Compeltion for matrix multiplication methods (PY-15390)

python/psi-api/src/com/jetbrains/python/PyNames.java

@@ -357,8 +357,23 @@ public class PyNames {
     .put("__round__", new BuiltinDescription("(self, n=None)"))
     .build();
 
+  public static ImmutableMap<String, BuiltinDescription> PY35_BUILTIN_METHODS = ImmutableMap.<String, BuiltinDescription>builder()
+    .putAll(PY3_BUILTIN_METHODS)
+    .put("__imatmul__", _self_other_descr)
+    .put("__matmul__", _self_other_descr)
+    .put("__rmatmul__", _self_other_descr)
+    .build();
+
   public static ImmutableMap<String, BuiltinDescription> getBuiltinMethods(LanguageLevel level) {
-    return level.isPy3K() ? PY3_BUILTIN_METHODS : PY2_BUILTIN_METHODS;
+    if (level.isAtLeast(LanguageLevel.PYTHON35)) {
+      return PY35_BUILTIN_METHODS;
+    }
+    else if (level.isAtLeast(LanguageLevel.PYTHON30)) {
+      return PY3_BUILTIN_METHODS;
+    }
+    else {
+      return PY2_BUILTIN_METHODS;
+    }
   }
 
   // canonical names, not forced by interpreter

python/testData/completion/matMul.after.py

@@ -0,0 +1,2 @@
+class C:
+    def __matmul__(self, other):

python/testData/completion/matMul.py

@@ -0,0 +1,2 @@
+class C:
+    def __matmul<caret>

python/testSrc/com/jetbrains/python/Py3CompletionTest.java

@@ -141,4 +141,14 @@ public class Py3CompletionTest extends PyTestCase {
   public void testNotImportedSubmodulesOfNamespacePackage() {
     doMultiFileTest();
   }
+
+  // PY-15390
+  public void testMatMul() {
+    runWithLanguageLevel(LanguageLevel.PYTHON35, new Runnable() {
+      @Override
+      public void run() {
+        doTest();
+      }
+    });
+  }
 }