implement complete_object(obj, prev_completions) generic function to provide custom completers for python object attributes (as opposed to string dispatching)

IPython/completer.py

@@ -75,7 +75,7 b' import IPython.rlineimpl as readline'
 import itertools
 from IPython.ipstruct import Struct
 from IPython import ipapi
-
+from IPython import generics
 import types
 
 # Python 2.4 offers sets as a builtin
@@ -200,10 +200,15 b' class Completer:'
                 return []
 
         words = dir2(obj)
-
+        
+        try:
+            words = generics.complete_object(obj, words)
+        except ipapi.TryNext:
+            pass
         # Build match list to return
         n = len(attr)
-        return ["%s.%s" % (expr, w) for w in words if w[:n] == attr ]
+        res = ["%s.%s" % (expr, w) for w in words if w[:n] == attr ]
+        return res
 
 class IPCompleter(Completer):
     """Extension of the completer class with IPython-specific features"""
@@ -243,8 +248,7 b' class IPCompleter(Completer):'
         self.readline.set_completer_delims(delims)
         self.get_line_buffer = self.readline.get_line_buffer
         self.omit__names = omit__names
-        self.merge_completions = shell.rc.readline_merge_completions
-
+        self.merge_completions = shell.rc.readline_merge_completions        
         if alias_table is None:
             alias_table = {}
         self.alias_table = alias_table
@@ -614,14 +618,18 b' class IPCompleter(Completer):'
                             self.matches = matcher(text)
                             if self.matches:
                                 break
-
+                    def uniq(alist):
+                        set = {}
+                        return [set.setdefault(e,e) for e in alist if e not in set]
+                    self.matches = uniq(self.matches)                
             try:
-                return self.matches[state].replace(magic_prefix,magic_escape)
+                ret = self.matches[state].replace(magic_prefix,magic_escape)                
+                return ret
             except IndexError:
                 return None
         except:
             #from IPython.ultraTB import AutoFormattedTB; # dbg
             #tb=AutoFormattedTB('Verbose');tb() #dbg
-
+            
             # If completion fails, don't annoy the user.
             return None

IPython/generics.py

@@ -28,3 +28,28 b' result_display = generic(result_display)'
 def inspect_object(obj):
     """ Called when you do obj? """
     raise TryNext
+inspect_object = generic(inspect_object)
+
+def complete_object(obj, prev_completions):
+    """ Custom completer dispatching for python objects
+    
+    obj is the object itself.
+    prev_completions is the list of attributes discovered so far.
+    
+    This should return the list of attributes in obj. If you only wish to
+    add to the attributes already discovered normally, return
+    own_attrs + prev_completions.
+    """
+  
+    raise TryNext
+complete_object = generic(complete_object)
+
+#import os
+#def my_demo_complete_object(obj, prev_completions):
+#    """ Demo completer that adds 'foobar' to the completions suggested
+#    for any object that has attribute (path), e.g. 'os'"""
+#    if hasattr(obj,'path'):
+#        return prev_completions + ['foobar']
+#    raise TryNext
+#
+#my_demo_complete_object = complete_object.when_type(type(os))(my_demo_complete_object)

doc/ChangeLog

@@ -1,3 +1,9 b''
[phone]  Ville Vainio  <[e-mail]>
+
+	* completer.py, generics.py(complete_object): Allow 
+	custom complers based on python objects via simplegeneric.
+	See generics.py / my_demo_complete_object
+
 2007-12-13  Ville Vainio  <[e-mail]>
 
 	* iplib.py(raw_input): unix readline does not allow unicode in