More work on refactoring things into components.

* Prefilters have been componentized (prefilter.py).
* We are not including auto_attr from NiPy in IPython.utils.
* All components are now using auto_attr when resolving refs to other
  components.
* The AliasManager component has been updated to reflect the prefilter
  refactor.
* prefilter.splitUserInput has been moved to
  IPython.core.splitinput.split_user_input as we are using this in other
  places in the IPython code base.

IPython/core/splitinput.py

@@ -0,0 +1,77 b''
+#!/usr/bin/env python
+# encoding: utf-8
+"""
+Simple utility for splitting user input.
+
+Authors:
+
+* Brian Granger
+* Fernando Perez
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2008-2009  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+import re
+
+#-----------------------------------------------------------------------------
+# Main function
+#-----------------------------------------------------------------------------
+
+
+# RegExp for splitting line contents into pre-char//first word-method//rest.
+# For clarity, each group in on one line.
+
+# WARNING: update the regexp if the escapes in iplib are changed, as they
+# are hardwired in.
+
+# Although it's not solely driven by the regex, note that:
+# ,;/% only trigger if they are the first character on the line
+# ! and !! trigger if they are first char(s) *or* follow an indent 
+# ? triggers as first or last char.
+
+# The three parts of the regex are:
+#  1) pre:     pre_char *or* initial whitespace 
+#  2) ifun:    first word/method (mix of \w and '.')
+#  3) the_rest: rest of line (separated from ifun by space if non-empty)
+line_split = re.compile(r'^([,;/%?]|!!?|\s*)'
+                        r'\s*([\w\.]+)'
+                        r'(\s+.*$|$)')
+
+
+def split_user_input(line, pattern=None):
+    """Split user input into pre-char/whitespace, function part and rest."""
+
+    if pattern is None:
+        pattern = line_split
+    match = pattern.match(line)
+    if not match:
+        #print "match failed for line '%s'" % line
+        try:
+            ifun, the_rest = line.split(None,1)
+        except ValueError:
+            #print "split failed for line '%s'" % line
+            ifun, the_rest = line,''
+        pre = re.match('^(\s*)(.*)',line).groups()[0]
+    else:
+        pre,ifun,the_rest = match.groups()
+
+    # ifun has to be a valid python identifier, so it better be only pure
+    # ascii, no unicode:
+    try:
+        ifun = ifun.encode('ascii')
+    except UnicodeEncodeError:
+        the_rest = ifun + u' ' + the_rest
+        ifun = u''
+
+    #print 'line:<%s>' % line # dbg
+    #print 'pre <%s> ifun <%s> rest <%s>' % (pre,ifun.strip(),the_rest) # dbg
+    return pre, ifun.strip(), the_rest.lstrip()

IPython/utils/autoattr.py

@@ -0,0 +1,162 b''
+#!/usr/bin/env python
+# encoding: utf-8
+"""Descriptor support for NIPY.
+
+Utilities to support special Python descriptors [1,2], in particular the use of
+a useful pattern for properties we call 'one time properties'.  These are
+object attributes which are declared as properties, but become regular
+attributes once they've been read the first time.  They can thus be evaluated
+later in the object's life cycle, but once evaluated they become normal, static
+attributes with no function call overhead on access or any other constraints.
+
+A special ResetMixin class is provided to add a .reset() method to users who
+may want to have their objects capable of resetting these computed properties
+to their 'untriggered' state.
+
+References
+----------
+[1] How-To Guide for Descriptors, Raymond
+Hettinger. http://users.rcn.com/python/download/Descriptor.htm
+
+[2] Python data model, http://docs.python.org/reference/datamodel.html
+
+Notes
+-----
+This module is taken from the NiPy project 
+(http://neuroimaging.scipy.org/site/index.html), and is BSD licensed.
+"""
+
+#-----------------------------------------------------------------------------
+# Classes and Functions
+#-----------------------------------------------------------------------------
+
+class ResetMixin(object):
+   """A Mixin class to add a .reset() method to users of OneTimeProperty.
+
+   By default, auto attributes once computed, become static.  If they happen to
+   depend on other parts of an object and those parts change, their values may
+   now be invalid.
+
+   This class offers a .reset() method that users can call *explicitly* when
+   they know the state of their objects may have changed and they want to
+   ensure that *all* their special attributes should be invalidated.  Once
+   reset() is called, all their auto attributes are reset to their
+   OneTimeProperty descriptors, and their accessor functions will be triggered
+   again.
+
+   Example
+   -------
+
+   >>> class A(ResetMixin):
+   ...     def __init__(self,x=1.0):
+   ...         self.x = x
+   ...
+   ...     @auto_attr
+   ...     def y(self):
+   ...         print '*** y computation executed ***'
+   ...         return self.x / 2.0
+   ... 
+
+   >>> a = A(10)
+
+   About to access y twice, the second time no computation is done:
+   >>> a.y
+   *** y computation executed ***
+   5.0
+   >>> a.y
+   5.0
+
+   Changing x
+   >>> a.x = 20
+   
+   a.y doesn't change to 10, since it is a static attribute:
+   >>> a.y
+   5.0
+
+   We now reset a, and this will then force all auto attributes to recompute
+   the next time we access them:
+   >>> a.reset()
+
+   About to access y twice again after reset():
+   >>> a.y
+   *** y computation executed ***
+   10.0
+   >>> a.y
+   10.0
+   """
+
+   def reset(self):
+      """Reset all OneTimeProperty attributes that may have fired already."""
+      instdict = self.__dict__
+      classdict = self.__class__.__dict__
+      # To reset them, we simply remove them from the instance dict.  At that
+      # point, it's as if they had never been computed.  On the next access,
+      # the accessor function from the parent class will be called, simply
+      # because that's how the python descriptor protocol works.
+      for mname, mval in classdict.items():
+         if mname in instdict and isinstance(mval, OneTimeProperty):
+            delattr(self, mname)
+
+
+class OneTimeProperty(object):
+   """A descriptor to make special properties that become normal attributes.
+
+   This is meant to be used mostly by the auto_attr decorator in this module.
+   """
+   def __init__(self,func):
+       """Create a OneTimeProperty instance.
+
+        Parameters
+        ----------
+          func : method
+          
+            The method that will be called the first time to compute a value.
+            Afterwards, the method's name will be a standard attribute holding
+            the value of this computation.
+            """
+       self.getter = func
+       self.name = func.func_name
+
+   def __get__(self,obj,type=None):
+       """This will be called on attribute access on the class or instance. """
+
+       if obj is None:
+           # Being called on the class, return the original function. This way,
+           # introspection works on the class.
+           #return func
+           return self.getter
+
+       val = self.getter(obj)
+       #print "** auto_attr - loading '%s'" % self.name  # dbg
+       setattr(obj, self.name, val)
+       return val
+
+
+def auto_attr(func):
+    """Decorator to create OneTimeProperty attributes.
+
+    Parameters
+    ----------
+      func : method
+        The method that will be called the first time to compute a value.
+        Afterwards, the method's name will be a standard attribute holding the
+        value of this computation.
+
+    Examples
+    --------
+    >>> class MagicProp(object):
+    ...     @auto_attr
+    ...     def a(self):
+    ...         return 99
+    ...     
+    >>> x = MagicProp()
+    >>> 'a' in x.__dict__
+    False
+    >>> x.a
+    99
+    >>> 'a' in x.__dict__
+    True
+    """
+    return OneTimeProperty(func)
+
+

IPython/core/alias.py

@@ -1,191 +1,257 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 IPython's alias component
 
 Authors:
 
 * Brian Granger
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import __builtin__
 import keyword
 import os
+import re
 import sys
 
 from IPython.core.component import Component
+from IPython.core.splitinput import split_user_input
 
 from IPython.utils.traitlets import CBool, List, Instance
 from IPython.utils.genutils import error
+from IPython.utils.autoattr import auto_attr
 
 #-----------------------------------------------------------------------------
-# Functions and classes
+# Utilities
 #-----------------------------------------------------------------------------
 
+# This is used as the pattern for calls to split_user_input.
+shell_line_split = re.compile(r'^(\s*)(\S*\s*)(.*$)')
+
 def default_aliases():
     # Make some aliases automatically
     # Prepare list of shell aliases to auto-define
     if os.name == 'posix':
         auto_alias = ('mkdir mkdir', 'rmdir rmdir',
                       'mv mv -i','rm rm -i','cp cp -i',
                       'cat cat','less less','clear clear',
                       # a better ls
                       'ls ls -F',
                       # long ls
                       'll ls -lF')
         # Extra ls aliases with color, which need special treatment on BSD
         # variants
         ls_extra = ( # color ls
                      'lc ls -F -o --color',
                      # ls normal files only
                      'lf ls -F -o --color %l | grep ^-',
                      # ls symbolic links
                      'lk ls -F -o --color %l | grep ^l',
                      # directories or links to directories,
                      'ldir ls -F -o --color %l | grep /$',
                      # things which are executable
                      'lx ls -F -o --color %l | grep ^-..x',
                      )
         # The BSDs don't ship GNU ls, so they don't understand the
         # --color switch out of the box
         if 'bsd' in sys.platform:
             ls_extra = ( # ls normal files only
                          'lf ls -lF | grep ^-',
                          # ls symbolic links
                          'lk ls -lF | grep ^l',
                          # directories or links to directories,
                          'ldir ls -lF | grep /$',
                          # things which are executable
                          'lx ls -lF | grep ^-..x',
                          )
         auto_alias = auto_alias + ls_extra
     elif os.name in ['nt','dos']:
         auto_alias = ('ls dir /on',
                       'ddir dir /ad /on', 'ldir dir /ad /on',
                       'mkdir mkdir','rmdir rmdir','echo echo',
                       'ren ren','cls cls','copy copy')
     else:
         auto_alias = ()
     return [s.split(None,1) for s in auto_alias]
 
 
 class AliasError(Exception):
     pass
 
 
 class InvalidAliasError(AliasError):
     pass
 
 
+#-----------------------------------------------------------------------------
+# Main AliasManager class
+#-----------------------------------------------------------------------------
+
+
 class AliasManager(Component):
 
     auto_alias = List(default_aliases())
     user_alias = List(default_value=[], config_key='USER_ALIAS')
 
     def __init__(self, parent, config=None):
         super(AliasManager, self).__init__(parent, config=config)
-        self.shell = Component.get_instances(
-            root=self.root,
-            klass='IPython.core.iplib.InteractiveShell'
-        )[0]
         self.alias_table = {}
         self.exclude_aliases()
         self.init_aliases()
 
+    @auto_attr
+    def shell(self):
+        shell = Component.get_instances(
+            root=self.root,
+            klass='IPython.core.iplib.InteractiveShell'
+        )[0]
+        return shell
+
     def __contains__(self, name):
         if name in self.alias_table:
             return True
         else:
             return False
 
     @property
     def aliases(self):
         return [(item[0], item[1][1]) for item in self.alias_table.iteritems()]
 
     def exclude_aliases(self):
         # set of things NOT to alias (keywords, builtins and some magics)
         no_alias = set(['cd','popd','pushd','dhist','alias','unalias'])
         no_alias.update(set(keyword.kwlist))
         no_alias.update(set(__builtin__.__dict__.keys()))
         self.no_alias = no_alias
 
     def init_aliases(self):
         # Load default aliases
         for name, cmd in self.auto_alias:
             self.soft_define_alias(name, cmd)
 
         # Load user aliases
         for name, cmd in self.user_alias:
             self.soft_define_alias(name, cmd)
 
     def soft_define_alias(self, name, cmd):
         """Define an alias, but don't raise on an AliasError."""
         try:
             self.define_alias(name, cmd)
         except AliasError, e:
             error("Invalid alias: %s" % e)
 
     def define_alias(self, name, cmd):
         """Define a new alias after validating it.
 
         This will raise an :exc:`AliasError` if there are validation
         problems.
         """
         nargs = self.validate_alias(name, cmd)
         self.alias_table[name] = (nargs, cmd)
 
     def validate_alias(self, name, cmd):
         """Validate an alias and return the its number of arguments."""
         if name in self.no_alias:
             raise InvalidAliasError("The name %s can't be aliased "
                                     "because it is a keyword or builtin." % name)
         if not (isinstance(cmd, basestring)):
             raise InvalidAliasError("An alias command must be a string, "
                                     "got: %r" % name)
         nargs = cmd.count('%s')
         if nargs>0 and cmd.find('%l')>=0:
             raise InvalidAliasError('The %s and %l specifiers are mutually '
                                     'exclusive in alias definitions.')
         return nargs
 
     def call_alias(self, alias, rest=''):
         """Call an alias given its name and the rest of the line."""
         cmd = self.transform_alias(alias, rest)
         try:
             self.shell.system(cmd)
         except:
             self.shell.showtraceback()
 
     def transform_alias(self, alias,rest=''):
         """Transform alias to system command string."""
         nargs, cmd = self.alias_table[alias]
 
         if ' ' in cmd and os.path.isfile(cmd):
             cmd = '"%s"' % cmd
 
         # Expand the %l special to be the user's input line
         if cmd.find('%l') >= 0:
             cmd = cmd.replace('%l', rest)
             rest = ''
         if nargs==0:
             # Simple, argument-less aliases
             cmd = '%s %s' % (cmd, rest)
         else:
             # Handle aliases with positional arguments
             args = rest.split(None, nargs)
             if len(args) < nargs:
                 raise AliasError('Alias <%s> requires %s arguments, %s given.' %
                       (alias, nargs, len(args)))
             cmd = '%s %s' % (cmd % tuple(args[:nargs]),' '.join(args[nargs:]))
         return cmd
+
+    def expand_alias(self, line):
+        """ Expand an alias in the command line 
+        
+        Returns the provided command line, possibly with the first word 
+        (command) translated according to alias expansion rules.
+        
+        [ipython]|16> _ip.expand_aliases("np myfile.txt")
+                 <16> 'q:/opt/np/notepad++.exe myfile.txt'
+        """
+        
+        pre,fn,rest = split_user_input(line)
+        res = pre + self.expand_aliases(fn, rest)
+        return res
+
+    def expand_aliases(self, fn, rest):
+        """Expand multiple levels of aliases:
+        
+        if:
+        
+        alias foo bar /tmp
+        alias baz foo
+        
+        then:
+        
+        baz huhhahhei -> bar /tmp huhhahhei
+        
+        """
+        line = fn + " " + rest
+        
+        done = set()
+        while 1:
+            pre,fn,rest = split_user_input(line, shell_line_split)
+            if fn in self.alias_table:
+                if fn in done:
+                    warn("Cyclic alias definition, repeated '%s'" % fn)
+                    return ""
+                done.add(fn)
+
+                l2 = self.transform_alias(fn, rest)
+                if l2 == line:
+                    break
+                # ls -> ls -F should not recurse forever
+                if l2.split(None,1)[0] == line.split(None,1)[0]:
+                    line = l2
+                    break
+                line=l2
+            else:
+                break
+                
+        return line

IPython/core/builtin_trap.py

@@ -1,108 +1,111 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 A context manager for managing things injected into :mod:`__builtin__`.
 
 Authors:
 
 * Brian Granger
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import __builtin__
 
 from IPython.core.component import Component
 from IPython.core.quitter import Quitter
 
-from IPython.utils.traitlets import Instance
+from IPython.utils.autoattr import auto_attr
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 
 class BuiltinUndefined(object): pass
 BuiltinUndefined = BuiltinUndefined()
 
 
 class BuiltinTrap(Component):
 
     def __init__(self, parent):
         super(BuiltinTrap, self).__init__(parent, None, None)
-        # Don't just grab parent!!!
-        self.shell = Component.get_instances(
+        self._orig_builtins = {}
+
+    @auto_attr
+    def shell(self):
+        shell = Component.get_instances(
             root=self.root,
             klass='IPython.core.iplib.InteractiveShell'
         )[0]
-        self._orig_builtins = {}
+        return shell
 
     def __enter__(self):
         self.set()
         # I return self, so callers can use add_builtin in a with clause.
         return self
 
     def __exit__(self, type, value, traceback):
         self.unset()
         return True
 
     def add_builtin(self, key, value):
         """Add a builtin and save the original."""
         orig = __builtin__.__dict__.get(key, BuiltinUndefined)
         self._orig_builtins[key] = orig
         __builtin__.__dict__[key] = value
 
     def remove_builtin(self, key):
         """Remove an added builtin and re-set the original."""
         try:
             orig = self._orig_builtins.pop(key)
         except KeyError:
             pass
         else:
             if orig is BuiltinUndefined:
                 del __builtin__.__dict__[key]
             else:
                 __builtin__.__dict__[key] = orig
 
     def set(self):
         """Store ipython references in the __builtin__ namespace."""
         self.add_builtin('exit', Quitter(self.shell, 'exit'))
         self.add_builtin('quit', Quitter(self.shell, 'quit'))
 
         # Recursive reload function
         try:
             from IPython.lib import deepreload
             if self.shell.deep_reload:
                 self.add_builtin('reload', deepreload.reload)
             else:
                 self.add_builtin('dreload', deepreload.reload)
             del deepreload
         except ImportError:
             pass
 
         # Keep in the builtins a flag for when IPython is active.  We set it
         # with setdefault so that multiple nested IPythons don't clobber one
         # another.  Each will increase its value by one upon being activated,
         # which also gives us a way to determine the nesting level.
         __builtin__.__dict__.setdefault('__IPYTHON__active',0)
 
     def unset(self):
         """Remove any builtins which might have been added by add_builtins, or
         restore overwritten ones to their previous values."""
         for key in self._orig_builtins.keys():
             self.remove_builtin(key)
         self._orig_builtins.clear()
         self._builtins_added = False
         try:
             del __builtin__.__dict__['__IPYTHON__active']
         except KeyError:
             pass
  No newline at end of file

IPython/core/completer.py

@@ -1,640 +1,642 b''
 """Word completion for IPython.
 
 This module is a fork of the rlcompleter module in the Python standard
 library.  The original enhancements made to rlcompleter have been sent
 upstream and were accepted as of Python 2.3, but we need a lot more
 functionality specific to IPython, so this module will continue to live as an
 IPython-specific utility.
 
 Original rlcompleter documentation:
 
 This requires the latest extension to the readline module (the
 completes keywords, built-ins and globals in __main__; when completing
 NAME.NAME..., it evaluates (!) the expression up to the last dot and
 completes its attributes.
 
 It's very cool to do "import string" type "string.", hit the
 completion key (twice), and see the list of names defined by the
 string module!
 
 Tip: to use the tab key as the completion key, call
 
     readline.parse_and_bind("tab: complete")
 
 Notes:
 
 - Exceptions raised by the completer function are *ignored* (and
 generally cause the completion to fail).  This is a feature -- since
 readline sets the tty device in raw (or cbreak) mode, printing a
 traceback wouldn't work well without some complicated hoopla to save,
 reset and restore the tty state.
 
 - The evaluation of the NAME.NAME... form may cause arbitrary
 application defined code to be executed if an object with a
 __getattr__ hook is found.  Since it is the responsibility of the
 application (or the user) to enable this feature, I consider this an
 acceptable risk.  More complicated expressions (e.g. function calls or
 indexing operations) are *not* evaluated.
 
 - GNU readline is also used by the built-in functions input() and
 raw_input(), and thus these also benefit/suffer from the completer
 features.  Clearly an interactive application can benefit by
 specifying its own completer function and using raw_input() for all
 its input.
 
 - When the original stdin is not a tty device, GNU readline is never
 used, and this module (and the readline module) are silently inactive.
 
 """
 
 #*****************************************************************************
 #
 # Since this file is essentially a minimally modified copy of the rlcompleter
 # module which is part of the standard Python distribution, I assume that the
 # proper procedure is to maintain its copyright as belonging to the Python
 # Software Foundation (in addition to my own, for all new code).
 #
 #       Copyright (C) 2001 Python Software Foundation, www.python.org
 #       Copyright (C) 2001-2006 Fernando Perez. <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #
 #*****************************************************************************
 
 import __builtin__
 import __main__
 import glob
 import keyword
 import os
 import re
 import shlex
 import sys
 import itertools
 import types
 
 from IPython.core.error import TryNext
-import IPython.utils.rlineimpl as readline    
+from IPython.core.prefilter import ESC_MAGIC
+
+import IPython.utils.rlineimpl as readline
 from IPython.utils.ipstruct import Struct
 from IPython.utils import generics
 
 # Python 2.4 offers sets as a builtin
 try:
     set()
 except NameError:
     from sets import Set as set
 
 from IPython.utils.genutils import debugx, dir2
 
 __all__ = ['Completer','IPCompleter']
 
 class Completer:
     def __init__(self,namespace=None,global_namespace=None):
         """Create a new completer for the command line.
 
         Completer([namespace,global_namespace]) -> completer instance.
 
         If unspecified, the default namespace where completions are performed
         is __main__ (technically, __main__.__dict__). Namespaces should be
         given as dictionaries.
 
         An optional second namespace can be given.  This allows the completer
         to handle cases where both the local and global scopes need to be
         distinguished.
 
         Completer instances should be used as the completion mechanism of
         readline via the set_completer() call:
 
         readline.set_completer(Completer(my_namespace).complete)
         """
 
         # Don't bind to namespace quite yet, but flag whether the user wants a
         # specific namespace or to use __main__.__dict__. This will allow us
         # to bind to __main__.__dict__ at completion time, not now.
         if namespace is None:
             self.use_main_ns = 1
         else:
             self.use_main_ns = 0
             self.namespace = namespace
 
         # The global namespace, if given, can be bound directly
         if global_namespace is None:
             self.global_namespace = {}
         else:
             self.global_namespace = global_namespace
 
     def complete(self, text, state):
         """Return the next possible completion for 'text'.
 
         This is called successively with state == 0, 1, 2, ... until it
         returns None.  The completion should begin with 'text'.
 
