Backport PR #10353 on branch 5.x

Merge pull request  #10353 from Carreau/btab

Allow to deactivate backslash-tab completions

IPython/core/completer.py

@@ -1,1184 +1,1188 b''
 # encoding: utf-8
 """Word completion for IPython.
 
 This module started as 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,
 
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 #
 # Some of this code originated from rlcompleter in the Python standard library
 # Copyright (C) 2001 Python Software Foundation, www.python.org
 
 from __future__ import print_function
 
 import __main__
 import glob
 import inspect
 import itertools
 import keyword
 import os
 import re
 import sys
 import unicodedata
 import string
 import warnings
 
 from traitlets.config.configurable import Configurable
 from IPython.core.error import TryNext
 from IPython.core.inputsplitter import ESC_MAGIC
 from IPython.core.latex_symbols import latex_symbols, reverse_latex_symbol
 from IPython.utils import generics
 from IPython.utils.decorators import undoc
 from IPython.utils.dir2 import dir2, get_real_method
 from IPython.utils.process import arg_split
 from IPython.utils.py3compat import builtin_mod, string_types, PY3, cast_unicode_py2
 from traitlets import Bool, Enum, observe
 
 
 # Public API
 __all__ = ['Completer','IPCompleter']
 
 if sys.platform == 'win32':
     PROTECTABLES = ' '
 else:
     PROTECTABLES = ' ()[]{}?=\\|;:\'#*"^&'
 
 
 def has_open_quotes(s):
     """Return whether a string has open quotes.
 
     This simply counts whether the number of quote characters of either type in
     the string is odd.
 
     Returns
     -------
     If there is an open quote, the quote character is returned.  Else, return
     False.
     """
     # We check " first, then ', so complex cases with nested quotes will get
     # the " to take precedence.
     if s.count('"') % 2:
         return '"'
     elif s.count("'") % 2:
         return "'"
     else:
         return False
 
 
 def protect_filename(s):
     """Escape a string to protect certain characters."""
     if set(s) & set(PROTECTABLES):
         if sys.platform == "win32":
             return '"' + s + '"'
         else:
             return "".join(("\\" + c if c in PROTECTABLES else c) for c in s)
     else:
         return s
 
 
 def expand_user(path):
     """Expand '~'-style usernames in strings.
 
     This is similar to :func:`os.path.expanduser`, but it computes and returns
     extra information that will be useful if the input was being used in
     computing completions, and you wish to return the completions with the
     original '~' instead of its expanded value.
 
     Parameters
     ----------
     path : str
       String to be expanded.  If no ~ is present, the output is the same as the
       input.
 
     Returns
     -------
     newpath : str
       Result of ~ expansion in the input path.
     tilde_expand : bool
       Whether any expansion was performed or not.
     tilde_val : str
       The value that ~ was replaced with.
     """
     # Default values
     tilde_expand = False
     tilde_val = ''
     newpath = path
 
     if path.startswith('~'):
         tilde_expand = True
         rest = len(path)-1
         newpath = os.path.expanduser(path)
         if rest:
             tilde_val = newpath[:-rest]
         else:
             tilde_val = newpath
 
     return newpath, tilde_expand, tilde_val
 
 
 def compress_user(path, tilde_expand, tilde_val):
     """Does the opposite of expand_user, with its outputs.
     """
     if tilde_expand:
         return path.replace(tilde_val, '~')
     else:
         return path
 
 
 def completions_sorting_key(word):
     """key for sorting completions
 
     This does several things:
 
     - Lowercase all completions, so they are sorted alphabetically with
       upper and lower case words mingled
     - Demote any completions starting with underscores to the end
     - Insert any %magic and %%cellmagic completions in the alphabetical order
       by their name
     """
     # Case insensitive sort
     word = word.lower()
 
     prio1, prio2 = 0, 0
 
     if word.startswith('__'):
         prio1 = 2
     elif word.startswith('_'):
         prio1 = 1
 
     if word.endswith('='):
         prio1 = -1
 
     if word.startswith('%%'):
         # If there's another % in there, this is something else, so leave it alone
         if not "%" in word[2:]:
             word = word[2:]
             prio2 = 2
     elif word.startswith('%'):
         if not "%" in word[1:]:
             word = word[1:]
             prio2 = 1
 
     return prio1, word, prio2
 
 
 @undoc
 class Bunch(object): pass
 
 
 if sys.platform == 'win32':
     DELIMS = ' \t\n`!@#$^&*()=+[{]}|;\'",<>?'
 else:
     DELIMS = ' \t\n`!@#$^&*()=+[{]}\\|;:\'",<>?'
 
 GREEDY_DELIMS = ' =\r\n'
 
 
 class CompletionSplitter(object):
     """An object to split an input line in a manner similar to readline.
 
