[SPARK-8271][SQL]string function: soundex

This PR brings SQL function soundex(), see https://issues.apache.org/jira/browse/HIVE-9738

It's based on #7115 , thanks to HuJiayin

Author: HuJiayin <jiayin.hu@intel.com>
Author: Davies Liu <davies@databricks.com>

Closes #7812 from davies/soundex and squashes the following commits:

fa75941 [Davies Liu] Merge branch 'master' of github.com:apache/spark into soundex
a4bd6d8 [Davies Liu] fix soundex
2538908 [HuJiayin] add codegen soundex
d15d329 [HuJiayin] add back ut
ded1a14 [HuJiayin] Merge branch 'master' of https://github.com/apache/spark
e2dec2c [HuJiayin] support soundex rebase code

3 files changed, 45 insertions, 0 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/FunctionRegistry.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/FunctionRegistry.scala
index 1bf7204a25..3f61a9af1f 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/FunctionRegistry.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/FunctionRegistry.scala
@@ -194,6 +194,7 @@ object FunctionRegistry {
     expression[StringRepeat]("repeat"),
     expression[StringReverse]("reverse"),
     expression[StringTrimRight]("rtrim"),
+    expression[SoundEx]("soundex"),
     expression[StringSpace]("space"),
     expression[StringSplit]("split"),
     expression[Substring]("substr"),
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringOperations.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringOperations.scala
index 684eac12bd..160e72f384 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringOperations.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringOperations.scala
@@ -719,6 +719,22 @@ case class Levenshtein(left: Expression, right: Expression) extends BinaryExpres
 }
 
 /**
+ * A function that return soundex code of the given string expression.
+ */
+case class SoundEx(child: Expression) extends UnaryExpression with ExpectsInputTypes {
+
+  override def dataType: DataType = StringType
+
+  override def inputTypes: Seq[DataType] = Seq(StringType)
+
+  override def nullSafeEval(input: Any): Any = input.asInstanceOf[UTF8String].soundex()
+
+  override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
+    defineCodeGen(ctx, ev, c => s"$c.soundex()")
+  }
+}
+
+/**
  * Returns the numeric value of the first character of str.
  */
 case class Ascii(child: Expression) extends UnaryExpression with ImplicitCastInputTypes {
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/StringExpressionsSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/StringExpressionsSuite.scala
index 3ecd0d374c..fb72fe1714 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/StringExpressionsSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/StringExpressionsSuite.scala
@@ -347,6 +347,34 @@ class StringExpressionsSuite extends SparkFunSuite with ExpressionEvalHelper {
     // scalastyle:on
   }
 
+  test("soundex unit test") {
+    checkEvaluation(SoundEx(Literal("ZIN")), "Z500")
+    checkEvaluation(SoundEx(Literal("SU")), "S000")
+    checkEvaluation(SoundEx(Literal("")), "")
+    checkEvaluation(SoundEx(Literal.create(null, StringType)), null)
+
+    // scalastyle:off
+    // non ascii characters are not allowed in the code, so we disable the scalastyle here.
+    checkEvaluation(SoundEx(Literal("测试")), "测试")
+    checkEvaluation(SoundEx(Literal("Tschüss")), "T220")
+    // scalastyle:on
+    checkEvaluation(SoundEx(Literal("zZ")), "Z000", create_row("s8"))
+    checkEvaluation(SoundEx(Literal("RAGSSEEESSSVEEWE")), "R221")
+    checkEvaluation(SoundEx(Literal("Ashcraft")), "A261")
+    checkEvaluation(SoundEx(Literal("Aswcraft")), "A261")
+    checkEvaluation(SoundEx(Literal("Tymczak")), "T522")
+    checkEvaluation(SoundEx(Literal("Pfister")), "P236")
+    checkEvaluation(SoundEx(Literal("Miller")), "M460")
+    checkEvaluation(SoundEx(Literal("Peterson")), "P362")
+    checkEvaluation(SoundEx(Literal("Peters")), "P362")
+    checkEvaluation(SoundEx(Literal("Auerbach")), "A612")
+    checkEvaluation(SoundEx(Literal("Uhrbach")), "U612")
+    checkEvaluation(SoundEx(Literal("Moskowitz")), "M232")
+    checkEvaluation(SoundEx(Literal("Moskovitz")), "M213")
+    checkEvaluation(SoundEx(Literal("relyheewsgeessg")), "R422")
+    checkEvaluation(SoundEx(Literal("!!")), "!!")
+  }
+
   test("TRIM/LTRIM/RTRIM") {
     val s = 'a.string.at(0)
     checkEvaluation(StringTrim(Literal(" aa  ")), "aa", create_row(" abdef "))