         """
         if self.use_main_ns:
             self.namespace = __main__.__dict__
             
         if state == 0:
             if "." in text:
                 self.matches = self.attr_matches(text)
             else:
                 self.matches = self.global_matches(text)
         try:
             return self.matches[state]
         except IndexError:
             return None
 
     def global_matches(self, text):
         """Compute matches when text is a simple name.
 
         Return a list of all keywords, built-in functions and names currently
         defined in self.namespace or self.global_namespace that match.
 
         """
         matches = []
         match_append = matches.append
         n = len(text)
         for lst in [keyword.kwlist,
                     __builtin__.__dict__.keys(),
                     self.namespace.keys(),
                     self.global_namespace.keys()]:
             for word in lst:
                 if word[:n] == text and word != "__builtins__":
                     match_append(word)
         return matches
 
     def attr_matches(self, text):
         """Compute matches when text contains a dot.
 
         Assuming the text is of the form NAME.NAME....[NAME], and is
         evaluatable in self.namespace or self.global_namespace, it will be
         evaluated and its attributes (as revealed by dir()) are used as
         possible completions.  (For class instances, class members are are
         also considered.)
 
         WARNING: this can still invoke arbitrary C code, if an object
         with a __getattr__ hook is evaluated.
 
         """
         import re
 
         # Another option, seems to work great. Catches things like ''.<tab>
         m = re.match(r"(\S+(\.\w+)*)\.(\w*)$", text)
 
         if not m:
             return []
         
         expr, attr = m.group(1, 3)
         try:
             obj = eval(expr, self.namespace)
         except:
             try:
                 obj = eval(expr, self.global_namespace)
             except:
                 return []
 
         words = dir2(obj)
         
         try:
             words = generics.complete_object(obj, words)
         except TryNext:
             pass
         # Build match list to return
         n = len(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"""
 
     def __init__(self,shell,namespace=None,global_namespace=None,
                  omit__names=0,alias_table=None):
         """IPCompleter() -> completer
 
         Return a completer object suitable for use by the readline library
         via readline.set_completer().
 
         Inputs:
 
         - shell: a pointer to the ipython shell itself.  This is needed
         because this completer knows about magic functions, and those can
         only be accessed via the ipython instance.
 
         - namespace: an optional dict where completions are performed.
 
         - global_namespace: secondary optional dict for completions, to
         handle cases (such as IPython embedded inside functions) where
         both Python scopes are visible.
 
         - The optional omit__names parameter sets the completer to omit the
         'magic' names (__magicname__) for python objects unless the text
         to be completed explicitly starts with one or more underscores.
 
         - If alias_table is supplied, it should be a dictionary of aliases
         to complete. """
 
         Completer.__init__(self,namespace,global_namespace)
         self.magic_prefix = shell.name+'.magic_'
-        self.magic_escape = shell.ESC_MAGIC
+        self.magic_escape = ESC_MAGIC
         self.readline = readline
         delims = self.readline.get_completer_delims()
         delims = delims.replace(self.magic_escape,'')
         self.readline.set_completer_delims(delims)
         self.get_line_buffer = self.readline.get_line_buffer
         self.get_endidx = self.readline.get_endidx
         self.omit__names = omit__names
         self.merge_completions = shell.readline_merge_completions        
         if alias_table is None:
             alias_table = {}
         self.alias_table = alias_table
         # Regexp to split filenames with spaces in them
         self.space_name_re = re.compile(r'([^\\] )')
         # Hold a local ref. to glob.glob for speed
         self.glob = glob.glob
 
         # Determine if we are running on 'dumb' terminals, like (X)Emacs
         # buffers, to avoid completion problems.
         term = os.environ.get('TERM','xterm')
         self.dumb_terminal = term in ['dumb','emacs']
         
         # Special handling of backslashes needed in win32 platforms
         if sys.platform == "win32":
             self.clean_glob = self._clean_glob_win32
         else:
             self.clean_glob = self._clean_glob
         self.matchers = [self.python_matches,
                          self.file_matches,
                          self.alias_matches,
                          self.python_func_kw_matches]
 
     
     # Code contributed by Alex Schmolck, for ipython/emacs integration
     def all_completions(self, text):
         """Return all possible completions for the benefit of emacs."""
 
         completions = []
         comp_append = completions.append
         try:
             for i in xrange(sys.maxint):
                 res = self.complete(text, i)
 
                 if not res: break
 
                 comp_append(res)
         #XXX workaround for ``notDefined.<tab>``
         except NameError:
             pass
         return completions
     # /end Alex Schmolck code.
 
     def _clean_glob(self,text):
         return self.glob("%s*" % text)
 
     def _clean_glob_win32(self,text):
         return [f.replace("\\","/")
                 for f in self.glob("%s*" % text)]            
 
     def file_matches(self, text):
         """Match filenames, expanding ~USER type strings.
 
         Most of the seemingly convoluted logic in this completer is an
         attempt to handle filenames with spaces in them.  And yet it's not
         quite perfect, because Python's readline doesn't expose all of the
         GNU readline details needed for this to be done correctly.
 
         For a filename with a space in it, the printed completions will be
         only the parts after what's already been typed (instead of the
         full completions, as is normally done).  I don't think with the
         current (as of Python 2.3) Python readline it's possible to do
         better."""
 
         #print 'Completer->file_matches: <%s>' % text # dbg
 
         # chars that require escaping with backslash - i.e. chars
         # that readline treats incorrectly as delimiters, but we
         # don't want to treat as delimiters in filename matching
         # when escaped with backslash
 
         if sys.platform == 'win32':
             protectables = ' '
         else:
             protectables = ' ()'
 
         if text.startswith('!'):
             text = text[1:]
             text_prefix = '!'
         else:
             text_prefix = ''
             
         def protect_filename(s):
             return "".join([(ch in protectables and '\\' + ch or ch)
                             for ch in s])
 
         def single_dir_expand(matches):
             "Recursively expand match lists containing a single dir."
             
             if len(matches) == 1 and os.path.isdir(matches[0]):
                 # Takes care of links to directories also.  Use '/'
                 # explicitly, even under Windows, so that name completions
                 # don't end up escaped.
                 d = matches[0]
                 if d[-1] in ['/','\\']:
                     d = d[:-1]
 
                 subdirs = os.listdir(d)
                 if subdirs:
                     matches = [ (d + '/' + p) for p in subdirs]
                     return single_dir_expand(matches)
                 else:
                     return matches
             else:
                 return matches
         
         lbuf = self.lbuf
         open_quotes = 0  # track strings with open quotes
         try:
             lsplit = shlex.split(lbuf)[-1]
         except ValueError:
             # typically an unmatched ", or backslash without escaped char.
             if lbuf.count('"')==1:
                 open_quotes = 1
                 lsplit = lbuf.split('"')[-1]
             elif lbuf.count("'")==1:
                 open_quotes = 1
                 lsplit = lbuf.split("'")[-1]
             else:
                 return []
         except IndexError:
             # tab pressed on empty line
             lsplit = ""
 
         if lsplit != protect_filename(lsplit):
             # if protectables are found, do matching on the whole escaped
             # name
             has_protectables = 1
             text0,text = text,lsplit
         else:
             has_protectables = 0
             text = os.path.expanduser(text)
 
         if text == "":
             return [text_prefix + protect_filename(f) for f in self.glob("*")]
 
         m0 = self.clean_glob(text.replace('\\',''))
         if has_protectables:
             # If we had protectables, we need to revert our changes to the
             # beginning of filename so that we don't double-write the part
             # of the filename we have so far
             len_lsplit = len(lsplit)
             matches = [text_prefix + text0 + 
                        protect_filename(f[len_lsplit:]) for f in m0]
         else:
             if open_quotes:
                 # if we have a string with an open quote, we don't need to
                 # protect the names at all (and we _shouldn't_, as it
                 # would cause bugs when the filesystem call is made).
                 matches = m0
             else:
                 matches = [text_prefix + 
                            protect_filename(f) for f in m0]
 
         #print 'mm',matches  # dbg
         return single_dir_expand(matches)
 
     def alias_matches(self, text):
         """Match internal system aliases"""        
         #print 'Completer->alias_matches:',text,'lb',self.lbuf # dbg
         
         # if we are not in the first 'item', alias matching 
         # doesn't make sense - unless we are starting with 'sudo' command.
         if ' ' in self.lbuf.lstrip() and not self.lbuf.lstrip().startswith('sudo'):
             return []
         text = os.path.expanduser(text)
         aliases =  self.alias_table.keys()
         if text == "":
             return aliases
         else:
             return [alias for alias in aliases if alias.startswith(text)]
 
     def python_matches(self,text):
         """Match attributes or global python names"""
 
         #print 'Completer->python_matches, txt=<%s>' % text # dbg
         if "." in text:
             try:
                 matches = self.attr_matches(text)
                 if text.endswith('.') and self.omit__names:
                     if self.omit__names == 1:
                         # true if txt is _not_ a __ name, false otherwise:
                         no__name = (lambda txt:
                                     re.match(r'.*\.__.*?__',txt) is None)
                     else:
                         # true if txt is _not_ a _ name, false otherwise:
                         no__name = (lambda txt:
                                     re.match(r'.*\._.*?',txt) is None)
                     matches = filter(no__name, matches)
             except NameError:
                 # catches <undefined attributes>.<tab>
                 matches = []
         else:
             matches = self.global_matches(text)
             # this is so completion finds magics when automagic is on:
             if (matches == [] and 
                  not text.startswith(os.sep) and
                  not ' ' in self.lbuf):
                 matches = self.attr_matches(self.magic_prefix+text)
         return matches
 
     def _default_arguments(self, obj):
         """Return the list of default arguments of obj if it is callable,
         or empty list otherwise."""
 
         if not (inspect.isfunction(obj) or inspect.ismethod(obj)):
             # for classes, check for __init__,__new__
             if inspect.isclass(obj):
                 obj = (getattr(obj,'__init__',None) or
                        getattr(obj,'__new__',None))
             # for all others, check if they are __call__able
             elif hasattr(obj, '__call__'):
                 obj = obj.__call__
             # XXX: is there a way to handle the builtins ?
         try:
             args,_,_1,defaults = inspect.getargspec(obj)
             if defaults:
                 return args[-len(defaults):]
         except TypeError: pass
         return []
 
     def python_func_kw_matches(self,text):
         """Match named parameters (kwargs) of the last open function"""
 
         if "." in text: # a parameter cannot be dotted
             return []
         try: regexp = self.__funcParamsRegex
         except AttributeError:
             regexp = self.__funcParamsRegex = re.compile(r'''
                 '.*?' |    # single quoted strings or
                 ".*?" |    # double quoted strings or
                 \w+   |    # identifier
                 \S         # other characters
                 ''', re.VERBOSE | re.DOTALL)
         # 1. find the nearest identifier that comes before an unclosed
         # parenthesis e.g. for "foo (1+bar(x), pa", the candidate is "foo"
         tokens = regexp.findall(self.get_line_buffer())
         tokens.reverse()
         iterTokens = iter(tokens); openPar = 0
         for token in iterTokens:
             if token == ')':
                 openPar -= 1
             elif token == '(':
                 openPar += 1
                 if openPar > 0:
                     # found the last unclosed parenthesis
                     break
         else:
             return []
         # 2. Concatenate dotted names ("foo.bar" for "foo.bar(x, pa" )
         ids = []
         isId = re.compile(r'\w+$').match
         while True:
             try:
                 ids.append(iterTokens.next())
                 if not isId(ids[-1]):
                     ids.pop(); break
                 if not iterTokens.next() == '.':
                     break
             except StopIteration:
                 break
         # lookup the candidate callable matches either using global_matches
         # or attr_matches for dotted names
         if len(ids) == 1:
             callableMatches = self.global_matches(ids[0])
         else:
             callableMatches = self.attr_matches('.'.join(ids[::-1]))
         argMatches = []
         for callableMatch in callableMatches:
             try: namedArgs = self._default_arguments(eval(callableMatch,
                                                          self.namespace))
             except: continue
             for namedArg in namedArgs:
                 if namedArg.startswith(text):
                     argMatches.append("%s=" %namedArg)
         return argMatches
 
     def dispatch_custom_completer(self,text):
         #print "Custom! '%s' %s" % (text, self.custom_completers) # dbg
         line = self.full_lbuf        
         if not line.strip():
             return None
 
         event = Struct()
         event.line = line
         event.symbol = text
         cmd = line.split(None,1)[0]
         event.command = cmd
         #print "\ncustom:{%s]\n" % event # dbg
         
         # for foo etc, try also to find completer for %foo
         if not cmd.startswith(self.magic_escape):
             try_magic = self.custom_completers.s_matches(
               self.magic_escape + cmd)            
         else:
             try_magic = []
         
         
         for c in itertools.chain(
                                  self.custom_completers.s_matches(cmd),
                                  try_magic,
                                  self.custom_completers.flat_matches(self.lbuf)):
             #print "try",c # dbg
             try:
                 res = c(event)
                 # first, try case sensitive match
                 withcase = [r for r in res if r.startswith(text)]
                 if withcase:
                     return withcase
                 # if none, then case insensitive ones are ok too
                 return [r for r in res if r.lower().startswith(text.lower())]
             except TryNext:
                 pass
             
         return None
                
     def complete(self, text, state,line_buffer=None):
         """Return the next possible completion for 'text'.
 
         This is called successively with state == 0, 1, 2, ... until it
         returns None.  The completion should begin with 'text'.
 
         :Keywords:
         - line_buffer: string
         If not given, the completer attempts to obtain the current line buffer
         via readline.  This keyword allows clients which are requesting for
         text completions in non-readline contexts to inform the completer of
         the entire text.
         """
 
         #print '\n*** COMPLETE: <%s> (%s)' % (text,state)  # dbg
 
         # if there is only a tab on a line with only whitespace, instead
         # of the mostly useless 'do you want to see all million
         # completions' message, just do the right thing and give the user
         # his tab!  Incidentally, this enables pasting of tabbed text from
         # an editor (as long as autoindent is off).
 
         # It should be noted that at least pyreadline still shows
         # file completions - is there a way around it?
         
         # don't apply this on 'dumb' terminals, such as emacs buffers, so we
         # don't interfere with their own tab-completion mechanism.
         if line_buffer is None:
             self.full_lbuf = self.get_line_buffer()
         else:
             self.full_lbuf = line_buffer
             
         if not (self.dumb_terminal or self.full_lbuf.strip()):
             self.readline.insert_text('\t')
             return None
         
         magic_escape = self.magic_escape
         magic_prefix = self.magic_prefix
 
         self.lbuf = self.full_lbuf[:self.get_endidx()]
 
         try:
             if text.startswith(magic_escape):
                 text = text.replace(magic_escape,magic_prefix)
             elif text.startswith('~'):
                 text = os.path.expanduser(text)
             if state == 0:
                 custom_res = self.dispatch_custom_completer(text)
                 if custom_res is not None:
                     # did custom completers produce something?
                     self.matches = custom_res
                 else:
                     # Extend the list of completions with the results of each
                     # matcher, so we return results to the user from all
                     # namespaces.
                     if self.merge_completions:
                         self.matches = []
                         for matcher in self.matchers:
                             self.matches.extend(matcher(text))
                     else:
                         for matcher in self.matchers:
                             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:
                 ret = self.matches[state].replace(magic_prefix,magic_escape)                
                 return ret
             except IndexError:
                 return None
         except:
             #from IPython.core.ultratb import AutoFormattedTB; # dbg
             #tb=AutoFormattedTB('Verbose');tb() #dbg
             
             # If completion fails, don't annoy the user.
             return None

IPython/core/component.py

@@ -1,305 +1,304 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 A lightweight component system for IPython.
 
 Authors:
 
 * Brian Granger
 * Fernando Perez
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from copy import deepcopy
 import datetime
 from weakref import WeakValueDictionary
 
 from IPython.utils.importstring import import_item
 from IPython.utils.ipstruct import Struct
 from IPython.utils.traitlets import (
     HasTraitlets, TraitletError, MetaHasTraitlets, Instance, This
 )
 
 
 #-----------------------------------------------------------------------------
 # Helper classes for Components
 #-----------------------------------------------------------------------------
 
 
 class ComponentError(Exception):
     pass
 
 class MetaComponentTracker(type):
     """A metaclass that tracks instances of Components and its subclasses."""
 
     def __init__(cls, name, bases, d):
         super(MetaComponentTracker, cls).__init__(name, bases, d)
         cls.__instance_refs = WeakValueDictionary()
         cls.__numcreated = 0
 
     def __call__(cls, *args, **kw):
         """Called when a class is called (instantiated)!!!
         
         When a Component or subclass is instantiated, this is called and
         the instance is saved in a WeakValueDictionary for tracking.
         """
         instance = cls.__new__(cls, *args, **kw)
 
         # Register the instance before __init__ is called so get_instances 
         # works inside __init__ methods!
         indices = cls.register_instance(instance)
 
         # This is in a try/except because of the __init__ method fails, the
         # instance is discarded and shouldn't be tracked.
         try:
             if isinstance(instance, cls):
                 cls.__init__(instance, *args, **kw)
         except:
             # Unregister the instance because __init__ failed!
             cls.unregister_instances(indices)
             raise
         else:
             return instance
 
     def register_instance(cls, instance):
         """Register instance with cls and its subclasses."""
         # indices is a list of the keys used to register the instance
         # with.  This list is needed if the instance needs to be unregistered.
         indices = []
         for c in cls.__mro__:
             if issubclass(cls, c) and issubclass(c, Component):
                 c.__numcreated += 1
                 indices.append(c.__numcreated)
                 c.__instance_refs[c.__numcreated] = instance
             else:
                 break
         return indices
 
     def unregister_instances(cls, indices):
         """Unregister instance with cls and its subclasses."""
         for c, index in zip(cls.__mro__, indices):
             try:
                 del c.__instance_refs[index]
             except KeyError:
                 pass
 
     def clear_instances(cls):
         """Clear all instances tracked by cls."""
         cls.__instance_refs.clear()
         cls.__numcreated = 0
 
     def get_instances(cls, name=None, root=None, klass=None):
         """Get all instances of cls and its subclasses.
 
         Parameters
         ----------
         name : str
             Limit to components with this name.
         root : Component or subclass
             Limit to components having this root.
         klass : class or str
             Limits to instances of the class or its subclasses.  If a str
             is given ut must be in the form 'foo.bar.MyClass'.  The str
             form of this argument is useful for forward declarations.
         """
         if klass is not None:
             if isinstance(klass, basestring):
                 klass = import_item(klass)
             # Limit search to instances of klass for performance
             if issubclass(klass, Component):
                 return klass.get_instances(name=name, root=root)
         instances = cls.__instance_refs.values()
         if name is not None:
             instances = [i for i in instances if i.name == name]
         if klass is not None:
             instances = [i for i in instances if isinstance(i, klass)]
         if root is not None:
             instances = [i for i in instances if i.root == root]
         return instances
 
     def get_instances_by_condition(cls, call, name=None, root=None,
                                    klass=None):
         """Get all instances of cls, i such that call(i)==True.
 
         This also takes the ``name`` and ``root`` and ``classname`` 
         arguments of :meth:`get_instance`
         """
         return [i for i in cls.get_instances(name, root, klass) if call(i)]
 
 
 def masquerade_as(instance, cls):
     """Let instance masquerade as an instance of cls.
 
     Sometimes, such as in testing code, it is useful to let a class
     masquerade as another.  Python, being duck typed, allows this by 
     default.  But, instances of components are tracked by their class type.
 
     After calling this, cls.get_instances() will return ``instance``.  This
     does not, however, cause isinstance(instance, cls) to return ``True``.
 
     Parameters
     ----------
     instance : an instance of a Component or Component subclass
         The instance that will pretend to be a cls.
     cls : subclass of Component
         The Component subclass that instance will pretend to be.
     """
     cls.register_instance(instance)
 
 
 class ComponentNameGenerator(object):
     """A Singleton to generate unique component names."""
 
     def __init__(self, prefix):
         self.prefix = prefix
         self.i = 0
 
     def __call__(self):
         count = self.i
         self.i += 1
         return "%s%s" % (self.prefix, count)
 
 
 ComponentNameGenerator = ComponentNameGenerator('ipython.component')
 
 
 class MetaComponent(MetaHasTraitlets, MetaComponentTracker):
     pass
 
 
 #-----------------------------------------------------------------------------
 # Component implementation
 #-----------------------------------------------------------------------------
 
 
 class Component(HasTraitlets):
 
     __metaclass__ = MetaComponent
 
     # Traitlets are fun!
     config = Instance(Struct,(),{})
     parent = This()
     root = This()
     created = None
 
     def __init__(self, parent, name=None, config=None):
         """Create a component given a parent and possibly and name and config.
 
         Parameters
         ----------
         parent : Component subclass
             The parent in the component graph.  The parent is used
             to get the root of the component graph.
         name : str
             The unique name of the component.  If empty, then a unique
             one will be autogenerated.
         config : Struct
             If this is empty, self.config = parent.config, otherwise
             self.config = config and root.config is ignored.  This argument
             should only be used to *override* the automatic inheritance of 
             parent.config.  If a caller wants to modify parent.config 
             (not override), the caller should make a copy and change 
             attributes and then pass the copy to this argument.
         
         Notes
         -----
         Subclasses of Component must call the :meth:`__init__` method of
         :class:`Component` *before* doing anything else and using 
         :func:`super`::
         
             class MyComponent(Component):
                 def __init__(self, parent, name=None, config=None):
                     super(MyComponent, self).__init__(parent, name, config)
                     # Then any other code you need to finish initialization.
 
