Code cleanup: several inspections applied

build-common/src/org/jetbrains/kotlin/incremental/ICReporter.kt

@@ -27,7 +27,7 @@ interface ICReporter {
     fun reportCompileIteration(sourceFiles: Collection<File>, exitCode: ExitCode) {}
 
     fun pathsAsString(files: Iterable<File>): String =
-            files.map { it.canonicalPath }.joinToString()
+            files.joinToString { it.canonicalPath }
 
     fun pathsAsString(vararg files: File): String =
             pathsAsString(files.toList())

build-common/src/org/jetbrains/kotlin/incremental/buildUtil.kt

@@ -41,9 +41,7 @@ import java.util.*
 
 
 fun Iterable<File>.javaSourceRoots(roots: Iterable<File>): Iterable<File> =
-        filter(File::isJavaFile)
-                .map { findSrcDirRoot(it, roots) }
-                .filterNotNull()
+        filter(File::isJavaFile).mapNotNull { findSrcDirRoot(it, roots) }
 
 fun makeModuleFile(name: String, isTest: Boolean, outputDir: File, sourcesToCompile: Iterable<File>, javaSourceRoots: Iterable<File>, classpath: Iterable<File>, friendDirs: Iterable<File>): File {
     val builder = KotlinModuleXmlBuilder()
@@ -166,7 +164,7 @@ fun<Target> OutputItemsCollectorImpl.generatedFiles(
     return outputs.map { outputItem ->
         val target =
                 outputItem.sourceFiles.firstOrNull()?.let { sourceToTarget[it] } ?:
-                targets.filter { getOutputDir(it)?.let { outputItem.outputFile.startsWith(it) } ?: false }.singleOrNull() ?:
+                targets.singleOrNull { getOutputDir(it)?.let { outputItem.outputFile.startsWith(it) } ?: false } ?:
                 representativeTarget
 
         when (outputItem.outputFile.extension) {

build-common/src/org/jetbrains/kotlin/incremental/storage/BasicMapsOwner.kt

@@ -42,5 +42,5 @@ open class BasicMapsOwner {
         maps.forEach { it.flush(memoryCachesOnly) }
     }
 
-    @TestOnly fun dump(): String = maps.map { it.dump() }.joinToString("\n\n")
+    @TestOnly fun dump(): String = maps.joinToString("\n\n") { it.dump() }
 }