From b9171e59ad26058157686469d925916dd44fd35a Mon Sep 17 00:00:00 2001
From: Pierre DAL-PRA <dalpra.pierre@gmail.com>
Date: Sat, 1 Aug 2015 02:19:25 +0200
Subject: [PATCH 1/2] Simplify operations on collections

---
 compile/api/src/main/scala/sbt/ClassToAPI.scala           | 2 +-
 compile/api/src/main/scala/xsbt/api/SameAPI.scala         | 2 +-
 compile/inc/src/main/scala/sbt/inc/ClassfileManager.scala | 2 +-
 .../src/main/scala/sbt/compiler/AggressiveCompile.scala   | 2 +-
 .../main/scala/sbt/compiler/MixedAnalyzingCompiler.scala  | 8 ++++----
 .../scala/sbt/compiler/javac/AnalyzingJavaCompiler.scala  | 2 +-
 .../src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala | 4 ++--
 .../scala/sbt/compiler/javac/ProcessLoggerWriter.scala    | 2 +-
 ivy/src/main/scala/sbt/JsonUtil.scala                     | 6 +++---
 ivy/src/main/scala/sbt/MakePom.scala                      | 4 ++--
 .../scala/sbt/ivyint/CachedResolutionResolveEngine.scala  | 2 +-
 main/actions/src/main/scala/sbt/TestResultLogger.scala    | 2 +-
 main/actions/src/main/scala/sbt/Tests.scala               | 4 ++--
 main/src/main/scala/sbt/Aggregation.scala                 | 4 ++--
 main/src/main/scala/sbt/Defaults.scala                    | 4 ++--
 main/src/main/scala/sbt/EvaluateTask.scala                | 2 +-
 main/src/main/scala/sbt/SettingCompletions.scala          | 2 +-
 run/src/main/scala/sbt/TrapExit.scala                     | 2 +-
 .../tests/it/changes/ClassFailModuleSuccess.scala         | 2 +-
 scripted/base/src/main/scala/xsbt/test/FileCommands.scala | 4 ++--
 tasks/standard/src/test/scala/TaskRunnerFork.scala        | 2 +-
 .../src/main/scala/sbt/classfile/ClassFile.scala          | 4 ++--
 util/classpath/src/main/scala/sbt/ReflectUtilities.scala  | 2 +-
 util/collection/src/main/scala/sbt/Settings.scala         | 2 +-
 util/complete/src/main/scala/sbt/LineReader.scala         | 2 +-
 util/log/src/main/scala/sbt/LoggerWriter.scala            | 2 +-
 util/relation/src/main/scala/sbt/Relation.scala           | 2 +-
 27 files changed, 39 insertions(+), 39 deletions(-)

diff --git a/compile/api/src/main/scala/sbt/ClassToAPI.scala b/compile/api/src/main/scala/sbt/ClassToAPI.scala
index 71a10ed22..acf593daf 100644
--- a/compile/api/src/main/scala/sbt/ClassToAPI.scala
+++ b/compile/api/src/main/scala/sbt/ClassToAPI.scala
@@ -293,7 +293,7 @@ object ClassToAPI {
   def referenceP(t: ParameterizedType): api.Parameterized =
     {
       val targs = t.getActualTypeArguments
-      val args = if (targs.length == 0) emptyTypeArray else arrayMap(targs)(t => reference(t): api.Type)
+      val args = if (targs.isEmpty) emptyTypeArray else arrayMap(targs)(t => reference(t): api.Type)
       val base = reference(t.getRawType)
       new api.Parameterized(base, args.toArray[api.Type])
     }
diff --git a/compile/api/src/main/scala/xsbt/api/SameAPI.scala b/compile/api/src/main/scala/xsbt/api/SameAPI.scala
index 4cc36084c..ebf03f5cd 100644
--- a/compile/api/src/main/scala/xsbt/api/SameAPI.scala
+++ b/compile/api/src/main/scala/xsbt/api/SameAPI.scala
@@ -44,7 +44,7 @@ object TopLevel {
 /** Checks the API of two source files for equality.*/
 object SameAPI {
   def apply(a: Source, b: Source): Boolean =
-    a.apiHash == b.apiHash && (a.hash.length > 0 && b.hash.length > 0) && apply(a.api, b.api)
+    a.apiHash == b.apiHash && (a.hash.nonEmpty && b.hash.nonEmpty) && apply(a.api, b.api)
 
   def apply(a: Def, b: Def): Boolean =
     (new SameAPI(false, true)).sameDefinitions(List(a), List(b), true)
diff --git a/compile/inc/src/main/scala/sbt/inc/ClassfileManager.scala b/compile/inc/src/main/scala/sbt/inc/ClassfileManager.scala
index 6d94295e3..20179b7bd 100644
--- a/compile/inc/src/main/scala/sbt/inc/ClassfileManager.scala
+++ b/compile/inc/src/main/scala/sbt/inc/ClassfileManager.scala
@@ -62,7 +62,7 @@ object ClassfileManager {
         logger.debug("Rolling back changes to class files.")
         logger.debug(s"Removing generated classes:\n${showFiles(generatedClasses)}")
         IO.deleteFilesEmptyDirs(generatedClasses)
-        logger.debug(s"Restoring class files: \n${showFiles(movedClasses.map(_._1))}")
+        logger.debug(s"Restoring class files: \n${showFiles(movedClasses.keys)}")
         for ((orig, tmp) <- movedClasses) IO.move(tmp, orig)
       }
       logger.debug(s"Removing the temporary directory used for backing up class files: $tempDir")
diff --git a/compile/integration/src/main/scala/sbt/compiler/AggressiveCompile.scala b/compile/integration/src/main/scala/sbt/compiler/AggressiveCompile.scala
index 201e6108d..92fb1a375 100644
--- a/compile/integration/src/main/scala/sbt/compiler/AggressiveCompile.scala
+++ b/compile/integration/src/main/scala/sbt/compiler/AggressiveCompile.scala
@@ -185,7 +185,7 @@ class AggressiveCompile(cacheFile: File) {
   def javaOnly(f: File) = f.getName.endsWith(".java")
 
