[SPARK-8721][SQL] Rename ExpectsInputTypes => AutoCastInputTypes.

Author: Reynold Xin <rxin@databricks.com>

Closes #7109 from rxin/auto-cast and squashes the following commits:

a914cc3 [Reynold Xin] [SPARK-8721][SQL] Rename ExpectsInputTypes => AutoCastInputTypes.

6 files changed, 71 insertions, 79 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/HiveTypeCoercion.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/HiveTypeCoercion.scala
index 976fa57cb9..c3d68197d6 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/HiveTypeCoercion.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/HiveTypeCoercion.scala
@@ -116,7 +116,7 @@ trait HiveTypeCoercion {
     IfCoercion ::
     Division ::
     PropagateTypes ::
-    ExpectedInputConversion ::
+    AddCastForAutoCastInputTypes ::
     Nil
 
   /**
@@ -709,15 +709,15 @@ trait HiveTypeCoercion {
 
   /**
    * Casts types according to the expected input types for Expressions that have the trait
-   * `ExpectsInputTypes`.
+   * [[AutoCastInputTypes]].
    */
-  object ExpectedInputConversion extends Rule[LogicalPlan] {
+  object AddCastForAutoCastInputTypes extends Rule[LogicalPlan] {
 
     def apply(plan: LogicalPlan): LogicalPlan = plan transformAllExpressions {
       // Skip nodes who's children have not been resolved yet.
       case e if !e.childrenResolved => e
 
-      case e: ExpectsInputTypes if e.children.map(_.dataType) != e.expectedChildTypes =>
+      case e: AutoCastInputTypes if e.children.map(_.dataType) != e.expectedChildTypes =>
         val newC = (e.children, e.children.map(_.dataType), e.expectedChildTypes).zipped.map {
           case (child, actual, expected) =>
             if (actual == expected) child else Cast(child, expected)
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Expression.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Expression.scala
index f59db3d5df..e5dc7b9b5c 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Expression.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Expression.scala
@@ -261,7 +261,7 @@ abstract class UnaryExpression extends Expression with trees.UnaryNode[Expressio
  * Expressions that require a specific `DataType` as input should implement this trait
  * so that the proper type conversions can be performed in the analyzer.
  */
-trait ExpectsInputTypes {
+trait AutoCastInputTypes {
   self: Expression =>
 
   def expectedChildTypes: Seq[DataType]
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala
index 4b57ddd9c5..a022f3727b 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/math.scala
@@ -56,7 +56,7 @@ abstract class LeafMathExpression(c: Double, name: String)
  * @param name The short name of the function
  */
 abstract class UnaryMathExpression(f: Double => Double, name: String)
-  extends UnaryExpression with Serializable with ExpectsInputTypes {
+  extends UnaryExpression with Serializable with AutoCastInputTypes {
   self: Product =>
 
   override def expectedChildTypes: Seq[DataType] = Seq(DoubleType)
@@ -99,7 +99,7 @@ abstract class UnaryMathExpression(f: Double => Double, name: String)
  * @param name The short name of the function
  */
 abstract class BinaryMathExpression(f: (Double, Double) => Double, name: String)
-  extends BinaryExpression with Serializable with ExpectsInputTypes { self: Product =>
+  extends BinaryExpression with Serializable with AutoCastInputTypes { self: Product =>
 
   override def expectedChildTypes: Seq[DataType] = Seq(DoubleType, DoubleType)
 
@@ -211,19 +211,11 @@ case class ToRadians(child: Expression) extends UnaryMathExpression(math.toRadia
 }
 
 case class Bin(child: Expression)
-  extends UnaryExpression with Serializable with ExpectsInputTypes {
-
-  val name: String = "BIN"
-
-  override def foldable: Boolean = child.foldable
-  override def nullable: Boolean = true
-  override def toString: String = s"$name($child)"
+  extends UnaryExpression with Serializable with AutoCastInputTypes {
 
   override def expectedChildTypes: Seq[DataType] = Seq(LongType)
   override def dataType: DataType = StringType
 
-  def funcName: String = name.toLowerCase
-
   override def eval(input: InternalRow): Any = {
     val evalE = child.eval(input)
     if (evalE == null) {
@@ -239,61 +231,13 @@ case class Bin(child: Expression)
   }
 }
 
