diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/TypeRefHelpers.kt b/compiler/frontend/src/org/jetbrains/jet/lang/psi/TypeRefHelpers.kt
index a826fe4681d..2b7d25ecb67 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/TypeRefHelpers.kt
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/TypeRefHelpers.kt
@@ -24,12 +24,12 @@ import org.jetbrains.jet.lang.psi.JetPsiFactory
 import com.intellij.psi.PsiWhiteSpace
 import com.intellij.psi.PsiErrorElement
 import org.jetbrains.jet.lang.psi.JetCallableDeclaration
-import org.jetbrains.jet.utils.addToStdlib.firstOrNullIsInstance
+import org.jetbrains.jet.utils.addToStdlib.firstIsInstanceOrNull
 
 fun getTypeReference(declaration: JetCallableDeclaration): JetTypeReference? {
     return declaration.getFirstChild()!!.siblings(forward = true)
             .dropWhile { it.getNode()!!.getElementType() != JetTokens.COLON }
-            .firstOrNullIsInstance<JetTypeReference>()
+            .firstIsInstanceOrNull<JetTypeReference>()
 }
 
 fun setTypeReference(declaration: JetCallableDeclaration, addAfter: PsiElement?, typeRef: JetTypeReference?): JetTypeReference? {
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/TypeResolver.kt b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/TypeResolver.kt
index eb343a65b59..8875e952082 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/TypeResolver.kt
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/TypeResolver.kt
@@ -34,7 +34,7 @@ import org.jetbrains.jet.storage.StorageManager
 import org.jetbrains.jet.context.LazinessToken
 import org.jetbrains.jet.lang.resolve.lazy.LazyEntity
 import org.jetbrains.jet.lang.resolve.lazy.ForceResolveUtil
-import org.jetbrains.jet.utils.addToStdlib.firstOrNullIsInstance
+import org.jetbrains.jet.utils.addToStdlib.firstIsInstanceOrNull
 
 public class TypeResolver(
         private val annotationResolver: AnnotationResolver,
@@ -276,7 +276,7 @@ public class TypeResolver(
 
     public fun resolveClass(scope: JetScope, userType: JetUserType, trace: BindingTrace): ClassifierDescriptor? {
         val classifierDescriptor = qualifiedExpressionResolver.lookupDescriptorsForUserType(userType, scope, trace)
-                                        .firstOrNullIsInstance<ClassifierDescriptor>()
+                                        .firstIsInstanceOrNull<ClassifierDescriptor>()
         if (classifierDescriptor != null) {
             ImportsResolver.reportPlatformClassMappedToKotlin(moduleDescriptor, trace, userType, classifierDescriptor)
         }
diff --git a/compiler/util/src/org/jetbrains/jet/utils/addToStdlib.kt b/compiler/util/src/org/jetbrains/jet/utils/addToStdlib.kt
index d80dee86026..9ca54e306ba 100644
--- a/compiler/util/src/org/jetbrains/jet/utils/addToStdlib.kt
+++ b/compiler/util/src/org/jetbrains/jet/utils/addToStdlib.kt
@@ -36,19 +36,19 @@ public fun <T: Any> T?.singletonOrEmptyList(): List<T> = if (this != null) Colle
 public fun <T: Any> T?.singletonOrEmptySet(): Set<T> = if (this != null) Collections.singleton(this) else Collections.emptySet()
 
 [suppress("NOTHING_TO_INLINE")]
-public inline fun <reified T : Any> Stream<*>.firstOrNullIsInstance(): T? {
+public inline fun <reified T : Any> Stream<*>.firstIsInstanceOrNull(): T? {
     for (element in this) if (element is T) return element
     return null
 }
 
 [suppress("NOTHING_TO_INLINE")]
-public inline fun <reified T : Any> Iterable<*>.firstOrNullIsInstance(): T? {
+public inline fun <reified T : Any> Iterable<*>.firstIsInstanceOrNull(): T? {
     for (element in this) if (element is T) return element
     return null
 }
 
 [suppress("NOTHING_TO_INLINE")]
-public inline fun <reified T : Any> Array<*>.firstOrNullIsInstance(): T? {
+public inline fun <reified T : Any> Array<*>.firstIsInstanceOrNull(): T? {
     for (element in this) if (element is T) return element
     return null
 }
diff --git a/idea/ide-common/src/org/jetbrains/jet/lang/resolve/lazy/PartialBodyResolveFilter.kt b/idea/ide-common/src/org/jetbrains/jet/lang/resolve/lazy/PartialBodyResolveFilter.kt
index 870c1769d63..de10e08a3dc 100644
--- a/idea/ide-common/src/org/jetbrains/jet/lang/resolve/lazy/PartialBodyResolveFilter.kt
+++ b/idea/ide-common/src/org/jetbrains/jet/lang/resolve/lazy/PartialBodyResolveFilter.kt
@@ -26,7 +26,7 @@ import java.util.HashMap
 import com.intellij.psi.PsiElement
 import org.jetbrains.jet.JetNodeTypes
 import org.jetbrains.jet.lang.psi.psiUtil.isProbablyNothing
-import org.jetbrains.jet.utils.addToStdlib.firstOrNullIsInstance
+import org.jetbrains.jet.utils.addToStdlib.firstIsInstanceOrNull
 import org.jetbrains.jet.lang.psi.psiUtil.isAncestor
 
