapply function?
I have Scala code with some boilerplate, and I figure it's Scala, so I must be doing something wrong. I need some help figuring out how to remove the redundancies.
trait Number {
val x: Int
}
case class EvenNumber(x: Int) extends Number
object…
W.P. McNeill
- 16,336
- 12
- 75
- 111
0
votes
1 answer
Scala for comprehension unapplySeq
I have a
object radExtractor{
def unapplySeq(row:HtmlTableRow):Option[List[String]]={
val lista = (for{
a<-row.getByXPath("td/span/a")
ah= a.asInstanceOf[DomNode]
if(ah.getFirstChild!=null)
} yield…
Arneball
- 359
- 3
- 10