-////////////////////////////////////////////////////////////////////////////////////////////////////
-////////////////////////////////////////////////////////////////////////////////////////////////////
-// Binary math functions
-////////////////////////////////////////////////////////////////////////////////////////////////////
-////////////////////////////////////////////////////////////////////////////////////////////////////
-
-
-case class Atan2(left: Expression, right: Expression)
-  extends BinaryMathExpression(math.atan2, "ATAN2") {
-
-  override def eval(input: InternalRow): Any = {
-    val evalE1 = left.eval(input)
-    if (evalE1 == null) {
-      null
-    } else {
-      val evalE2 = right.eval(input)
-      if (evalE2 == null) {
-        null
-      } else {
-        // With codegen, the values returned by -0.0 and 0.0 are different. Handled with +0.0
-        val result = math.atan2(evalE1.asInstanceOf[Double] + 0.0,
-          evalE2.asInstanceOf[Double] + 0.0)
-        if (result.isNaN) null else result
-      }
-    }
-  }
-
-  override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
-    defineCodeGen(ctx, ev, (c1, c2) => s"java.lang.Math.atan2($c1 + 0.0, $c2 + 0.0)") + s"""
-      if (Double.valueOf(${ev.primitive}).isNaN()) {
-        ${ev.isNull} = true;
-      }
-      """
-  }
-}
-
-case class Pow(left: Expression, right: Expression)
-  extends BinaryMathExpression(math.pow, "POWER") {
-  override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
-    defineCodeGen(ctx, ev, (c1, c2) => s"java.lang.Math.pow($c1, $c2)") + s"""
-      if (Double.valueOf(${ev.primitive}).isNaN()) {
-        ${ev.isNull} = true;
-      }
-      """
-  }
-}
 
 /**
  * If the argument is an INT or binary, hex returns the number as a STRING in hexadecimal format.
- * Otherwise if the number is a STRING,
- * it converts each character into its hexadecimal representation and returns the resulting STRING.
- * Negative numbers would be treated as two's complement.
+ * Otherwise if the number is a STRING, it converts each character into its hex representation
+ * and returns the resulting STRING. Negative numbers would be treated as two's complement.
  */
-case class Hex(child: Expression)
-  extends UnaryExpression with Serializable  {
+case class Hex(child: Expression) extends UnaryExpression with Serializable  {
 
   override def dataType: DataType = StringType
 
@@ -337,7 +281,7 @@ case class Hex(child: Expression)
   private def doHex(bytes: Array[Byte], length: Int): UTF8String = {
     val value = new Array[Byte](length * 2)
     var i = 0
-    while(i < length) {
+    while (i < length) {
       value(i * 2) = Character.toUpperCase(Character.forDigit(
         (bytes(i) & 0xF0) >>> 4, 16)).toByte
       value(i * 2 + 1) = Character.toUpperCase(Character.forDigit(
@@ -362,6 +306,54 @@ case class Hex(child: Expression)
   }
 }
 
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Binary math functions
+////////////////////////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+
+case class Atan2(left: Expression, right: Expression)
+  extends BinaryMathExpression(math.atan2, "ATAN2") {
+
+  override def eval(input: InternalRow): Any = {
+    val evalE1 = left.eval(input)
+    if (evalE1 == null) {
+      null
+    } else {
+      val evalE2 = right.eval(input)
+      if (evalE2 == null) {
+        null
+      } else {
+        // With codegen, the values returned by -0.0 and 0.0 are different. Handled with +0.0
+        val result = math.atan2(evalE1.asInstanceOf[Double] + 0.0,
+          evalE2.asInstanceOf[Double] + 0.0)
+        if (result.isNaN) null else result
+      }
+    }
+  }
+
+  override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
+    defineCodeGen(ctx, ev, (c1, c2) => s"java.lang.Math.atan2($c1 + 0.0, $c2 + 0.0)") + s"""
+      if (Double.valueOf(${ev.primitive}).isNaN()) {
+        ${ev.isNull} = true;
+      }
+      """
+  }
+}
+
+case class Pow(left: Expression, right: Expression)
+  extends BinaryMathExpression(math.pow, "POWER") {
+  override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
+    defineCodeGen(ctx, ev, (c1, c2) => s"java.lang.Math.pow($c1, $c2)") + s"""
+      if (Double.valueOf(${ev.primitive}).isNaN()) {
+        ${ev.isNull} = true;
+      }
+      """
+  }
+}
+
 case class Hypot(left: Expression, right: Expression)
   extends BinaryMathExpression(math.hypot, "HYPOT")
 
