Format Scala codes according to scalastyle-config.xml (mostly follows…

… Apache Spark)

scala-package/core/scalastyle-config.xml

@@ -0,0 +1,145 @@
+<!--
+  ~ Licensed to the Apache Software Foundation (ASF) under one or more
+  ~ contributor license agreements.  See the NOTICE file distributed with
+  ~ this work for additional information regarding copyright ownership.
+  ~ The ASF licenses this file to You under the Apache License, Version 2.0
+  ~ (the "License"); you may not use this file except in compliance with
+  ~ the License.  You may obtain a copy of the License at
+  ~
+  ~    http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<!--
+If you wish to turn off checking for a section of code, you can put a comment in the source
+before and after the section, with the following syntax:
+  // scalastyle:off
+  ...  // stuff that breaks the styles
+  // scalastyle:on
+
+You can also disable only one rule, by specifying its rule id, as specified in:
+  http://www.scalastyle.org/rules-0.7.0.html
+
+  // scalastyle:off println 
+  println("I do want to print something here")
+  // scalastyle:on println 
+-->
+
+<scalastyle>
+  <name>Scalastyle standard configuration</name>
+
+  <check level="error" class="org.scalastyle.file.FileTabChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.scalariform.SpacesAfterPlusChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.scalariform.SpacesBeforePlusChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.file.FileLineLengthChecker" enabled="true">
+    <parameters>
+      <parameter name="maxLineLength"><![CDATA[100]]></parameter>
+      <parameter name="tabSize"><![CDATA[2]]></parameter>
+      <parameter name="ignoreImports">true</parameter>
+    </parameters>
+  </check>
+
+  <check level="error" class="org.scalastyle.scalariform.ClassNamesChecker" enabled="true">
+    <parameters><parameter name="regex"><![CDATA[[A-Z][A-Za-z]*]]></parameter></parameters>
+  </check>
+
+  <check level="error" class="org.scalastyle.scalariform.ObjectNamesChecker" enabled="true">
+    <parameters><parameter name="regex"><![CDATA[[A-Z][A-Za-z]*]]></parameter></parameters>
+  </check>
+
+  <check level="error" class="org.scalastyle.scalariform.PackageObjectNamesChecker" enabled="true">
+    <parameters><parameter name="regex"><![CDATA[^[a-z][A-Za-z]*$]]></parameter></parameters>
+  </check>
+
+  <check level="error" class="org.scalastyle.scalariform.ParameterNumberChecker" enabled="true">
+    <parameters><parameter name="maxParameters"><![CDATA[10]]></parameter></parameters>
+  </check>
+
+  <check customId="finalize" level="error" class="org.scalastyle.scalariform.NoFinalizeChecker" enabled="true">
+    <customMessage><![CDATA[Are you sure you want to implement finalize? If yes, wrap the class block with
+      // scalastyle:off finalize
+      class XXX {
+        ...
+      }
+      // scalastyle:on finalize
+    ]]></customMessage>
+  </check>
+
+  <check level="error" class="org.scalastyle.scalariform.CovariantEqualsChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.scalariform.StructuralTypeChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.scalariform.UppercaseLChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.scalariform.IfBraceChecker" enabled="true">
+    <parameters>
+      <parameter name="singleLineAllowed"><![CDATA[true]]></parameter>
+      <parameter name="doubleLineAllowed"><![CDATA[true]]></parameter>
+    </parameters>
+  </check>
+
+  <check level="error" class="org.scalastyle.scalariform.PublicMethodsHaveTypeChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.file.NewLineAtEofChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.scalariform.NonASCIICharacterChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.scalariform.SpaceAfterCommentStartChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.scalariform.EnsureSingleSpaceBeforeTokenChecker" enabled="true">
+   <parameters>
+     <parameter name="tokens">ARROW, EQUALS, ELSE, TRY, CATCH, FINALLY, LARROW, RARROW</parameter>
+   </parameters>
+  </check>
+
+  <check level="error" class="org.scalastyle.scalariform.EnsureSingleSpaceAfterTokenChecker" enabled="true">
+    <parameters>
+     <parameter name="tokens">ARROW, EQUALS, COMMA, COLON, IF, ELSE, DO, WHILE, FOR, MATCH, TRY, CATCH, FINALLY, LARROW, RARROW</parameter>
+    </parameters>
+  </check>
+
+  <!-- We should enable this rule once the code base is stable enough -->
+  <check level="error" class="org.scalastyle.scalariform.NotImplementedErrorUsage" enabled="false"></check>
+
+  <!-- all printlns need to be wrapped in '// scalastyle:off/on println' -->
+  <check customId="println" level="error" class="org.scalastyle.scalariform.TokenChecker" enabled="true">
+    <parameters><parameter name="regex">^println$</parameter></parameters>
+    <customMessage><![CDATA[Are you sure you want to println? If yes, wrap the code block with
+      // scalastyle:off println
+      println(...)
+      // scalastyle:on println]]></customMessage>
+  </check>
+
+  <check customId="classforname" level="error" class="org.scalastyle.file.RegexChecker" enabled="true">
+    <parameters><parameter name="regex">Class\.forName</parameter></parameters>
+    <customMessage><![CDATA[
+      Are you sure that you want to use Class.forName? In most cases, you should use Utils.classForName instead.
+      If you must use Class.forName, wrap the code block with
+      // scalastyle:off classforname
+      Class.forName(...)
+      // scalastyle:on classforname
+    ]]></customMessage>
+  </check>
+
+  <!-- JavaConversions should be replaced with JavaConverters -->
+  <check customId="javaconversions" level="error" class="org.scalastyle.scalariform.TokenChecker" enabled="true">
+    <parameters><parameter name="regex">JavaConversions</parameter></parameters>
+    <customMessage>Instead of importing implicits in scala.collection.JavaConversions._, import
+    scala.collection.JavaConverters._ and use .asScala / .asJava methods</customMessage>
+  </check>
+
+  <check level="error" class="org.scalastyle.scalariform.EqualsHashCodeChecker" enabled="true"></check>
+
+  <check level="error" class="org.scalastyle.scalariform.IllegalImportsChecker" enabled="true">
+    <parameters><parameter name="illegalImports"><![CDATA[sun._,java.awt._]]></parameter></parameters>
+  </check>
+</scalastyle>