   private[this] def explicitBootClasspath(options: Seq[String]): Seq[File] =
-    options.dropWhile(_ != CompilerArguments.BootClasspathOption).drop(1).take(1).headOption.toList.flatMap(IO.parseClasspath)
+    options.dropWhile(_ != CompilerArguments.BootClasspathOption).slice(1, 2).headOption.toList.flatMap(IO.parseClasspath)
 
   val store = MixedAnalyzingCompiler.staticCachedStore(cacheFile)
 
diff --git a/compile/integration/src/main/scala/sbt/compiler/MixedAnalyzingCompiler.scala b/compile/integration/src/main/scala/sbt/compiler/MixedAnalyzingCompiler.scala
index ea599b993..f3f4bf21d 100644
--- a/compile/integration/src/main/scala/sbt/compiler/MixedAnalyzingCompiler.scala
+++ b/compile/integration/src/main/scala/sbt/compiler/MixedAnalyzingCompiler.scala
@@ -43,7 +43,7 @@ final class MixedAnalyzingCompiler(
     logInputs(log, javaSrcs.size, scalaSrcs.size, outputDirs)
     /** compiles the scala code necessary using the analyzing compiler. */
     def compileScala(): Unit =
-      if (!scalaSrcs.isEmpty) {
+      if (scalaSrcs.nonEmpty) {
         val sources = if (order == Mixed) incSrc else scalaSrcs
         val arguments = cArgs(Nil, absClasspath, None, options.options)
         timed("Scala compilation", log) {
@@ -54,7 +54,7 @@ final class MixedAnalyzingCompiler(
      * Compiles the Java code necessary.  All analysis code is included in this method.
      */
     def compileJava(): Unit =
-      if (!javaSrcs.isEmpty) {
+      if (javaSrcs.nonEmpty) {
         // Runs the analysis portion of Javac.
         timed("Java compile + analysis", log) {
           javac.compile(javaSrcs, options.javacOptions.toArray[String], output, callback, reporter, log, progress)
@@ -81,7 +81,7 @@ final class MixedAnalyzingCompiler(
     val scalaMsg = Analysis.counted("Scala source", "", "s", scalaCount)
     val javaMsg = Analysis.counted("Java source", "", "s", javaCount)
     val combined = scalaMsg ++ javaMsg
-    if (!combined.isEmpty)
+    if (combined.nonEmpty)
       log.info(combined.mkString("Compiling ", " and ", " to " + outputDirs.map(_.getAbsolutePath).mkString(",") + "..."))
   }
 
@@ -187,7 +187,7 @@ object MixedAnalyzingCompiler {
   def withBootclasspath(args: CompilerArguments, classpath: Seq[File]): Seq[File] =
     args.bootClasspathFor(classpath) ++ args.extClasspath ++ args.finishClasspath(classpath)
   private[this] def explicitBootClasspath(options: Seq[String]): Seq[File] =
-    options.dropWhile(_ != CompilerArguments.BootClasspathOption).drop(1).take(1).headOption.toList.flatMap(IO.parseClasspath)
+    options.dropWhile(_ != CompilerArguments.BootClasspathOption).slice(1, 2).headOption.toList.flatMap(IO.parseClasspath)
 
   private[this] val cache = new collection.mutable.HashMap[File, Reference[AnalysisStore]]
   private def staticCache(file: File, backing: => AnalysisStore): AnalysisStore =
diff --git a/compile/integration/src/main/scala/sbt/compiler/javac/AnalyzingJavaCompiler.scala b/compile/integration/src/main/scala/sbt/compiler/javac/AnalyzingJavaCompiler.scala
index d49bf9515..9bae1d5af 100644
--- a/compile/integration/src/main/scala/sbt/compiler/javac/AnalyzingJavaCompiler.scala
+++ b/compile/integration/src/main/scala/sbt/compiler/javac/AnalyzingJavaCompiler.scala
@@ -36,7 +36,7 @@ final class AnalyzingJavaCompiler private[sbt] (
    * @param progressOpt An optional compilation progress reporter.  Where we can report back what files we're currently compiling.
    */
   def compile(sources: Seq[File], options: Seq[String], output: Output, callback: AnalysisCallback, reporter: Reporter, log: Logger, progressOpt: Option[CompileProgress]): Unit = {
-    if (!sources.isEmpty) {
+    if (sources.nonEmpty) {
       val absClasspath = classpath.map(_.getAbsoluteFile)
       @annotation.tailrec def ancestor(f1: File, f2: File): Boolean =
         if (f2 eq null) false else if (f1 == f2) true else ancestor(f1, f2.getParentFile)
diff --git a/compile/interface/src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala b/compile/interface/src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala
index 0338d2658..1c4eee353 100644
--- a/compile/interface/src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala
+++ b/compile/interface/src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala
@@ -62,8 +62,8 @@ class ScalaCompilerForUnitTesting(nameHashing: Boolean = false) {
    * file system-independent way of testing dependencies between source code "files".
    */
   def extractDependenciesFromSrcs(srcs: List[Map[Symbol, String]]): ExtractedSourceDependencies = {
-    val rawGroupedSrcs = srcs.map(_.values.toList).toList
-    val symbols = srcs.map(_.keys).flatten
+    val rawGroupedSrcs = srcs.map(_.values.toList)
+    val symbols = srcs.flatMap(_.keys)
     val (tempSrcFiles, testCallback) = compileSrcs(rawGroupedSrcs)
     val fileToSymbol = (tempSrcFiles zip symbols).toMap
 
