address PR feedback

Author: martijnhoekstra

compiler/src/dotty/tools/dotc/config/CompilerCommand.scala

@@ -116,10 +116,10 @@ object CompilerCommand {
     }
 
     def phasesMessage: String = {
-      (new Compiler()).phases.map(phasegroup => {
-        if(phasegroup.length == 1) phasegroup.head.phaseName
-        else phasegroup.mkString("{", ", ", "}")
-      }).mkString("\n")
+      (new Compiler()).phases.map {
+        case List(single) => single.phaseName
+        case more => more.map(_.phaseName).mkString("{", ", ", "}")
+      }.mkString("\n")
     }
 
     def infoMessage: String = {

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -77,9 +77,9 @@ class ScalaSettings extends Settings.SettingGroup {
   val XprintDiff: Setting[Boolean] = BooleanSetting("-Xprint-diff", "Print changed parts of the tree since last print.")
   val XprintDiffDel: Setting[Boolean] = BooleanSetting("-Xprint-diff-del", "Print changed parts of the tree since last print including deleted parts.")
   val XprintInline: Setting[Boolean] = BooleanSetting("-Xprint-inline", "Show where inlined code comes from")
-  val XshowPhases: Setting[Boolean] = BooleanSetting("-Xprint-phases", "Print all compiler phases")
   val XprintSuspension: Setting[Boolean] = BooleanSetting("-Xprint-suspension", "Show when code is suspended until macros are compiled")
   val Xprompt: Setting[Boolean] = BooleanSetting("-Xprompt", "Display a prompt after each error (debugging option).")
+  val XshowPhases: Setting[Boolean] = BooleanSetting("-Xshow-phases", "Print all compiler phases")
   val XnoValueClasses: Setting[Boolean] = BooleanSetting("-Xno-value-classes", "Do not use value classes. Helps debugging.")
   val XreplLineWidth: Setting[Int] = IntSetting("-Xrepl-line-width", "Maximal number of columns per line for REPL output", 390)
   val XfatalWarnings: Setting[Boolean] = BooleanSetting("-Xfatal-warnings", "Fail the compilation if there are any warnings.")