         This ensures that the :attr:`parent`, :attr:`name` and :attr:`config`
         attributes are handled properly.
         """
         super(Component, self).__init__()
         self._children = []
         if name is None:
             self.name = ComponentNameGenerator()
         else:
             self.name = name
         self.root = self # This is the default, it is set when parent is set
         self.parent = parent     
         if config is not None:
             self.config = deepcopy(config)
         else:
             if self.parent is not None:
                 self.config = deepcopy(self.parent.config)
 
         self.created = datetime.datetime.now()
 
     #-------------------------------------------------------------------------
     # Static traitlet notifiations
     #-------------------------------------------------------------------------
 
     def _parent_changed(self, name, old, new):
         if old is not None:
             old._remove_child(self)
         if new is not None:
             new._add_child(self)
 
         if new is None:
             self.root = self
         else:
             self.root = new.root
 
     def _root_changed(self, name, old, new):
         if self.parent is None:
             if not (new is self):
                 raise ComponentError("Root not self, but parent is None.")
         else:
             if not self.parent.root is new:
                 raise ComponentError("Error in setting the root attribute: "
                                      "root != parent.root")
 
     def _config_changed(self, name, old, new):
         """Update all the class traits having a config_key with the config.
 
         For any class traitlet with a ``config_key`` metadata attribute, we
         update the traitlet with the value of the corresponding config entry.
 
         In the future, we might want to do a pop here so stale config info
         is not passed onto children.
         """
         # Get all traitlets with a config_key metadata entry
         traitlets = self.traitlets('config_key')
         for k, v in traitlets.items():
             try:
                 config_value = new[v.get_metadata('config_key')]
             except KeyError:
                 pass
             else:
                 setattr(self, k, config_value)
 
     @property
     def children(self):
         """A list of all my child components."""
         return self._children
 
     def _remove_child(self, child):
         """A private method for removing children components."""
         if child in self._children:
             index = self._children.index(child)
             del self._children[index]
 
     def _add_child(self, child):
         """A private method for adding children components."""
         if child not in self._children:
             self._children.append(child)
 
     def __repr__(self):
-        return "<%s('%s')>" % (self.__class__.__name__, "DummyName")
-        # return "<Component('%s')>" % self.name
+        return "<%s('%s')>" % (self.__class__.__name__, self.name)

IPython/core/display_trap.py

@@ -1,62 +1,72 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 A context manager for handling sys.displayhook.
 
 Authors:
 
 * Robert Kern
 * Brian Granger
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import sys
 
 from IPython.core.component import Component
 
+from IPython.utils.autoattr import auto_attr
+
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 
 class DisplayTrap(Component):
     """Object to manage sys.displayhook.
 
     This came from IPython.core.kernel.display_hook, but is simplified
     (no callbacks or formatters) until more of the core is refactored.
     """
 
     def __init__(self, parent, hook):
         super(DisplayTrap, self).__init__(parent, None, None)
 
         self.hook = hook
         self.old_hook = None
 
+    @auto_attr
+    def shell(self):
+        shell = Component.get_instances(
+            root=self.root,
+            klass='IPython.core.iplib.InteractiveShell'
+        )[0]
+        return shell
+
     def __enter__(self):
         self.set()
         return self
 
     def __exit__(self, type, value, traceback):
         self.unset()
         return True
 
     def set(self):
         """Set the hook."""
         if sys.displayhook is not self.hook:
             self.old_hook = sys.displayhook
             sys.displayhook = self.hook
 
     def unset(self):
         """Unset the hook."""
         sys.displayhook = self.old_hook
 

IPython/core/iplib.py

@@ -1,2849 +1,2506 b''
 # -*- coding: utf-8 -*-
 """
 Main IPython Component
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2001 Janko Hauser <[e-mail]>
 #  Copyright (C) 2001-2007 Fernando Perez. <[e-mail]>
 #  Copyright (C) 2008-2009  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from __future__ import with_statement
 
 import __main__
 import __builtin__
 import StringIO
 import bdb
 import codeop
 import exceptions
 import glob
 import keyword
 import new
 import os
 import re
 import shutil
 import string
 import sys
 import tempfile
 from contextlib import nested
 
 from IPython.core import ultratb
 from IPython.core import debugger, oinspect
 from IPython.core import shadowns
 from IPython.core import history as ipcorehist
 from IPython.core import prefilter
 from IPython.core.alias import AliasManager
 from IPython.core.autocall import IPyAutocall
 from IPython.core.builtin_trap import BuiltinTrap
 from IPython.core.display_trap import DisplayTrap
 from IPython.core.fakemodule import FakeModule, init_fakemod_dict
 from IPython.core.logger import Logger
 from IPython.core.magic import Magic
 from IPython.core.prompts import CachedOutput
 from IPython.core.page import page
+from IPython.core.prefilter import PrefilterManager
 from IPython.core.component import Component
 from IPython.core.oldusersetup import user_setup
 from IPython.core.usage import interactive_usage, default_banner
 from IPython.core.error import TryNext, UsageError
+from IPython.core.splitinput import split_user_input
 
 from IPython.extensions import pickleshare
 from IPython.external.Itpl import ItplNS
 from IPython.lib.backgroundjobs import BackgroundJobManager
 from IPython.utils.ipstruct import Struct
 from IPython.utils import PyColorize
 from IPython.utils.genutils import *
 from IPython.utils.strdispatch import StrDispatch
 from IPython.utils.platutils import toggle_set_term_title, set_term_title
 
-from IPython.utils import growl
-growl.start("IPython")
+# from IPython.utils import growl
+# growl.start("IPython")
 
 from IPython.utils.traitlets import (
     Int, Float, Str, CBool, CaselessStrEnum, Enum, List, Unicode
 )
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 
 
 # store the builtin raw_input globally, and use this always, in case user code
 # overwrites it (like wx.py.PyShell does)
 raw_input_original = raw_input
 
 # compiled regexps for autoindent management
 dedent_re = re.compile(r'^\s+raise|^\s+return|^\s+pass')
 
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 
 ini_spaces_re = re.compile(r'^(\s+)')
 
 
 def num_ini_spaces(strng):
     """Return the number of initial spaces in a string"""
 
     ini_spaces = ini_spaces_re.match(strng)
     if ini_spaces:
         return ini_spaces.end()
     else:
         return 0
 
 
 def softspace(file, newvalue):
     """Copied from code.py, to remove the dependency"""
 
     oldvalue = 0
     try:
         oldvalue = file.softspace
     except AttributeError:
         pass
     try:
         file.softspace = newvalue
     except (AttributeError, TypeError):
         # "attribute-less object" or "read-only attributes"
         pass
     return oldvalue
 
 
 class SpaceInInput(exceptions.Exception): pass
 
 class Bunch: pass
 
 class InputList(list):
     """Class to store user input.
 
     It's basically a list, but slices return a string instead of a list, thus
     allowing things like (assuming 'In' is an instance):
 
     exec In[4:7]
 
     or
 
     exec In[5:9] + In[14] + In[21:25]"""
 
     def __getslice__(self,i,j):
         return ''.join(list.__getslice__(self,i,j))
 
 
 class SyntaxTB(ultratb.ListTB):
     """Extension which holds some state: the last exception value"""
 
     def __init__(self,color_scheme = 'NoColor'):
         ultratb.ListTB.__init__(self,color_scheme)
         self.last_syntax_error = None
 
     def __call__(self, etype, value, elist):
         self.last_syntax_error = value
         ultratb.ListTB.__call__(self,etype,value,elist)
 
     def clear_err_state(self):
         """Return the current error state and clear it"""
         e = self.last_syntax_error
         self.last_syntax_error = None
         return e
 
 
 def get_default_editor():
     try:
         ed = os.environ['EDITOR']
     except KeyError:
         if os.name == 'posix':
             ed = 'vi'  # the only one guaranteed to be there!
         else:
             ed = 'notepad' # same in Windows!
     return ed
 
 
 class SeparateStr(Str):
     """A Str subclass to validate separate_in, separate_out, etc.
 
     This is a Str based traitlet that converts '0'->'' and '\\n'->'\n'.
     """
 
     def validate(self, obj, value):
         if value == '0': value = ''
         value = value.replace('\\n','\n')
         return super(SeparateStr, self).validate(obj, value)
 
 
 #-----------------------------------------------------------------------------
 # Main IPython class
 #-----------------------------------------------------------------------------
 
 
 class InteractiveShell(Component, Magic):
     """An enhanced, interactive shell for Python."""
 
     autocall = Enum((0,1,2), config_key='AUTOCALL')
     autoedit_syntax = CBool(False, config_key='AUTOEDIT_SYNTAX')
     autoindent = CBool(True, config_key='AUTOINDENT')
     automagic = CBool(True, config_key='AUTOMAGIC')
     display_banner = CBool(True, config_key='DISPLAY_BANNER')
     banner = Str('')
     banner1 = Str(default_banner, config_key='BANNER1')
     banner2 = Str('', config_key='BANNER2')
     c = Str('', config_key='C')
     cache_size = Int(1000, config_key='CACHE_SIZE')
     classic = CBool(False, config_key='CLASSIC')
     color_info = CBool(True, config_key='COLOR_INFO')
     colors = CaselessStrEnum(('NoColor','LightBG','Linux'), 
                              default_value='LightBG', config_key='COLORS')
     confirm_exit = CBool(True, config_key='CONFIRM_EXIT')
     debug = CBool(False, config_key='DEBUG')
     deep_reload = CBool(False, config_key='DEEP_RELOAD')
     embedded = CBool(False)
     embedded_active = CBool(False)
     editor = Str(get_default_editor(), config_key='EDITOR')
     filename = Str("<ipython console>")
     interactive = CBool(False, config_key='INTERACTIVE')
     ipythondir= Unicode('', config_key='IPYTHONDIR') # Set to os.getcwd() in __init__
     logstart = CBool(False, config_key='LOGSTART')
     logfile = Str('', config_key='LOGFILE')
     logplay = Str('', config_key='LOGPLAY')
-    multi_line_specials = CBool(True, config_key='MULTI_LINE_SPECIALS')
     object_info_string_level = Enum((0,1,2), default_value=0,
                                     config_keys='OBJECT_INFO_STRING_LEVEL')
     pager = Str('less', config_key='PAGER')
     pdb = CBool(False, config_key='PDB')
     pprint = CBool(True, config_key='PPRINT')
     profile = Str('', config_key='PROFILE')
     prompt_in1 = Str('In [\\#]: ', config_key='PROMPT_IN1')
     prompt_in2 = Str('   .\\D.: ', config_key='PROMPT_IN2')
     prompt_out = Str('Out[\\#]: ', config_key='PROMPT_OUT1')
     prompts_pad_left = CBool(True, config_key='PROMPTS_PAD_LEFT')
     quiet = CBool(False, config_key='QUIET')
 
     readline_use = CBool(True, config_key='READLINE_USE')
     readline_merge_completions = CBool(True, 
                                        config_key='READLINE_MERGE_COMPLETIONS')
     readline_omit__names = Enum((0,1,2), default_value=0, 
                                 config_key='READLINE_OMIT_NAMES')
     readline_remove_delims = Str('-/~', config_key='READLINE_REMOVE_DELIMS')
     readline_parse_and_bind = List([
             'tab: complete',
             '"\C-l": possible-completions',
             'set show-all-if-ambiguous on',
             '"\C-o": tab-insert',
             '"\M-i": "    "',
             '"\M-o": "\d\d\d\d"',
             '"\M-I": "\d\d\d\d"',
             '"\C-r": reverse-search-history',
             '"\C-s": forward-search-history',
             '"\C-p": history-search-backward',
             '"\C-n": history-search-forward',
             '"\e[A": history-search-backward',
             '"\e[B": history-search-forward',
             '"\C-k": kill-line',
             '"\C-u": unix-line-discard',
         ], allow_none=False, config_key='READLINE_PARSE_AND_BIND'
     )
 
     screen_length = Int(0, config_key='SCREEN_LENGTH')
     
     # Use custom TraitletTypes that convert '0'->'' and '\\n'->'\n'
     separate_in = SeparateStr('\n', config_key='SEPARATE_IN')
     separate_out = SeparateStr('', config_key='SEPARATE_OUT')
     separate_out2 = SeparateStr('', config_key='SEPARATE_OUT2')
 
     system_header = Str('IPython system call: ', config_key='SYSTEM_HEADER')
     system_verbose = CBool(False, config_key='SYSTEM_VERBOSE')
     term_title = CBool(False, config_key='TERM_TITLE')
     wildcards_case_sensitive = CBool(True, config_key='WILDCARDS_CASE_SENSITIVE')
     xmode = CaselessStrEnum(('Context','Plain', 'Verbose'), 
                             default_value='Context', config_key='XMODE')
 
     alias = List(allow_none=False, config_key='ALIAS')
     autoexec = List(allow_none=False)
 
     # class attribute to indicate whether the class supports threads or not.
     # Subclasses with thread support should override this as needed.
     isthreaded = False
 
     def __init__(self, parent=None, config=None, ipythondir=None, usage=None,
                  user_ns=None, user_global_ns=None,
                  banner1=None, banner2=None,
                  custom_exceptions=((),None)):
 
         # This is where traitlets with a config_key argument are updated
         # from the values on config.
         super(InteractiveShell, self).__init__(parent, config=config, name='__IP')
 
         # These are relatively independent and stateless
         self.init_ipythondir(ipythondir)
         self.init_instance_attrs()
         self.init_term_title()
         self.init_usage(usage)
         self.init_banner(banner1, banner2)
 
         # Create namespaces (user_ns, user_global_ns, alias_table, etc.)
         self.init_create_namespaces(user_ns, user_global_ns)
         # This has to be done after init_create_namespaces because it uses
         # something in self.user_ns, but before init_sys_modules, which
         # is the first thing to modify sys.
         self.save_sys_module_state()
         self.init_sys_modules()
 
         self.init_history()
         self.init_encoding()
-        self.init_handlers()
+        self.init_prefilter()
 
         Magic.__init__(self, self)
 
         self.init_syntax_highlighting()
         self.init_hooks()
         self.init_pushd_popd_magic()
         self.init_traceback_handlers(custom_exceptions)
         self.init_user_ns()
         self.init_logger()
         self.init_alias()
         self.init_builtins()
         
         # pre_config_initialization
         self.init_shadow_hist()
 
         # The next section should contain averything that was in ipmaker.
         self.init_logstart()
 
         # The following was in post_config_initialization
         self.init_inspector()
         self.init_readline()
         self.init_prompts()
         self.init_displayhook()
         self.init_reload_doctest()
         self.init_magics()
         self.init_pdb()
         self.hooks.late_startup_hook()
 
     #-------------------------------------------------------------------------
     # Traitlet changed handlers
     #-------------------------------------------------------------------------
 
     def _banner1_changed(self):
         self.compute_banner()
 
     def _banner2_changed(self):
         self.compute_banner()
 
     @property
     def usable_screen_length(self):
         if self.screen_length == 0:
             return 0
         else:
             num_lines_bot = self.separate_in.count('\n')+1
             return self.screen_length - num_lines_bot
 
     def _term_title_changed(self, name, new_value):
         self.init_term_title()
 
     def set_autoindent(self,value=None):
         """Set the autoindent flag, checking for readline support.
 
         If called with no arguments, it acts as a toggle."""
 
         if not self.has_readline:
             if os.name == 'posix':
                 warn("The auto-indent feature requires the readline library")
             self.autoindent = 0
             return
         if value is None:
             self.autoindent = not self.autoindent
         else:
             self.autoindent = value
 
     #-------------------------------------------------------------------------
     # init_* methods called by __init__
     #-------------------------------------------------------------------------
 
     def init_ipythondir(self, ipythondir):
         if ipythondir is not None:
             self.ipythondir = ipythondir
             self.config.IPYTHONDIR = self.ipythondir
             return
 
         if hasattr(self.config, 'IPYTHONDIR'):
             self.ipythondir = self.config.IPYTHONDIR
         if not hasattr(self.config, 'IPYTHONDIR'):
             # cdw is always defined
             self.ipythondir = os.getcwd()
 
         # The caller must make sure that ipythondir exists.  We should
         # probably handle this using a Dir traitlet.
         if not os.path.isdir(self.ipythondir):
             raise IOError('IPython dir does not exist: %s' % self.ipythondir)
 
         # All children can just read this
         self.config.IPYTHONDIR = self.ipythondir
 
     def init_instance_attrs(self):
         self.jobs = BackgroundJobManager()
         self.more = False
 
         # command compiler
         self.compile = codeop.CommandCompiler()
 
         # User input buffer
         self.buffer = []
 
         # Make an empty namespace, which extension writers can rely on both
         # existing and NEVER being used by ipython itself.  This gives them a
         # convenient location for storing additional information and state
         # their extensions may require, without fear of collisions with other
         # ipython names that may develop later.
         self.meta = Struct()
 
         # Object variable to store code object waiting execution.  This is
         # used mainly by the multithreaded shells, but it can come in handy in
         # other situations.  No need to use a Queue here, since it's a single
         # item which gets cleared once run.
         self.code_to_run = None
 
         # Flag to mark unconditional exit
         self.exit_now = False
 
         # Temporary files used for various purposes.  Deleted at exit.
         self.tempfiles = []
 
         # Keep track of readline usage (later set by init_readline)
         self.has_readline = False
 
         # keep track of where we started running (mainly for crash post-mortem)
         # This is not being used anywhere currently.
         self.starting_dir = os.getcwd()
 
         # Indentation management
         self.indent_current_nsp = 0
 
     def init_term_title(self):
         # Enable or disable the terminal title.
         if self.term_title:
             toggle_set_term_title(True)
             set_term_title('IPython: ' + abbrev_cwd())
         else:
             toggle_set_term_title(False)
 
     def init_usage(self, usage=None):
         if usage is None:
             self.usage = interactive_usage
         else:
             self.usage = usage
 
     def init_banner(self, banner1, banner2):
         if self.c:  # regular python doesn't print the banner with -c
             self.display_banner = False
         if banner1 is not None:
             self.banner1 = banner1
         if banner2 is not None:
             self.banner2 = banner2
         self.compute_banner()
 
     def compute_banner(self):
         self.banner = self.banner1 + '\n'
         if self.profile:
             self.banner += '\nIPython profile: %s\n' % self.profile
         if self.banner2:
             self.banner += '\n' + self.banner2 + '\n'
 
     def init_encoding(self):
         # Get system encoding at startup time.  Certain terminals (like Emacs
         # under Win32 have it set to None, and we need to have a known valid
         # encoding to use in the raw_input() method
         try:
             self.stdin_encoding = sys.stdin.encoding or 'ascii'
         except AttributeError:
             self.stdin_encoding = 'ascii'
 
     def init_syntax_highlighting(self):
         # Python source parser/formatter for syntax highlighting
         pyformat = PyColorize.Parser().format
         self.pycolorize = lambda src: pyformat(src,'str',self.colors)
 
     def init_pushd_popd_magic(self):
         # for pushd/popd management
         try:
             self.home_dir = get_home_dir()
         except HomeDirError, msg:
             fatal(msg)
 
         self.dir_stack = []
 
     def init_logger(self):
         self.logger = Logger(self, logfname='ipython_log.py', logmode='rotate')
         # local shortcut, this is used a LOT
         self.log = self.logger.log
         # template for logfile headers.  It gets resolved at runtime by the
         # logstart method.
         self.loghead_tpl = \
 """#log# Automatic Logger file. *** THIS MUST BE THE FIRST LINE ***
 #log# DO NOT CHANGE THIS LINE OR THE TWO BELOW
 #log# opts = %s
 #log# args = %s
 #log# It is safe to make manual edits below here.
 #log#-----------------------------------------------------------------------
 """
 
     def init_logstart(self):
         if self.logplay:
             self.magic_logstart(self.logplay + ' append')
         elif  self.logfile:
             self.magic_logstart(self.logfile)
         elif self.logstart:
             self.magic_logstart()
 
     def init_builtins(self):
         self.builtin_trap = BuiltinTrap(self)
 
     def init_inspector(self):
         # Object inspector
         self.inspector = oinspect.Inspector(oinspect.InspectColors,
                                             PyColorize.ANSICodeColors,
                                             'NoColor',
                                             self.object_info_string_level)
 
     def init_prompts(self):
         # Initialize cache, set in/out prompts and printing system
         self.outputcache = CachedOutput(self,
                                         self.cache_size,
                                         self.pprint,
                                         input_sep = self.separate_in,
                                         output_sep = self.separate_out,
                                         output_sep2 = self.separate_out2,
                                         ps1 = self.prompt_in1,
                                         ps2 = self.prompt_in2,
                                         ps_out = self.prompt_out,
                                         pad_left = self.prompts_pad_left)
 
         # user may have over-ridden the default print hook:
         try:
             self.outputcache.__class__.display = self.hooks.display
         except AttributeError:
             pass
 
     def init_displayhook(self):
         self.display_trap = DisplayTrap(self, self.outputcache)
 
     def init_reload_doctest(self):
         # Do a proper resetting of doctest, including the necessary displayhook
         # monkeypatching
         try:
             doctest_reload()
         except ImportError:
             warn("doctest module does not exist.")
 
     #-------------------------------------------------------------------------
     # Things related to injections into the sys module
     #-------------------------------------------------------------------------
 
     def save_sys_module_state(self):
         """Save the state of hooks in the sys module.
 