diff --git a/compile/src/main/scala/sbt/compiler/javac/ProcessLoggerWriter.scala b/compile/src/main/scala/sbt/compiler/javac/ProcessLoggerWriter.scala
index eb64bfdae..a399f755a 100644
--- a/compile/src/main/scala/sbt/compiler/javac/ProcessLoggerWriter.scala
+++ b/compile/src/main/scala/sbt/compiler/javac/ProcessLoggerWriter.scala
@@ -8,7 +8,7 @@ private class ProcessLoggerWriter(delegate: ProcessLogger, level: Level.Value, n
   override def close() = flush()
   override def flush(): Unit =
     synchronized {
-      if (buffer.length > 0) {
+      if (buffer.nonEmpty) {
         log(buffer.toString)
         buffer.clear()
       }
diff --git a/ivy/src/main/scala/sbt/JsonUtil.scala b/ivy/src/main/scala/sbt/JsonUtil.scala
index e3983e7b4..d4db781f7 100644
--- a/ivy/src/main/scala/sbt/JsonUtil.scala
+++ b/ivy/src/main/scala/sbt/JsonUtil.scala
@@ -50,9 +50,9 @@ private[sbt] object JsonUtil {
         (c.caller.organization != sbtOrgTemp) &&
           (c.caller.organization != fakeCallerOrganization)
       }
-      val interProj = (callers filter { c =>
-        (c.caller.organization == sbtOrgTemp)
-      }).headOption.toList
+      val interProj = (callers find { c =>
+        c.caller.organization == sbtOrgTemp
+      }).toList
       interProj ::: nonArtificial.toList
     }
 
diff --git a/ivy/src/main/scala/sbt/MakePom.scala b/ivy/src/main/scala/sbt/MakePom.scala
index 530070dda..81121bf7f 100644
--- a/ivy/src/main/scala/sbt/MakePom.scala
+++ b/ivy/src/main/scala/sbt/MakePom.scala
@@ -248,7 +248,7 @@ class MakePom(val log: Logger) {
     val includeArtifacts = artifacts.filter(d => includeTypes(d.getType))
     if (artifacts.isEmpty) {
       val configs = dependency.getModuleConfigurations
-      if (configs.filterNot(Set("sources", "docs")).nonEmpty) {
+      if (!configs.forall(Set("sources", "docs"))) {
         warnIntransitve()
         val (scope, optional) = getScopeAndOptional(dependency.getModuleConfigurations)
         makeDependencyElem(dependency, scope, optional, None, None, excludes)
@@ -271,7 +271,7 @@ class MakePom(val log: Logger) {
         case Nil | "*" :: Nil => dependency.getModuleConfigurations
         case x                => x.toArray
       }
-      if (configs.filterNot(Set("sources", "docs")).nonEmpty) {
+      if (!configs.forall(Set("sources", "docs"))) {
         val (scope, optional) = getScopeAndOptional(configs)
         val classifier = artifactClassifier(artifact)
         val baseType = artifactType(artifact)
diff --git a/ivy/src/main/scala/sbt/ivyint/CachedResolutionResolveEngine.scala b/ivy/src/main/scala/sbt/ivyint/CachedResolutionResolveEngine.scala
index 07a157107..5052a46ef 100644
--- a/ivy/src/main/scala/sbt/ivyint/CachedResolutionResolveEngine.scala
+++ b/ivy/src/main/scala/sbt/ivyint/CachedResolutionResolveEngine.scala
@@ -430,7 +430,7 @@ private[sbt] trait CachedResolutionResolveEngine extends ResolveEngine {
         cs match {
           case Nil => Nil
           case (k, Vector()) :: rest => resolveConflicts(rest)
-          case (k, Vector(oa)) :: rest if (oa.modules.size == 0) => resolveConflicts(rest)
+          case (k, Vector(oa)) :: rest if (oa.modules.isEmpty) => resolveConflicts(rest)
           case (k, Vector(oa)) :: rest if (oa.modules.size == 1 && !oa.modules.head.evicted) =>
             log.debug(s":: no conflict $rootModuleConf: ${oa.organization}:${oa.name}")
             oa :: resolveConflicts(rest)
diff --git a/main/actions/src/main/scala/sbt/TestResultLogger.scala b/main/actions/src/main/scala/sbt/TestResultLogger.scala
index 0f2e01378..01d7317a1 100644
--- a/main/actions/src/main/scala/sbt/TestResultLogger.scala
+++ b/main/actions/src/main/scala/sbt/TestResultLogger.scala
@@ -112,7 +112,7 @@ object TestResultLogger {
     val printStandard_? : Output => Boolean =
       results =>
         // Print the standard one-liner statistic if no framework summary is defined, or when > 1 framework is in used.
-        results.summaries.size > 1 || results.summaries.headOption.forall(_.summaryText.size == 0)
+        results.summaries.size > 1 || results.summaries.headOption.forall(_.summaryText.isEmpty)
 
     val printStandard = TestResultLogger((log, results, _) => {
       val (skippedCount, errorsCount, passedCount, failuresCount, ignoredCount, canceledCount, pendingCount) =
diff --git a/main/actions/src/main/scala/sbt/Tests.scala b/main/actions/src/main/scala/sbt/Tests.scala
index fb8b156e6..829b50c6d 100644
--- a/main/actions/src/main/scala/sbt/Tests.scala
+++ b/main/actions/src/main/scala/sbt/Tests.scala
@@ -142,9 +142,9 @@ object Tests {
         }
       }
 
-      if (excludeTestsSet.size > 0)
+      if (excludeTestsSet.nonEmpty)
         log.debug(excludeTestsSet.mkString("Excluding tests: \n\t", "\n\t", ""))
-      if (undefinedFrameworks.size > 0)
+      if (undefinedFrameworks.nonEmpty)
         log.warn("Arguments defined for test frameworks that are not present:\n\t" + undefinedFrameworks.mkString("\n\t"))
 
