[sql] Rename Expression.apply to eval for better readability.

Also used this opportunity to add a bunch of override's and made some members private.

Author: Reynold Xin <rxin@apache.org>

Closes #340 from rxin/eval and squashes the following commits:

a7c7ca7 [Reynold Xin] Fixed conflicts in merge.
9069de6 [Reynold Xin] Merge branch 'master' into eval
3ccc313 [Reynold Xin] Merge branch 'master' into eval
1a47e10 [Reynold Xin] Renamed apply to eval for generators and added a bunch of override's.
ea061de [Reynold Xin] Rename Expression.apply to eval for better readability.

4 files changed, 10 insertions, 10 deletions

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/Generate.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/Generate.scala
index e902e6ced5..cff4887936 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/Generate.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/Generate.scala
@@ -36,10 +36,10 @@ case class Generate(
     child: SparkPlan)
   extends UnaryNode {
 
-  def output =
+  override def output =
     if (join) child.output ++ generator.output else generator.output
 
-  def execute() = {
+  override def execute() = {
     if (join) {
       child.execute().mapPartitions { iter =>
         val nullValues = Seq.fill(generator.output.size)(Literal(null))
@@ -52,7 +52,7 @@ case class Generate(
         val joinedRow = new JoinedRow
 
         iter.flatMap {row =>
-          val outputRows = generator(row)
+          val outputRows = generator.eval(row)
           if (outer && outputRows.isEmpty) {
             outerProjection(row) :: Nil
           } else {
@@ -61,7 +61,7 @@ case class Generate(
         }
       }
     } else {
-      child.execute().mapPartitions(iter => iter.flatMap(generator))
+      child.execute().mapPartitions(iter => iter.flatMap(row => generator.eval(row)))
     }
   }
 }
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregates.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregates.scala
index 2a4f7b5670..0890faa33b 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregates.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregates.scala
@@ -144,7 +144,7 @@ case class Aggregate(
 
         var i = 0
         while (i < buffer.length) {
-          aggregateResults(i) = buffer(i).apply(EmptyRow)
+          aggregateResults(i) = buffer(i).eval(EmptyRow)
           i += 1
         }
 
@@ -190,7 +190,7 @@ case class Aggregate(
             while (i < currentBuffer.length) {
               // Evaluating an aggregate buffer returns the result.  No row is required since we
               // already added all rows in the group using update.
-              aggregateResults(i) = currentBuffer(i).apply(EmptyRow)
+              aggregateResults(i) = currentBuffer(i).eval(EmptyRow)
               i += 1
             }
             resultProjection(joinedRow(aggregateResults, currentGroup))
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/basicOperators.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/basicOperators.scala
index 524e5022ee..ab2e624637 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/basicOperators.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/basicOperators.scala
@@ -41,7 +41,7 @@ case class Filter(condition: Expression, child: SparkPlan) extends UnaryNode {
   override def output = child.output
 
   override def execute() = child.execute().mapPartitions { iter =>
-    iter.filter(condition.apply(_).asInstanceOf[Boolean])
+    iter.filter(condition.eval(_).asInstanceOf[Boolean])
   }
 }
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/TgfSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/TgfSuite.scala
index ca5c8b8eb6..e55648b8ed 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/TgfSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/TgfSuite.scala
@@ -39,9 +39,9 @@ case class ExampleTGF(input: Seq[Attribute] = Seq('name, 'age)) extends Generato
 
   val Seq(nameAttr, ageAttr) = input
 
-  override def apply(input: Row): TraversableOnce[Row] = {
-    val name = nameAttr.apply(input)
-    val age = ageAttr.apply(input).asInstanceOf[Int]
+  override def eval(input: Row): TraversableOnce[Row] = {
+    val name = nameAttr.eval(input)
+    val age = ageAttr.eval(input).asInstanceOf[Int]
 
     Iterator(
       new GenericRow(Array[Any](s"$name is $age years old")),