Iterators replaced with streams where appropriate

idea/src/org/jetbrains/jet/plugin/hierarchy/overrides/KotlinOverrideTreeStructure.kt

@@ -57,7 +57,7 @@ class KotlinOverrideTreeStructure(project: Project, val element: PsiElement) : H
         }
 
         return javaTreeStructures
-                .iterator()
+                .stream()
                 .map (::buildChildrenByTreeStructure)
                 .reduce { (a, b) -> ContainerUtil.union(a.toSet(), b.toSet()).copyToArray() }
     }

idea/src/org/jetbrains/jet/plugin/refactoring/move/moveTopLevelDeclarations/MoveKotlinTopLevelDeclarationsProcessor.kt

@@ -265,7 +265,7 @@ public class MoveKotlinTopLevelDeclarationsProcessor(project: Project, val optio
                 }
 
                 getTransaction()!!.getElementListener(oldDeclaration).elementMoved(newDeclaration)
-                for ((oldElement, newElement) in oldLightElements.iterator() zip newDeclaration.toLightElements().iterator()) {
+                for ((oldElement, newElement) in oldLightElements.stream() zip newDeclaration.toLightElements().stream()) {
                     oldToNewElementsMapping[oldElement] = newElement
                 }
             }

idea/src/org/jetbrains/jet/plugin/refactoring/safeDelete/KotlinSafeDeleteProcessor.kt

@@ -105,7 +105,7 @@ public class KotlinSafeDeleteProcessor : JavaSafeDeleteProcessor() {
             return searchInfo
         }
 
-        fun findUsagesByJavaProcessor(elements: Iterator<PsiElement>, insideDeleted: Condition<PsiElement>): Condition<PsiElement> =
+        fun findUsagesByJavaProcessor(elements: Stream<PsiElement>, insideDeleted: Condition<PsiElement>): Condition<PsiElement> =
                 elements
                         .map { element -> findUsagesByJavaProcessor(element, true)?.getInsideDeletedCondition() }
                         .filterNotNull()
@@ -114,7 +114,7 @@ public class KotlinSafeDeleteProcessor : JavaSafeDeleteProcessor() {
         fun findUsagesByJavaProcessor(jetDeclaration: JetDeclaration): NonCodeUsageSearchInfo {
             return NonCodeUsageSearchInfo(
                     findUsagesByJavaProcessor(
-                            jetDeclaration.toLightElements().iterator(),
+                            jetDeclaration.toLightElements().stream(),
                             getIgnoranceCondition()
                     ),
                     jetDeclaration
@@ -123,7 +123,7 @@ public class KotlinSafeDeleteProcessor : JavaSafeDeleteProcessor() {
 
         fun findKotlinDeclarationUsages(declaration: JetDeclaration): NonCodeUsageSearchInfo {
             ReferencesSearch.search(declaration, declaration.getUseScope())
-                    .iterator()
+                    .stream()
                     .filterNot { reference -> getIgnoranceCondition().value(reference.getElement()) }
                     .mapTo(usages) { reference ->
                         reference.getElement().getParentByType(javaClass<JetImportDirective>())?.let { importDirective ->
@@ -214,7 +214,7 @@ public class KotlinSafeDeleteProcessor : JavaSafeDeleteProcessor() {
             if (declarationDescriptor !is CallableMemberDescriptor) return null
 
             return declarationDescriptor.getOverriddenDescriptors()
-                    .iterator()
+                    .stream()
                     .filter { overridenDescriptor -> overridenDescriptor.getModality() == Modality.ABSTRACT }
                     .mapTo(ArrayList<String>()) { overridenDescriptor ->
                         JetBundle.message(

idea/src/org/jetbrains/jet/plugin/refactoring/safeDelete/utils.kt

@@ -64,7 +64,7 @@ fun PsiElement.removeOverrideModifier() {
 fun PsiMethod.cleanUpOverrides() {
     val superMethods = findSuperMethods(true)
     for (overridingMethod in OverridingMethodsSearch.search(this, true).findAll()) {
-        val currentSuperMethods = overridingMethod.findSuperMethods(true).iterator() + superMethods.iterator()
+        val currentSuperMethods = overridingMethod.findSuperMethods(true).stream() + superMethods.stream()
         if (currentSuperMethods.all { superMethod -> superMethod.unwrapped == unwrapped }) {
             overridingMethod.unwrapped?.removeOverrideModifier()
         }

idea/src/org/jetbrains/jet/plugin/search/ideaExtensions/KotlinDirectInheritorsSearcher.kt

@@ -46,7 +46,7 @@ public open class KotlinDirectInheritorsSearcher() : QueryExecutorBase<PsiClass,
         if (scope == null) return
 
         ApplicationManager.getApplication()?.runReadAction {
-            JetSuperClassIndex.getInstance().get(name, baseClass.getProject(), scope).iterator()
+            JetSuperClassIndex.getInstance().get(name, baseClass.getProject(), scope).stream()
                     .map { candidate -> JetSourceNavigationHelper.getOriginalPsiClassOrCreateLightClass(candidate)}
                     .filterNotNull()
                     .filter { candidate -> candidate.isInheritor(baseClass, false) }