     By having our own implementation, we can expose readline-like completion in
     a uniform manner to all frontends.  This object only needs to be given the
     line of text to be split and the cursor position on said line, and it
     returns the 'word' to be completed on at the cursor after splitting the
     entire line.
 
     What characters are used as splitting delimiters can be controlled by
     setting the `delims` attribute (this is a property that internally
     automatically builds the necessary regular expression)"""
 
     # Private interface
 
     # A string of delimiter characters.  The default value makes sense for
     # IPython's most typical usage patterns.
     _delims = DELIMS
 
     # The expression (a normal string) to be compiled into a regular expression
     # for actual splitting.  We store it as an attribute mostly for ease of
     # debugging, since this type of code can be so tricky to debug.
     _delim_expr = None
 
     # The regular expression that does the actual splitting
     _delim_re = None
 
     def __init__(self, delims=None):
         delims = CompletionSplitter._delims if delims is None else delims
         self.delims = delims
 
     @property
     def delims(self):
         """Return the string of delimiter characters."""
         return self._delims
 
     @delims.setter
     def delims(self, delims):
         """Set the delimiters for line splitting."""
         expr = '[' + ''.join('\\'+ c for c in delims) + ']'
         self._delim_re = re.compile(expr)
         self._delims = delims
         self._delim_expr = expr
 
     def split_line(self, line, cursor_pos=None):
         """Split a line of text with a cursor at the given position.
         """
         l = line if cursor_pos is None else line[:cursor_pos]
         return self._delim_re.split(l)[-1]
 
 
 class Completer(Configurable):
 
     greedy = Bool(False,
         help="""Activate greedy completion
         PENDING DEPRECTION. this is now mostly taken care of with Jedi.
 
         This will enable completion on elements of lists, results of function calls, etc.,
         but can be unsafe because the code is actually evaluated on TAB.
         """
     ).tag(config=True)
     
+    backslash_combining_completions = Bool(True, 
+        help="Enable unicode completions, e.g. \\alpha<tab> . "
+             "Includes completion of latex commands, unicode names, and expanding "
+             "unicode characters back to latex commands.").tag(config=True)
 
     def __init__(self, namespace=None, global_namespace=None, **kwargs):
         """Create a new completer for the command line.
 
         Completer(namespace=ns, global_namespace=ns2) -> 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
 
         super(Completer, self).__init__(**kwargs)
 
     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_mod.__dict__.keys(),
                     self.namespace.keys(),
                     self.global_namespace.keys()]:
             for word in lst:
                 if word[:n] == text and word != "__builtins__":
                     match_append(word)
         return [cast_unicode_py2(m) for m in 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.
 
         """
 
         # Another option, seems to work great. Catches things like ''.<tab>
         m = re.match(r"(\S+(\.\w+)*)\.(\w*)$", text)
     
         if m:
             expr, attr = m.group(1, 3)
         elif self.greedy:
             m2 = re.match(r"(.+)\.(\w*)$", self.line_buffer)
             if not m2:
                 return []
             expr, attr = m2.group(1,2)
         else:
             return []
     
         try:
             obj = eval(expr, self.namespace)
         except:
             try:
                 obj = eval(expr, self.global_namespace)
             except:
                 return []
 
         if self.limit_to__all__ and hasattr(obj, '__all__'):
             words = get__all__entries(obj)
         else: 
             words = dir2(obj)
 
         try:
             words = generics.complete_object(obj, words)
         except TryNext:
             pass
         except Exception:
             # Silence errors from completion function
             #raise # dbg
             pass
         # Build match list to return
         n = len(attr)
         return [u"%s.%s" % (expr, w) for w in words if w[:n] == attr ]
 
 
 def get__all__entries(obj):
     """returns the strings in the __all__ attribute"""
     try:
         words = getattr(obj, '__all__')
     except:
         return []
     
     return [cast_unicode_py2(w) for w in words if isinstance(w, string_types)]
 
 
 def match_dict_keys(keys, prefix, delims):
     """Used by dict_key_matches, matching the prefix to a list of keys"""
     if not prefix:
         return None, 0, [repr(k) for k in keys
                       if isinstance(k, (string_types, bytes))]
     quote_match = re.search('["\']', prefix)
     quote = quote_match.group()
     try:
         prefix_str = eval(prefix + quote, {})
     except Exception:
         return None, 0, []
 
     pattern = '[^' + ''.join('\\' + c for c in delims) + ']*$'
     token_match = re.search(pattern, prefix, re.UNICODE)
     token_start = token_match.start()
     token_prefix = token_match.group()
 
     # TODO: support bytes in Py3k
     matched = []
     for key in keys:
         try:
             if not key.startswith(prefix_str):
                 continue
         except (AttributeError, TypeError, UnicodeError):
             # Python 3+ TypeError on b'a'.startswith('a') or vice-versa
             continue
 