       def includeTest(test: TestDefinition) = !excludeTestsSet.contains(test.name) && testFilters.forall(filter => filter(test.name))
diff --git a/main/src/main/scala/sbt/Aggregation.scala b/main/src/main/scala/sbt/Aggregation.scala
index 1a9cf039c..324b3c53b 100644
--- a/main/src/main/scala/sbt/Aggregation.scala
+++ b/main/src/main/scala/sbt/Aggregation.scala
@@ -138,8 +138,8 @@ final object Aggregation {
         //  tasks, and input tasks in the same call.  The code below allows settings and tasks to be mixed, but not input tasks.
         // One problem with input tasks in `all` is that many input tasks consume all input and would need syntactic delimiters.
         // Once that is addressed, the tasks constructed by the input tasks would need to be combined with the explicit tasks.
-        if (inputTasks.size > 0) {
-          if (other.size > 0) {
+        if (inputTasks.nonEmpty) {
+          if (other.nonEmpty) {
             val inputStrings = inputTasks.map(_.key).mkString("Input task(s):\n\t", "\n\t", "\n")
             val otherStrings = other.map(_.key).mkString("Task(s)/setting(s):\n\t", "\n\t", "\n")
             failure(s"Cannot mix input tasks with plain tasks/settings.  $inputStrings $otherStrings")
diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index 33b2ef0c0..47567034d 100755
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -1181,7 +1181,7 @@ object Classpaths {
       (confs ++ confs.map(internalConfigurationMap.value) ++ (if (autoCompilerPlugins.value) CompilerPlugin :: Nil else Nil)).distinct
     },
     ivyConfigurations ++= Configurations.auxiliary,
-    ivyConfigurations ++= { if (managedScalaInstance.value && !scalaHome.value.isDefined) Configurations.ScalaTool :: Nil else Nil },
+    ivyConfigurations ++= { if (managedScalaInstance.value && scalaHome.value.isEmpty) Configurations.ScalaTool :: Nil else Nil },
     moduleSettings <<= moduleSettings0,
     makePomConfiguration := new MakePomConfiguration(artifactPath in makePom value, projectInfo.value, None, pomExtra.value, pomPostProcess.value, pomIncludeRepository.value, pomAllRepositories.value),
     deliverLocalConfiguration := deliverConfig(crossTarget.value, status = if (isSnapshot.value) "integration" else "release", logging = ivyLoggingLevel.value),
@@ -1239,7 +1239,7 @@ object Classpaths {
   )
 
   val jvmBaseSettings: Seq[Setting[_]] = Seq(
-    libraryDependencies ++= autoLibraryDependency(autoScalaLibrary.value && !scalaHome.value.isDefined && managedScalaInstance.value, sbtPlugin.value, scalaOrganization.value, scalaVersion.value),
+    libraryDependencies ++= autoLibraryDependency(autoScalaLibrary.value && scalaHome.value.isEmpty && managedScalaInstance.value, sbtPlugin.value, scalaOrganization.value, scalaVersion.value),
     // Override the default to handle mixing in the sbtPlugin + scala dependencies.
     allDependencies := {
       val base = projectDependencies.value ++ libraryDependencies.value
diff --git a/main/src/main/scala/sbt/EvaluateTask.scala b/main/src/main/scala/sbt/EvaluateTask.scala
index 8ced3cd4b..0bb93ec29 100644
--- a/main/src/main/scala/sbt/EvaluateTask.scala
+++ b/main/src/main/scala/sbt/EvaluateTask.scala
@@ -415,7 +415,7 @@ object EvaluateTask {
 
   def liftAnonymous: Incomplete => Incomplete = {
     case i @ Incomplete(node, tpe, None, causes, None) =>
-      causes.find(inc => !inc.node.isDefined && (inc.message.isDefined || inc.directCause.isDefined)) match {
+      causes.find(inc => inc.node.isEmpty && (inc.message.isDefined || inc.directCause.isDefined)) match {
         case Some(lift) => i.copy(directCause = lift.directCause, message = lift.message)
         case None       => i
       }
diff --git a/main/src/main/scala/sbt/SettingCompletions.scala b/main/src/main/scala/sbt/SettingCompletions.scala
index 6b94c4c6b..44c706785 100644
--- a/main/src/main/scala/sbt/SettingCompletions.scala
+++ b/main/src/main/scala/sbt/SettingCompletions.scala
@@ -27,7 +27,7 @@ private[sbt] object SettingCompletions {
     {
       import extracted._
       val r = relation(extracted.structure, true)
-      val allDefs = Def.flattenLocals(Def.compiled(extracted.structure.settings, true)(structure.delegates, structure.scopeLocal, implicitly[Show[ScopedKey[_]]])).map(_._1)
+      val allDefs = Def.flattenLocals(Def.compiled(extracted.structure.settings, true)(structure.delegates, structure.scopeLocal, implicitly[Show[ScopedKey[_]]])).keys
       val projectScope = Load.projectScope(currentRef)
       def resolve(s: Setting[_]): Seq[Setting[_]] = Load.transformSettings(projectScope, currentRef.build, rootProject, s :: Nil)
       def rescope[T](setting: Setting[T]): Seq[Setting[_]] =
diff --git a/run/src/main/scala/sbt/TrapExit.scala b/run/src/main/scala/sbt/TrapExit.scala
index 7c62d809e..a5f981896 100644
--- a/run/src/main/scala/sbt/TrapExit.scala
+++ b/run/src/main/scala/sbt/TrapExit.scala
@@ -478,7 +478,7 @@ private final class TrapExit(delegateManager: SecurityManager) extends SecurityM
 
   private def disposeAllFrames(log: Logger) {
     val allFrames = java.awt.Frame.getFrames
-    if (allFrames.length > 0) {
+    if (allFrames.nonEmpty) {
       log.debug(s"Disposing ${allFrames.length} top-level windows...")
       allFrames.foreach(_.dispose) // dispose all top-level windows, which will cause the AWT-EventQueue-* threads to exit
       val waitSeconds = 2
diff --git a/sbt/src/sbt-test/tests/it/changes/ClassFailModuleSuccess.scala b/sbt/src/sbt-test/tests/it/changes/ClassFailModuleSuccess.scala
index 47d17d531..e9d477c5d 100644
--- a/sbt/src/sbt-test/tests/it/changes/ClassFailModuleSuccess.scala
+++ b/sbt/src/sbt-test/tests/it/changes/ClassFailModuleSuccess.scala
@@ -3,7 +3,7 @@ import org.specs2.mutable._
 class B extends Specification
 {	
   "'hello world' has 11 characters" in {
-     "hello world".size must be equalTo(122)
+     "hello world".length must be equalTo(122)
   }
 }
 