         This has to be called after self.user_ns is created.
         """
         self._orig_sys_module_state = {}
         self._orig_sys_module_state['stdin'] = sys.stdin
         self._orig_sys_module_state['stdout'] = sys.stdout
         self._orig_sys_module_state['stderr'] = sys.stderr
         self._orig_sys_module_state['excepthook'] = sys.excepthook
         try:
             self._orig_sys_modules_main_name = self.user_ns['__name__']
         except KeyError:
             pass
 
     def restore_sys_module_state(self):
         """Restore the state of the sys module."""
         try:
             for k, v in self._orig_sys_module_state.items():
                 setattr(sys, k, v)
         except AttributeError:
             pass
         try:
             delattr(sys, 'ipcompleter')
         except AttributeError:
             pass
         # Reset what what done in self.init_sys_modules
         try:
             sys.modules[self.user_ns['__name__']] = self._orig_sys_modules_main_name
         except (AttributeError, KeyError):
             pass
 
     #-------------------------------------------------------------------------
     # Things related to hooks
     #-------------------------------------------------------------------------
 
     def init_hooks(self):
         # hooks holds pointers used for user-side customizations
         self.hooks = Struct()
 
         self.strdispatchers = {}
 
         # Set all default hooks, defined in the IPython.hooks module.
         import IPython.core.hooks
         hooks = IPython.core.hooks
         for hook_name in hooks.__all__:
             # default hooks have priority 100, i.e. low; user hooks should have
             # 0-100 priority
             self.set_hook(hook_name,getattr(hooks,hook_name), 100)
 
     def set_hook(self,name,hook, priority = 50, str_key = None, re_key = None):
         """set_hook(name,hook) -> sets an internal IPython hook.
 
         IPython exposes some of its internal API as user-modifiable hooks.  By
         adding your function to one of these hooks, you can modify IPython's 
         behavior to call at runtime your own routines."""
 
         # At some point in the future, this should validate the hook before it
         # accepts it.  Probably at least check that the hook takes the number
         # of args it's supposed to.
         
         f = new.instancemethod(hook,self,self.__class__)
 
         # check if the hook is for strdispatcher first
         if str_key is not None:
             sdp = self.strdispatchers.get(name, StrDispatch())
             sdp.add_s(str_key, f, priority )
             self.strdispatchers[name] = sdp
             return
         if re_key is not None:
             sdp = self.strdispatchers.get(name, StrDispatch())
             sdp.add_re(re.compile(re_key), f, priority )
             self.strdispatchers[name] = sdp
             return
             
         dp = getattr(self.hooks, name, None)
         if name not in IPython.core.hooks.__all__:
             print "Warning! Hook '%s' is not one of %s" % (name, IPython.core.hooks.__all__ )
         if not dp:
             dp = IPython.core.hooks.CommandChainDispatcher()
         
         try:
             dp.add(f,priority)
         except AttributeError:
             # it was not commandchain, plain old func - replace
             dp = f
 
         setattr(self.hooks,name, dp)
 
     #-------------------------------------------------------------------------
     # Things related to the "main" module
     #-------------------------------------------------------------------------
 
     def new_main_mod(self,ns=None):
         """Return a new 'main' module object for user code execution.
         """
         main_mod = self._user_main_module
         init_fakemod_dict(main_mod,ns)
         return main_mod
 
     def cache_main_mod(self,ns,fname):
         """Cache a main module's namespace.
 
         When scripts are executed via %run, we must keep a reference to the
         namespace of their __main__ module (a FakeModule instance) around so
         that Python doesn't clear it, rendering objects defined therein
         useless.
 
         This method keeps said reference in a private dict, keyed by the
         absolute path of the module object (which corresponds to the script
         path).  This way, for multiple executions of the same script we only
         keep one copy of the namespace (the last one), thus preventing memory
         leaks from old references while allowing the objects from the last
         execution to be accessible.
 
         Note: we can not allow the actual FakeModule instances to be deleted,
         because of how Python tears down modules (it hard-sets all their
         references to None without regard for reference counts).  This method
         must therefore make a *copy* of the given namespace, to allow the
         original module's __dict__ to be cleared and reused.
 
         
         Parameters
         ----------
           ns : a namespace (a dict, typically)
 
           fname : str
             Filename associated with the namespace.
 
         Examples
         --------
 
         In [10]: import IPython
 
         In [11]: _ip.cache_main_mod(IPython.__dict__,IPython.__file__)
 
         In [12]: IPython.__file__ in _ip._main_ns_cache
         Out[12]: True
         """
         self._main_ns_cache[os.path.abspath(fname)] = ns.copy()
 
     def clear_main_mod_cache(self):
         """Clear the cache of main modules.
 
         Mainly for use by utilities like %reset.
 
         Examples
         --------
 
         In [15]: import IPython
 
         In [16]: _ip.cache_main_mod(IPython.__dict__,IPython.__file__)
 
         In [17]: len(_ip._main_ns_cache) > 0
         Out[17]: True
 
         In [18]: _ip.clear_main_mod_cache()
 
         In [19]: len(_ip._main_ns_cache) == 0
         Out[19]: True
         """
         self._main_ns_cache.clear()
 
     #-------------------------------------------------------------------------
     # Things related to debugging
     #-------------------------------------------------------------------------
 
     def init_pdb(self):
         # Set calling of pdb on exceptions
         # self.call_pdb is a property
         self.call_pdb = self.pdb
 
     def _get_call_pdb(self):
         return self._call_pdb
 
     def _set_call_pdb(self,val):
 
         if val not in (0,1,False,True):
             raise ValueError,'new call_pdb value must be boolean'
 
         # store value in instance
         self._call_pdb = val
 
         # notify the actual exception handlers
         self.InteractiveTB.call_pdb = val
         if self.isthreaded:
             try:
                 self.sys_excepthook.call_pdb = val
             except:
                 warn('Failed to activate pdb for threaded exception handler')
 
     call_pdb = property(_get_call_pdb,_set_call_pdb,None,
                         'Control auto-activation of pdb at exceptions')
 
     def debugger(self,force=False):
         """Call the pydb/pdb debugger.
 
         Keywords:
 
           - force(False): by default, this routine checks the instance call_pdb
           flag and does not actually invoke the debugger if the flag is false.
           The 'force' option forces the debugger to activate even if the flag
           is false.
         """
 
         if not (force or self.call_pdb):
             return
 
         if not hasattr(sys,'last_traceback'):
             error('No traceback has been produced, nothing to debug.')
             return
 
         # use pydb if available
         if debugger.has_pydb:
             from pydb import pm
         else:
             # fallback to our internal debugger
             pm = lambda : self.InteractiveTB.debugger(force=True)
         self.history_saving_wrapper(pm)()
 
     #-------------------------------------------------------------------------
     # Things related to IPython's various namespaces
     #-------------------------------------------------------------------------
 
     def init_create_namespaces(self, user_ns=None, user_global_ns=None):
         # Create the namespace where the user will operate.  user_ns is
         # normally the only one used, and it is passed to the exec calls as
         # the locals argument.  But we do carry a user_global_ns namespace
         # given as the exec 'globals' argument,  This is useful in embedding
         # situations where the ipython shell opens in a context where the
         # distinction between locals and globals is meaningful.  For
         # non-embedded contexts, it is just the same object as the user_ns dict.
 
         # FIXME. For some strange reason, __builtins__ is showing up at user
         # level as a dict instead of a module. This is a manual fix, but I
         # should really track down where the problem is coming from. Alex
         # Schmolck reported this problem first.
 
         # A useful post by Alex Martelli on this topic:
         # Re: inconsistent value from __builtins__
         # Von: Alex Martelli <[e-mail]>
         # Datum: Freitag 01 Oktober 2004 04:45:34 nachmittags/abends
         # Gruppen: comp.lang.python
 
         # Michael Hohn <[e-mail]> wrote:
         # > >>> print type(builtin_check.get_global_binding('__builtins__'))
         # > <type 'dict'>
         # > >>> print type(__builtins__)
         # > <type 'module'>
         # > Is this difference in return value intentional?
 
         # Well, it's documented that '__builtins__' can be either a dictionary
         # or a module, and it's been that way for a long time. Whether it's
         # intentional (or sensible), I don't know. In any case, the idea is
         # that if you need to access the built-in namespace directly, you
         # should start with "import __builtin__" (note, no 's') which will
         # definitely give you a module. Yeah, it's somewhat confusing:-(.
 
         # These routines return properly built dicts as needed by the rest of
         # the code, and can also be used by extension writers to generate
         # properly initialized namespaces.
         user_ns, user_global_ns = self.make_user_namespaces(user_ns,
             user_global_ns)
 
         # Assign namespaces
         # This is the namespace where all normal user variables live
         self.user_ns = user_ns
         self.user_global_ns = user_global_ns
 
         # An auxiliary namespace that checks what parts of the user_ns were
         # loaded at startup, so we can list later only variables defined in
         # actual interactive use.  Since it is always a subset of user_ns, it
         # doesn't need to be seaparately tracked in the ns_table
         self.user_config_ns = {}
 
         # A namespace to keep track of internal data structures to prevent
         # them from cluttering user-visible stuff.  Will be updated later
         self.internal_ns = {}
 
         # Namespace of system aliases.  Each entry in the alias
         # table must be a 2-tuple of the form (N,name), where N is the number
         # of positional arguments of the alias.
         self.alias_table = {}
 
         # Now that FakeModule produces a real module, we've run into a nasty
         # problem: after script execution (via %run), the module where the user
         # code ran is deleted.  Now that this object is a true module (needed
         # so docetst and other tools work correctly), the Python module
         # teardown mechanism runs over it, and sets to None every variable
         # present in that module.  Top-level references to objects from the
         # script survive, because the user_ns is updated with them.  However,
         # calling functions defined in the script that use other things from
         # the script will fail, because the function's closure had references
         # to the original objects, which are now all None.  So we must protect
         # these modules from deletion by keeping a cache.
         # 
         # To avoid keeping stale modules around (we only need the one from the
         # last run), we use a dict keyed with the full path to the script, so
         # only the last version of the module is held in the cache.  Note,
         # however, that we must cache the module *namespace contents* (their
         # __dict__).  Because if we try to cache the actual modules, old ones
         # (uncached) could be destroyed while still holding references (such as
         # those held by GUI objects that tend to be long-lived)>
         # 
         # The %reset command will flush this cache.  See the cache_main_mod()
         # and clear_main_mod_cache() methods for details on use.
 
         # This is the cache used for 'main' namespaces
         self._main_ns_cache = {}
         # And this is the single instance of FakeModule whose __dict__ we keep
         # copying and clearing for reuse on each %run
         self._user_main_module = FakeModule()
 
         # A table holding all the namespaces IPython deals with, so that
         # introspection facilities can search easily.
         self.ns_table = {'user':user_ns,
                          'user_global':user_global_ns,
                          'alias':self.alias_table,
                          'internal':self.internal_ns,
                          'builtin':__builtin__.__dict__
                          }
 
         # Similarly, track all namespaces where references can be held and that
         # we can safely clear (so it can NOT include builtin).  This one can be
         # a simple list.
         self.ns_refs_table = [ user_ns, user_global_ns, self.user_config_ns,
                                self.alias_table, self.internal_ns,
                                self._main_ns_cache ]
 
     def init_sys_modules(self):
         # We need to insert into sys.modules something that looks like a
         # module but which accesses the IPython namespace, for shelve and
         # pickle to work interactively. Normally they rely on getting
         # everything out of __main__, but for embedding purposes each IPython
         # instance has its own private namespace, so we can't go shoving
         # everything into __main__.
 
         # note, however, that we should only do this for non-embedded
         # ipythons, which really mimic the __main__.__dict__ with their own
         # namespace.  Embedded instances, on the other hand, should not do
         # this because they need to manage the user local/global namespaces
         # only, but they live within a 'normal' __main__ (meaning, they
         # shouldn't overtake the execution environment of the script they're
         # embedded in).
 
         # This is overridden in the InteractiveShellEmbed subclass to a no-op.
 
         try:
             main_name = self.user_ns['__name__']
         except KeyError:
             raise KeyError('user_ns dictionary MUST have a "__name__" key')
         else:
             sys.modules[main_name] = FakeModule(self.user_ns)
 
     def make_user_namespaces(self, user_ns=None, user_global_ns=None):
         """Return a valid local and global user interactive namespaces.
 
         This builds a dict with the minimal information needed to operate as a
         valid IPython user namespace, which you can pass to the various
         embedding classes in ipython. The default implementation returns the
         same dict for both the locals and the globals to allow functions to
         refer to variables in the namespace. Customized implementations can
         return different dicts. The locals dictionary can actually be anything
         following the basic mapping protocol of a dict, but the globals dict
         must be a true dict, not even a subclass. It is recommended that any
         custom object for the locals namespace synchronize with the globals
         dict somehow.
 
         Raises TypeError if the provided globals namespace is not a true dict.
 
         :Parameters:
             user_ns : dict-like, optional
                 The current user namespace. The items in this namespace should
                 be included in the output. If None, an appropriate blank
                 namespace should be created.
             user_global_ns : dict, optional
                 The current user global namespace. The items in this namespace
                 should be included in the output. If None, an appropriate
                 blank namespace should be created.
 
         :Returns:
             A tuple pair of dictionary-like object to be used as the local namespace
             of the interpreter and a dict to be used as the global namespace.
         """
 
         if user_ns is None:
             # Set __name__ to __main__ to better match the behavior of the
             # normal interpreter.
             user_ns = {'__name__'     :'__main__',
                        '__builtins__' : __builtin__,
                       }
         else:
             user_ns.setdefault('__name__','__main__')
             user_ns.setdefault('__builtins__',__builtin__)
 
         if user_global_ns is None:
             user_global_ns = user_ns
         if type(user_global_ns) is not dict:
             raise TypeError("user_global_ns must be a true dict; got %r"
                 % type(user_global_ns))
 
         return user_ns, user_global_ns
 
     def init_user_ns(self):
         """Initialize all user-visible namespaces to their minimum defaults.
 
         Certain history lists are also initialized here, as they effectively
         act as user namespaces.
 
         Notes
         -----
         All data structures here are only filled in, they are NOT reset by this
         method.  If they were not empty before, data will simply be added to
         therm.
         """
         # The user namespace MUST have a pointer to the shell itself.
         self.user_ns[self.name] = self
 
         # Store myself as the public api!!!
         self.user_ns['_ip'] = self
 
         # make global variables for user access to the histories
         self.user_ns['_ih'] = self.input_hist
         self.user_ns['_oh'] = self.output_hist
         self.user_ns['_dh'] = self.dir_hist
 
         # user aliases to input and output histories
         self.user_ns['In']  = self.input_hist
         self.user_ns['Out'] = self.output_hist
 
         self.user_ns['_sh'] = shadowns
 
         # Put 'help' in the user namespace
         try:
             from site import _Helper
             self.user_ns['help'] = _Helper()
         except ImportError:
             warn('help() not available - check site.py')
 
     def reset(self):
         """Clear all internal namespaces.
 
         Note that this is much more aggressive than %reset, since it clears
         fully all namespaces, as well as all input/output lists.
         """
         for ns in self.ns_refs_table:
             ns.clear()
 
         # Clear input and output histories
         self.input_hist[:] = []
         self.input_hist_raw[:] = []
         self.output_hist.clear()
         # Restore the user namespaces to minimal usability
         self.init_user_ns()
 
     def push(self, variables, interactive=True):
         """Inject a group of variables into the IPython user namespace.
 
         Parameters
         ----------
         variables : dict, str or list/tuple of str
             The variables to inject into the user's namespace.  If a dict,
             a simple update is done.  If a str, the string is assumed to 
             have variable names separated by spaces.  A list/tuple of str
             can also be used to give the variable names.  If just the variable
             names are give (list/tuple/str) then the variable values looked
             up in the callers frame.
         interactive : bool
             If True (default), the variables will be listed with the ``who``
             magic.
         """
         vdict = None
 
         # We need a dict of name/value pairs to do namespace updates.
         if isinstance(variables, dict):
             vdict = variables
         elif isinstance(variables, (basestring, list, tuple)):
             if isinstance(variables, basestring):
                 vlist = variables.split()
             else:
                 vlist = variables
             vdict = {}
             cf = sys._getframe(1)
             for name in vlist:
                 try:
                     vdict[name] = eval(name, cf.f_globals, cf.f_locals)
                 except:
                     print ('Could not get variable %s from %s' %
                            (name,cf.f_code.co_name))
         else:
             raise ValueError('variables must be a dict/str/list/tuple')
             
         # Propagate variables to user namespace
         self.user_ns.update(vdict)
 
         # And configure interactive visibility
         config_ns = self.user_config_ns
         if interactive:
             for name, val in vdict.iteritems():
                 config_ns.pop(name, None)
         else:
             for name,val in vdict.iteritems():
                 config_ns[name] = val
 
     #-------------------------------------------------------------------------
     # Things related to history management
     #-------------------------------------------------------------------------
 
     def init_history(self):
         # List of input with multi-line handling.
         self.input_hist = InputList()
         # This one will hold the 'raw' input history, without any
         # pre-processing.  This will allow users to retrieve the input just as
         # it was exactly typed in by the user, with %hist -r.
         self.input_hist_raw = InputList()
 
         # list of visited directories
         try:
             self.dir_hist = [os.getcwd()]
         except OSError:
             self.dir_hist = []
 
         # dict of output history
         self.output_hist = {}
 
         # Now the history file
         try:
             histfname = 'history-%s' % self.profile
         except AttributeError:
             histfname = 'history'
         self.histfile = os.path.join(self.config.IPYTHONDIR, histfname)
 
         # Fill the history zero entry, user counter starts at 1
         self.input_hist.append('\n')
         self.input_hist_raw.append('\n')
 
     def init_shadow_hist(self):
         try:
             self.db = pickleshare.PickleShareDB(self.config.IPYTHONDIR + "/db")
         except exceptions.UnicodeDecodeError:
             print "Your ipythondir can't be decoded to unicode!"
             print "Please set HOME environment variable to something that"
             print r"only has ASCII characters, e.g. c:\home"
             print "Now it is", self.config.IPYTHONDIR
             sys.exit()
         self.shadowhist = ipcorehist.ShadowHist(self.db)
 
     def savehist(self):
         """Save input history to a file (via readline library)."""
 
         if not self.has_readline:
             return
         
         try:
             self.readline.write_history_file(self.histfile)
         except:
             print 'Unable to save IPython command history to file: ' + \
                   `self.histfile`
 
     def reloadhist(self):
         """Reload the input history from disk file."""
 
         if self.has_readline:
             try:
                 self.readline.clear_history()
                 self.readline.read_history_file(self.shell.histfile)
             except AttributeError:
                 pass
 
     def history_saving_wrapper(self, func):
         """ Wrap func for readline history saving
 
         Convert func into callable that saves & restores
         history around the call """
 
         if not self.has_readline:
             return func
 
         def wrapper():
             self.savehist()
             try:
                 func()
             finally:
                 readline.read_history_file(self.histfile)
         return wrapper
 
     #-------------------------------------------------------------------------
     # Things related to exception handling and tracebacks (not debugging)
     #-------------------------------------------------------------------------
 
     def init_traceback_handlers(self, custom_exceptions):
         # Syntax error handler.
         self.SyntaxTB = SyntaxTB(color_scheme='NoColor')
         
         # The interactive one is initialized with an offset, meaning we always
         # want to remove the topmost item in the traceback, which is our own
         # internal code. Valid modes: ['Plain','Context','Verbose']
         self.InteractiveTB = ultratb.AutoFormattedTB(mode = 'Plain',
                                                      color_scheme='NoColor',
                                                      tb_offset = 1)
 
         # IPython itself shouldn't crash. This will produce a detailed
         # post-mortem if it does.  But we only install the crash handler for
         # non-threaded shells, the threaded ones use a normal verbose reporter
         # and lose the crash handler.  This is because exceptions in the main
         # thread (such as in GUI code) propagate directly to sys.excepthook,
         # and there's no point in printing crash dumps for every user exception.
         if self.isthreaded:
             ipCrashHandler = ultratb.FormattedTB()
         else:
             from IPython.core import crashhandler
             ipCrashHandler = crashhandler.IPythonCrashHandler(self)
         self.set_crash_handler(ipCrashHandler)
 
         # and add any custom exception handlers the user may have specified
         self.set_custom_exc(*custom_exceptions)
 
     def set_crash_handler(self, crashHandler):
         """Set the IPython crash handler.
 
         This must be a callable with a signature suitable for use as
         sys.excepthook."""
 
         # Install the given crash handler as the Python exception hook
         sys.excepthook = crashHandler
         
         # The instance will store a pointer to this, so that runtime code
         # (such as magics) can access it.  This is because during the
         # read-eval loop, it gets temporarily overwritten (to deal with GUI
         # frameworks).
         self.sys_excepthook = sys.excepthook
 
     def set_custom_exc(self,exc_tuple,handler):
         """set_custom_exc(exc_tuple,handler)
 
         Set a custom exception handler, which will be called if any of the
         exceptions in exc_tuple occur in the mainloop (specifically, in the
         runcode() method.
 
         Inputs:
 
           - exc_tuple: a *tuple* of valid exceptions to call the defined
           handler for.  It is very important that you use a tuple, and NOT A
           LIST here, because of the way Python's except statement works.  If
           you only want to trap a single exception, use a singleton tuple:
 
             exc_tuple == (MyCustomException,)
 
           - handler: this must be defined as a function with the following
           basic interface: def my_handler(self,etype,value,tb).
 
           This will be made into an instance method (via new.instancemethod)
           of IPython itself, and it will be called if any of the exceptions
           listed in the exc_tuple are caught.  If the handler is None, an
           internal basic one is used, which just prints basic info.
 
         WARNING: by putting in your own exception handler into IPython's main
         execution loop, you run a very good chance of nasty crashes.  This
         facility should only be used if you really know what you are doing."""
 
         assert type(exc_tuple)==type(()) , \
                "The custom exceptions must be given AS A TUPLE."
 
         def dummy_handler(self,etype,value,tb):
             print '*** Simple custom exception handler ***'
             print 'Exception type :',etype
             print 'Exception value:',value
             print 'Traceback      :',tb
             print 'Source code    :','\n'.join(self.buffer)
 
         if handler is None: handler = dummy_handler
 
         self.CustomTB = new.instancemethod(handler,self,self.__class__)
         self.custom_exceptions = exc_tuple
 
     def excepthook(self, etype, value, tb):
       """One more defense for GUI apps that call sys.excepthook.
 
