Replace a lot more of empty sets and unite calls.

jedi/evaluate/stdlib.py

@@ -24,6 +24,7 @@ from jedi.evaluate import precedence
 from jedi.evaluate import param
 from jedi.evaluate import analysis
 from jedi.evaluate.context import LazyTreeContext, ContextualizedNode
+from jedi.common import NO_CONTEXTS, ContextSet
 
 # Now this is all part of fake tuples in Jedi. However super doesn't work on
 # __init__ and __new__ doesn't work at all. So adding this to nametuples is
@@ -77,7 +78,7 @@ def _follow_param(evaluator, arguments, index):
     try:
         key, lazy_context = list(arguments.unpack())[index]
     except IndexError:
-        return set()
+        return NO_CONTEXTS
     else:
         return lazy_context.infer()
 
@@ -109,7 +110,7 @@ def argument_clinic(string, want_obj=False, want_context=False, want_arguments=F
             try:
                 lst = list(arguments.eval_argument_clinic(clinic_args))
             except ValueError:
-                return set()
+                return NO_CONTEXTS
             else:
                 kwargs = {}
                 if want_context:
@@ -137,15 +138,16 @@ def builtins_next(evaluator, iterators, defaults):
     else:
         name = '__next__'
 
-    types = set()
+    context_set = NO_CONTEXTS
     for iterator in iterators:
         if isinstance(iterator, AbstractInstanceContext):
-            for filter in iterator.get_filters(include_self_names=True):
-                for n in filter.get(name):
-                    for context in n.infer():
-                        types |= context.execute_evaluated()
-    if types:
-        return types
+            context_set = ContextSet.from_sets(
+                n.infer()
+                for filter in iterator.get_filters(include_self_names=True)
+                for n in filter.get(name)
+            ).execute_evaluated()
+    if context_set:
+        return context_set
     return defaults
 
 
@@ -159,16 +161,16 @@ def builtins_getattr(evaluator, objects, names, defaults=None):
             else:
                 debug.warning('getattr called without str')
                 continue
-    return set()
+    return NO_CONTEXTS
 
 
 @argument_clinic('object[, bases, dict], /')
 def builtins_type(evaluator, objects, bases, dicts):
     if bases or dicts:
         # It's a type creation... maybe someday...
-        return set()
+        return NO_CONTEXTS
     else:
-        return set([o.py__class__() for o in objects])
+        return ContextSet.from_iterable(o.py__class__() for o in objects)
 
 
 class SuperInstance(AbstractInstanceContext):
@@ -185,7 +187,7 @@ def builtins_super(evaluator, types, objects, context):
                             AnonymousInstanceFunctionExecution)):
         su = context.instance.py__class__().py__bases__()
         return unite(context.execute_evaluated() for context in su[0].infer())
-    return set()
+    return NO_CONTEXTS
 
 
 @argument_clinic('sequence, /', want_obj=True, want_arguments=True)
@@ -207,12 +209,12 @@ def builtins_reversed(evaluator, sequences, obj, arguments):
     # just returned the result directly.
     seq = iterable.FakeSequence(evaluator, 'list', rev)
     arguments = param.ValuesArguments([[seq]])
-    return set([CompiledInstance(evaluator, evaluator.BUILTINS, obj, arguments)])
+    return ContextSet(CompiledInstance(evaluator, evaluator.BUILTINS, obj, arguments))
 
 
 @argument_clinic('obj, type, /', want_arguments=True)
 def builtins_isinstance(evaluator, objects, types, arguments):
-    bool_results = set([])
+    bool_results = set()
     for o in objects:
         try:
             mro_func = o.py__class__().py__mro__
@@ -220,7 +222,7 @@ def builtins_isinstance(evaluator, objects, types, arguments):
             # This is temporary. Everything should have a class attribute in
             # Python?! Maybe we'll leave it here, because some numpy objects or
             # whatever might not.
-            return set([compiled.create(True), compiled.create(False)])
+            return ContextSet(compiled.create(True), compiled.create(False))
 
         mro = mro_func()
 
@@ -244,7 +246,7 @@ def builtins_isinstance(evaluator, objects, types, arguments):
                               'not %s.' % cls_or_tup
                     analysis.add(lazy_context._context, 'type-error-isinstance', node, message)
 
-    return set(compiled.create(evaluator, x) for x in bool_results)
+    return ContextSet.from_iterable(compiled.create(evaluator, x) for x in bool_results)
 
 
 def collections_namedtuple(evaluator, obj, arguments):
@@ -259,7 +261,7 @@ def collections_namedtuple(evaluator, obj, arguments):
     """
     # Namedtuples are not supported on Python 2.6
     if not hasattr(collections, '_class_template'):
-        return set()
+        return NO_CONTEXTS
 
     # Process arguments
     # TODO here we only use one of the types, we should use all.
@@ -274,7 +276,7 @@ def collections_namedtuple(evaluator, obj, arguments):
             for v in lazy_context.infer() if hasattr(v, 'obj')
         ]
     else:
-        return set()
+        return NO_CONTEXTS
 
     base = collections._class_template
     base += _NAMEDTUPLE_INIT
@@ -293,7 +295,7 @@ def collections_namedtuple(evaluator, obj, arguments):
     module = evaluator.grammar.parse(source)
     generated_class = next(module.iter_classdefs())
     parent_context = er.ModuleContext(evaluator, module, '')
-    return set([er.ClassContext(evaluator, generated_class, parent_context)])
+    return ContextSet(er.ClassContext(evaluator, generated_class, parent_context))
 
 
 @argument_clinic('first, /')
@@ -314,8 +316,8 @@ _implemented = {
         'deepcopy': _return_first_param,
     },
     'json': {
-        'load': lambda *args: set(),
-        'loads': lambda *args: set(),
+        'load': lambda *args: NO_CONTEXTS,
+        'loads': lambda *args: NO_CONTEXTS,
     },
     'collections': {
         'namedtuple': collections_namedtuple,