diff --git a/scripted/base/src/main/scala/xsbt/test/FileCommands.scala b/scripted/base/src/main/scala/xsbt/test/FileCommands.scala
index b06cbac2c..e3af22cce 100644
--- a/scripted/base/src/main/scala/xsbt/test/FileCommands.scala
+++ b/scripted/base/src/main/scala/xsbt/test/FileCommands.scala
@@ -60,12 +60,12 @@ class FileCommands(baseDirectory: File) extends BasicStatementHandler {
     }
   def exists(paths: List[String]) {
     val notPresent = fromStrings(paths).filter(!_.exists)
-    if (notPresent.length > 0)
+    if (notPresent.nonEmpty)
       scriptError("File(s) did not exist: " + notPresent.mkString("[ ", " , ", " ]"))
   }
   def absent(paths: List[String]) {
     val present = fromStrings(paths).filter(_.exists)
-    if (present.length > 0)
+    if (present.nonEmpty)
       scriptError("File(s) existed: " + present.mkString("[ ", " , ", " ]"))
   }
   def execute(command: List[String]): Unit = execute0(command.head, command.tail)
diff --git a/tasks/standard/src/test/scala/TaskRunnerFork.scala b/tasks/standard/src/test/scala/TaskRunnerFork.scala
index ba40e4c5c..45b661dc0 100644
--- a/tasks/standard/src/test/scala/TaskRunnerFork.scala
+++ b/tasks/standard/src/test/scala/TaskRunnerFork.scala
@@ -28,7 +28,7 @@ object TaskRunnerForkTest extends Properties("TaskRunner Fork") {
   }
   property("fork and reduce") = forAll(TaskListGen, MaxWorkersGen) { (m: List[Int], workers: Int) =>
     m.nonEmpty ==> {
-      val expected = m.reduceLeft(_ + _)
+      val expected = m.sum
       checkResult(tryRun(m.tasks.reduced(_ + _), false, workers), expected)
     }
   }
diff --git a/util/classfile/src/main/scala/sbt/classfile/ClassFile.scala b/util/classfile/src/main/scala/sbt/classfile/ClassFile.scala
index d230dbfe9..3f1a0d915 100644
--- a/util/classfile/src/main/scala/sbt/classfile/ClassFile.scala
+++ b/util/classfile/src/main/scala/sbt/classfile/ClassFile.scala
@@ -56,10 +56,10 @@ private[sbt] final case class Constant(tag: Byte, nameIndex: Int, typeIndex: Int
 private[sbt] final case class FieldOrMethodInfo(accessFlags: Int, name: Option[String], descriptor: Option[String], attributes: IndexedSeq[AttributeInfo]) extends NotNull {
   def isStatic = (accessFlags & ACC_STATIC) == ACC_STATIC
   def isPublic = (accessFlags & ACC_PUBLIC) == ACC_PUBLIC
-  def isMain = isPublic && isStatic && descriptor.filter(_ == "([Ljava/lang/String;)V").isDefined
+  def isMain = isPublic && isStatic && descriptor.exists(_ == "([Ljava/lang/String;)V")
 }
 private[sbt] final case class AttributeInfo(name: Option[String], value: Array[Byte]) extends NotNull {
-  def isNamed(s: String) = name.filter(s == _).isDefined
+  def isNamed(s: String) = name.exists(s == _)
   def isSignature = isNamed("Signature")
   def isSourceFile = isNamed("SourceFile")
 }
diff --git a/util/classpath/src/main/scala/sbt/ReflectUtilities.scala b/util/classpath/src/main/scala/sbt/ReflectUtilities.scala
index 0781880f9..c60772ad4 100644
--- a/util/classpath/src/main/scala/sbt/ReflectUtilities.scala
+++ b/util/classpath/src/main/scala/sbt/ReflectUtilities.scala
@@ -40,7 +40,7 @@ object ReflectUtilities {
       var mappings = new immutable.TreeMap[String, T]
       val correspondingFields = fields(self.getClass)
       for (method <- self.getClass.getMethods) {
-        if (method.getParameterTypes.length == 0 && clazz.isAssignableFrom(method.getReturnType)) {
+        if (method.getParameterTypes.isEmpty && clazz.isAssignableFrom(method.getReturnType)) {
           for (field <- correspondingFields.get(method.getName) if field.getType == method.getReturnType) {
             val value = method.invoke(self).asInstanceOf[T]
             if (value == null) throw new UninitializedVal(method.getName, method.getDeclaringClass.getName)
diff --git a/util/collection/src/main/scala/sbt/Settings.scala b/util/collection/src/main/scala/sbt/Settings.scala
index 4266af1b6..0196b0a09 100644
--- a/util/collection/src/main/scala/sbt/Settings.scala
+++ b/util/collection/src/main/scala/sbt/Settings.scala
@@ -296,7 +296,7 @@ trait Init[Scope] {
   def definedAtString(settings: Seq[Setting[_]]): String =
     {
       val posDefined = settings.flatMap(_.positionString.toList)
-      if (posDefined.size > 0) {
+      if (posDefined.nonEmpty) {
         val header = if (posDefined.size == settings.size) "defined at:" else
           "some of the defining occurrences:"
         header + (posDefined.distinct mkString ("\n\t", "\n\t", "\n"))
diff --git a/util/complete/src/main/scala/sbt/LineReader.scala b/util/complete/src/main/scala/sbt/LineReader.scala
index 8f9fc219f..b85190f92 100644
--- a/util/complete/src/main/scala/sbt/LineReader.scala
+++ b/util/complete/src/main/scala/sbt/LineReader.scala
@@ -45,7 +45,7 @@ abstract class JLine extends LineReader {
 