       GUI frameworks like wxPython trap exceptions and call
       sys.excepthook themselves.  I guess this is a feature that
       enables them to keep running after exceptions that would
       otherwise kill their mainloop. This is a bother for IPython
       which excepts to catch all of the program exceptions with a try:
       except: statement.
 
       Normally, IPython sets sys.excepthook to a CrashHandler instance, so if
       any app directly invokes sys.excepthook, it will look to the user like
       IPython crashed.  In order to work around this, we can disable the
       CrashHandler and replace it with this excepthook instead, which prints a
       regular traceback using our InteractiveTB.  In this fashion, apps which
       call sys.excepthook will generate a regular-looking exception from
       IPython, and the CrashHandler will only be triggered by real IPython
       crashes.
 
       This hook should be used sparingly, only in places which are not likely
       to be true IPython errors.
       """
       self.showtraceback((etype,value,tb),tb_offset=0)
 
     def showtraceback(self,exc_tuple = None,filename=None,tb_offset=None):
         """Display the exception that just occurred.
 
         If nothing is known about the exception, this is the method which
         should be used throughout the code for presenting user tracebacks,
         rather than directly invoking the InteractiveTB object.
 
         A specific showsyntaxerror() also exists, but this method can take
         care of calling it if needed, so unless you are explicitly catching a
         SyntaxError exception, don't try to analyze the stack manually and
         simply call this method."""
 
         
         # Though this won't be called by syntax errors in the input line,
         # there may be SyntaxError cases whith imported code.
         
         try:
             if exc_tuple is None:
                 etype, value, tb = sys.exc_info()
             else:
                 etype, value, tb = exc_tuple
     
             if etype is SyntaxError:
                 self.showsyntaxerror(filename)
             elif etype is UsageError:
                 print "UsageError:", value
             else:
                 # WARNING: these variables are somewhat deprecated and not
                 # necessarily safe to use in a threaded environment, but tools
                 # like pdb depend on their existence, so let's set them.  If we
                 # find problems in the field, we'll need to revisit their use.
                 sys.last_type = etype
                 sys.last_value = value
                 sys.last_traceback = tb
     
                 if etype in self.custom_exceptions:
                     self.CustomTB(etype,value,tb)
                 else:
                     self.InteractiveTB(etype,value,tb,tb_offset=tb_offset)
                     if self.InteractiveTB.call_pdb and self.has_readline:
                         # pdb mucks up readline, fix it back
                         self.set_completer()
         except KeyboardInterrupt:
             self.write("\nKeyboardInterrupt\n")
 
     def showsyntaxerror(self, filename=None):
         """Display the syntax error that just occurred.
 
         This doesn't display a stack trace because there isn't one.
 
         If a filename is given, it is stuffed in the exception instead
         of what was there before (because Python's parser always uses
         "<string>" when reading from a string).
         """
         etype, value, last_traceback = sys.exc_info()
 
         # See note about these variables in showtraceback() below
         sys.last_type = etype
         sys.last_value = value
         sys.last_traceback = last_traceback
         
         if filename and etype is SyntaxError:
             # Work hard to stuff the correct filename in the exception
             try:
                 msg, (dummy_filename, lineno, offset, line) = value
             except:
                 # Not the format we expect; leave it alone
                 pass
             else:
                 # Stuff in the right filename
                 try:
                     # Assume SyntaxError is a class exception
                     value = SyntaxError(msg, (filename, lineno, offset, line))
                 except:
                     # If that failed, assume SyntaxError is a string
                     value = msg, (filename, lineno, offset, line)
         self.SyntaxTB(etype,value,[])
 
     def edit_syntax_error(self):
         """The bottom half of the syntax error handler called in the main loop.
 
         Loop until syntax error is fixed or user cancels.
         """
 
         while self.SyntaxTB.last_syntax_error:
             # copy and clear last_syntax_error
             err = self.SyntaxTB.clear_err_state()
             if not self._should_recompile(err):
                 return
             try:
                 # may set last_syntax_error again if a SyntaxError is raised
                 self.safe_execfile(err.filename,self.user_ns)
             except:
                 self.showtraceback()
             else:
                 try:
                     f = file(err.filename)
                     try:
                         # This should be inside a display_trap block and I 
                         # think it is.
                         sys.displayhook(f.read())
                     finally:
                         f.close()
                 except:
                     self.showtraceback()
 
     def _should_recompile(self,e):
         """Utility routine for edit_syntax_error"""
 
         if e.filename in ('<ipython console>','<input>','<string>',
                           '<console>','<BackgroundJob compilation>',
                           None):
                               
             return False
         try:
             if (self.autoedit_syntax and 
                 not self.ask_yes_no('Return to editor to correct syntax error? '
                               '[Y/n] ','y')):
                 return False
         except EOFError:
             return False
 
         def int0(x):
             try:
                 return int(x)
             except TypeError:
                 return 0
         # always pass integer line and offset values to editor hook
         try:
             self.hooks.fix_error_editor(e.filename,
                 int0(e.lineno),int0(e.offset),e.msg)
         except TryNext:
             warn('Could not open editor')
             return False
         return True
 
     #-------------------------------------------------------------------------
     # Things related to tab completion
     #-------------------------------------------------------------------------
 
     def complete(self, text):
         """Return a sorted list of all possible completions on text.
 
         Inputs:
 
           - text: a string of text to be completed on.
 
         This is a wrapper around the completion mechanism, similar to what
         readline does at the command line when the TAB key is hit.  By
         exposing it as a method, it can be used by other non-readline
         environments (such as GUIs) for text completion.
 
         Simple usage example:
 
         In [7]: x = 'hello'
 
         In [8]: x
         Out[8]: 'hello'
 
         In [9]: print x
         hello
 
         In [10]: _ip.complete('x.l')
         Out[10]: ['x.ljust', 'x.lower', 'x.lstrip']
         """
 
         # Inject names into __builtin__ so we can complete on the added names.
         with self.builtin_trap:
             complete = self.Completer.complete
             state = 0
             # use a dict so we get unique keys, since ipyhton's multiple
             # completers can return duplicates.  When we make 2.4 a requirement,
             # start using sets instead, which are faster.
             comps = {}
             while True:
                 newcomp = complete(text,state,line_buffer=text)
                 if newcomp is None:
                     break
                 comps[newcomp] = 1
                 state += 1
             outcomps = comps.keys()
             outcomps.sort()
             #print "T:",text,"OC:",outcomps  # dbg
             #print "vars:",self.user_ns.keys()
             return outcomps
 
     def set_custom_completer(self,completer,pos=0):
         """set_custom_completer(completer,pos=0)
 
         Adds a new custom completer function.
 
         The position argument (defaults to 0) is the index in the completers
         list where you want the completer to be inserted."""
 
         newcomp = new.instancemethod(completer,self.Completer,
                                      self.Completer.__class__)
         self.Completer.matchers.insert(pos,newcomp)
 
     def set_completer(self):
         """reset readline's completer to be our own."""
         self.readline.set_completer(self.Completer.complete)
 
     #-------------------------------------------------------------------------
     # Things related to readline
     #-------------------------------------------------------------------------
 
     def init_readline(self):
         """Command history completion/saving/reloading."""
 
         self.rl_next_input = None
         self.rl_do_indent = False
 
         if not self.readline_use:
             return
 
         import IPython.utils.rlineimpl as readline
                   
         if not readline.have_readline:
             self.has_readline = 0
             self.readline = None
             # no point in bugging windows users with this every time:
             warn('Readline services not available on this platform.')
         else:
             sys.modules['readline'] = readline
             import atexit
             from IPython.core.completer import IPCompleter
             self.Completer = IPCompleter(self,
                                             self.user_ns,
                                             self.user_global_ns,
                                             self.readline_omit__names,
                                             self.alias_table)
             sdisp = self.strdispatchers.get('complete_command', StrDispatch())
             self.strdispatchers['complete_command'] = sdisp
             self.Completer.custom_completers = sdisp
             # Platform-specific configuration
             if os.name == 'nt':
                 self.readline_startup_hook = readline.set_pre_input_hook
             else:
                 self.readline_startup_hook = readline.set_startup_hook
 
             # Load user's initrc file (readline config)
             # Or if libedit is used, load editrc.
             inputrc_name = os.environ.get('INPUTRC')
             if inputrc_name is None:
                 home_dir = get_home_dir()
                 if home_dir is not None:
                     inputrc_name = '.inputrc'
                     if readline.uses_libedit:
                         inputrc_name = '.editrc'
                     inputrc_name = os.path.join(home_dir, inputrc_name)
             if os.path.isfile(inputrc_name):
                 try:
                     readline.read_init_file(inputrc_name)
                 except:
                     warn('Problems reading readline initialization file <%s>'
                          % inputrc_name)
             
             self.has_readline = 1
             self.readline = readline
             # save this in sys so embedded copies can restore it properly
             sys.ipcompleter = self.Completer.complete
             self.set_completer()
 
             # Configure readline according to user's prefs
             # This is only done if GNU readline is being used.  If libedit
             # is being used (as on Leopard) the readline config is
             # not run as the syntax for libedit is different.
             if not readline.uses_libedit:
                 for rlcommand in self.readline_parse_and_bind:
                     #print "loading rl:",rlcommand  # dbg
                     readline.parse_and_bind(rlcommand)
 
             # Remove some chars from the delimiters list.  If we encounter
             # unicode chars, discard them.
             delims = readline.get_completer_delims().encode("ascii", "ignore")
             delims = delims.translate(string._idmap,
                                       self.readline_remove_delims)
             readline.set_completer_delims(delims)
             # otherwise we end up with a monster history after a while:
             readline.set_history_length(1000)
             try:
                 #print '*** Reading readline history'  # dbg
                 readline.read_history_file(self.histfile)
             except IOError:
                 pass  # It doesn't exist yet.
 
             atexit.register(self.atexit_operations)
             del atexit
 
         # Configure auto-indent for all platforms
         self.set_autoindent(self.autoindent)
 
     def set_next_input(self, s):
         """ Sets the 'default' input string for the next command line.
         
         Requires readline.
         
         Example:
         
         [D:\ipython]|1> _ip.set_next_input("Hello Word")
         [D:\ipython]|2> Hello Word_  # cursor is here        
         """
 
         self.rl_next_input = s
 
     def pre_readline(self):
         """readline hook to be used at the start of each line.
 
         Currently it handles auto-indent only."""
 
         #debugx('self.indent_current_nsp','pre_readline:')
 
         if self.rl_do_indent:
             self.readline.insert_text(self._indent_current_str())
         if self.rl_next_input is not None:
             self.readline.insert_text(self.rl_next_input)
             self.rl_next_input = None
 
     def _indent_current_str(self):
         """return the current level of indentation as a string"""
         return self.indent_current_nsp * ' '
 
     #-------------------------------------------------------------------------
     # Things related to magics
     #-------------------------------------------------------------------------
 
     def init_magics(self):
         # Set user colors (don't do it in the constructor above so that it
         # doesn't crash if colors option is invalid)
         self.magic_colors(self.colors)
 
     def magic(self,arg_s):
         """Call a magic function by name.
 
         Input: a string containing the name of the magic function to call and any
         additional arguments to be passed to the magic.
 
         magic('name -opt foo bar') is equivalent to typing at the ipython
         prompt:
 
         In[1]: %name -opt foo bar
 
         To call a magic without arguments, simply use magic('name').
 
         This provides a proper Python function to call IPython's magics in any
         valid Python code you can type at the interpreter, including loops and
         compound statements.
         """
 
         args = arg_s.split(' ',1)
         magic_name = args[0]
-        magic_name = magic_name.lstrip(self.ESC_MAGIC)
+        magic_name = magic_name.lstrip(prefilter.ESC_MAGIC)
 
         try:
             magic_args = args[1]
         except IndexError:
             magic_args = ''
         fn = getattr(self,'magic_'+magic_name,None)
         if fn is None:
             error("Magic function `%s` not found." % magic_name)
         else:
             magic_args = self.var_expand(magic_args,1)
             with nested(self.builtin_trap, self.display_trap):
                 return fn(magic_args)
-            # return result
 
     def define_magic(self, magicname, func):
         """Expose own function as magic function for ipython 
     
         def foo_impl(self,parameter_s=''):
             'My very own magic!. (Use docstrings, IPython reads them).'
             print 'Magic function. Passed parameter is between < >:'
             print '<%s>' % parameter_s
             print 'The self object is:',self
     
         self.define_magic('foo',foo_impl)
         """
         
         import new
         im = new.instancemethod(func,self, self.__class__)
         old = getattr(self, "magic_" + magicname, None)
         setattr(self, "magic_" + magicname, im)
         return old
 
     #-------------------------------------------------------------------------
     # Things related to macros
     #-------------------------------------------------------------------------
 
     def define_macro(self, name, themacro):
         """Define a new macro
 
         Parameters
         ----------
         name : str
             The name of the macro.
         themacro : str or Macro
             The action to do upon invoking the macro.  If a string, a new 
             Macro object is created by passing the string to it.
         """
         
         from IPython.core import macro
 
         if isinstance(themacro, basestring):
             themacro = macro.Macro(themacro)
         if not isinstance(themacro, macro.Macro):
             raise ValueError('A macro must be a string or a Macro instance.')
         self.user_ns[name] = themacro
 
     #-------------------------------------------------------------------------
     # Things related to the running of system commands
     #-------------------------------------------------------------------------
 
     def system(self, cmd):
         """Make a system call, using IPython."""
         return self.hooks.shell_hook(self.var_expand(cmd, depth=2))
 
     #-------------------------------------------------------------------------
     # Things related to aliases
     #-------------------------------------------------------------------------
 
     def init_alias(self):
         self.alias_manager = AliasManager(self, config=self.config)
 
-    def expand_alias(self, line):
-        """ Expand an alias in the command line 
-        
-        Returns the provided command line, possibly with the first word 
-        (command) translated according to alias expansion rules.
-        
-        [ipython]|16> _ip.expand_aliases("np myfile.txt")
-                 <16> 'q:/opt/np/notepad++.exe myfile.txt'
-        """
-        
-        pre,fn,rest = self.split_user_input(line)
-        res = pre + self.expand_aliases(fn, rest)
-        return res
-
-    def expand_aliases(self, fn, rest):
-        """Expand multiple levels of aliases:
-        
-        if:
-        
-        alias foo bar /tmp
-        alias baz foo
-        
-        then:
-        
-        baz huhhahhei -> bar /tmp huhhahhei
-        
-        """
-        line = fn + " " + rest
-        
-        done = set()
-        while 1:
-            pre,fn,rest = prefilter.splitUserInput(line,
-                                                   prefilter.shell_line_split)
-            if fn in self.alias_manager.alias_table:
-                if fn in done:
-                    warn("Cyclic alias definition, repeated '%s'" % fn)
-                    return ""
-                done.add(fn)
-
-                l2 = self.alias_manager.transform_alias(fn, rest)
-                if l2 == line:
-                    break
-                # ls -> ls -F should not recurse forever
-                if l2.split(None,1)[0] == line.split(None,1)[0]:
-                    line = l2
-                    break
-                line=l2
-            else:
-                break
-                
-        return line
-
     #-------------------------------------------------------------------------
     # Things related to the running of code
     #-------------------------------------------------------------------------
 
     def ex(self, cmd):
         """Execute a normal python statement in user namespace."""
         with nested(self.builtin_trap, self.display_trap):
             exec cmd in self.user_global_ns, self.user_ns
 
     def ev(self, expr):
         """Evaluate python expression expr in user namespace.
 
         Returns the result of evaluation
         """
         with nested(self.builtin_trap, self.display_trap):
             return eval(expr, self.user_global_ns, self.user_ns)
 
     def mainloop(self, banner=None):
         """Start the mainloop.
 
         If an optional banner argument is given, it will override the
         internally created default banner.
         """
         
         with nested(self.builtin_trap, self.display_trap):
             if self.c:  # Emulate Python's -c option
                 self.exec_init_cmd()
 
             if self.display_banner:
                 if banner is None:
                     banner = self.banner
 
             # if you run stuff with -c <cmd>, raw hist is not updated
             # ensure that it's in sync
             if len(self.input_hist) != len (self.input_hist_raw):
                 self.input_hist_raw = InputList(self.input_hist)
 
             while 1:
                 try:
                     self.interact()
                     #self.interact_with_readline()                
                     # XXX for testing of a readline-decoupled repl loop, call
                     # interact_with_readline above
                     break
                 except KeyboardInterrupt:
                     # this should not be necessary, but KeyboardInterrupt
                     # handling seems rather unpredictable...
                     self.write("\nKeyboardInterrupt in interact()\n")
 
     def exec_init_cmd(self):
         """Execute a command given at the command line.
 
         This emulates Python's -c option."""
 
         #sys.argv = ['-c']
-        self.push_line(self.prefilter(self.c, False))
+        self.push_line(self.prefilter_manager.prefilter_lines(self.c, False))
         if not self.interactive:
             self.ask_exit()
 
     def interact_prompt(self):
         """ Print the prompt (in read-eval-print loop) 
 
         Provided for those who want to implement their own read-eval-print loop (e.g. GUIs), not 
         used in standard IPython flow.
         """
         if self.more:
             try:
                 prompt = self.hooks.generate_prompt(True)
             except:
                 self.showtraceback()
             if self.autoindent:
                 self.rl_do_indent = True
 
         else:
             try:
                 prompt = self.hooks.generate_prompt(False)
             except:
                 self.showtraceback()
         self.write(prompt)
 
     def interact_handle_input(self,line):
         """ Handle the input line (in read-eval-print loop)
         
         Provided for those who want to implement their own read-eval-print loop (e.g. GUIs), not 
         used in standard IPython flow.        
         """
         if line.lstrip() == line:
             self.shadowhist.add(line.strip())
-        lineout = self.prefilter(line,self.more)
+        lineout = self.prefilter_manager.prefilter_lines(line,self.more)
 
         if line.strip():
             if self.more:
                 self.input_hist_raw[-1] += '%s\n' % line
             else:
                 self.input_hist_raw.append('%s\n' % line)                
 
         
         self.more = self.push_line(lineout)
         if (self.SyntaxTB.last_syntax_error and
             self.autoedit_syntax):
             self.edit_syntax_error()
 
     def interact_with_readline(self):
         """ Demo of using interact_handle_input, interact_prompt
         
         This is the main read-eval-print loop. If you need to implement your own (e.g. for GUI),
         it should work like this.
         """ 
         self.readline_startup_hook(self.pre_readline)
         while not self.exit_now:
             self.interact_prompt()
             if self.more:
                 self.rl_do_indent = True
             else:
                 self.rl_do_indent = False
             line = raw_input_original().decode(self.stdin_encoding)
             self.interact_handle_input(line)
 
     def interact(self, banner=None):
         """Closely emulate the interactive Python console."""
 
         # batch run -> do not interact        
         if self.exit_now:
             return
 
         if self.display_banner:
             if banner is None:
                 banner = self.banner
             self.write(banner)
 
         more = 0
         
         # Mark activity in the builtins
         __builtin__.__dict__['__IPYTHON__active'] += 1
         
         if self.has_readline:
             self.readline_startup_hook(self.pre_readline)
         # exit_now is set by a call to %Exit or %Quit, through the
         # ask_exit callback.
         
         while not self.exit_now:
             self.hooks.pre_prompt_hook()
             if more:
                 try:
                     prompt = self.hooks.generate_prompt(True)
                 except:
                     self.showtraceback()
                 if self.autoindent:
                     self.rl_do_indent = True
                     
             else:
                 try:
                     prompt = self.hooks.generate_prompt(False)
                 except:
                     self.showtraceback()
             try:
                 line = self.raw_input(prompt, more)
                 if self.exit_now:
                     # quick exit on sys.std[in|out] close
                     break
                 if self.autoindent:
                     self.rl_do_indent = False
                     
             except KeyboardInterrupt:
                 #double-guard against keyboardinterrupts during kbdint handling
                 try:
                     self.write('\nKeyboardInterrupt\n')
                     self.resetbuffer()
                     # keep cache in sync with the prompt counter:
                     self.outputcache.prompt_count -= 1
     
                     if self.autoindent:
                         self.indent_current_nsp = 0
                     more = 0
                 except KeyboardInterrupt:
                     pass
             except EOFError:
                 if self.autoindent:
                     self.rl_do_indent = False
                     self.readline_startup_hook(None)
                 self.write('\n')
                 self.exit()
             except bdb.BdbQuit:
                 warn('The Python debugger has exited with a BdbQuit exception.\n'
                      'Because of how pdb handles the stack, it is impossible\n'
                      'for IPython to properly format this particular exception.\n'
                      'IPython will resume normal operation.')
             except:
                 # exceptions here are VERY RARE, but they can be triggered
                 # asynchronously by signal handlers, for example.
                 self.showtraceback()
             else:
                 more = self.push_line(line)
                 if (self.SyntaxTB.last_syntax_error and
                     self.autoedit_syntax):
                     self.edit_syntax_error()
             
         # We are off again...
         __builtin__.__dict__['__IPYTHON__active'] -= 1
 
     def safe_execfile(self,fname,*where,**kw):
         """A safe version of the builtin execfile().
 
         This version will never throw an exception, and knows how to handle
         ipython logs as well.
 
         :Parameters:
           fname : string
             Name of the file to be executed.
             
           where : tuple
             One or two namespaces, passed to execfile() as (globals,locals).
             If only one is given, it is passed as both.
 
