Refactored (and more correct) getOutermostLastBlockElement and its usages

compiler/frontend/src/org/jetbrains/kotlin/psi/JetPsiUtil.java

@@ -600,21 +600,6 @@ public class JetPsiUtil {
                ((JetBinaryExpression) element).getOperationToken().equals(JetTokens.EQ);
     }
 
-    @Nullable
-    public static JetElement getOutermostLastBlockElement(@Nullable JetElement element, @NotNull Predicate<JetElement> checkElement) {
-        if (element == null) return null;
-
-        if (!(element instanceof JetBlockExpression)) return checkElement.apply(element) ? element : null;
-
-        JetBlockExpression block = (JetBlockExpression)element;
-        int n = block.getStatements().size();
-
-        if (n == 0) return null;
-
-        JetElement lastElement = block.getStatements().get(n - 1);
-        return checkElement.apply(lastElement) ? lastElement : null;
-    }
-
     public static boolean checkVariableDeclarationInBlock(@NotNull JetBlockExpression block, @NotNull String varName) {
         for (JetElement element : block.getStatements()) {
             if (element instanceof JetVariableDeclaration) {

compiler/frontend/src/org/jetbrains/kotlin/psi/psiUtil/jetPsiUtil.kt

@@ -44,6 +44,7 @@ import com.intellij.openapi.util.TextRange
 import com.intellij.psi.stubs.StubElement
 import org.jetbrains.kotlin.JetNodeTypes
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.utils.addToStdlib.lastIsInstanceOrNull
 
 public fun JetCallElement.getCallNameExpression(): JetSimpleNameExpression? {
     val calleeExpression = getCalleeExpression() ?: return null
@@ -135,8 +136,11 @@ public fun <T: PsiElement> T.copied(): T = copy() as T
 public fun JetElement.blockExpressionsOrSingle(): Sequence<JetElement> =
         if (this is JetBlockExpression) getStatements().asSequence() else sequenceOf(this)
 
-public fun JetElement.outermostLastBlockElement(predicate: (JetElement) -> Boolean = { true }): JetElement? {
-    return JetPsiUtil.getOutermostLastBlockElement(this) { e -> e != null && predicate(e) }
+public fun JetExpression.lastBlockStatementOrThis(): JetExpression {
+    return if (this is JetBlockExpression)
+        this.getStatements().lastIsInstanceOrNull<JetExpression>() ?: this
+    else
+        this
 }
 
 public fun JetBlockExpression.appendElement(element: JetElement): JetElement {

compiler/util/src/org/jetbrains/kotlin/utils/addToStdlib.kt

@@ -53,6 +53,24 @@ public inline fun <reified T> Array<*>.firstIsInstance(): T {
     throw NoSuchElementException("No element of given type found")
 }
 
+public inline fun <reified T : Any> Iterable<*>.lastIsInstanceOrNull(): T? {
+    when (this) {
+        is List<*> -> {
+            for (i in this.indices.reversed()) {
+                val element = this[i]
+                if (element is T) return element
+            }
+            return null
+        }
+
+        else -> {
+            return reverse().firstIsInstanceOrNull<T>()
+        }
+    }
+}
+
 public fun <T> streamOfLazyValues(vararg elements: () -> T): Stream<T> = elements.stream().map { it() }
 
-public fun <T1, T2> Pair<T1, T2>.swap(): Pair<T2, T1> = Pair(second, first)
+public fun <T1, T2> Pair<T1, T2>.swap(): Pair<T2, T1> = Pair(second, first)
+
+public fun <T: Any> T.check(predicate: (T) -> Boolean): T? = if (predicate(this)) this else null