   private[this] def handleMultilinePrompt(prompt: String): String = {
     val lines = """\r?\n""".r.split(prompt)
-    lines.size match {
+    lines.length match {
       case 0 | 1 => prompt
       case _     => reader.print(lines.init.mkString("\n") + "\n"); lines.last;
     }
diff --git a/util/log/src/main/scala/sbt/LoggerWriter.scala b/util/log/src/main/scala/sbt/LoggerWriter.scala
index 0165676f5..bc6062563 100644
--- a/util/log/src/main/scala/sbt/LoggerWriter.scala
+++ b/util/log/src/main/scala/sbt/LoggerWriter.scala
@@ -17,7 +17,7 @@ class LoggerWriter(delegate: Logger, unbufferedLevel: Option[Level.Value], nl: S
   override def close() = flush()
   override def flush(): Unit =
     synchronized {
-      if (buffer.length > 0) {
+      if (buffer.nonEmpty) {
         log(buffer.toString)
         buffer.clear()
       }
diff --git a/util/relation/src/main/scala/sbt/Relation.scala b/util/relation/src/main/scala/sbt/Relation.scala
index 987aafb14..9a648ad64 100644
--- a/util/relation/src/main/scala/sbt/Relation.scala
+++ b/util/relation/src/main/scala/sbt/Relation.scala
@@ -123,7 +123,7 @@ private final class MRelation[A, B](fwd: Map[A, Set[B]], rev: Map[B, Set[A]]) ex
   def _1s = fwd.keySet
   def _2s = rev.keySet
 
-  def size = (fwd.valuesIterator map { _.size }).foldLeft(0)(_ + _)
+  def size = (fwd.valuesIterator map (_.size)).sum
 
   def all: Traversable[(A, B)] = fwd.iterator.flatMap { case (a, bs) => bs.iterator.map(b => (a, b)) }.toTraversable
 

From f0bd9001e6b35d92591f7a2b1c2dc4d7dcebb43f Mon Sep 17 00:00:00 2001
From: Pierre DAL-PRA <dalpra.pierre@gmail.com>
Date: Sat, 1 Aug 2015 12:05:35 +0200
Subject: [PATCH 2/2] Remove redundant collection conversions

---
 compile/inc/src/main/scala/sbt/inc/Compile.scala          | 2 +-
 .../src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala | 4 ++--
 ivy/src/main/scala/sbt/IvyRetrieve.scala                  | 8 ++++----
 .../scala/sbt/ivyint/CachedResolutionResolveEngine.scala  | 4 ++--
 ivy/src/main/scala/sbt/ivyint/MergeDescriptors.scala      | 2 +-
 main/actions/src/main/scala/sbt/Package.scala             | 2 +-
 main/src/main/scala/sbt/Defaults.scala                    | 4 ++--
 main/src/main/scala/sbt/Load.scala                        | 6 +++---
 main/src/main/scala/sbt/Project.scala                     | 2 +-
 scripted/plugin/src/main/scala/sbt/ScriptedPlugin.scala   | 2 +-
 util/collection/src/main/scala/sbt/PMap.scala             | 2 +-
 util/collection/src/main/scala/sbt/Settings.scala         | 4 ++--
 12 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/compile/inc/src/main/scala/sbt/inc/Compile.scala b/compile/inc/src/main/scala/sbt/inc/Compile.scala
index 6d6b616c3..a7ccb3dd2 100644
--- a/compile/inc/src/main/scala/sbt/inc/Compile.scala
+++ b/compile/inc/src/main/scala/sbt/inc/Compile.scala
@@ -84,7 +84,7 @@ private final class AnalysisCallback(internalMap: File => Option[File], external
     val outputSettings = output match {
       case single: SingleOutput => Array(new OutputSetting("/", single.outputDirectory.getAbsolutePath))
       case multi: MultipleOutput =>
-        multi.outputGroups.map(out => new OutputSetting(out.sourceDirectory.getAbsolutePath, out.outputDirectory.getAbsolutePath)).toArray
+        multi.outputGroups.map(out => new OutputSetting(out.sourceDirectory.getAbsolutePath, out.outputDirectory.getAbsolutePath))
     }
     new Compilation(System.currentTimeMillis, outputSettings)
   }
diff --git a/compile/interface/src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala b/compile/interface/src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala
index 1c4eee353..019590dfc 100644
--- a/compile/interface/src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala
+++ b/compile/interface/src/test/scala/xsbt/ScalaCompilerForUnitTesting.scala
@@ -33,7 +33,7 @@ class ScalaCompilerForUnitTesting(nameHashing: Boolean = false) {
 
   def extractUsedNamesFromSrc(src: String): Set[String] = {
     val (Seq(tempSrcFile), analysisCallback) = compileSrcs(src)
-    analysisCallback.usedNames(tempSrcFile).toSet
+    analysisCallback.usedNames(tempSrcFile)
   }
 
   /**
@@ -46,7 +46,7 @@ class ScalaCompilerForUnitTesting(nameHashing: Boolean = false) {
   def extractUsedNamesFromSrc(definitionSrc: String, actualSrc: String): Set[String] = {
     // we drop temp src file corresponding to the definition src file
     val (Seq(_, tempSrcFile), analysisCallback) = compileSrcs(definitionSrc, actualSrc)
-    analysisCallback.usedNames(tempSrcFile).toSet
+    analysisCallback.usedNames(tempSrcFile)
   }
 