         :Keywords:
           islog : boolean (False)
 
           quiet : boolean (True)
 
           exit_ignore : boolean (False)
           """
 
         def syspath_cleanup():
             """Internal cleanup routine for sys.path."""
             if add_dname:
                 try:
                     sys.path.remove(dname)
                 except ValueError:
                     # For some reason the user has already removed it, ignore.
                     pass
         
         fname = os.path.expanduser(fname)
 
         # Find things also in current directory.  This is needed to mimic the
         # behavior of running a script from the system command line, where
         # Python inserts the script's directory into sys.path
         dname = os.path.dirname(os.path.abspath(fname))
         add_dname = False
         if dname not in sys.path:
             sys.path.insert(0,dname)
             add_dname = True
 
         try:
             xfile = open(fname)
         except:
             print >> Term.cerr, \
                   'Could not open file <%s> for safe execution.' % fname
             syspath_cleanup()
             return None
 
         kw.setdefault('islog',0)
         kw.setdefault('quiet',1)
         kw.setdefault('exit_ignore',0)
         
         first = xfile.readline()
         loghead = str(self.loghead_tpl).split('\n',1)[0].strip()
         xfile.close()
         # line by line execution
         if first.startswith(loghead) or kw['islog']:
             print 'Loading log file <%s> one line at a time...' % fname
             if kw['quiet']:
                 stdout_save = sys.stdout
                 sys.stdout = StringIO.StringIO()
             try:
                 globs,locs = where[0:2]
             except:
                 try:
                     globs = locs = where[0]
                 except:
                     globs = locs = globals()
             badblocks = []
 
             # we also need to identify indented blocks of code when replaying
             # logs and put them together before passing them to an exec
             # statement. This takes a bit of regexp and look-ahead work in the
             # file. It's easiest if we swallow the whole thing in memory
             # first, and manually walk through the lines list moving the
             # counter ourselves.
             indent_re = re.compile('\s+\S')
             xfile = open(fname)
             filelines = xfile.readlines()
             xfile.close()
             nlines = len(filelines)
             lnum = 0
             while lnum < nlines:
                 line = filelines[lnum]
                 lnum += 1
                 # don't re-insert logger status info into cache
                 if line.startswith('#log#'):
                     continue
                 else:
                     # build a block of code (maybe a single line) for execution
                     block = line
                     try:
                         next = filelines[lnum] # lnum has already incremented
                     except:
                         next = None
                     while next and indent_re.match(next):
                         block += next
                         lnum += 1
                         try:
                             next = filelines[lnum]
                         except:
                             next = None
                     # now execute the block of one or more lines
                     try:
                         exec block in globs,locs
                     except SystemExit:
                         pass
                     except:
                         badblocks.append(block.rstrip())
             if kw['quiet']:  # restore stdout
                 sys.stdout.close()
                 sys.stdout = stdout_save
             print 'Finished replaying log file <%s>' % fname
             if badblocks:
                 print >> sys.stderr, ('\nThe following lines/blocks in file '
                                       '<%s> reported errors:' % fname)
                     
                 for badline in badblocks:
                     print >> sys.stderr, badline
         else:  # regular file execution
             try:
                 if sys.platform == 'win32' and sys.version_info < (2,5,1):
                     # Work around a bug in Python for Windows.  The bug was
                     # fixed in in Python 2.5 r54159 and 54158, but that's still
                     # SVN Python as of March/07.  For details, see:
                     # http://projects.scipy.org/ipython/ipython/ticket/123
                     try:
                         globs,locs = where[0:2]
                     except:
                         try:
                             globs = locs = where[0]
                         except:
                             globs = locs = globals()
                     exec file(fname) in globs,locs
                 else:
                     execfile(fname,*where)
             except SyntaxError:
                 self.showsyntaxerror()
                 warn('Failure executing file: <%s>' % fname)
             except SystemExit,status:
                 # Code that correctly sets the exit status flag to success (0)
                 # shouldn't be bothered with a traceback.  Note that a plain
                 # sys.exit() does NOT set the message to 0 (it's empty) so that
                 # will still get a traceback.  Note that the structure of the
                 # SystemExit exception changed between Python 2.4 and 2.5, so
                 # the checks must be done in a version-dependent way.
                 show = False
 
                 if sys.version_info[:2] > (2,5):
                     if status.message!=0 and not kw['exit_ignore']:
                         show = True
                 else:
                     if status.code and not kw['exit_ignore']:
                         show = True
                 if show:
                     self.showtraceback()
                     warn('Failure executing file: <%s>' % fname)
             except:
                 self.showtraceback()
                 warn('Failure executing file: <%s>' % fname)
 
         syspath_cleanup()
 
     def cleanup_ipy_script(self, script):
         """Make a script safe for self.runlines()
 
         Notes
         -----
         This was copied over from the old ipapi and probably can be done
         away with once we move to block based interpreter.
         
         - Removes empty lines Suffixes all indented blocks that end with
         - unindented lines with empty lines
         """
         
         res = []
         lines = script.splitlines()
 
         level = 0
         for l in lines:
             lstripped = l.lstrip()
             stripped = l.strip()                
             if not stripped:
                 continue
             newlevel = len(l) - len(lstripped)
             def is_secondary_block_start(s):
                 if not s.endswith(':'):
                     return False
                 if (s.startswith('elif') or 
                     s.startswith('else') or 
                     s.startswith('except') or
                     s.startswith('finally')):
                     return True
                     
             if level > 0 and newlevel == 0 and \
                    not is_secondary_block_start(stripped): 
                 # add empty line
                 res.append('')
                 
             res.append(l)
             level = newlevel
         return '\n'.join(res) + '\n'
 
     def runlines(self, lines, clean=False):
         """Run a string of one or more lines of source.
 
         This method is capable of running a string containing multiple source
         lines, as if they had been entered at the IPython prompt.  Since it
         exposes IPython's processing machinery, the given strings can contain
         magic calls (%magic), special shell access (!cmd), etc.
         """
 
         if isinstance(lines, (list, tuple)):
             lines = '\n'.join(lines)
 
         if clean:
             lines = self.cleanup_ipy_script(lines)
 
         # We must start with a clean buffer, in case this is run from an
         # interactive IPython session (via a magic, for example).
         self.resetbuffer()
         lines = lines.splitlines()
         more = 0
 
         with nested(self.builtin_trap, self.display_trap):
             for line in lines:
                 # skip blank lines so we don't mess up the prompt counter, but do
                 # NOT skip even a blank line if we are in a code block (more is
                 # true)
             
                 if line or more:
                     # push to raw history, so hist line numbers stay in sync
                     self.input_hist_raw.append("# " + line + "\n")
-                    more = self.push_line(self.prefilter(line,more))
+                    more = self.push_line(self.prefilter_manager.prefilter_lines(line,more))
                     # IPython's runsource returns None if there was an error
                     # compiling the code.  This allows us to stop processing right
                     # away, so the user gets the error message at the right place.
                     if more is None:
                         break
                 else:
                     self.input_hist_raw.append("\n")
             # final newline in case the input didn't have it, so that the code
             # actually does get executed
             if more:
                 self.push_line('\n')
 
     def runsource(self, source, filename='<input>', symbol='single'):
         """Compile and run some source in the interpreter.
 
         Arguments are as for compile_command().
 
         One several things can happen:
 
         1) The input is incorrect; compile_command() raised an
         exception (SyntaxError or OverflowError).  A syntax traceback
         will be printed by calling the showsyntaxerror() method.
 
         2) The input is incomplete, and more input is required;
         compile_command() returned None.  Nothing happens.
 
         3) The input is complete; compile_command() returned a code
         object.  The code is executed by calling self.runcode() (which
         also handles run-time exceptions, except for SystemExit).
 
         The return value is:
 
           - True in case 2
 
           - False in the other cases, unless an exception is raised, where
           None is returned instead.  This can be used by external callers to
           know whether to continue feeding input or not.
 
         The return value can be used to decide whether to use sys.ps1 or
         sys.ps2 to prompt the next line."""
 
         # if the source code has leading blanks, add 'if 1:\n' to it
         # this allows execution of indented pasted code. It is tempting
         # to add '\n' at the end of source to run commands like ' a=1'
         # directly, but this fails for more complicated scenarios
         source=source.encode(self.stdin_encoding)
         if source[:1] in [' ', '\t']:
             source = 'if 1:\n%s' % source
 
         try:
             code = self.compile(source,filename,symbol)
         except (OverflowError, SyntaxError, ValueError, TypeError, MemoryError):
             # Case 1
             self.showsyntaxerror(filename)
             return None
 
         if code is None:
             # Case 2
             return True
 
         # Case 3
         # We store the code object so that threaded shells and
         # custom exception handlers can access all this info if needed.
         # The source corresponding to this can be obtained from the
         # buffer attribute as '\n'.join(self.buffer).
         self.code_to_run = code
         # now actually execute the code object
         if self.runcode(code) == 0:
             return False
         else:
             return None
 
     def runcode(self,code_obj):
         """Execute a code object.
 
         When an exception occurs, self.showtraceback() is called to display a
         traceback.
 
         Return value: a flag indicating whether the code to be run completed
         successfully:
 
           - 0: successful execution.
           - 1: an error occurred.
         """
 
         # Set our own excepthook in case the user code tries to call it
         # directly, so that the IPython crash handler doesn't get triggered
         old_excepthook,sys.excepthook = sys.excepthook, self.excepthook
 
         # we save the original sys.excepthook in the instance, in case config
         # code (such as magics) needs access to it.
         self.sys_excepthook = old_excepthook
         outflag = 1  # happens in more places, so it's easier as default
         try:
             try:
                 self.hooks.pre_runcode_hook()
                 exec code_obj in self.user_global_ns, self.user_ns
             finally:
                 # Reset our crash handler in place
                 sys.excepthook = old_excepthook
         except SystemExit:
             self.resetbuffer()
             self.showtraceback()
             warn("Type %exit or %quit to exit IPython "
                  "(%Exit or %Quit do so unconditionally).",level=1)
         except self.custom_exceptions:
             etype,value,tb = sys.exc_info()
             self.CustomTB(etype,value,tb)
         except:
             self.showtraceback()
         else:
             outflag = 0
             if softspace(sys.stdout, 0):
                 print
         # Flush out code object which has been run (and source)
         self.code_to_run = None
         return outflag
         
     def push_line(self, line):
         """Push a line to the interpreter.
 
         The line should not have a trailing newline; it may have
         internal newlines.  The line is appended to a buffer and the
         interpreter's runsource() method is called with the
         concatenated contents of the buffer as source.  If this
         indicates that the command was executed or invalid, the buffer
         is reset; otherwise, the command is incomplete, and the buffer
         is left as it was after the line was appended.  The return
         value is 1 if more input is required, 0 if the line was dealt
         with in some way (this is the same as runsource()).
         """
 
         # autoindent management should be done here, and not in the
         # interactive loop, since that one is only seen by keyboard input.  We
         # need this done correctly even for code run via runlines (which uses
         # push).
 
         #print 'push line: <%s>' % line  # dbg
         for subline in line.splitlines():
             self._autoindent_update(subline)
         self.buffer.append(line)
         more = self.runsource('\n'.join(self.buffer), self.filename)
         if not more:
             self.resetbuffer()
         return more
 
     def _autoindent_update(self,line):
         """Keep track of the indent level."""
 
         #debugx('line')
         #debugx('self.indent_current_nsp')
         if self.autoindent:
             if line:
                 inisp = num_ini_spaces(line)
                 if inisp < self.indent_current_nsp:
                     self.indent_current_nsp = inisp
 
                 if line[-1] == ':':
                     self.indent_current_nsp += 4
                 elif dedent_re.match(line):
                     self.indent_current_nsp -= 4
             else:
                 self.indent_current_nsp = 0
 
-    def split_user_input(self, line):
-        # This is really a hold-over to support ipapi and some extensions
-        return prefilter.splitUserInput(line)
-
     def resetbuffer(self):
         """Reset the input buffer."""
         self.buffer[:] = []
         
     def raw_input(self,prompt='',continue_prompt=False):
         """Write a prompt and read a line.
 
         The returned line does not include the trailing newline.
         When the user enters the EOF key sequence, EOFError is raised.
 
         Optional inputs:
 
           - prompt(''): a string to be printed to prompt the user.
 
           - continue_prompt(False): whether this line is the first one or a
           continuation in a sequence of inputs.
         """
-        growl.notify("raw_input: ", "prompt = %r\ncontinue_prompt = %s" % (prompt, continue_prompt))
+        # growl.notify("raw_input: ", "prompt = %r\ncontinue_prompt = %s" % (prompt, continue_prompt))
+
         # Code run by the user may have modified the readline completer state.
         # We must ensure that our completer is back in place.
 
         if self.has_readline:
             self.set_completer()
         
         try:
             line = raw_input_original(prompt).decode(self.stdin_encoding)
         except ValueError:
             warn("\n********\nYou or a %run:ed script called sys.stdin.close()"
                  " or sys.stdout.close()!\nExiting IPython!")
             self.ask_exit()
             return ""
 
         # Try to be reasonably smart about not re-indenting pasted input more
         # than necessary.  We do this by trimming out the auto-indent initial
         # spaces, if the user's actual input started itself with whitespace.
         #debugx('self.buffer[-1]')
 
         if self.autoindent:
             if num_ini_spaces(line) > self.indent_current_nsp:
                 line = line[self.indent_current_nsp:]
                 self.indent_current_nsp = 0
             
         # store the unfiltered input before the user has any chance to modify
         # it.
         if line.strip():
             if continue_prompt:
                 self.input_hist_raw[-1] += '%s\n' % line
                 if self.has_readline: # and some config option is set?
                     try:
                         histlen = self.readline.get_current_history_length()
                         if histlen > 1:
                             newhist = self.input_hist_raw[-1].rstrip()
                             self.readline.remove_history_item(histlen-1)
                             self.readline.replace_history_item(histlen-2,
                                             newhist.encode(self.stdin_encoding))
                     except AttributeError:
                         pass # re{move,place}_history_item are new in 2.4.                
             else:
                 self.input_hist_raw.append('%s\n' % line)                
             # only entries starting at first column go to shadow history
             if line.lstrip() == line:
                 self.shadowhist.add(line.strip())
         elif not continue_prompt:
             self.input_hist_raw.append('\n')
         try:
-            lineout = self.prefilter(line,continue_prompt)
+            lineout = self.prefilter_manager.prefilter_lines(line,continue_prompt)
         except:
             # blanket except, in case a user-defined prefilter crashes, so it
             # can't take all of ipython with it.
             self.showtraceback()
             return ''
         else:
             return lineout
 
     # def init_exec_commands(self):
     #     for cmd in self.config.EXECUTE:
     #         print "execute:", cmd
     #         self.api.runlines(cmd)
     #         
     #     batchrun = False
     #     if self.config.has_key('EXECFILE'):
     #         for batchfile in [path(arg) for arg in self.config.EXECFILE
     #             if arg.lower().endswith('.ipy')]:
     #             if not batchfile.isfile():
     #                 print "No such batch file:", batchfile
     #                 continue
     #             self.api.runlines(batchfile.text())
     #             batchrun = True
     #     # without -i option, exit after running the batch file
     #     if batchrun and not self.interactive:
     #         self.ask_exit()            
 
     # def load(self, mod):
     #     """ Load an extension.
     #     
     #     Some modules should (or must) be 'load()':ed, rather than just imported.
     #     
     #     Loading will do:
     #     
     #     - run init_ipython(ip)
     #     - run ipython_firstrun(ip)
     #     """
     # 
     #     if mod in self.extensions:
     #         # just to make sure we don't init it twice
     #         # note that if you 'load' a module that has already been
     #         # imported, init_ipython gets run anyway
     #         
     #         return self.extensions[mod]
     #     __import__(mod)
     #     m = sys.modules[mod]
     #     if hasattr(m,'init_ipython'):
     #         m.init_ipython(self)
     #         
     #     if hasattr(m,'ipython_firstrun'):
     #         already_loaded = self.db.get('firstrun_done', set())
     #         if mod not in already_loaded:
     #             m.ipython_firstrun(self)
     #             already_loaded.add(mod)
     #             self.db['firstrun_done'] = already_loaded
     #         
     #     self.extensions[mod] = m
     #     return m
 
     #-------------------------------------------------------------------------
     # Things related to the prefilter
     #-------------------------------------------------------------------------
 
-    def init_handlers(self):
-        # escapes for automatic behavior on the command line
-        self.ESC_SHELL  = '!'
-        self.ESC_SH_CAP = '!!'
-        self.ESC_HELP   = '?'
-        self.ESC_MAGIC  = '%'
-        self.ESC_QUOTE  = ','
-        self.ESC_QUOTE2 = ';'
-        self.ESC_PAREN  = '/'
-
-        # And their associated handlers
-        self.esc_handlers = {self.ESC_PAREN  : self.handle_auto,
-                             self.ESC_QUOTE  : self.handle_auto,
-                             self.ESC_QUOTE2 : self.handle_auto,
-                             self.ESC_MAGIC  : self.handle_magic,
-                             self.ESC_HELP   : self.handle_help,
-                             self.ESC_SHELL  : self.handle_shell_escape,
-                             self.ESC_SH_CAP : self.handle_shell_escape,
-                             }
-
-    def _prefilter(self, line, continue_prompt):
-        """Calls different preprocessors, depending on the form of line."""
-
-        # All handlers *must* return a value, even if it's blank ('').
-
-        # Lines are NOT logged here. Handlers should process the line as
-        # needed, update the cache AND log it (so that the input cache array
-        # stays synced).
-
-        #.....................................................................
-        # Code begins
-
-        #if line.startswith('%crash'): raise RuntimeError,'Crash now!'  # dbg
-
-        # save the line away in case we crash, so the post-mortem handler can
-        # record it
-        growl.notify("_prefilter: ", "line = %s\ncontinue_prompt = %s" % (line, continue_prompt))
-        
-        self._last_input_line = line
-
-        #print '***line: <%s>' % line # dbg
-
-        if not line:
-            # Return immediately on purely empty lines, so that if the user
-            # previously typed some whitespace that started a continuation
-            # prompt, he can break out of that loop with just an empty line.
-            # This is how the default python prompt works.
-
-            # Only return if the accumulated input buffer was just whitespace!
-            if ''.join(self.buffer).isspace():
-                self.buffer[:] = []
-            return ''
-        
-        line_info = prefilter.LineInfo(line, continue_prompt)
-        
-        # the input history needs to track even empty lines
-        stripped = line.strip()
-        
-        if not stripped:
-            if not continue_prompt:
-                self.outputcache.prompt_count -= 1
-            return self.handle_normal(line_info)
-
-        # print '***cont',continue_prompt  # dbg
-        # special handlers are only allowed for single line statements
-        if continue_prompt and not self.multi_line_specials:
-            return self.handle_normal(line_info)
-
-
-        # See whether any pre-existing handler can take care of it  
-        rewritten = self.hooks.input_prefilter(stripped)
-        if rewritten != stripped: # ok, some prefilter did something
-            rewritten = line_info.pre + rewritten  # add indentation
-            return self.handle_normal(prefilter.LineInfo(rewritten,
-                                                         continue_prompt))
-            
-        #print 'pre <%s> iFun <%s> rest <%s>' % (pre,iFun,theRest)  # dbg
-        
-        return prefilter.prefilter(line_info, self)
-
-
-    def _prefilter_dumb(self, line, continue_prompt):
-        """simple prefilter function, for debugging"""
-        return self.handle_normal(line,continue_prompt)
-
-    
-    def multiline_prefilter(self, line, continue_prompt):
-        """ Run _prefilter for each line of input
-        
-        Covers cases where there are multiple lines in the user entry,
-        which is the case when the user goes back to a multiline history
-        entry and presses enter.
-        
-        """
-        growl.notify("multiline_prefilter: ", "%s\n%s" % (line, continue_prompt))
-        out = []
-        for l in line.rstrip('\n').split('\n'):
-            out.append(self._prefilter(l, continue_prompt))
-        growl.notify("multiline_prefilter return: ", '\n'.join(out))
-        return '\n'.join(out)
-    
-    # Set the default prefilter() function (this can be user-overridden)
-    prefilter = multiline_prefilter
-
-    def handle_normal(self, line_info):
-        """Handle normal input lines. Use as a template for handlers."""
-
-        # With autoindent on, we need some way to exit the input loop, and I
-        # don't want to force the user to have to backspace all the way to
-        # clear the line.  The rule will be in this case, that either two
-        # lines of pure whitespace in a row, or a line of pure whitespace but
-        # of a size different to the indent level, will exit the input loop.
-        line = line_info.line
-        continue_prompt = line_info.continue_prompt
-        
-        if (continue_prompt and self.autoindent and line.isspace() and
-            (0 < abs(len(line) - self.indent_current_nsp) <= 2 or
-             (self.buffer[-1]).isspace() )):
-            line = ''
-
-        self.log(line,line,continue_prompt)
-        return line
-
-    def handle_alias(self, line_info):
-        """Handle alias input lines. """
-        tgt = self.alias_manager.alias_table[line_info.iFun]
-        if callable(tgt):
-            if '$' in line_info.line:
-                call_meth = '(_ip, _ip.var_expand(%s))'
-            else:
-                call_meth = '(_ip,%s)'
-            line_out = ("%s_sh.%s" + call_meth) % (line_info.preWhitespace,
-                                         line_info.iFun, 
-            make_quoted_expr(line_info.line))
-        else:
-            transformed = self.expand_aliases(line_info.iFun,line_info.theRest)
-
-            # pre is needed, because it carries the leading whitespace.  Otherwise
-            # aliases won't work in indented sections.
-            line_out = '%s_ip.system(%s)' % (line_info.preWhitespace,
-                                             make_quoted_expr( transformed ))
-        
-        self.log(line_info.line,line_out,line_info.continue_prompt)
-        #print 'line out:',line_out # dbg
-        return line_out
-
-    def handle_shell_escape(self, line_info):
-        """Execute the line in a shell, empty return value"""
-        #print 'line in :', `line` # dbg
-        line = line_info.line
-        if line.lstrip().startswith('!!'):
-            # rewrite LineInfo's line, iFun and theRest to properly hold the
-            # call to %sx and the actual command to be executed, so
-            # handle_magic can work correctly.  Note that this works even if
-            # the line is indented, so it handles multi_line_specials
-            # properly.
-            new_rest = line.lstrip()[2:]
-            line_info.line = '%ssx %s' % (self.ESC_MAGIC,new_rest)
-            line_info.iFun = 'sx'
-            line_info.theRest = new_rest
-            return self.handle_magic(line_info)
-        else:
-            cmd = line.lstrip().lstrip('!')
-            line_out = '%s_ip.system(%s)' % (line_info.preWhitespace,
-                                             make_quoted_expr(cmd))
-        # update cache/log and return
-        self.log(line,line_out,line_info.continue_prompt)
-        return line_out
-
-    def handle_magic(self, line_info):
-        """Execute magic functions."""
-        iFun    = line_info.iFun
-        theRest = line_info.theRest
-        cmd = '%s_ip.magic(%s)' % (line_info.preWhitespace,
-                                   make_quoted_expr(iFun + " " + theRest))
-        self.log(line_info.line,cmd,line_info.continue_prompt)
-        #print 'in handle_magic, cmd=<%s>' % cmd  # dbg
-        return cmd
-
-    def handle_auto(self, line_info):
-        """Hande lines which can be auto-executed, quoting if requested."""
-
-        line    = line_info.line
-        iFun    = line_info.iFun
-        theRest = line_info.theRest
-        pre     = line_info.pre
-        continue_prompt = line_info.continue_prompt
-        obj = line_info.ofind(self)['obj']
-
-        #print 'pre <%s> iFun <%s> rest <%s>' % (pre,iFun,theRest)  # dbg
-
-        # This should only be active for single-line input!
-        if continue_prompt:
-            self.log(line,line,continue_prompt)
-            return line
-
-        force_auto = isinstance(obj, IPyAutocall)
-        auto_rewrite = True
-        
-        if pre == self.ESC_QUOTE:
-            # Auto-quote splitting on whitespace
-            newcmd = '%s("%s")' % (iFun,'", "'.join(theRest.split()) )
-        elif pre == self.ESC_QUOTE2:
-            # Auto-quote whole string
-            newcmd = '%s("%s")' % (iFun,theRest)
-        elif pre == self.ESC_PAREN:
-            newcmd = '%s(%s)' % (iFun,",".join(theRest.split()))
-        else:
-            # Auto-paren.
-            # We only apply it to argument-less calls if the autocall
-            # parameter is set to 2.  We only need to check that autocall is <
-            # 2, since this function isn't called unless it's at least 1.
-            if not theRest and (self.autocall < 2) and not force_auto:
-                newcmd = '%s %s' % (iFun,theRest)
-                auto_rewrite = False
-            else:
-                if not force_auto and theRest.startswith('['):
-                    if hasattr(obj,'__getitem__'):
-                        # Don't autocall in this case: item access for an object
-                        # which is BOTH callable and implements __getitem__.
-                        newcmd = '%s %s' % (iFun,theRest)
-                        auto_rewrite = False
-                    else:
-                        # if the object doesn't support [] access, go ahead and
-                        # autocall
-                        newcmd = '%s(%s)' % (iFun.rstrip(),theRest)
-                elif theRest.endswith(';'):
-                    newcmd = '%s(%s);' % (iFun.rstrip(),theRest[:-1])
-                else:
-                    newcmd = '%s(%s)' % (iFun.rstrip(), theRest)
-
-        if auto_rewrite:
-            rw = self.outputcache.prompt1.auto_rewrite() + newcmd
-            
-            try:
-                # plain ascii works better w/ pyreadline, on some machines, so
-                # we use it and only print uncolored rewrite if we have unicode
-                rw = str(rw)
-                print >>Term.cout, rw
-            except UnicodeEncodeError:
-                print "-------------->" + newcmd
-            
-        # log what is now valid Python, not the actual user input (without the
-        # final newline)
-        self.log(line,newcmd,continue_prompt)
-        return newcmd
-
-    def handle_help(self, line_info):
-        """Try to get some help for the object.
-
-        obj? or ?obj   -> basic information.
-        obj?? or ??obj -> more details.
-        """
-        
-        line = line_info.line
-        # We need to make sure that we don't process lines which would be
-        # otherwise valid python, such as "x=1 # what?"
-        try:
-            codeop.compile_command(line)
-        except SyntaxError:
-            # We should only handle as help stuff which is NOT valid syntax
-            if line[0]==self.ESC_HELP:
-                line = line[1:]
-            elif line[-1]==self.ESC_HELP:
-                line = line[:-1]
-            self.log(line,'#?'+line,line_info.continue_prompt)
-            if line:
-                #print 'line:<%r>' % line  # dbg
-                self.magic_pinfo(line)
-            else:
-                page(self.usage,screen_lines=self.usable_screen_length)
-            return '' # Empty string is needed here!
-        except:
-            # Pass any other exceptions through to the normal handler
-            return self.handle_normal(line_info)
-        else:
-            # If the code compiles ok, we should handle it normally
-            return self.handle_normal(line_info)
-
-    def handle_emacs(self, line_info):
-        """Handle input lines marked by python-mode."""
-
-        # Currently, nothing is done.  Later more functionality can be added
-        # here if needed.
-
-        # The input cache shouldn't be updated
-        return line_info.line
+    def init_prefilter(self):
+        self.prefilter_manager = PrefilterManager(self, config=self.config)
 
