Polish Maybe API a bit, removing useless creativity and fixing some signatures.

src/contexts.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/bootstrapper.h"
 #include "src/debug.h"
 #include "src/scopeinfo.h"
 
@@ skipping 113 matching lines @@
   Maybe<PropertyAttributes> attrs = JSReceiver::GetPropertyAttributes(it);
   DCHECK(attrs.has_value || isolate->has_pending_exception());
   if (!attrs.has_value || attrs.value == ABSENT) return attrs;
 
   Handle<Symbol> unscopables_symbol = isolate->factory()->unscopables_symbol();
   Handle<Object> receiver = it->GetReceiver();
   Handle<Object> unscopables;
   MaybeHandle<Object> maybe_unscopables =
       Object::GetProperty(receiver, unscopables_symbol);
   if (!maybe_unscopables.ToHandle(&unscopables)) {
-    return Maybe<PropertyAttributes>();
+    return Nothing<PropertyAttributes>();
   }
   if (!unscopables->IsSpecObject()) return attrs;
   Handle<Object> blacklist;
   MaybeHandle<Object> maybe_blacklist =
       Object::GetProperty(unscopables, it->name());
   if (!maybe_blacklist.ToHandle(&blacklist)) {
     DCHECK(isolate->has_pending_exception());
-    return Maybe<PropertyAttributes>();
+    return Nothing<PropertyAttributes>();
   }
-  if (!blacklist->IsUndefined()) return maybe(ABSENT);
-  return attrs;
+  return blacklist->IsUndefined() ? attrs : Just(ABSENT);
 }
 
 static void GetAttributesAndBindingFlags(VariableMode mode,
                                          InitializationFlag init_flag,
                                          PropertyAttributes* attributes,
                                          BindingFlags* binding_flags) {
   switch (mode) {
     case INTERNAL:  // Fall through.
     case VAR:
       *attributes = NONE;
@@ skipping 91 matching lines @@
           GetAttributesAndBindingFlags(r.mode, r.init_flag, attributes,
                                        binding_flags);
           return ScriptContextTable::GetContext(script_contexts,
                                                 r.context_index);
         }
       }
 
       // Context extension objects needs to behave as if they have no
       // prototype.  So even if we want to follow prototype chains, we need
       // to only do a local lookup for context extension objects.
-      Maybe<PropertyAttributes> maybe;
+      Maybe<PropertyAttributes> maybe = Nothing<PropertyAttributes>();
       if ((flags & FOLLOW_PROTOTYPE_CHAIN) == 0 ||
           object->IsJSContextExtensionObject()) {
         maybe = JSReceiver::GetOwnPropertyAttributes(object, name);
       } else if (context->IsWithContext()) {
         LookupIterator it(object, name);
         maybe = UnscopableLookup(&it);
       } else {
         maybe = JSReceiver::GetPropertyAttributes(object, name);
       }
 
@@ skipping 221 matching lines @@
 bool Context::IsBootstrappingOrGlobalObject(Isolate* isolate, Object* object) {
   // During bootstrapping we allow all objects to pass as global
   // objects. This is necessary to fix circular dependencies.
   return isolate->heap()->gc_state() != Heap::NOT_IN_GC ||
       isolate->bootstrapper()->IsActive() ||
       object->IsGlobalObject();
 }
 #endif
 
 } }  // namespace v8::internal