Cleanup and refactoring - semicolons, unused or commented out code

This commit contains some minor changes made by the way when
implementing flat classpath.

Sample JUnit test that shows that all pieces of JUnit infrastructure
work correctly now uses assert method form JUnit as it should do from
the beginning.

I removed commented out lines which were obvious to me. In the case
of less obvious commented out lines I added TODOs as someone should
look at such places some day and clean them up.

I removed also some unnecessary semicolons and unused imports.

Many string concatenations using + have been changed to string
interpolation.

There's removed unused, private walkIterator method from ZipArchive.
It seems that it was unused since this commit:
https://github.com/scala/scala/commit/9d4994b96c77d914687433586eb6d1f9e49c520f
However, I had to add an exception for the compatibility checker
because it was complaining about this change.

I made some trivial corrections/optimisations like use 'findClassFile'
method instead of 'findClass' in combination with 'binary' to find
the class file.

7 files changed, 14 insertions, 17 deletions

diff --git a/src/compiler/scala/tools/nsc/Global.scala b/src/compiler/scala/tools/nsc/Global.scala
index 01e8829d6e..9cb4159e60 100644
--- a/src/compiler/scala/tools/nsc/Global.scala
+++ b/src/compiler/scala/tools/nsc/Global.scala
@@ -332,7 +332,7 @@ class Global(var currentSettings: Settings, var reporter: Reporter)
           None
       }
 
-    val charset = ( if (settings.encoding.isSetByUser) Some(settings.encoding.value) else None ) flatMap loadCharset getOrElse {
+    val charset = settings.encoding.valueSetByUser flatMap loadCharset getOrElse {
       settings.encoding.value = defaultEncoding // A mandatory charset
       Charset.forName(defaultEncoding)
     }
@@ -347,7 +347,7 @@ class Global(var currentSettings: Settings, var reporter: Reporter)
       }
     }
 
-    ( if (settings.sourceReader.isSetByUser) Some(settings.sourceReader.value) else None ) flatMap loadReader getOrElse {
+    settings.sourceReader.valueSetByUser flatMap loadReader getOrElse {
       new SourceReader(charset.newDecoder(), reporter)
     }
   }
diff --git a/src/compiler/scala/tools/nsc/PhaseAssembly.scala b/src/compiler/scala/tools/nsc/PhaseAssembly.scala
index cfb4cd23a1..1eb6c9da2c 100644
--- a/src/compiler/scala/tools/nsc/PhaseAssembly.scala
+++ b/src/compiler/scala/tools/nsc/PhaseAssembly.scala
@@ -199,7 +199,7 @@ trait PhaseAssembly {
     // Add all phases in the set to the graph
     val graph = phasesSetToDepGraph(phasesSet)
 
-    val dot = if (settings.genPhaseGraph.isSetByUser) Some(settings.genPhaseGraph.value) else None
+    val dot = settings.genPhaseGraph.valueSetByUser
 
     // Output the phase dependency graph at this stage
     def dump(stage: Int) = dot foreach (n => graphToDotFile(graph, s"$n-$stage.dot"))
diff --git a/src/compiler/scala/tools/nsc/plugins/Plugins.scala b/src/compiler/scala/tools/nsc/plugins/Plugins.scala
index 6e3d013e52..4b1805479d 100644
--- a/src/compiler/scala/tools/nsc/plugins/Plugins.scala
+++ b/src/compiler/scala/tools/nsc/plugins/Plugins.scala
@@ -7,7 +7,7 @@
 package scala.tools.nsc
 package plugins
 
-import scala.reflect.io.{ File, Path }
+import scala.reflect.io.Path
 import scala.tools.nsc.util.ClassPath
 import scala.tools.util.PathResolver.Defaults
 
diff --git a/src/compiler/scala/tools/nsc/symtab/SymbolLoaders.scala b/src/compiler/scala/tools/nsc/symtab/SymbolLoaders.scala
index 6386da5725..9af3efbece 100644
--- a/src/compiler/scala/tools/nsc/symtab/SymbolLoaders.scala
+++ b/src/compiler/scala/tools/nsc/symtab/SymbolLoaders.scala
@@ -88,8 +88,7 @@ abstract class SymbolLoaders {
       // require yjp.jar at runtime. See SI-2089.
       if (settings.termConflict.isDefault)
         throw new TypeError(
-          root+" contains object and package with same name: "+
-          name+"\none of them needs to be removed from classpath"
+          s"$root contains object and package with same name: $name\none of them needs to be removed from classpath"
         )
       else if (settings.termConflict.value == "package") {
         warning(
@@ -252,7 +251,7 @@ abstract class SymbolLoaders {
    * Load contents of a package
    */
   class PackageLoader(classpath: ClassPath[AbstractFile]) extends SymbolLoader with FlagAgnosticCompleter {
-    protected def description = "package loader "+ classpath.name
+    protected def description = s"package loader ${classpath.name}"
 