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/misc.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/misc.scala
index 9a39165a1f..27805bff29 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/misc.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/misc.scala
@@ -31,7 +31,7 @@ import org.apache.spark.unsafe.types.UTF8String
  * For input of type [[BinaryType]]
  */
 case class Md5(child: Expression)
-  extends UnaryExpression with ExpectsInputTypes {
+  extends UnaryExpression with AutoCastInputTypes {
 
   override def dataType: DataType = StringType
 
@@ -61,7 +61,7 @@ case class Md5(child: Expression)
  * the hash length is not one of the permitted values, the return value is NULL.
  */
 case class Sha2(left: Expression, right: Expression)
-  extends BinaryExpression with Serializable with ExpectsInputTypes {
+  extends BinaryExpression with Serializable with AutoCastInputTypes {
 
   override def dataType: DataType = StringType
 
@@ -146,7 +146,7 @@ case class Sha2(left: Expression, right: Expression)
  * A function that calculates a sha1 hash value and returns it as a hex string
  * For input of type [[BinaryType]] or [[StringType]]
  */
-case class Sha1(child: Expression) extends UnaryExpression with ExpectsInputTypes {
+case class Sha1(child: Expression) extends UnaryExpression with AutoCastInputTypes {
 
   override def dataType: DataType = StringType
 
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/predicates.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/predicates.scala
index 3a12d03ba6..386cf6a8df 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/predicates.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/predicates.scala
@@ -70,7 +70,7 @@ trait PredicateHelper {
 }
 
 
-case class Not(child: Expression) extends UnaryExpression with Predicate with ExpectsInputTypes {
+case class Not(child: Expression) extends UnaryExpression with Predicate with AutoCastInputTypes {
   override def foldable: Boolean = child.foldable
   override def nullable: Boolean = child.nullable
   override def toString: String = s"NOT $child"
@@ -123,7 +123,7 @@ case class InSet(value: Expression, hset: Set[Any])
 }
 
 case class And(left: Expression, right: Expression)
-  extends BinaryExpression with Predicate with ExpectsInputTypes {
+  extends BinaryExpression with Predicate with AutoCastInputTypes {
 
   override def expectedChildTypes: Seq[DataType] = Seq(BooleanType, BooleanType)
 
@@ -172,7 +172,7 @@ case class And(left: Expression, right: Expression)
 }
 
 case class Or(left: Expression, right: Expression)
-  extends BinaryExpression with Predicate with ExpectsInputTypes {
+  extends BinaryExpression with Predicate with AutoCastInputTypes {
 
   override def expectedChildTypes: Seq[DataType] = Seq(BooleanType, BooleanType)
 
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 a6225fdafe..ce184e4f32 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
@@ -24,7 +24,7 @@ import org.apache.spark.sql.catalyst.expressions.codegen._
 import org.apache.spark.sql.types._
 import org.apache.spark.unsafe.types.UTF8String
 
-trait StringRegexExpression extends ExpectsInputTypes {
+trait StringRegexExpression extends AutoCastInputTypes {
   self: BinaryExpression =>
 
   def escape(v: String): String
@@ -111,7 +111,7 @@ case class RLike(left: Expression, right: Expression)
   override def matches(regex: Pattern, str: String): Boolean = regex.matcher(str).find(0)
 }
 
-trait CaseConversionExpression extends ExpectsInputTypes {
+trait CaseConversionExpression extends AutoCastInputTypes {
   self: UnaryExpression =>
 
   def convert(v: UTF8String): UTF8String
@@ -158,7 +158,7 @@ case class Lower(child: Expression) extends UnaryExpression with CaseConversionE
 }
 
 /** A base trait for functions that compare two strings, returning a boolean. */
-trait StringComparison extends ExpectsInputTypes {
+trait StringComparison extends AutoCastInputTypes {
   self: BinaryExpression =>
 
   def compare(l: UTF8String, r: UTF8String): Boolean
@@ -221,7 +221,7 @@ case class EndsWith(left: Expression, right: Expression)
  * Defined for String and Binary types.
  */
 case class Substring(str: Expression, pos: Expression, len: Expression)
-  extends Expression with ExpectsInputTypes {
+  extends Expression with AutoCastInputTypes {
 
   def this(str: Expression, pos: Expression) = {
     this(str, pos, Literal(Integer.MAX_VALUE))
@@ -295,7 +295,7 @@ case class Substring(str: Expression, pos: Expression, len: Expression)
 /**
  * A function that return the length of the given string expression.
  */
-case class StringLength(child: Expression) extends UnaryExpression with ExpectsInputTypes {
+case class StringLength(child: Expression) extends UnaryExpression with AutoCastInputTypes {
   override def dataType: DataType = IntegerType
   override def expectedChildTypes: Seq[DataType] = Seq(StringType)