1 files changed, 40 insertions, 0 deletions
diff --git a/core/source/core/scala/com/rockymadden/stringmetric/phonetic/NysiisMetric.scala b/core/source/core/scala/com/rockymadden/stringmetric/phonetic/NysiisMetric.scala
new file mode 100755
index 0000000..6d1c22c
--- /dev/null
+++ b/core/source/core/scala/com/rockymadden/stringmetric/phonetic/NysiisMetric.scala
@@ -0,0 +1,40 @@
+package com.rockymadden.stringmetric.phonetic
+
+import com.rockymadden.stringmetric.{StringFilter, StringMetric}
+import com.rockymadden.stringmetric.Alphabet.Alpha
+
+/** An implementation of the NYSIIS metric. */
+class NysiisMetric extends StringMetric[DummyImplicit, Boolean] { this: StringFilter =>
+	final override def compare(charArray1: Array[Char], charArray2: Array[Char])
+		(implicit di: DummyImplicit): Option[Boolean] = {
+
+		val unequal = (c1: Char, c2: Char) => {
+			val lc1 = c1.toLower
+			val lc2 = c2.toLower
+
+			(if (lc1 == 'k') 'c' else lc1) != (if (lc2 == 'k') 'c' else lc2)
+		}
+
+		val fca1 = filter(charArray1)
+		lazy val fca2 = filter(charArray2)
+
+		if (fca1.length == 0 || !(Alpha isSuperset fca1.head) || fca2.length == 0 || !(Alpha isSuperset fca2.head)) None
+		else if (unequal(fca1.head, fca2.head)) Some(false)
+		else NysiisAlgorithm.compute(fca1).filter(_.length > 0).flatMap(ny1 =>
+			NysiisAlgorithm.compute(fca2).filter(_.length > 0).map(ny1.sameElements(_))
+		)
+	}
+
+	final override def compare(string1: String, string2: String)(implicit di: DummyImplicit): Option[Boolean] =
+		compare(string1.toCharArray, string2.toCharArray)
+}
+
+object NysiisMetric {
+	private lazy val self = apply()
+
+	def apply(): NysiisMetric = new NysiisMetric with StringFilter
+
+	def compare(charArray1: Array[Char], charArray2: Array[Char]) = self.compare(charArray1, charArray2)
+
+	def compare(string1: String, string2: String) = self.compare(string1, string2)
+}