Bad Scala Trie

trie.scala

import scala.collection.mutable

class TrieNode(var children: mutable.Map[Char, TrieNode] = mutable.Map()) {
  // Inserts into current Trie
  def insert(c: Char): TrieNode = {
      children.get(c).getOrElse({
        children.put(c, new TrieNode())
        this
       }
      )
  }
}


class Trie() {

    /** Initialize your data structure here. */
    
    val trie = new TrieNode()

    /** Inserts a word into the trie. */
    def insert(word: String) = {
        var currentTrie = trie
        for {
            c <- word
        } {
            currentTrie = currentTrie.children.get(c).getOrElse(new TrieNode())
            currentTrie.insert(c)
        }
    }

    /** Returns if the word is in the trie. */
    def search(word: String): Boolean = {
        var currentTrie = Option(trie)
        (for {
            c <- word
        } yield {
            currentTrie = currentTrie.map(_.children(c))
            currentTrie
        }).flatten.nonEmpty
    }

    /** Returns if there is any word in the trie that starts with the given prefix. */
    def startsWith(prefix: String): Boolean = {
        true
    }

}