[SPARK-9154][SQL] codegen string format

Author: tarekbecker

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringOperations.scala

@@ -503,9 +503,11 @@ case class StringFormat(children: Expression*) extends Expression with CodegenFa
 
   override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
     val pattern = children.head.gen(ctx)
-    val argListGen = children.tail.map(x => (x.dataType, x.gen(ctx)))
-    val argListCode = argListGen.map(_._2.code + "\n")
-    val argListString = argListGen.foldLeft("")((s, x) => s + s", ${x._2.primitive}" + (if (!ctx.isPrimitiveType(x._1)) ".toString()" else ""))
+
+    val argListGen = children.tail.map(_.gen(ctx))
+    val argListCode = argListGen.map(_.code + "\n")
+    val argListString = argListGen.foldLeft("")((s, v) => s + s", ${v.primitive}")
+
     val form = ctx.freshName("formatter")
     val formatter = classOf[java.util.Formatter].getName
     val sb = ctx.freshName("sb")

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/StringExpressionsSuite.scala

@@ -353,15 +353,14 @@ class StringExpressionsSuite extends SparkFunSuite with ExpressionEvalHelper {
   test("FORMAT") {
     val f = 'f.string.at(0)
     val d1 = 'd.int.at(1)
-    val s1 = 's.int.at(2)
+    val s1 = 's.string.at(2)
 
     val row1 = create_row("aa%d%s", 12, "cc")
     val row2 = create_row(null, 12, "cc")
     checkEvaluation(StringFormat(Literal("aa%d%s"), Literal(123), Literal("a")), "aa123a", row1)
     checkEvaluation(StringFormat(Literal("aa")), "aa", create_row(null))
     checkEvaluation(StringFormat(Literal("aa%d%s"), Literal(123), Literal("a")), "aa123a", row1)
 
-    println(StringFormat(f, d1, s1).eval(row1))
     checkEvaluation(StringFormat(f, d1, s1), "aa12cc", row1)
     checkEvaluation(StringFormat(f, d1, s1), null, row2)
   }