CODEWITHSUNDEEP
scala
Cokorda Raka
Cokorda Raka

Reputation: 4515

Making this code with Map and Set more Scala-ish

How do I make these line of codes more scala-ish (shorter?). I still get the Java feeling in it (which I want to stay away from). Thanks in advance!

import scala.collection.mutable
val outstandingUserIds: mutable.LinkedHashSet[String] = mutable.LinkedHashSet[String]()    

val tweetJson = JacksMapper.readValue[Map[String, AnyRef]](body)     
val userObj = tweetJson.get("user")    
tweetJson.get("user").foreach(userObj => {
  userObj.asInstanceOf[Map[String, AnyRef]].get("id_str").foreach(idStrObj => {
    if (outstandingUserIds.exists(outstandingIdStr => outstandingIdStr.equals(idStrObj))) {
      outstandingUserIds.remove(idStrObj.asInstanceOf[String])
    }
  })
})

Upvotes: 0

Views: 82

Answers (1)

Brent Faust
Brent Faust

Reputation: 9309

One thing you want to do in Scala is take advantage of type inference. That way, you don't need to repeat yourself on the LHS:

val outstandingUserIds = mutable.LinkedHashSet[String]()

You also don't need the inner braces after the closure variable userObj =>. Instead, use braces after foreach {} to execute multiple statements:

tweetJson.get("user").foreach { userObj =>

}

In fact, you could use the anonymous variable '_' and say:

tweetJson.get("user").foreach {
   _.get("id_str").foreach ...
}

Scala encourages the use of immutable collections. One way to simplify the above even further would be to use collect (instead of exists+delete) which would return a new collection with only the elements you want.

Upvotes: 1

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