     protected def doComplete(root: Symbol) {
       assert(root.isPackageClass, root)
diff --git a/src/compiler/scala/tools/nsc/transform/AddInterfaces.scala b/src/compiler/scala/tools/nsc/transform/AddInterfaces.scala
index c5f46dc140..f786ffb8f3 100644
--- a/src/compiler/scala/tools/nsc/transform/AddInterfaces.scala
+++ b/src/compiler/scala/tools/nsc/transform/AddInterfaces.scala
@@ -351,6 +351,7 @@ abstract class AddInterfaces extends InfoTransform { self: Erasure =>
           while (owner != sym && owner != impl) owner = owner.owner;
           if (owner == impl) This(impl) setPos tree.pos
           else tree
+        //TODO what about this commented out code?
 /* !!!
         case Super(qual, mix) =>
           val mix1 = mix
diff --git a/src/compiler/scala/tools/reflect/ReflectMain.scala b/src/compiler/scala/tools/reflect/ReflectMain.scala
index a998a44643..8d8418945a 100644
--- a/src/compiler/scala/tools/reflect/ReflectMain.scala
+++ b/src/compiler/scala/tools/reflect/ReflectMain.scala
@@ -1,10 +1,10 @@
 package scala.tools
 package reflect
 
+import scala.reflect.internal.util.ScalaClassLoader
 import scala.tools.nsc.Driver
 import scala.tools.nsc.Global
 import scala.tools.nsc.Settings
-import scala.tools.nsc.util.ScalaClassLoader
 import scala.tools.util.PathResolverFactory
 
 object ReflectMain extends Driver {
diff --git a/src/compiler/scala/tools/util/PathResolver.scala b/src/compiler/scala/tools/util/PathResolver.scala
index 315476953d..8e5b1e0a5c 100644
--- a/src/compiler/scala/tools/util/PathResolver.scala
+++ b/src/compiler/scala/tools/util/PathResolver.scala
@@ -51,9 +51,8 @@ object PathResolver {
   /** Values found solely by inspecting environment or property variables.
    */
   object Environment {
-    private def searchForBootClasspath = (
+    private def searchForBootClasspath =
       systemProperties find (_._1 endsWith ".boot.class.path") map (_._2) getOrElse ""
-    )
 
     /** Environment variables which java pays attention to so it
      *  seems we do as well.
@@ -107,7 +106,7 @@ object PathResolver {
       else if (scalaLibAsDir.isDirectory) scalaLibAsDir.path
       else ""
 
-    // XXX It must be time for someone to figure out what all these things
+    // TODO It must be time for someone to figure out what all these things
     // are intended to do.  This is disabled here because it was causing all
     // the scala jars to end up on the classpath twice: one on the boot
     // classpath as set up by the runner (or regular classpath under -nobootcp)
@@ -177,7 +176,7 @@ object PathResolver {
   def fromPathString(path: String, context: JavaContext = DefaultJavaContext): JavaClassPath = {
     val s = new Settings()
     s.classpath.value = path
-    new PathResolver(s, context) result
+    new PathResolver(s, context).result
   }
 
   /** With no arguments, show the interesting values in Environment and Defaults.
@@ -263,11 +262,9 @@ abstract class PathResolverBase[BaseClassPathType <: ClassFileLookup[AbstractFil
      *  - Otherwise, if CLASSPATH is set, it is that
      *  - If neither of those, then "." is used.
      */
-    def userClassPath = (
-      if (!settings.classpath.isDefault)
-        settings.classpath.value
+    def userClassPath =
+      if (!settings.classpath.isDefault) settings.classpath.value
       else sys.env.getOrElse("CLASSPATH", ".")
-    )
 
     import classPathFactory._
 
@@ -291,7 +288,7 @@ abstract class PathResolverBase[BaseClassPathType <: ClassFileLookup[AbstractFil
       |  javaBootClassPath    = ${ppcp(javaBootClassPath)}
       |  javaExtDirs          = ${ppcp(javaExtDirs)}
       |  javaUserClassPath    = ${ppcp(javaUserClassPath)}
-      |    useJavaClassPath   = $useJavaClassPath
+      |  useJavaClassPath     = $useJavaClassPath
       |  scalaBootClassPath   = ${ppcp(scalaBootClassPath)}
       |  scalaExtDirs         = ${ppcp(scalaExtDirs)}
       |  userClassPath        = ${ppcp(userClassPath)}