From 059b1e135397115a98f62432268d9fd29709508a Mon Sep 17 00:00:00 2001
From: Dave Halter <davidhalter88@gmail.com>
Date: Wed, 15 Jan 2014 15:57:43 +0100
Subject: [PATCH] underscore_memoization is now even easier in fast parser

---
 jedi/cache.py       | 13 -------------
 jedi/parser/fast.py | 16 ++++++++++------
 2 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/jedi/cache.py b/jedi/cache.py
index 8ab3656b..6afb5f2f 100644
--- a/jedi/cache.py
+++ b/jedi/cache.py
@@ -131,19 +131,6 @@ def underscore_memoization(func):
     return wrapper
 
 
-def underscore_none_memoization(func):
-    """Like ``underscore_memoization`` just with None instead of exceptions."""
-    def wrapper(self):
-        name = '_' + func.__name__
-        value = getattr(self, name)
-        if value is None:
-            value = func(self)
-            setattr(self, name, value)
-        return value
-
-    return wrapper
-
-
 def cache_star_import(func):
     def wrapper(evaluator, scope, *args, **kwargs):
         with common.ignored(KeyError):
diff --git a/jedi/parser/fast.py b/jedi/parser/fast.py
index bd05b55d..cdd73df8 100644
--- a/jedi/parser/fast.py
+++ b/jedi/parser/fast.py
@@ -7,6 +7,7 @@ import re
 
 from jedi._compatibility import use_metaclass
 from jedi import settings
+from jedi import common
 from jedi.parser import Parser
 from jedi.parser import representation as pr
 from jedi.parser import tokenize
@@ -28,7 +29,8 @@ class Module(pr.Simple, pr.Module):
     def reset_caches(self):
         """ This module does a whole lot of caching, because it uses different
         parsers. """
-        self._used_names = None
+        with common.ignored(AttributeError):
+            del self._used_names
         for p in self.parsers:
             p.user_scope = None
             p.user_stmt = None
@@ -40,7 +42,7 @@ class Module(pr.Simple, pr.Module):
             return getattr(self.parsers[0].module, name)
 
     @property
-    @cache.underscore_none_memoization
+    @cache.underscore_memoization
     def used_names(self):
         used_names = {}
         for p in self.parsers:
@@ -198,7 +200,7 @@ class FastParser(use_metaclass(CachedFastParser)):
             raise
 
     @property
-    @cache.underscore_none_memoization
+    @cache.underscore_memoization
     def user_scope(self):
         user_scope = None
         for p in self.parsers:
@@ -212,7 +214,7 @@ class FastParser(use_metaclass(CachedFastParser)):
         return user_scope
 
     @property
-    @cache.underscore_none_memoization
+    @cache.underscore_memoization
     def user_stmt(self):
         user_stmt = None
         for p in self.parsers:
@@ -431,8 +433,10 @@ class FastParser(use_metaclass(CachedFastParser)):
         return p, node
 
     def reset_caches(self):
-        self._user_scope = None
-        self._user_stmt = None
+        with common.ignored(AttributeError):
+            del self._user_scope
+        with common.ignored(AttributeError):
+            del self._user_stmt
         self.module.reset_caches()
         if self.current_node is not None:
             self.current_node.reset_contents()