 //TODO: do resolve anonymous object's body
@@ -432,7 +432,7 @@ class PartialBodyResolveFilter(
     }
 
     private fun JetBlockExpression.lastStatement(): JetExpression?
-            = getLastChild()?.siblings(forward = false)?.firstOrNullIsInstance<JetExpression>()
+            = getLastChild()?.siblings(forward = false)?.firstIsInstanceOrNull<JetExpression>()
 
     //TODO: declarations with special names (e.g. "get")
     private class NameFilter {
diff --git a/idea/src/org/jetbrains/jet/plugin/completion/CompletionSession.kt b/idea/src/org/jetbrains/jet/plugin/completion/CompletionSession.kt
index 34d63ed7ed5..3515980c7bc 100644
--- a/idea/src/org/jetbrains/jet/plugin/completion/CompletionSession.kt
+++ b/idea/src/org/jetbrains/jet/plugin/completion/CompletionSession.kt
@@ -36,7 +36,7 @@ import org.jetbrains.jet.lang.resolve.java.descriptor.SamConstructorDescriptorKi
 import org.jetbrains.jet.lang.resolve.scopes.DescriptorKindFilter
 import org.jetbrains.jet.lang.resolve.calls.smartcasts.SmartCastUtils
 import org.jetbrains.jet.lang.resolve.bindingContextUtil.getDataFlowInfo
-import org.jetbrains.jet.utils.addToStdlib.firstOrNullIsInstance
+import org.jetbrains.jet.utils.addToStdlib.firstIsInstanceOrNull
 
 class CompletionSessionConfiguration(
         val completeNonImportedDeclarations: Boolean,
@@ -50,7 +50,7 @@ abstract class CompletionSessionBase(protected val configuration: CompletionSess
                                      protected val parameters: CompletionParameters,
                                      resultSet: CompletionResultSet) {
     protected val position: PsiElement = parameters.getPosition()
-    protected val jetReference: JetSimpleNameReference? = position.getParent()?.getReferences()?.filterIsInstance(javaClass<JetSimpleNameReference>())?.firstOrNull()
+    protected val jetReference: JetSimpleNameReference? = position.getParent()?.getReferences()?.firstIsInstanceOrNull<JetSimpleNameReference>()
     private val file = position.getContainingFile() as JetFile
     protected val resolutionFacade: ResolutionFacade = file.getResolutionFacade()
     protected val moduleDescriptor: ModuleDescriptor = resolutionFacade.findModuleDescriptor(file)
diff --git a/idea/src/org/jetbrains/jet/plugin/quickfix/createFromUsage/createVariable/CreateParameterActionFactory.kt b/idea/src/org/jetbrains/jet/plugin/quickfix/createFromUsage/createVariable/CreateParameterActionFactory.kt
index 0cc0f0c5220..0c05574bff2 100644
--- a/idea/src/org/jetbrains/jet/plugin/quickfix/createFromUsage/createVariable/CreateParameterActionFactory.kt
+++ b/idea/src/org/jetbrains/jet/plugin/quickfix/createFromUsage/createVariable/CreateParameterActionFactory.kt
@@ -13,7 +13,6 @@ import org.jetbrains.jet.lang.psi.JetSimpleNameExpression
 import org.jetbrains.jet.lang.psi.psiUtil.getQualifiedElement
 import org.jetbrains.jet.lang.psi.JetClass
 import org.jetbrains.jet.plugin.quickfix.createFromUsage.callableBuilder.guessTypes
-import org.jetbrains.jet.plugin.caches.resolve.analyzeFully
 import org.jetbrains.jet.lang.resolve.BindingContext
 import org.jetbrains.jet.lang.descriptors.ClassDescriptor
 import org.jetbrains.jet.lang.descriptors.FunctionDescriptor
@@ -41,6 +40,7 @@ import org.jetbrains.jet.lang.psi.JetNamedFunction
 import org.jetbrains.jet.lang.psi.psiUtil.getAssignmentByLHS
 import org.jetbrains.jet.plugin.quickfix.createFromUsage.callableBuilder.getExpressionForTypeGuess
 import org.jetbrains.jet.plugin.caches.resolve.analyzeFullyAndGetResult
+import org.jetbrains.jet.utils.addToStdlib.firstIsInstanceOrNull
 
 object CreateParameterActionFactory: JetSingleIntentionActionFactory() {
     private fun JetType.hasTypeParametersToAdd(functionDescriptor: FunctionDescriptor, context: BindingContext): Boolean {
@@ -86,7 +86,7 @@ object CreateParameterActionFactory: JetSingleIntentionActionFactory() {
 
         fun chooseContainingClass(it: PsiElement): JetClass? {
             parameterInfo.setValOrVar(if (varExpected) JetValVar.Var else JetValVar.Val)
-            return it.parents(false).filterIsInstance(javaClass<JetClassOrObject>()).firstOrNull() as? JetClass
+            return it.parents(false).firstIsInstanceOrNull<JetClassOrObject>() as? JetClass
         }
 
         // todo: skip lambdas for now because Change Signature doesn't apply to them yet