[SQL][Minor] rename DataTypeParser.apply to DataTypeParser.parse

rename DataTypeParser.apply to DataTypeParser.parse to make it more clear and readable.
/cc rxin

Author: wangfei <wangfei1@huawei.com>

Closes apache#5710 from scwf/apply and squashes the following commits:

c319977 [wangfei] rename apply to parse

Author: scwf

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/planning/patterns.scala

@@ -92,7 +92,7 @@ object PhysicalOperation extends PredicateHelper {
     }
 
   def collectAliases(fields: Seq[Expression]): Map[Attribute, Expression] = fields.collect {
-    case a @ Alias(child, _) => a.toAttribute.asInstanceOf[Attribute] -> child
+    case a @ Alias(child, _) => a.toAttribute -> child
   }.toMap
 
   def substitute(aliases: Map[Attribute, Expression])(expr: Expression): Expression = {

sql/catalyst/src/main/scala/org/apache/spark/sql/types/DataTypeParser.scala

@@ -108,7 +108,7 @@ private[sql] object DataTypeParser {
     override val lexical = new SqlLexical
   }
 
-  def apply(dataTypeString: String): DataType = dataTypeParser.toDataType(dataTypeString)
+  def parse(dataTypeString: String): DataType = dataTypeParser.toDataType(dataTypeString)
 }
 
 /** The exception thrown from the [[DataTypeParser]]. */

sql/catalyst/src/test/scala/org/apache/spark/sql/types/DataTypeParserSuite.scala

@@ -23,13 +23,13 @@ class DataTypeParserSuite extends FunSuite {
 
   def checkDataType(dataTypeString: String, expectedDataType: DataType): Unit = {
     test(s"parse ${dataTypeString.replace("\n", "")}") {
-      assert(DataTypeParser(dataTypeString) === expectedDataType)
+      assert(DataTypeParser.parse(dataTypeString) === expectedDataType)
     }
   }
 
   def unsupported(dataTypeString: String): Unit = {
     test(s"$dataTypeString is not supported") {
-      intercept[DataTypeException](DataTypeParser(dataTypeString))
+      intercept[DataTypeException](DataTypeParser.parse(dataTypeString))
     }
   }
 

sql/core/src/main/scala/org/apache/spark/sql/Column.scala

@@ -647,7 +647,7 @@ class Column(protected[sql] val expr: Expression) extends Logging {
    *
    * @group expr_ops
    */
-  def cast(to: String): Column = cast(DataTypeParser(to))
+  def cast(to: String): Column = cast(DataTypeParser.parse(to))
 
   /**
    * Returns an ordering used in sorting.

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveMetastoreCatalog.scala

@@ -871,7 +871,7 @@ private[hive] case class MetastoreRelation
 
 
 private[hive] object HiveMetastoreTypes {
-  def toDataType(metastoreType: String): DataType = DataTypeParser(metastoreType)
+  def toDataType(metastoreType: String): DataType = DataTypeParser.parse(metastoreType)
 
   def toMetastoreType(dt: DataType): String = dt match {
     case ArrayType(elementType, _) => s"array<${toMetastoreType(elementType)}>"