scala-package/core/src/main/scala/ml/dmlc/mxnet/EvalMetric.scala

@@ -50,7 +50,8 @@ class Accuracy extends EvalMetric("accuracy") {
       val pred: NDArray = preds.slice(i, i)
       val label: NDArray = labels.slice(i, i)
 
-//      require(label.shape(0) < predLabel.shape(0), "Should not have more predict labels than actual labels ")
+      // require(label.shape(0) < predLabel.shape(0),
+      // "Should not have more predict labels than actual labels ")
     })
   }
 }

scala-package/core/src/main/scala/ml/dmlc/mxnet/Executor.scala

@@ -16,7 +16,8 @@ object Executor {
    * @param batchSize The number of samples in a mini-batch.
    * @param workLoadList The list of work load for different devices, in the same order as ctx
    * @return The split slices to get a specific slice.
-   * @throws IllegalArgumentException If there are two many splits such that some slice can be empty.
+   * @throws IllegalArgumentException
+   *         If there are two many splits such that some slice can be empty.
    */
   private def splitInputSlice[@specialized(Int, Float, Double) V]
                               (batchSize: Int, workLoadList: Array[V])
@@ -84,6 +85,7 @@ object Executor {
  * @param symbol
  * @see Symbol.bind : to create executor
  */
+// scalastyle:off finalize
 class Executor(val handle: ExecutorHandle, val symbol: Symbol) {
   var argArrays: Array[NDArray] = null
   protected var gradArrays: Array[NDArray] = null
@@ -131,7 +133,7 @@ class Executor(val handle: ExecutorHandle, val symbol: Symbol) {
    *   This parameter is only needed when bind is called
    *   on outputs that are not a loss function.
    */
-  def backward(outGrads: Array[NDArray]):Unit = {
+  def backward(outGrads: Array[NDArray]): Unit = {
     require(outGrads != null)
     val ndArrayPtrs = outGrads.map(_.handle.value)
     checkCall(_LIB.mxExecutorBackward(handle, outGrads.length, ndArrayPtrs))
@@ -188,7 +190,8 @@ class Executor(val handle: ExecutorHandle, val symbol: Symbol) {
    *        Whether allow extra parameters that are not needed by symbol
    *        If this is True, no error will be thrown when arg_params or aux_params
    *        contain extra parameters that is not needed by the executor.
-   * @throws IllegalArgumentException If there is additional parameters in the dict but allow_extra_params=False
+   * @throws IllegalArgumentException
+   *         If there is additional parameters in the dict but allow_extra_params=False
    */
   def copyParamsFrom(argParams: Map[String, NDArray],
                      auxParams: Map[String, NDArray],
@@ -229,3 +232,4 @@ class Executor(val handle: ExecutorHandle, val symbol: Symbol) {
     str.value
   }
 }
+// scalastyle:on finalize