simple generator static analysis subscript check

jedi/evaluate/analysis.py

@@ -8,6 +8,7 @@ from jedi import debug
 CODES = {
     'attribute-error': (1, 'Potential AttributeError.'),
     'import-error': (2, 'Potential ImportError.'),
+    'type-error-generator': (3, "TypeError: 'generator' object is not subscriptable."),
 }
 
 

jedi/evaluate/iterable.py

@@ -32,6 +32,7 @@ from jedi.evaluate import helpers
 from jedi.evaluate import precedence
 from jedi.evaluate.cache import CachedMetaClass, memoize_default, NO_DEFAULT
 from jedi.cache import underscore_memoization
+from jedi.evaluate import analysis
 
 
 class Generator(use_metaclass(CachedMetaClass, pr.Base)):
@@ -61,7 +62,8 @@ class Generator(use_metaclass(CachedMetaClass, pr.Base)):
         return self._evaluator.execute(self.func, self.var_args, True)
 
     def get_index_types(self, index_array):
-        debug.warning('Tried to get array access on a generator: %s', self)
+        #debug.warning('Tried to get array access on a generator: %s', self)
+        analysis.add(self._evaluator, 'type-error-generator', index_array)
         return []
 
     def __getattr__(self, name):

test/static_analysis/generators.py

@@ -0,0 +1,8 @@
+def generator():
+    yield 1
+
+#! type-error-generator
+generator()[0]
+
+list(generator())[0]
+