     #-------------------------------------------------------------------------
     # Utilities
     #-------------------------------------------------------------------------
 
     def getoutput(self, cmd):
         return getoutput(self.var_expand(cmd,depth=2),
                          header=self.system_header,
                          verbose=self.system_verbose)
 
     def getoutputerror(self, cmd):
         return getoutputerror(self.var_expand(cmd,depth=2),
                               header=self.system_header,
                               verbose=self.system_verbose)
 
     def var_expand(self,cmd,depth=0):
         """Expand python variables in a string.
 
         The depth argument indicates how many frames above the caller should
         be walked to look for the local namespace where to expand variables.
 
         The global namespace for expansion is always the user's interactive
         namespace.
         """
 
         return str(ItplNS(cmd,
                           self.user_ns,  # globals
                           # Skip our own frame in searching for locals:
                           sys._getframe(depth+1).f_locals # locals
                           ))
 
     def mktempfile(self,data=None):
         """Make a new tempfile and return its filename.
 
         This makes a call to tempfile.mktemp, but it registers the created
         filename internally so ipython cleans it up at exit time.
 
         Optional inputs:
 
           - data(None): if data is given, it gets written out to the temp file
           immediately, and the file is closed again."""
 
         filename = tempfile.mktemp('.py','ipython_edit_')
         self.tempfiles.append(filename)
         
         if data:
             tmp_file = open(filename,'w')
             tmp_file.write(data)
             tmp_file.close()
         return filename
 
     def write(self,data):
         """Write a string to the default output"""
         Term.cout.write(data)
 
     def write_err(self,data):
         """Write a string to the default error output"""
         Term.cerr.write(data)
 
     def ask_yes_no(self,prompt,default=True):
         if self.quiet:
             return True
         return ask_yes_no(prompt,default)
 
     #-------------------------------------------------------------------------
     # Things related to IPython exiting
     #-------------------------------------------------------------------------
 
     def ask_exit(self):
         """ Call for exiting. Can be overiden and used as a callback. """
         self.exit_now = True
 
     def exit(self):
         """Handle interactive exit.
 
         This method calls the ask_exit callback."""
         if self.confirm_exit:
             if self.ask_yes_no('Do you really want to exit ([y]/n)?','y'):
                 self.ask_exit()
         else:
             self.ask_exit()
 
     def atexit_operations(self):
         """This will be executed at the time of exit.
 
         Saving of persistent data should be performed here.
         """
         self.savehist()
 
         # Cleanup all tempfiles left around
         for tfile in self.tempfiles:
             try:
                 os.unlink(tfile)
             except OSError:
                 pass
 
         # Clear all user namespaces to release all references cleanly.
         self.reset()
 
         # Run user hooks
         self.hooks.shutdown_hook()
 
     def cleanup(self):
         self.restore_sys_module_state()
 
 
-
-
-

IPython/core/prefilter.py

@@ -1,321 +1,777 b''
-# -*- coding: utf-8 -*-
+#!/usr/bin/env python
+# encoding: utf-8
 """
-Classes and functions for prefiltering (transforming) a line of user input.
-This module is responsible, primarily, for breaking the line up into useful
-pieces and triggering the appropriate handlers in iplib to do the actual
-transforming work.
+Prefiltering components.
+
+Authors:
+
+* Brian Granger
+* Fernando Perez
+* Dan Milstein
 """
-__docformat__ = "restructuredtext en"
 
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2008-2009  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+import __builtin__
+import codeop
+import keyword
+import os
 import re
+import sys
+
+from IPython.core.alias import AliasManager
 from IPython.core.autocall import IPyAutocall
+from IPython.core.component import Component
+from IPython.core.splitinput import split_user_input
+
+from IPython.utils.traitlets import List, Int, Any, Str, CBool
+from IPython.utils.genutils import make_quoted_expr
+from IPython.utils.autoattr import auto_attr
+
+#-----------------------------------------------------------------------------
+# Global utilities, errors and constants
+#-----------------------------------------------------------------------------
+
+
+ESC_SHELL  = '!'
+ESC_SH_CAP = '!!'
+ESC_HELP   = '?'
+ESC_MAGIC  = '%'
+ESC_QUOTE  = ','
+ESC_QUOTE2 = ';'
+ESC_PAREN  = '/'
+
+
+class PrefilterError(Exception):
+    pass
+
+
+# RegExp to identify potential function names
+re_fun_name = re.compile(r'[a-zA-Z_]([a-zA-Z0-9_.]*) *$')
+
+# RegExp to exclude strings with this start from autocalling.  In
+# particular, all binary operators should be excluded, so that if foo is
+# callable, foo OP bar doesn't become foo(OP bar), which is invalid.  The
+# characters '!=()' don't need to be checked for, as the checkPythonChars
+# routine explicitely does so, to catch direct calls and rebindings of
+# existing names.
+
+# Warning: the '-' HAS TO BE AT THE END of the first group, otherwise
+# it affects the rest of the group in square brackets.
+re_exclude_auto = re.compile(r'^[,&^\|\*/\+-]'
+                             r'|^is |^not |^in |^and |^or ')
+
+# try to catch also methods for stuff in lists/tuples/dicts: off
+# (experimental). For this to work, the line_split regexp would need
+# to be modified so it wouldn't break things at '['. That line is
+# nasty enough that I shouldn't change it until I can test it _well_.
+#self.re_fun_name = re.compile (r'[a-zA-Z_]([a-zA-Z0-9_.\[\]]*) ?$')
+
+
+# Handler Check Utilities
+def is_shadowed(identifier, ip):
+    """Is the given identifier defined in one of the namespaces which shadow
+    the alias and magic namespaces?  Note that an identifier is different
+    than ifun, because it can not contain a '.' character."""
+    # This is much safer than calling ofind, which can change state
+    return (identifier in ip.user_ns \
+            or identifier in ip.internal_ns \
+            or identifier in ip.ns_table['builtin'])
+
+
+#-----------------------------------------------------------------------------
+# The LineInfo class used throughout
+#-----------------------------------------------------------------------------
 
 
 class LineInfo(object):
     """A single line of input and associated info.
 
     Includes the following as properties: 
 
     line
       The original, raw line
     
     continue_prompt
       Is this line a continuation in a sequence of multiline input?
     
     pre
       The initial esc character or whitespace.
     
-    preChar
+    pre_char
       The escape character(s) in pre or the empty string if there isn't one.
-      Note that '!!' is a possible value for preChar.  Otherwise it will
+      Note that '!!' is a possible value for pre_char.  Otherwise it will
       always be a single character.
     
-    preWhitespace
-      The leading whitespace from pre if it exists.  If there is a preChar,
+    pre_whitespace
+      The leading whitespace from pre if it exists.  If there is a pre_char,
       this is just ''.
     
-    iFun
+    ifun
       The 'function part', which is basically the maximal initial sequence
       of valid python identifiers and the '.' character.  This is what is
       checked for alias and magic transformations, used for auto-calling,
       etc.
     
-    theRest
+    the_rest
       Everything else on the line.
     """
     def __init__(self, line, continue_prompt):
         self.line            = line
         self.continue_prompt = continue_prompt
-        self.pre, self.iFun, self.theRest = splitUserInput(line)
+        self.pre, self.ifun, self.the_rest = split_user_input(line)
 
-        self.preChar       = self.pre.strip()
-        if self.preChar:
-            self.preWhitespace = '' # No whitespace allowd before esc chars
+        self.pre_char       = self.pre.strip()
+        if self.pre_char:
+            self.pre_whitespace = '' # No whitespace allowd before esc chars
         else: 
-            self.preWhitespace = self.pre
+            self.pre_whitespace = self.pre
 
         self._oinfo = None
 
     def ofind(self, ip):
-        """Do a full, attribute-walking lookup of the iFun in the various
+        """Do a full, attribute-walking lookup of the ifun in the various
         namespaces for the given IPython InteractiveShell instance.
 
         Return a dict with keys: found,obj,ospace,ismagic
 
         Note: can cause state changes because of calling getattr, but should
         only be run if autocall is on and if the line hasn't matched any
         other, less dangerous handlers.
 
         Does cache the results of the call, so can be called multiple times
         without worrying about *further* damaging state.
         """
         if not self._oinfo:
-            self._oinfo = ip._ofind(self.iFun)
+            self._oinfo = ip._ofind(self.ifun)
         return self._oinfo
+
     def __str__(self):                                                         
-        return "Lineinfo [%s|%s|%s]" %(self.pre,self.iFun,self.theRest)        
+        return "Lineinfo [%s|%s|%s]" %(self.pre,self.ifun,self.the_rest) 
+
 
-def splitUserInput(line, pattern=None):
-    """Split user input into pre-char/whitespace, function part and rest.
+#-----------------------------------------------------------------------------
+# Main Prefilter manager
+#-----------------------------------------------------------------------------
 
-    Mostly internal to this module, but also used by iplib.expand_aliases,
-    which passes in a shell pattern.
+
+class PrefilterManager(Component):
+    """Main prefilter component.
+
+    The IPython prefilter is run on all user input before it is run.  The
+    prefilter consumes lines of input and produces transformed lines of 
+    input.  The implementation consists of checkers and handlers.  The 
+    checkers inspect the input line and select which handler will be used
+    to transform the input line.
     """
-    # It seems to me that the shell splitting should be a separate method.
-    
-    if not pattern:
-        pattern = line_split
-    match = pattern.match(line)
-    if not match:
-        #print "match failed for line '%s'" % line
+
+    multi_line_specials = CBool(True, config_key='MULTI_LINE_SPECIALS')
+
+    def __init__(self, parent, config=None):
+        super(PrefilterManager, self).__init__(parent, config=config)
+        self.init_handlers()
+        self.init_checkers()
+
+    @auto_attr
+    def shell(self):
+        shell = Component.get_instances(
+            root=self.root,
+            klass='IPython.core.iplib.InteractiveShell'
+        )[0]
+        return shell
+
+    def init_checkers(self):
+        self._checkers = []
+        for checker in _default_checkers:
+            self._checkers.append(checker(self, config=self.config))
+
+    def init_handlers(self):
+        self._handlers = {}
+        self._esc_handlers = {}
+        for handler in _default_handlers:
+            handler(self, config=self.config)
+
+    @property
+    def sorted_checkers(self):
+        """Return a list of checkers, sorted by priority."""
+        return sorted(self._checkers, cmp=lambda x,y: x.priority-y.priority)
+
+    def register_handler(self, name, handler, esc_strings):
+        """Register a handler instance by name with esc_strings."""
+        self._handlers[name] = handler
+        for esc_str in esc_strings:
+            self._esc_handlers[esc_str] = handler
+
+    def unregister_handler(self, name, handler, esc_strings):
+        """Unregister a handler instance by name with esc_strings."""
         try:
-            iFun,theRest = line.split(None,1)
-        except ValueError:
-            #print "split failed for line '%s'" % line
-            iFun,theRest = line,''
-        pre = re.match('^(\s*)(.*)',line).groups()[0]
-    else:
-        pre,iFun,theRest = match.groups()
-
-    # iFun has to be a valid python identifier, so it better be only pure
-    # ascii, no unicode:
-    try:
-        iFun = iFun.encode('ascii')
-    except UnicodeEncodeError:
-        theRest = iFun + u' ' + theRest
-        iFun = u''
-
-    #print 'line:<%s>' % line # dbg
-    #print 'pre <%s> iFun <%s> rest <%s>' % (pre,iFun.strip(),theRest) # dbg
-    return pre,iFun.strip(),theRest.lstrip()
-
-
-# RegExp for splitting line contents into pre-char//first word-method//rest.
-# For clarity, each group in on one line.
-
-# WARNING: update the regexp if the escapes in iplib are changed, as they
-# are hardwired in.
-
-# Although it's not solely driven by the regex, note that:
-# ,;/% only trigger if they are the first character on the line
-# ! and !! trigger if they are first char(s) *or* follow an indent 
-# ? triggers as first or last char.
-
-# The three parts of the regex are:
-#  1) pre:     pre_char *or* initial whitespace 
-#  2) iFun:    first word/method (mix of \w and '.')
-#  3) theRest: rest of line (separated from iFun by space if non-empty)
-line_split = re.compile(r'^([,;/%?]|!!?|\s*)'
-                        r'\s*([\w\.]+)'
-                        r'(\s+.*$|$)')
-
-shell_line_split = re.compile(r'^(\s*)(\S*\s*)(.*$)')
-
-def prefilter(line_info, ip):
-    """Call one of the passed-in InteractiveShell's handler preprocessors,
-    depending on the form of the line.  Return the results, which must be a
-    value, even if it's a blank ('')."""
-    # Note: the order of these checks does matter. 
-    for check in [ checkEmacs,
-                   checkShellEscape,
-                   checkIPyAutocall,
-                   checkMultiLineMagic,
-                   checkEscChars,
-                   checkAssignment,
-                   checkAutomagic,
-                   checkAlias,
-                   checkPythonOps,
-                   checkAutocall,
-                   ]:
-        handler = check(line_info, ip)
-        if handler:
-            return handler(line_info)
-
-    return ip.handle_normal(line_info)
-
-# Handler checks
-#
-# All have the same interface: they take a LineInfo object and a ref to the
-# iplib.InteractiveShell object.  They check the line to see if a particular
-# handler should be called, and return either a handler or None.  The
-# handlers which they return are *bound* methods of the InteractiveShell
-# object. 
-#
-# In general, these checks should only take responsibility for their 'own'
-# handler.  If it doesn't get triggered, they should just return None and
-# let the rest of the check sequence run.
-
-def checkShellEscape(l_info,ip):
-    if l_info.line.lstrip().startswith(ip.ESC_SHELL):
-        return ip.handle_shell_escape
-
-def checkEmacs(l_info,ip):
-    "Emacs ipython-mode tags certain input lines."
-    if l_info.line.endswith('# PYTHON-MODE'):
-        return ip.handle_emacs
-    else:
-        return None
+            del self._handlers[name]
+        except KeyError:
+            pass
+        for esc_str in esc_strings:
+            h = self._esc_handlers.get(esc_str)
+            if h is handler:
+                del self._esc_handlers[esc_str]
+
+    def get_handler_by_name(self, name):
+        """Get a handler by its name."""
+        return self._handlers.get(name)
+
+    def get_handler_by_esc(self, esc_str):
+        """Get a handler by its escape string."""
+        return self._esc_handlers.get(esc_str)
+
+    def prefilter_line_info(self, line_info):
+        """Prefilter a line that has been converted to a LineInfo object."""
+        handler = self.find_handler(line_info)
+        return handler.handle(line_info)
+
+    def find_handler(self, line_info):
+        """Find a handler for the line_info by trying checkers."""
+        for checker in self.sorted_checkers:
+            handler = checker.check(line_info)
+            if handler:
+                return handler
+        return self.get_handler_by_name('normal')
+
+    def prefilter_line(self, line, continue_prompt):
+        """Prefilter a single input line as text."""
+
+        # All handlers *must* return a value, even if it's blank ('').
+
+        # Lines are NOT logged here. Handlers should process the line as
+        # needed, update the cache AND log it (so that the input cache array
+        # stays synced).
+
+        # growl.notify("_prefilter: ", "line = %s\ncontinue_prompt = %s" % (line, continue_prompt))
+
+        # save the line away in case we crash, so the post-mortem handler can
+        # record it        
+        self.shell._last_input_line = line
+
+        if not line:
+            # Return immediately on purely empty lines, so that if the user
+            # previously typed some whitespace that started a continuation
+            # prompt, he can break out of that loop with just an empty line.
+            # This is how the default python prompt works.
+
+            # Only return if the accumulated input buffer was just whitespace!
+            if ''.join(self.shell.buffer).isspace():
+                self.shell.buffer[:] = []
+            return ''
+        
+        line_info = LineInfo(line, continue_prompt)
+        
+        # the input history needs to track even empty lines
+        stripped = line.strip()
 
-def checkIPyAutocall(l_info,ip):
-    "Instances of IPyAutocall in user_ns get autocalled immediately"
-    obj = ip.user_ns.get(l_info.iFun, None)
-    if isinstance(obj, IPyAutocall):
-        obj.set_ip(ip)
-        return ip.handle_auto
-    else:
-        return None
-    
-    
-def checkMultiLineMagic(l_info,ip):
-    "Allow ! and !! in multi-line statements if multi_line_specials is on"
-    # Note that this one of the only places we check the first character of
-    # iFun and *not* the preChar.  Also note that the below test matches
-    # both ! and !!.    
-    if l_info.continue_prompt \
-        and ip.multi_line_specials:
-            if l_info.iFun.startswith(ip.ESC_MAGIC):
-                return ip.handle_magic
-    else:
-        return None
+        handle_normal = self.get_handler_by_name('normal')        
+        if not stripped:
+            if not continue_prompt:
+                self.shell.outputcache.prompt_count -= 1
 
-def checkEscChars(l_info,ip):
-    """Check for escape character and return either a handler to handle it,
-    or None if there is no escape char."""
-    if l_info.line[-1] == ip.ESC_HELP \
-           and l_info.preChar != ip.ESC_SHELL \
-           and l_info.preChar != ip.ESC_SH_CAP:
-        # the ? can be at the end, but *not* for either kind of shell escape,
-        # because a ? can be a vaild final char in a shell cmd
-        return ip.handle_help
-    elif l_info.preChar in ip.esc_handlers:
-        return ip.esc_handlers[l_info.preChar]
-    else:
-        return None
+            return handle_normal(line_info)
 
+        # special handlers are only allowed for single line statements
+        if continue_prompt and not self.multi_line_specials:
+            return handle_normal(line_info)
 
-def checkAssignment(l_info,ip):
-    """Check to see if user is assigning to a var for the first time, in
-    which case we want to avoid any sort of automagic / autocall games.
-    
-    This allows users to assign to either alias or magic names true python
-    variables (the magic/alias systems always take second seat to true
-    python code).  E.g. ls='hi', or ls,that=1,2"""
-    if l_info.theRest and l_info.theRest[0] in '=,':
-        return ip.handle_normal
-    else:
-        return None
+        return self.prefilter_line_info(line_info)
 
+    def prefilter_lines(self, lines, continue_prompt):
+        """Prefilter multiple input lines of text.
 