   /**
diff --git a/ivy/src/main/scala/sbt/IvyRetrieve.scala b/ivy/src/main/scala/sbt/IvyRetrieve.scala
index f453efb1f..14ad917fa 100644
--- a/ivy/src/main/scala/sbt/IvyRetrieve.scala
+++ b/ivy/src/main/scala/sbt/IvyRetrieve.scala
@@ -74,7 +74,7 @@ object IvyRetrieve {
       }: _*)
     def toCaller(caller: IvyCaller): Caller = {
       val m = toModuleID(caller.getModuleRevisionId)
-      val callerConfigurations = caller.getCallerConfigurations.toArray.toVector collect {
+      val callerConfigurations = caller.getCallerConfigurations.toVector collect {
         case x if nonEmptyString(x).isDefined => x
       }
       val ddOpt = Option(caller.getDependencyDescriptor)
@@ -128,16 +128,16 @@ object IvyRetrieve {
       case _        => dep.getResolvedId.getExtraAttributes
     })
     val isDefault = Option(dep.getDescriptor) map { _.isDefault }
-    val configurations = dep.getConfigurations(confReport.getConfiguration).toArray.toList
+    val configurations = dep.getConfigurations(confReport.getConfiguration).toList
     val licenses: Seq[(String, Option[String])] = mdOpt match {
-      case Some(md) => md.getLicenses.toArray.toVector collect {
+      case Some(md) => md.getLicenses.toVector collect {
         case lic: IvyLicense if Option(lic.getName).isDefined =>
           val temporaryURL = "http://localhost"
           (lic.getName, nonEmptyString(lic.getUrl) orElse { Some(temporaryURL) })
       }
       case _ => Nil
     }
-    val callers = dep.getCallers(confReport.getConfiguration).toArray.toVector map { toCaller }
+    val callers = dep.getCallers(confReport.getConfiguration).toVector map { toCaller }
     val (resolved, missing) = artifacts(moduleId, confReport getDownloadReports revId)
 
     new ModuleReport(moduleId, resolved, missing, status, publicationDate, resolver, artifactResolver,
diff --git a/ivy/src/main/scala/sbt/ivyint/CachedResolutionResolveEngine.scala b/ivy/src/main/scala/sbt/ivyint/CachedResolutionResolveEngine.scala
index 5052a46ef..049130132 100644
--- a/ivy/src/main/scala/sbt/ivyint/CachedResolutionResolveEngine.scala
+++ b/ivy/src/main/scala/sbt/ivyint/CachedResolutionResolveEngine.scala
@@ -57,7 +57,7 @@ private[sbt] class CachedResolutionResolveCache() {
     {
       log.debug(s":: building artificial module descriptors from ${md0.getModuleRevisionId}")
       // val expanded = expandInternalDependencies(md0, data, prOpt, log)
-      val rootModuleConfigs = md0.getConfigurations.toArray.toVector
+      val rootModuleConfigs = md0.getConfigurations.toVector
       directDependencies(md0) map { dd =>
         val arts = dd.getAllDependencyArtifacts.toVector map { x => s"""${x.getName}:${x.getType}:${x.getExt}:${x.getExtraAttributes}""" }
         log.debug(s"::: dd: $dd (artifacts: ${arts.mkString(",")})")
@@ -599,7 +599,7 @@ private[sbt] trait CachedResolutionResolveEngine extends ResolveEngine {
           case None => Vector()
         }
       // These are the configurations from the original project we want to resolve.
-      val rootModuleConfs = md0.getConfigurations.toArray.toVector
+      val rootModuleConfs = md0.getConfigurations.toVector
       val configurations0 = ur.configurations.toVector
       // This is how md looks from md0 via dd's mapping.
       val remappedConfigs0: Map[String, Vector[String]] = Map(rootModuleConfs map { conf0 =>
diff --git a/ivy/src/main/scala/sbt/ivyint/MergeDescriptors.scala b/ivy/src/main/scala/sbt/ivyint/MergeDescriptors.scala
index 4e2cb1fc2..76bb4d2af 100644
--- a/ivy/src/main/scala/sbt/ivyint/MergeDescriptors.scala
+++ b/ivy/src/main/scala/sbt/ivyint/MergeDescriptors.scala
@@ -109,7 +109,7 @@ private final class MergedDescriptors(a: DependencyDescriptor, b: DependencyDesc
   private[this] def addConfigurations(dd: DefaultDependencyArtifactDescriptor, confs: Seq[String]): Unit =
     confs foreach dd.addConfiguration
 
-  private[this] def concat[T: reflect.ClassTag](a: Array[T], b: Array[T]): Array[T] = (a ++ b).distinct.toArray
+  private[this] def concat[T: reflect.ClassTag](a: Array[T], b: Array[T]): Array[T] = (a ++ b).distinct
 
   def getAllExcludeRules = concat(a.getAllExcludeRules, b.getAllExcludeRules)
 
diff --git a/main/actions/src/main/scala/sbt/Package.scala b/main/actions/src/main/scala/sbt/Package.scala
index 67a32fc82..df9af955d 100644
--- a/main/actions/src/main/scala/sbt/Package.scala
+++ b/main/actions/src/main/scala/sbt/Package.scala
@@ -68,7 +68,7 @@ object Package {
     }
 
     val map = conf.sources.toMap
-    val inputs = map :+: lastModified(map.keySet.toSet) :+: manifest :+: HNil
+    val inputs = map :+: lastModified(map.keySet) :+: manifest :+: HNil
     cachedMakeJar(inputs)(() => exists(conf.jar))
   }
   def setVersion(main: Attributes) {
diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index 47567034d..311d87a28 100755
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -635,12 +635,12 @@ object Defaults extends BuildCommon {
 
   // drop base directories, since there are no valid mappings for these
   def sourceMappings = (unmanagedSources, unmanagedSourceDirectories, baseDirectory) map { (srcs, sdirs, base) =>
-    ((srcs --- sdirs --- base) pair (relativeTo(sdirs) | relativeTo(base) | flat)) toSeq
+    (srcs --- sdirs --- base) pair (relativeTo(sdirs) | relativeTo(base) | flat)
   }
   def resourceMappings = relativeMappings(unmanagedResources, unmanagedResourceDirectories)
   def relativeMappings(files: ScopedTaskable[Seq[File]], dirs: ScopedTaskable[Seq[File]]): Initialize[Task[Seq[(File, String)]]] =
     (files, dirs) map { (rs, rdirs) =>
-      (rs --- rdirs) pair (relativeTo(rdirs) | flat) toSeq
+      (rs --- rdirs) pair (relativeTo(rdirs) | flat)
     }
 
