kata5.scala

import scala.collection.mutable.{Set => MutableSet}
import scala.io.Source
import java.security.MessageDigest

class BloomSet(numHashes: Int) {
  
  protected val hashes = MutableSet.empty[String]
  
  def add(word: String) {
    hashes ++= digest(word)
  }
  
  def contains(word: String) = digest(word).forall { x => hashes contains x }
  
  protected def digest(word: String) = {
    val md = MessageDigest getInstance "sha"
    md update word.toLowerCase.getBytes
    val hash = md.digest map { byte => (byte.toInt.abs).toChar }
    for (i <- 0 until numHashes) yield hash.slice(i, i+3).mkString
  }
  
}

val bs = new BloomSet(3)
for (line <- Source.fromFile("/usr/share/dict/words").getLines)
  bs add line.trim.toLowerCase

println(bs contains "hello")
println(bs contains "fhqwhgads")