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package com.rockymadden.stringmetric
object Algorithm {
import scala.collection.immutable.Map
import Transform._
trait Algorithm[A] {
def compute(a: A): Option[A]
}
object Algorithm {
implicit def toStringAlgorithmDecorator(sa: StringAlgorithm): StringAlgorithmDecorator =
new StringAlgorithmDecorator(sa)
}
trait StringAlgorithm extends Algorithm[Array[Char]] {
def compute(a: String): Option[String]
}
object StringAlgorithm {
val Metaphone = phonetic.MetaphoneAlgorithm
val Nysiis = phonetic.NysiisAlgorithm
val RefinedNysiis = phonetic.RefinedNysiisAlgorithm
val RefinedSoundex = phonetic.RefinedSoundexAlgorithm
val Soundex = phonetic.SoundexAlgorithm
def computeWithMetaphone(a: Array[Char]) = Metaphone.compute(a)
def computeWithNysiis(a: Array[Char]) = Nysiis.compute(a)
def computeWithRefinedNysiis(a: Array[Char]) = RefinedNysiis.compute(a)
def computeWithRefinedSoundex(a: Array[Char]) = RefinedSoundex.compute(a)
def computeWithSoundex(a: Array[Char]) = Soundex.compute(a)
}
sealed trait AlgorithmDecorator[A] {
val withMemoization: Algorithm[A]
val withTransform: (Transform[A] => Algorithm[A])
}
final case class StringAlgorithmDecorator(sa: StringAlgorithm) extends AlgorithmDecorator[Array[Char]] {
override val withMemoization: StringAlgorithm = new StringAlgorithm {
private val base: StringAlgorithm = sa
private var memo: Map[String, Option[String]] = Map()
override def compute(a: Array[Char]): Option[Array[Char]] = compute(a.toString).map(_.toCharArray)
override def compute(a: String): Option[String] =
if (memo.contains(a)) memo(a)
else {
memo = memo + (a -> base.compute(a))
memo(a)
}
}
override val withTransform: (StringTransform => StringAlgorithm) = (st) => new StringAlgorithm {
private val base: StringAlgorithm = sa
private val transform: StringTransform = st
override def compute(a: Array[Char]): Option[Array[Char]] = base.compute(transform(a))
override def compute(a: String): Option[String] = compute(a.toCharArray).map(_.mkString)
}
}
}
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