Added ‘-i’ command line option to spark REPL.

We had to create a new implementation of both scala.tools.nsc.CompilerCommand and scala.tools.nsc.Settings, because using scala.tools.nsc.GenericRunnerSettings would bring in other options (-howtorun, -save and -execute) which don’t make sense in Spark.
Any new Spark specific command line option could now be added to org.apache.spark.repl.SparkRunnerSettings class.

Since the behavior of loading a script from the command line should be the same as loading it using the “:load” command inside the shell, the script should be loaded when the SparkContext is available, that’s why we had to move the call to ‘loadfiles(settings)’ _after_ the call to postInitialization(). This still doesn’t work if ‘isAsync = true’.

repl/src/main/scala/org/apache/spark/repl/SparkCommandLine.scala

+package org.apache.spark.repl
+
+import scala.tools.nsc.{Settings, CompilerCommand}
+import scala.Predef._
+
+/**
+ * Command class enabling Spark-specific command line options (provided by
+ * <i>org.apache.spark.repl.SparkRunnerSettings</i>).
+ *
+ * @author Luca Rosellini <luca@stratio.com>
+ */
+class SparkCommandLine(args: List[String], override val settings: Settings)
+    extends CompilerCommand(args, settings) {
+
+  def this(args: List[String], error: String => Unit) {
+    this(args, new SparkRunnerSettings(error))
+  }
+
+  def this(args: List[String]) {
+    this(args, str => Console.println("Error: " + str))
+  }
+}

repl/src/main/scala/org/apache/spark/repl/SparkILoop.scala

@@ -835,7 +835,7 @@ class SparkILoop(in0: Option[BufferedReader], protected val out: JPrintWriter,
 
   // runs :load `file` on any files passed via -i
   def loadFiles(settings: Settings) = settings match {
-    case settings: GenericRunnerSettings =>
+    case settings: SparkRunnerSettings =>
       for (filename <- settings.loadfiles.value) {
         val cmd = ":load " + filename
         command(cmd)
@@ -902,7 +902,6 @@ class SparkILoop(in0: Option[BufferedReader], protected val out: JPrintWriter,
     addThunk(printWelcome())
     addThunk(initializeSpark())
 
-    loadFiles(settings)
     // it is broken on startup; go ahead and exit
     if (intp.reporter.hasErrors)
       return false
@@ -922,6 +921,8 @@ class SparkILoop(in0: Option[BufferedReader], protected val out: JPrintWriter,
     }
     // printWelcome()
 
+    loadFiles(settings)
+
     try loop()
     catch AbstractOrMissingHandler()
     finally closeInterpreter()
@@ -955,7 +956,7 @@ class SparkILoop(in0: Option[BufferedReader], protected val out: JPrintWriter,
 
   /** process command-line arguments and do as they request */
   def process(args: Array[String]): Boolean = {
-    val command = new CommandLine(args.toList, echo)
+    val command = new SparkCommandLine(args.toList, msg => echo(msg))
     def neededHelp(): String =
       (if (command.settings.help.value) command.usageMsg + "\n" else "") +
       (if (command.settings.Xhelp.value) command.xusageMsg + "\n" else "")

repl/src/main/scala/org/apache/spark/repl/SparkRunnerSettings.scala

+package org.apache.spark.repl
+
+import scala.tools.nsc.Settings
+
+/**
+ * <i>scala.tools.nsc.Settings</i> implementation adding Spark-specific REPL
+ * command line options.
+ *
+ * @author Luca Rosellini <luca@stratio.com>
+ */
+class SparkRunnerSettings(error: String => Unit) extends Settings(error){
+
+  val loadfiles = MultiStringSetting(
+      "-i",
+      "file",
+      "load a file (assumes the code is given interactively)")
+}