-def checkAutomagic(l_info,ip):
-    """If the iFun is magic, and automagic is on, run it.  Note: normal,
-    non-auto magic would already have been triggered via '%' in
-    check_esc_chars. This just checks for automagic.  Also, before
-    triggering the magic handler, make sure that there is nothing in the
-    user namespace which could shadow it."""
-    if not ip.automagic or not hasattr(ip,'magic_'+l_info.iFun):
-        return None
+        Covers cases where there are multiple lines in the user entry,
+        which is the case when the user goes back to a multiline history
+        entry and presses enter.
+        """
+        # growl.notify("multiline_prefilter: ", "%s\n%s" % (line, continue_prompt))
+        out = []
+        for line in lines.rstrip('\n').split('\n'):
+            out.append(self.prefilter_line(line, continue_prompt))
+        # growl.notify("multiline_prefilter return: ", '\n'.join(out))
+        return '\n'.join(out)
 
-    # We have a likely magic method.  Make sure we should actually call it.
-    if l_info.continue_prompt and not ip.multi_line_specials:
-        return None
 
-    head = l_info.iFun.split('.',1)[0]
-    if isShadowed(head,ip):
-        return None
+#-----------------------------------------------------------------------------
+# Prefilter checkers
+#-----------------------------------------------------------------------------
 
-    return ip.handle_magic
 
-        
-def checkAlias(l_info,ip):
-    "Check if the initital identifier on the line is an alias."
-    # Note: aliases can not contain '.'
-    head = l_info.iFun.split('.',1)[0]
-    
-    if l_info.iFun not in ip.alias_manager \
-           or head not in ip.alias_manager \
-           or isShadowed(head,ip): 
-        return None
+class PrefilterChecker(Component):
+    """Inspect an input line and return a handler for that line."""
 
-    return ip.handle_alias
+    priority = Int(100)
+    shell = Any
+    prefilter_manager = Any
 
+    def __init__(self, parent, config=None):
+        super(PrefilterChecker, self).__init__(parent, config=config)
 
-def checkPythonOps(l_info,ip):
-    """If the 'rest' of the line begins with a function call or pretty much
-    any python operator, we should simply execute the line (regardless of
-    whether or not there's a possible autocall expansion).  This avoids
-    spurious (and very confusing) geattr() accesses."""
-    if l_info.theRest and l_info.theRest[0] in '!=()<>,+*/%^&|':
-        return ip.handle_normal
-    else:
-        return None
+    @auto_attr
+    def shell(self):
+        shell = Component.get_instances(
+            root=self.root,
+            klass='IPython.core.iplib.InteractiveShell'
+        )[0]
+        return shell
 
+    @auto_attr
+    def prefilter_manager(self):
+        return PrefilterManager.get_instances(root=self.root)[0]
 
-def checkAutocall(l_info,ip):
-    "Check if the initial word/function is callable and autocall is on."
-    if not ip.autocall:
+    def check(self, line_info):
+        """Inspect line_info and return a handler or None."""
         return None
 
-    oinfo = l_info.ofind(ip) # This can mutate state via getattr
-    if not oinfo['found']:
-        return None
-        
-    if callable(oinfo['obj']) \
-           and (not re_exclude_auto.match(l_info.theRest)) \
-           and re_fun_name.match(l_info.iFun):
-        #print 'going auto'  # dbg
-        return ip.handle_auto
-    else:
-        #print 'was callable?', callable(l_info.oinfo['obj'])  # dbg
-        return None
+
+class EmacsChecker(PrefilterChecker):
+
+    priority = Int(100)
+
+    def check(self, line_info):
+        "Emacs ipython-mode tags certain input lines."
+        if line_info.line.endswith('# PYTHON-MODE'):
+            return self.prefilter_manager.get_handler_by_name('emacs')
+        else:
+            return None
+
+
+class ShellEscapeChecker(PrefilterChecker):
+
+    priority = Int(200)
+
+    def check(self, line_info):
+        if line_info.line.lstrip().startswith(ESC_SHELL):
+            return self.prefilter_manager.get_handler_by_name('shell')
+
+
+class IPyAutocallChecker(PrefilterChecker):
+
+    priority = Int(300)
+
+    def check(self, line_info):
+        "Instances of IPyAutocall in user_ns get autocalled immediately"
+        obj = self.shell.user_ns.get(line_info.ifun, None)
+        if isinstance(obj, IPyAutocall):
+            obj.set_ip(self.shell)
+            return self.prefilter_manager.get_handler_by_name('auto')
+        else:
+            return None
+
+
+class MultiLineMagicChecker(PrefilterChecker):
+
+    priority = Int(400)
+
+    def check(self, line_info):
+        "Allow ! and !! in multi-line statements if multi_line_specials is on"
+        # Note that this one of the only places we check the first character of
+        # ifun and *not* the pre_char.  Also note that the below test matches
+        # both ! and !!.    
+        if line_info.continue_prompt \
+            and self.prefilter_manager.multi_line_specials:
+                if line_info.ifun.startswith(ESC_MAGIC):
+                    return self.prefilter_manager.get_handler_by_name('magic')
+        else:
+            return None
+
+
+class EscCharsChecker(PrefilterChecker):
+
+    priority = Int(500)
+
+    def check(self, line_info):
+        """Check for escape character and return either a handler to handle it,
+        or None if there is no escape char."""
+        if line_info.line[-1] == ESC_HELP \
+               and line_info.pre_char != ESC_SHELL \
+               and line_info.pre_char != ESC_SH_CAP:
+            # the ? can be at the end, but *not* for either kind of shell escape,
+            # because a ? can be a vaild final char in a shell cmd
+            return self.prefilter_manager.get_handler_by_name('help')
+        else:
+            # This returns None like it should if no handler exists
+            return self.prefilter_manager.get_handler_by_esc(line_info.pre_char)
+
+
+class AssignmentChecker(PrefilterChecker):
+
+    priority = Int(600)
+
+    def check(self, line_info):
+        """Check to see if user is assigning to a var for the first time, in
+        which case we want to avoid any sort of automagic / autocall games.
     
-# RegExp to identify potential function names
-re_fun_name = re.compile(r'[a-zA-Z_]([a-zA-Z0-9_.]*) *$')
+        This allows users to assign to either alias or magic names true python
+        variables (the magic/alias systems always take second seat to true
+        python code).  E.g. ls='hi', or ls,that=1,2"""
+        if line_info.the_rest and line_info.the_rest[0] in '=,':
+            return self.prefilter_manager.get_handler_by_name('normal')
+        else:
+            return None
 
-# RegExp to exclude strings with this start from autocalling.  In
-# particular, all binary operators should be excluded, so that if foo is
-# callable, foo OP bar doesn't become foo(OP bar), which is invalid.  The
-# characters '!=()' don't need to be checked for, as the checkPythonChars
-# routine explicitely does so, to catch direct calls and rebindings of
-# existing names.
 
-# Warning: the '-' HAS TO BE AT THE END of the first group, otherwise
-# it affects the rest of the group in square brackets.
-re_exclude_auto = re.compile(r'^[,&^\|\*/\+-]'
-                             r'|^is |^not |^in |^and |^or ')
+class AutoMagicChecker(PrefilterChecker):
 
-# try to catch also methods for stuff in lists/tuples/dicts: off
-# (experimental). For this to work, the line_split regexp would need
-# to be modified so it wouldn't break things at '['. That line is
-# nasty enough that I shouldn't change it until I can test it _well_.
-#self.re_fun_name = re.compile (r'[a-zA-Z_]([a-zA-Z0-9_.\[\]]*) ?$')
+    priority = Int(700)
 
-# Handler Check Utilities
-def isShadowed(identifier,ip):
-    """Is the given identifier defined in one of the namespaces which shadow
-    the alias and magic namespaces?  Note that an identifier is different
-    than iFun, because it can not contain a '.' character."""
-    # This is much safer than calling ofind, which can change state
-    return (identifier in ip.user_ns \
-            or identifier in ip.internal_ns \
-            or identifier in ip.ns_table['builtin'])
+    def check(self, line_info):
+        """If the ifun is magic, and automagic is on, run it.  Note: normal,
+        non-auto magic would already have been triggered via '%' in
+        check_esc_chars. This just checks for automagic.  Also, before
+        triggering the magic handler, make sure that there is nothing in the
+        user namespace which could shadow it."""
+        if not self.shell.automagic or not hasattr(self.shell,'magic_'+line_info.ifun):
+            return None
+
+        # We have a likely magic method.  Make sure we should actually call it.
+        if line_info.continue_prompt and not self.shell.multi_line_specials:
+            return None
+
+        head = line_info.ifun.split('.',1)[0]
+        if is_shadowed(head, self.shell):
+            return None
+
+        return self.prefilter_manager.get_handler_by_name('magic')
+
+
+class AliasChecker(PrefilterChecker):
+
+    priority = Int(800)
+
+    @auto_attr
+    def alias_manager(self):
+        return AliasManager.get_instances(root=self.root)[0]
+
+    def check(self, line_info):
+        "Check if the initital identifier on the line is an alias."
+        # Note: aliases can not contain '.'
+        head = line_info.ifun.split('.',1)[0]
+        if line_info.ifun not in self.alias_manager \
+               or head not in self.alias_manager \
+               or is_shadowed(head, self.shell):
+            return None
+
+        return self.prefilter_manager.get_handler_by_name('alias')
+
+
+class PythonOpsChecker(PrefilterChecker):
+
+    priority = Int(900)
+
+    def check(self, line_info):
+        """If the 'rest' of the line begins with a function call or pretty much
+        any python operator, we should simply execute the line (regardless of
+        whether or not there's a possible autocall expansion).  This avoids
+        spurious (and very confusing) geattr() accesses."""
+        if line_info.the_rest and line_info.the_rest[0] in '!=()<>,+*/%^&|':
+            return self.prefilter_manager.get_handler_by_name('normal')
+        else:
+            return None
+
+
+class AutocallChecker(PrefilterChecker):
+
+    priority = Int(1000)
+
+    def check(self, line_info):
+        "Check if the initial word/function is callable and autocall is on."
+        if not self.shell.autocall:
+            return None
+
+        oinfo = line_info.ofind(self.shell) # This can mutate state via getattr
+        if not oinfo['found']:
+            return None
+        
+        if callable(oinfo['obj']) \
+               and (not re_exclude_auto.match(line_info.the_rest)) \
+               and re_fun_name.match(line_info.ifun):
+            return self.prefilter_manager.get_handler_by_name('auto')
+        else:
+            return None
+
+
+#-----------------------------------------------------------------------------
+# Prefilter handlers
+#-----------------------------------------------------------------------------
+
+
+class PrefilterHandler(Component):
+
+    handler_name = Str('normal')
+    esc_strings = List([])
+    shell = Any
+    prefilter_manager = Any
+
+    def __init__(self, parent, config=None):
+        super(PrefilterHandler, self).__init__(parent, config=config)
+        self.prefilter_manager.register_handler(
+            self.handler_name,
+            self,
+            self.esc_strings
+        )
+
+    @auto_attr
+    def shell(self):
+        shell = Component.get_instances(
+            root=self.root,
+            klass='IPython.core.iplib.InteractiveShell'
+        )[0]
+        return shell
+
+    @auto_attr
+    def prefilter_manager(self):
+        return PrefilterManager.get_instances(root=self.root)[0]
+
+    def handle(self, line_info):
+        """Handle normal input lines. Use as a template for handlers."""
+
+        # With autoindent on, we need some way to exit the input loop, and I
+        # don't want to force the user to have to backspace all the way to
+        # clear the line.  The rule will be in this case, that either two
+        # lines of pure whitespace in a row, or a line of pure whitespace but
+        # of a size different to the indent level, will exit the input loop.
+        line = line_info.line
+        continue_prompt = line_info.continue_prompt
+
+        if (continue_prompt and self.shell.autoindent and line.isspace() and
+            (0 < abs(len(line) - self.shell.indent_current_nsp) <= 2 or
+             (self.shell.buffer[-1]).isspace() )):
+            line = ''
+
+        self.shell.log(line, line, continue_prompt)
+        return line
+
+
+class AliasHandler(PrefilterHandler):
+
+    handler_name = Str('alias')
+    esc_strings = List([])
+
+    @auto_attr
+    def alias_manager(self):
+        return AliasManager.get_instances(root=self.root)[0]
+
+    def handle(self, line_info):
+        """Handle alias input lines. """
+        transformed = self.alias_manager.expand_aliases(line_info.ifun,line_info.the_rest)
+        # pre is needed, because it carries the leading whitespace.  Otherwise
+        # aliases won't work in indented sections.
+        line_out = '%s_ip.system(%s)' % (line_info.pre_whitespace,
+                                         make_quoted_expr(transformed))
+        
+        self.shell.log(line_info.line, line_out, line_info.continue_prompt)
+        return line_out
+
+
+class ShellEscapeHandler(PrefilterHandler):
+
+    handler_name = Str('shell')
+    esc_strings = List([ESC_SHELL, ESC_SH_CAP])
+
+    def handle(self, line_info):
+        """Execute the line in a shell, empty return value"""
+        magic_handler = self.prefilter_manager.get_handler_by_name('magic')
+
+        line = line_info.line
+        if line.lstrip().startswith(ESC_SH_CAP):
+            # rewrite LineInfo's line, ifun and the_rest to properly hold the
+            # call to %sx and the actual command to be executed, so
+            # handle_magic can work correctly.  Note that this works even if
+            # the line is indented, so it handles multi_line_specials
+            # properly.
+            new_rest = line.lstrip()[2:]
+            line_info.line = '%ssx %s' % (ESC_MAGIC, new_rest)
+            line_info.ifun = 'sx'
+            line_info.the_rest = new_rest
+            return magic_handler.handle(line_info)
+        else:
+            cmd = line.lstrip().lstrip(ESC_SHELL)
+            line_out = '%s_ip.system(%s)' % (line_info.pre_whitespace,
+                                             make_quoted_expr(cmd))
+        # update cache/log and return
+        self.shell.log(line, line_out, line_info.continue_prompt)
+        return line_out
+
+
+class MagicHandler(PrefilterHandler):
+
+    handler_name = Str('magic')
+    esc_strings = List(['%'])
+
+    def handle(self, line_info):
+        """Execute magic functions."""
+        ifun    = line_info.ifun
+        the_rest = line_info.the_rest
+        cmd = '%s_ip.magic(%s)' % (line_info.pre_whitespace,
+                                   make_quoted_expr(ifun + " " + the_rest))
+        self.shell.log(line_info.line, cmd, line_info.continue_prompt)
+        return cmd
+
+
+class AutoHandler(PrefilterHandler):
+
+    handler_name = Str('auto')
+    esc_strings = List([ESC_PAREN, ESC_QUOTE, ESC_QUOTE2])
+
+    def handle(self, line_info):
+        """Hande lines which can be auto-executed, quoting if requested."""
+        line    = line_info.line
+        ifun    = line_info.ifun
+        the_rest = line_info.the_rest
+        pre     = line_info.pre
+        continue_prompt = line_info.continue_prompt
+        obj = line_info.ofind(self)['obj']
+
+        #print 'pre <%s> ifun <%s> rest <%s>' % (pre,ifun,the_rest)  # dbg
+
+        # This should only be active for single-line input!
+        if continue_prompt:
+            self.log(line,line,continue_prompt)
+            return line
+
+        force_auto = isinstance(obj, IPyAutocall)
+        auto_rewrite = True
+        
+        if pre == ESC_QUOTE:
+            # Auto-quote splitting on whitespace
+            newcmd = '%s("%s")' % (ifun,'", "'.join(the_rest.split()) )
+        elif pre == ESC_QUOTE2:
+            # Auto-quote whole string
+            newcmd = '%s("%s")' % (ifun,the_rest)
+        elif pre == ESC_PAREN:
+            newcmd = '%s(%s)' % (ifun,",".join(the_rest.split()))
+        else:
+            # Auto-paren.
+            # We only apply it to argument-less calls if the autocall
+            # parameter is set to 2.  We only need to check that autocall is <
+            # 2, since this function isn't called unless it's at least 1.
+            if not the_rest and (self.autocall < 2) and not force_auto:
+                newcmd = '%s %s' % (ifun,the_rest)
+                auto_rewrite = False
+            else:
+                if not force_auto and the_rest.startswith('['):
+                    if hasattr(obj,'__getitem__'):
+                        # Don't autocall in this case: item access for an object
+                        # which is BOTH callable and implements __getitem__.
+                        newcmd = '%s %s' % (ifun,the_rest)
+                        auto_rewrite = False
+                    else:
+                        # if the object doesn't support [] access, go ahead and
+                        # autocall
+                        newcmd = '%s(%s)' % (ifun.rstrip(),the_rest)
+                elif the_rest.endswith(';'):
+                    newcmd = '%s(%s);' % (ifun.rstrip(),the_rest[:-1])
+                else:
+                    newcmd = '%s(%s)' % (ifun.rstrip(), the_rest)
+
+        if auto_rewrite:
+            rw = self.shell.outputcache.prompt1.auto_rewrite() + newcmd
+            
+            try:
+                # plain ascii works better w/ pyreadline, on some machines, so
+                # we use it and only print uncolored rewrite if we have unicode
+                rw = str(rw)
+                print >>Term.cout, rw
+            except UnicodeEncodeError:
+                print "-------------->" + newcmd
+            
+        # log what is now valid Python, not the actual user input (without the
+        # final newline)
+        self.shell.log(line,newcmd,continue_prompt)
+        return newcmd
+
+
+class HelpHandler(PrefilterHandler):
+
+    handler_name = Str('help')
+    esc_strings = List([ESC_HELP])
+
+    def handle(self, line_info):
+        """Try to get some help for the object.
+
+        obj? or ?obj   -> basic information.
+        obj?? or ??obj -> more details.
+        """
+        normal_handler = self.prefilter_manager.get_handler_by_name('normal')
+        line = line_info.line
+        # We need to make sure that we don't process lines which would be
+        # otherwise valid python, such as "x=1 # what?"
+        try:
+            codeop.compile_command(line)
+        except SyntaxError:
+            # We should only handle as help stuff which is NOT valid syntax
+            if line[0]==ESC_HELP:
+                line = line[1:]
+            elif line[-1]==ESC_HELP:
+                line = line[:-1]
+            self.shell.log(line, '#?'+line, line_info.continue_prompt)
+            if line:
+                #print 'line:<%r>' % line  # dbg
+                self.shell.magic_pinfo(line)
+            else:
+                page(self.shell.usage, screen_lines=self.shell.usable_screen_length)
+            return '' # Empty string is needed here!
+        except:
+            raise
+            # Pass any other exceptions through to the normal handler
+            return normal_handler.handle(line_info)
+        else:
+            raise
+            # If the code compiles ok, we should handle it normally
+            return normal_handler.handle(line_info)
+
+
+class EmacsHandler(PrefilterHandler):
+
+    handler_name = Str('emacs')
+    esc_strings = List([])
+
+    def handle(self, line_info):
+        """Handle input lines marked by python-mode."""
+
+        # Currently, nothing is done.  Later more functionality can be added
+        # here if needed.
+
+        # The input cache shouldn't be updated
+        return line_info.line
+
+
+#-----------------------------------------------------------------------------
+# Defaults
+#-----------------------------------------------------------------------------
+
+
+_default_checkers = [
+    EmacsChecker,
+    ShellEscapeChecker,
+    IPyAutocallChecker,
+    MultiLineMagicChecker,
+    EscCharsChecker,
+    AssignmentChecker,
+    AutoMagicChecker,
+    AliasChecker,
+    PythonOpsChecker,
+    AutocallChecker
+]
+
+_default_handlers = [
+    PrefilterHandler,
+    AliasHandler,
+    ShellEscapeHandler,
+    MagicHandler,
+    AutoHandler,
+    HelpHandler,
+    EmacsHandler
+]