Added PyCallableType.getReturnType() for forthcoming return types caching

python/pluginSrc/com/jetbrains/python/psi/impl/PyJavaClassType.java

@@ -104,13 +104,19 @@ public class PyJavaClassType implements PyClassLikeType {
 
   @Nullable
   @Override
-  public PyType getCallType(@NotNull TypeEvalContext context, @Nullable PyQualifiedExpression callSite) {
+  public PyType getReturnType(@NotNull TypeEvalContext context) {
     if (myDefinition) {
       return new PyJavaClassType(myClass, false);
     }
     return null;
   }
 
+  @Nullable
+  @Override
+  public PyType getCallType(@NotNull TypeEvalContext context, @Nullable PyQualifiedExpression callSite) {
+    return getReturnType(context);
+  }
+
   @Nullable
   @Override
   public List<PyCallableParameter> getParameters(@NotNull TypeEvalContext context) {

python/pluginSrc/com/jetbrains/python/psi/impl/PyJavaMethodType.java

@@ -52,10 +52,16 @@ public class PyJavaMethodType implements PyCallableType {
 
   @Nullable
   @Override
-  public PyType getCallType(@NotNull TypeEvalContext context, @Nullable PyQualifiedExpression callSite) {
+  public PyType getReturnType(@NotNull TypeEvalContext context) {
     return PyJavaTypeProvider.asPyType(myMethod.getReturnType());
   }
 
+  @Nullable
+  @Override
+  public PyType getCallType(@NotNull TypeEvalContext context, @Nullable PyQualifiedExpression callSite) {
+    return getReturnType(context);
+  }
+
   @Nullable
   @Override
   public List<PyCallableParameter> getParameters(@NotNull TypeEvalContext context) {

python/psi-api/src/com/jetbrains/python/psi/types/PyCallableType.java

@@ -34,11 +34,15 @@ public interface PyCallableType extends PyType {
   boolean isCallable();
 
   /**
-   * Returns the type which is the result of calling an instance of this type.
+   * Returns the return type of a function independent of a call site.
    *
-   * @return the call result type or null if invalid.
-   * @param context
-   * @param callSite
+   * For example, it may return a generic type.
+   */
+  @Nullable
+  PyType getReturnType(@NotNull TypeEvalContext context);
+
+  /**
+   * Returns the type which is the result of calling an instance of this type.
    */
   @Nullable
   PyType getCallType(@NotNull TypeEvalContext context, @Nullable PyQualifiedExpression callSite);

python/src/com/jetbrains/python/psi/types/PyCallableTypeImpl.java

@@ -47,6 +47,13 @@ public class PyCallableTypeImpl implements PyCallableType {
     return true;
   }
 
+  @Nullable
+  @Override
+  public PyType getReturnType(@NotNull TypeEvalContext context) {
+    // TODO: Check that this return type doesn't depend on the call site for all PyCallableTypeImpl objects
+    return myReturnType;
+  }
+
   @Nullable
   @Override
   public PyType getCallType(@NotNull TypeEvalContext context, @Nullable PyQualifiedExpression callSite) {

python/src/com/jetbrains/python/psi/types/PyClassTypeImpl.java

@@ -307,13 +307,19 @@ public class PyClassTypeImpl extends UserDataHolderBase implements PyClassType {
 
   @Nullable
   @Override
-  public PyType getCallType(@NotNull TypeEvalContext context, @Nullable PyQualifiedExpression callSite) {
+  public PyType getReturnType(@NotNull TypeEvalContext context) {
     if (isDefinition()) {
       return new PyClassTypeImpl(getPyClass(), false);
     }
     return null;
   }
 
+  @Nullable
+  @Override
+  public PyType getCallType(@NotNull TypeEvalContext context, @Nullable PyQualifiedExpression callSite) {
+    return getReturnType(context);
+  }
+
   @Nullable
   @Override
   public List<PyCallableParameter> getParameters(@NotNull TypeEvalContext context) {

python/src/com/jetbrains/python/psi/types/PyFunctionType.java

@@ -44,6 +44,13 @@ public class PyFunctionType implements PyCallableType {
     return true;
   }
 
+  @Nullable
+  @Override
+  public PyType getReturnType(@NotNull TypeEvalContext context) {
+    // TODO: Make Callable.getReturnType() call site independent, extract getCallType()
+    return myCallable.getReturnType(context, null);
+  }
+
   @Nullable
   @Override
   public PyType getCallType(@NotNull TypeEvalContext context, @Nullable PyQualifiedExpression callSite) {