Move Repl.clean_object and Repl.restore_object into a context manager.

Trundle · Trundle · commit 3047fe25cb2b · 2009-06-13T20:29:01.000+02:00
getpydocspec() now uses the __name__ attribute of the function for
matching the name found in the docstring.
diff --git a/bpython/cli.py b/bpython/cli.py
@@ -252,6 +252,54 @@ def writetb(self, l):
         fancy."""
         map(self.write, ["\x01%s\x03%s" % (OPTS.color_scheme['error'], i) for i in l])
 
+class AttrCleaner(object):
+    """A context manager that tries to make an object not exhibit side-effects
+       on attribute lookup."""
+    def __init__(self, obj):
+        self.obj = obj
+
+    def __enter__(self):
+        """Try to make an object not exhibit side-effects on attribute
+        lookup.""" 
+        type_ = type(self.obj)
+        __getattribute__ = None
+        __getattr__ = None
+        # Dark magic:
+        # If __getattribute__ doesn't exist on the class and __getattr__ does
+        # then __getattr__ will be called when doing
+        #   getattr(type_, '__getattribute__', None)
+        # so we need to first remove the __getattr__, then the
+        # __getattribute__, then look up the attributes and then restore the
+        # original methods. :-(
+        # The upshot being that introspecting on an object to display its
+        # attributes will avoid unwanted side-effects.
+        if type_ != types.InstanceType:
+            __getattr__ = getattr(type_, '__getattr__', None)
+            if __getattr__ is not None:
+                try:
+                    setattr(type_, '__getattr__', (lambda _: None))
+                except TypeError:
+                    __getattr__ = None
+            __getattribute__ = getattr(type_, '__getattribute__', None)
+            if __getattribute__ is not None:
+                try:
+                    setattr(type_, '__getattribute__', object.__getattribute__)
+                except TypeError:
+                    # XXX: This happens for e.g. built-in types
+                    __getattribute__ = None
+        self.attribs = (__getattribute__, __getattr__)
+        # /Dark magic
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        """Restore an object's magic methods."""
+        type_ = type(self.obj)
+        __getattribute__, __getattr__ = self.attribs
+        # Dark magic:
+        if __getattribute__ is not None:
+            setattr(type_, '__getattribute__', __getattribute__)
+        if __getattr__ is not None:
+            setattr(type_, '__getattr__', __getattr__)
+        # /Dark magic
 
 class Repl(object):
     """Implements the necessary guff for a Python-repl-alike interface
@@ -344,50 +392,6 @@ def __init__(self, scr, interp, statusbar=None, idle=None):
                              'ignore') as hfile:
                 self.rl_hist = hfile.readlines()
 
-    def clean_object(self, obj):
-        """Try to make an object not exhibit side-effects on attribute
-        lookup. Return the type's magic attributes so they can be reapplied
-        with restore_object"""
-        type_ = type(obj)
-        __getattribute__ = None
-        __getattr__ = None
-        # Dark magic:
-        # If __getattribute__ doesn't exist on the class and __getattr__ does
-        # then __getattr__ will be called when doing
-        #   getattr(type_, '__getattribute__', None)
-        # so we need to first remove the __getattr__, then the
-        # __getattribute__, then look up the attributes and then restore the
-        # original methods. :-(
-        # The upshot being that introspecting on an object to display its
-        # attributes will avoid unwanted side-effects.
-        if type_ != types.InstanceType:
-            __getattr__ = getattr(type_, '__getattr__', None)
-            if __getattr__ is not None:
-                try:
-                    setattr(type_, '__getattr__', (lambda _: None))
-                except TypeError:
-                    __getattr__ = None
-            __getattribute__ = getattr(type_, '__getattribute__', None)
-            if __getattribute__ is not None:
-                try:
-                    setattr(type_, '__getattribute__', object.__getattribute__)
-                except TypeError:
-                    # XXX: This happens for e.g. built-in types
-                    __getattribute__ = None
-        # /Dark magic
-        return __getattribute__, __getattr__
-
-    def restore_object(self, obj, attribs):
-        """Restore an object's magic methods as returned from clean_object"""
-        type_ = type(obj)
-        __getattribute__, __getattr__ = attribs
-        # Dark magic:
-        if __getattribute__ is not None:
-            setattr(type_, '__getattribute__', __getattribute__)
-        if __getattr__ is not None:
-            setattr(type_, '__getattr__', __getattr__)
-        # /Dark magic
-
     def attr_matches(self, text):
         """Taken from rlcompleter.py and bent to my will."""
 
@@ -397,11 +401,8 @@ def attr_matches(self, text):
 
         expr, attr = m.group(1, 3)
         obj = eval(expr, self.interp.locals)
-        attribs = self.clean_object(obj)
-        try:
+        with AttrCleaner(obj):
             matches = self.attr_lookup(obj, expr, attr)
-        finally:
-            self.restore_object(obj, attribs)
         return matches
 
     def attr_lookup(self, obj, expr, attr):
@@ -422,12 +423,9 @@ def attr_lookup(self, obj, expr, attr):
 
     def _callable_postfix(self, value, word):
         """rlcompleter's _callable_postfix done right."""
-        attribs = self.clean_object(value)
-        try:
+        with AttrCleaner(value):
             if hasattr(value, '__call__'):
                 word += '('
-        finally:
-            self.restore_object(value, attribs)
         return word
 
     def cw(self):
@@ -469,7 +467,7 @@ def getpydocspec(f, func):
             if s is None:
                 return None
 
-            if s.groups()[0] != func:
+            if not hasattr(f, '__name__') or s.groups()[0] != f.__name__:
                 return None
 
             args = [i.strip() for i in s.groups()[1].split(',')]
@@ -500,7 +498,8 @@ def getargspec(func):
                 return True
 
             except (NameError, TypeError, KeyError):
-                t = getpydocspec(f, func)
+                with AttrCleaner(f):
+                    t = getpydocspec(f, func)
                 if t is None:
                     return None
                 self.argspec = t
