[SPARK-8356] [SQL] Reconcile callUDF and callUdf

Deprecates ```callUdf``` in favor of ```callUDF```.

Author: BenFradet <benjamin.fradet@gmail.com>

Closes #6902 from BenFradet/SPARK-8356 and squashes the following commits:

ef4e9d8 [BenFradet] deprecated callUDF, use udf instead
9b1de4d [BenFradet] reinstated unit test for the deprecated callUdf
cbd80a5 [BenFradet] deprecated callUdf in favor of callUDF

2 files changed, 55 insertions, 1 deletions

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/functions.scala b/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
index 7e7a099a83..8cea826ae6 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
@@ -1448,7 +1448,9 @@ object functions {
      *
      * @group udf_funcs
      * @since 1.3.0
+     * @deprecated As of 1.5.0, since it's redundant with udf()
      */
+    @deprecated("Use udf", "1.5.0")
     def callUDF(f: Function$x[$fTypes], returnType: DataType${if (args.length > 0) ", " + args else ""}): Column = {
       ScalaUdf(f, returnType, Seq($argsInUdf))
     }""")
@@ -1584,7 +1586,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function0[_], returnType: DataType): Column = {
     ScalaUdf(f, returnType, Seq())
   }
@@ -1595,7 +1599,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function1[_, _], returnType: DataType, arg1: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr))
   }
@@ -1606,7 +1612,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function2[_, _, _], returnType: DataType, arg1: Column, arg2: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr, arg2.expr))
   }
@@ -1617,7 +1625,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function3[_, _, _, _], returnType: DataType, arg1: Column, arg2: Column, arg3: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr, arg2.expr, arg3.expr))
   }
@@ -1628,7 +1638,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function4[_, _, _, _, _], returnType: DataType, arg1: Column, arg2: Column, arg3: Column, arg4: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr, arg2.expr, arg3.expr, arg4.expr))
   }
@@ -1639,7 +1651,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function5[_, _, _, _, _, _], returnType: DataType, arg1: Column, arg2: Column, arg3: Column, arg4: Column, arg5: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr, arg2.expr, arg3.expr, arg4.expr, arg5.expr))
   }
@@ -1650,7 +1664,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function6[_, _, _, _, _, _, _], returnType: DataType, arg1: Column, arg2: Column, arg3: Column, arg4: Column, arg5: Column, arg6: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr, arg2.expr, arg3.expr, arg4.expr, arg5.expr, arg6.expr))
   }
@@ -1661,7 +1677,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function7[_, _, _, _, _, _, _, _], returnType: DataType, arg1: Column, arg2: Column, arg3: Column, arg4: Column, arg5: Column, arg6: Column, arg7: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr, arg2.expr, arg3.expr, arg4.expr, arg5.expr, arg6.expr, arg7.expr))
   }
@@ -1672,7 +1690,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function8[_, _, _, _, _, _, _, _, _], returnType: DataType, arg1: Column, arg2: Column, arg3: Column, arg4: Column, arg5: Column, arg6: Column, arg7: Column, arg8: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr, arg2.expr, arg3.expr, arg4.expr, arg5.expr, arg6.expr, arg7.expr, arg8.expr))
   }
@@ -1683,7 +1703,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function9[_, _, _, _, _, _, _, _, _, _], returnType: DataType, arg1: Column, arg2: Column, arg3: Column, arg4: Column, arg5: Column, arg6: Column, arg7: Column, arg8: Column, arg9: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr, arg2.expr, arg3.expr, arg4.expr, arg5.expr, arg6.expr, arg7.expr, arg8.expr, arg9.expr))
   }
@@ -1694,7 +1716,9 @@ object functions {
    *
    * @group udf_funcs
    * @since 1.3.0
+   * @deprecated As of 1.5.0, since it's redundant with udf()
    */
+  @deprecated("Use udf", "1.5.0")
   def callUDF(f: Function10[_, _, _, _, _, _, _, _, _, _, _], returnType: DataType, arg1: Column, arg2: Column, arg3: Column, arg4: Column, arg5: Column, arg6: Column, arg7: Column, arg8: Column, arg9: Column, arg10: Column): Column = {
     ScalaUdf(f, returnType, Seq(arg1.expr, arg2.expr, arg3.expr, arg4.expr, arg5.expr, arg6.expr, arg7.expr, arg8.expr, arg9.expr, arg10.expr))
   }
@@ -1710,12 +1734,33 @@ object functions {
    *  val df = Seq(("id1", 1), ("id2", 4), ("id3", 5)).toDF("id", "value")
    *  val sqlContext = df.sqlContext
    *  sqlContext.udf.register("simpleUdf", (v: Int) => v * v)
+   *  df.select($"id", callUDF("simpleUdf", $"value"))
+   * }}}
+   *
+   * @group udf_funcs
+   * @since 1.5.0
+   */
+  def callUDF(udfName: String, cols: Column*): Column = {
+    UnresolvedFunction(udfName, cols.map(_.expr))
+  }
+
+  /**
+   * Call an user-defined function.
+   * Example:
+   * {{{
+   *  import org.apache.spark.sql._
+   *
+   *  val df = Seq(("id1", 1), ("id2", 4), ("id3", 5)).toDF("id", "value")
+   *  val sqlContext = df.sqlContext
+   *  sqlContext.udf.register("simpleUdf", (v: Int) => v * v)
    *  df.select($"id", callUdf("simpleUdf", $"value"))
    * }}}
    *
    * @group udf_funcs
    * @since 1.4.0
+   * @deprecated As of 1.5.0, since it was not coherent to have two functions callUdf and callUDF
    */
+  @deprecated("Use callUDF", "1.5.0")
   def callUdf(udfName: String, cols: Column*): Column = {
      UnresolvedFunction(udfName, cols.map(_.expr))
   }
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/DataFrameSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/DataFrameSuite.scala
index ba1d020f22..47443a917b 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/DataFrameSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/DataFrameSuite.scala
@@ -301,7 +301,7 @@ class DataFrameSuite extends QueryTest {
     )
   }
 
-  test("call udf in SQLContext") {
+  test("deprecated callUdf in SQLContext") {
     val df = Seq(("id1", 1), ("id2", 4), ("id3", 5)).toDF("id", "value")
     val sqlctx = df.sqlContext
     sqlctx.udf.register("simpleUdf", (v: Int) => v * v)
@@ -310,6 +310,15 @@ class DataFrameSuite extends QueryTest {
       Row("id1", 1) :: Row("id2", 16) :: Row("id3", 25) :: Nil)
   }
 
+  test("callUDF in SQLContext") {
+    val df = Seq(("id1", 1), ("id2", 4), ("id3", 5)).toDF("id", "value")
+    val sqlctx = df.sqlContext
+    sqlctx.udf.register("simpleUDF", (v: Int) => v * v)
+    checkAnswer(
+      df.select($"id", callUDF("simpleUDF", $"value")),
+      Row("id1", 1) :: Row("id2", 16) :: Row("id3", 25) :: Nil)
+  }
+
   test("withColumn") {
     val df = testData.toDF().withColumn("newCol", col("key") + 1)
     checkAnswer(