   def collectFiles(dirs: ScopedTaskable[Seq[File]], filter: ScopedTaskable[FileFilter], excludes: ScopedTaskable[FileFilter]): Initialize[Task[Seq[File]]] =
diff --git a/main/src/main/scala/sbt/Load.scala b/main/src/main/scala/sbt/Load.scala
index 6c2d914c6..6d12523cd 100755
--- a/main/src/main/scala/sbt/Load.scala
+++ b/main/src/main/scala/sbt/Load.scala
@@ -174,7 +174,7 @@ object Load {
       val keys = Index.allKeys(settings)
       val attributeKeys = Index.attributeKeys(data) ++ keys.map(_.key)
       val scopedKeys = keys ++ data.allKeys((s, k) => ScopedKey(s, k))
-      val projectsMap = projects.mapValues(_.defined.keySet).toMap
+      val projectsMap = projects.mapValues(_.defined.keySet)
       val keyIndex = KeyIndex(scopedKeys, projectsMap)
       val aggIndex = KeyIndex.aggregate(scopedKeys, extra(keyIndex), projectsMap)
       new sbt.StructureIndex(Index.stringToKeyMap(attributeKeys), Index.taskToKeyMap(data), Index.triggers(data), keyIndex, aggIndex)
@@ -358,7 +358,7 @@ object Load {
       builds map {
         case (uri, unit) =>
           (uri, unit.resolveRefs(ref => Scope.resolveProjectRef(uri, rootProject, ref)))
-      } toMap;
+      }
     }
   def checkAll(referenced: Map[URI, List[ProjectReference]], builds: Map[URI, sbt.PartBuildUnit]) {
     val rootProject = getRootProject(builds)
@@ -396,7 +396,7 @@ object Load {
     {
       IO.assertAbsolute(uri)
       val resolve = (_: Project).resolve(ref => Scope.resolveProjectRef(uri, rootProject, ref))
-      new sbt.LoadedBuildUnit(unit.unit, unit.defined mapValues resolve toMap, unit.rootProjects, unit.buildSettings)
+      new sbt.LoadedBuildUnit(unit.unit, unit.defined mapValues resolve, unit.rootProjects, unit.buildSettings)
     }
   def projects(unit: sbt.BuildUnit): Seq[Project] =
     {
diff --git a/main/src/main/scala/sbt/Project.scala b/main/src/main/scala/sbt/Project.scala
index c2d2bf39d..dba3c0f45 100755
--- a/main/src/main/scala/sbt/Project.scala
+++ b/main/src/main/scala/sbt/Project.scala
@@ -510,7 +510,7 @@ object Project extends ProjectExtra {
 
   val ProjectReturn = AttributeKey[List[File]]("project-return", "Maintains a stack of builds visited using reload.")
   def projectReturn(s: State): List[File] = getOrNil(s, ProjectReturn)
-  def inPluginProject(s: State): Boolean = projectReturn(s).toList.length > 1
+  def inPluginProject(s: State): Boolean = projectReturn(s).length > 1
   def setProjectReturn(s: State, pr: List[File]): State = s.copy(attributes = s.attributes.put(ProjectReturn, pr))
   def loadAction(s: State, action: LoadAction.Value) = action match {
     case Return =>
diff --git a/scripted/plugin/src/main/scala/sbt/ScriptedPlugin.scala b/scripted/plugin/src/main/scala/sbt/ScriptedPlugin.scala
index 4195846fd..5d7a776e7 100644
--- a/scripted/plugin/src/main/scala/sbt/ScriptedPlugin.scala
+++ b/scripted/plugin/src/main/scala/sbt/ScriptedPlugin.scala
@@ -48,7 +48,7 @@ object ScriptedPlugin extends Plugin {
       val pairMap = pairs.groupBy(_._1).mapValues(_.map(_._2).toSet)
 
       val id = charClass(c => !c.isWhitespace && c != '/').+.string
-      val groupP = token(id.examples(pairMap.keySet.toSet)) <~ token('/')
+      val groupP = token(id.examples(pairMap.keySet)) <~ token('/')
       def nameP(group: String) = token("*".id | id.examples(pairMap(group)))
       val testID = for (group <- groupP; name <- nameP(group)) yield (group, name)
       (token(Space) ~> matched(testID)).*
diff --git a/util/collection/src/main/scala/sbt/PMap.scala b/util/collection/src/main/scala/sbt/PMap.scala
index 51c942112..cf0454fd9 100644
--- a/util/collection/src/main/scala/sbt/PMap.scala
+++ b/util/collection/src/main/scala/sbt/PMap.scala
@@ -52,7 +52,7 @@ object IMap {
       put(k, f(this get k getOrElse init))
 
     def mapValues[V2[_]](f: V ~> V2) =
-      new IMap0[K, V2](backing.mapValues(x => f(x)).toMap)
+      new IMap0[K, V2](backing.mapValues(x => f(x)))
 
     def mapSeparate[VL[_], VR[_]](f: V ~> ({ type l[T] = Either[VL[T], VR[T]] })#l) =
       {
diff --git a/util/collection/src/main/scala/sbt/Settings.scala b/util/collection/src/main/scala/sbt/Settings.scala
index 0196b0a09..03173d6ce 100644
--- a/util/collection/src/main/scala/sbt/Settings.scala
+++ b/util/collection/src/main/scala/sbt/Settings.scala
@@ -17,9 +17,9 @@ sealed trait Settings[Scope] {
 }
 
 private final class Settings0[Scope](val data: Map[Scope, AttributeMap], val delegates: Scope => Seq[Scope]) extends Settings[Scope] {
-  def scopes: Set[Scope] = data.keySet.toSet
+  def scopes: Set[Scope] = data.keySet
   def keys(scope: Scope) = data(scope).keys.toSet
-  def allKeys[T](f: (Scope, AttributeKey[_]) => T): Seq[T] = data.flatMap { case (scope, map) => map.keys.map(k => f(scope, k)) } toSeq;
+  def allKeys[T](f: (Scope, AttributeKey[_]) => T): Seq[T] = data.flatMap { case (scope, map) => map.keys.map(k => f(scope, k)) } toSeq
 
   def get[T](scope: Scope, key: AttributeKey[T]): Option[T] =
     delegates(scope).toStream.flatMap(sc => getDirect(sc, key)).headOption