CODEWITHSUNDEEP
scalatuples
raj
raj

Reputation: 3

How to make Tuple4 less verbose with Map and Functions in Scala

I have a ListMap with Tuple4 as values:

val dbCons = ListMap (
    "con1" -> ("str 1", "str 2", "str 3", true)
    // etc.
)

/*line A*/def testAllCon(map: ListMap[String, Tuple4[String,String, String, Boolean]]): Unit = {
  map.keySet.foreach{ key =>
    val prop = map.get(key).get
    /*line B*/val dbSchema = DbSchema(prop._1, prop._2, prop._3, prop._4)      
  }

How do I make declaration at "Line A" and, if possible, its usage at "Line B," less verbose.

I checked a similar question here, please direct.

Upvotes: 0

Views: 63

Answers (2)

jwvh
jwvh

Reputation: 51271

As @JackLeow has pointed out, you can use a type alias to create a shorter reference for the tuple.

The testAllCon() method can also be shortened like so.

def testAllCon(map: ListMap[String, Record]): Unit =
  map.values.foreach{ prop =>
    val dbSchema = DbSchema.apply _ tupled prop
  }

Upvotes: 1

Jack Leow
Jack Leow

Reputation: 22487

You could define a type alias for the 4-tuple. I'm calling it Record in my example here, but you'd probably want to give it a more descriptive name.

Also, for "line B", you can define the function as a pattern-match:

type Record = (String, String, String, Boolean)

val dbCons = ListMap (
    "con1" -> ("str 1", "str 2", "str 3", true)
    // etc.
)

// With the for-comprehension syntax
/*line A*/def testAllCon(map: ListMap[String, Record]): Unit = {
  for ((key, (s1, s2, s3, b)) <- map) {
    /*line B*/val dbSchema = DbSchema(s1, s2, s3, b)      
  }
}

// Without for-comprehension syntax
/*line A*/def testAllCon(map: ListMap[String, Record]): Unit = {
  map.foreach {
    case (key, (s1, s2, s3, b)) =>
      /*line B*/val dbSchema = DbSchema(s1, s2, s3, b)      
  }
}

Upvotes: 1

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