CODEWITHSUNDEEP
stringscalapattern-matchingscala-collections
elm
elm

Reputation: 20415

Scala string pattern matching by multiple possible groups

Given an input Map[String,String] such as 

val in = Map("name1"                -> "description1",
             "name2.name22"         -> "description 22",
             "name3.name33.name333" -> "description 333")

what is a simple way to extract each name and each description and feed them into a method such as

def process(description: String, name: String*): Unit = name match {
  case Seq(n)     =>  // find(n).set(description)
  case Seq(n,m)   =>  // find(n).find(m).set(description)
  case Seq(n,m,o) =>  // find(n).find(m).find(o).set(description)
  case _          =>  // possible error reporting
}

Many Thanks

Upvotes: 0

Views: 122

Answers (2)

cchantep
cchantep

Reputation: 9168

You can do something like:

in foreach { case (ns, d) => process(d, ns.split("\\."): _*) }

Upvotes: 1

Ende Neu
Ende Neu

Reputation: 15783

You can use the splat operator _*:

val in = Map("name1" -> "description1",
  "name2.name22" -> "description 22",
  "name3.name33.name333" -> "description 333")

def process(description: String, name: String*) = ???


in.map { x =>
  process(x._2, x._1.split("\\."): _*)
}

Note that * parameters must come last in the function signature (otherwise the compiler won't be able to decide where to stop).

From the REPL:

scala>   def process(description: String, name: String*) = {
     |     name.foreach(println)
     |     println(description)
     |   }
process: (description: String, name: String*)Unit

scala>   in.map { x =>
      |    process(x._2, x._1.split("\\."): _*)
      |   }
    name1
    description1
    name2
    name22
    description 22
    name3
    name33
    name333
    description 333

Upvotes: 2

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