From 45cb54cacf50fb72305b949c69896662a9a3d1d3 Mon Sep 17 00:00:00 2001
From: "Ilya.Kazakevich" <Ilya.Kazakevich@jetbrains.com>
Date: Tue, 8 Apr 2014 22:06:57 +0400
Subject: [PATCH] PY-12565 Django: default template names for generic
 class-based views are not resolved

---
 .../nameResolver/NameResolverTools.java       | 18 +++++++++++++++
 .../src/com/jetbrains/python/psi/PyUtil.java  | 23 +++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/python/psi-api/src/com/jetbrains/python/nameResolver/NameResolverTools.java b/python/psi-api/src/com/jetbrains/python/nameResolver/NameResolverTools.java
index a8929fd440fa..aaf32760898e 100644
--- a/python/psi-api/src/com/jetbrains/python/nameResolver/NameResolverTools.java
+++ b/python/psi-api/src/com/jetbrains/python/nameResolver/NameResolverTools.java
@@ -19,6 +19,23 @@ public final class NameResolverTools {
 
   }
 
+  /**
+   * For each provided element checks if FQ element name is one of provided names
+   *
+   * @param elements       element to check
+   * @param namesProviders some enum that has one or more names
+   * @return true if element's fqn is one of names, provided by provider
+   */
+  public static boolean isElementWithName(@NotNull final Collection<? extends PyElement> elements,
+                                          @NotNull final FQNamesProvider... namesProviders) {
+    for (final PyElement element : elements) {
+      if (isName(element, namesProviders)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   /**
    * Checks if FQ element name is one of provided names
    *
@@ -44,6 +61,7 @@ public final class NameResolverTools {
 
   /**
    * Returns set of names all providers provide
+   *
    * @param providers providers to check
    * @return set of names
    */
diff --git a/python/src/com/jetbrains/python/psi/PyUtil.java b/python/src/com/jetbrains/python/psi/PyUtil.java
index ec2ac31cb5ea..7ea85fbea186 100644
--- a/python/src/com/jetbrains/python/psi/PyUtil.java
+++ b/python/src/com/jetbrains/python/psi/PyUtil.java
@@ -804,6 +804,29 @@ public class PyUtil {
     return LanguageLevel.getDefault();
   }
 
+  /**
+   * Clone of C# "as" operator.
+   * Checks if expression has correct type and casts it if it has. Returns null otherwise.
+   * It saves coder from "instanceof / cast" chains.
+   *
+   * @param expression expression to check
+   * @param clazz class to cast
+   * @param <T> class to cast
+   * @return expression casted to appropriate type (if could be casted). Null otherwise.
+   */
+  @Nullable
+  @SuppressWarnings("unchecked")
+  public static <T>T as(@Nullable final Object expression, @NotNull final Class<T> clazz) {
+    if (expression == null) {
+      return null;
+    }
+    if (clazz.isAssignableFrom(expression.getClass())) {
+      return (T)expression;
+    }
+    return null;
+
+  }
+
   public static class KnownDecoratorProviderHolder {
     public static PyKnownDecoratorProvider[] KNOWN_DECORATOR_PROVIDERS = Extensions.getExtensions(PyKnownDecoratorProvider.EP_NAME);