         # reformat remainder of key to begin with prefix
         rem = key[len(prefix_str):]
         # force repr wrapped in '
         rem_repr = repr(rem + '"')
         if rem_repr.startswith('u') and prefix[0] not in 'uU':
             # Found key is unicode, but prefix is Py2 string.
             # Therefore attempt to interpret key as string.
             try:
                 rem_repr = repr(rem.encode('ascii') + '"')
             except UnicodeEncodeError:
                 continue
 
         rem_repr = rem_repr[1 + rem_repr.index("'"):-2]
         if quote == '"':
             # The entered prefix is quoted with ",
             # but the match is quoted with '.
             # A contained " hence needs escaping for comparison:
             rem_repr = rem_repr.replace('"', '\\"')
 
         # then reinsert prefix from start of token
         matched.append('%s%s' % (token_prefix, rem_repr))
     return quote, token_start, matched
 
 
 def _safe_isinstance(obj, module, class_name):
     """Checks if obj is an instance of module.class_name if loaded
     """
     return (module in sys.modules and
             isinstance(obj, getattr(__import__(module), class_name)))
 
 
 def back_unicode_name_matches(text):
     u"""Match unicode characters back to unicode name
     
     This does  ☃ -> \\snowman
 
     Note that snowman is not a valid python3 combining character but will be expanded.
     Though it will not recombine back to the snowman character by the completion machinery.
 
     This will not either back-complete standard sequences like \\n, \\b ...
     
     Used on Python 3 only.
     """
     if len(text)<2:
         return u'', ()
     maybe_slash = text[-2]
     if maybe_slash != '\\':
         return u'', ()
 
     char = text[-1]
     # no expand on quote for completion in strings.
     # nor backcomplete standard ascii keys
     if char in string.ascii_letters or char in ['"',"'"]:
         return u'', ()
     try :
         unic = unicodedata.name(char)
         return '\\'+char,['\\'+unic]
     except KeyError:
         pass
     return u'', ()
 
 def back_latex_name_matches(text):
     u"""Match latex characters back to unicode name
     
     This does  ->\\sqrt
 
     Used on Python 3 only.
     """
     if len(text)<2:
         return u'', ()
     maybe_slash = text[-2]
     if maybe_slash != '\\':
         return u'', ()
 
 
     char = text[-1]
     # no expand on quote for completion in strings.
     # nor backcomplete standard ascii keys
     if char in string.ascii_letters or char in ['"',"'"]:
         return u'', ()
     try :
         latex = reverse_latex_symbol[char]
         # '\\' replace the \ as well
         return '\\'+char,[latex]
     except KeyError:
         pass
     return u'', ()
 
 
 class IPCompleter(Completer):
     """Extension of the completer class with IPython-specific features"""
     
     @observe('greedy')
     def _greedy_changed(self, change):
         """update the splitter and readline delims when greedy is changed"""
         if change['new']:
             self.splitter.delims = GREEDY_DELIMS
         else:
             self.splitter.delims = DELIMS
 
         if self.readline:
             self.readline.set_completer_delims(self.splitter.delims)
     
     merge_completions = Bool(True,
         help="""Whether to merge completion results into a single list
         
         If False, only the completion results from the first non-empty
         completer will be returned.
         """
     ).tag(config=True)
     omit__names = Enum((0,1,2), default_value=2,
         help="""Instruct the completer to omit private method names
         
         Specifically, when completing on ``object.<tab>``.
         
         When 2 [default]: all names that start with '_' will be excluded.
         
         When 1: all 'magic' names (``__foo__``) will be excluded.
         
         When 0: nothing will be excluded.
         """
     ).tag(config=True)
     limit_to__all__ = Bool(False,
         help="""
         DEPRECATED as of version 5.0.
         
         Instruct the completer to use __all__ for the completion
         
         Specifically, when completing on ``object.<tab>``.
         
         When True: only those names in obj.__all__ will be included.
         
         When False [default]: the __all__ attribute is ignored 
         """,
     ).tag(config=True)
 
     @observe('limit_to__all__')
     def _limit_to_all_changed(self, change):
         warnings.warn('`IPython.core.IPCompleter.limit_to__all__` configuration '
             'value has been deprecated since IPython 5.0, will be made to have '
             'no effects and then removed in future version of IPython.',
             UserWarning)
 
     def __init__(self, shell=None, namespace=None, global_namespace=None,
                  use_readline=True, config=None, **kwargs):
         """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.
 
         use_readline : bool, optional
           If true, use the readline library.  This completer can still function
           without readline, though in that case callers must provide some extra
           information on each call about the current line."""
 
         self.magic_escape = ESC_MAGIC
         self.splitter = CompletionSplitter()
 
         # Readline configuration, only used by the rlcompleter method.
         if use_readline:
             # We store the right version of readline so that later code
             import IPython.utils.rlineimpl as readline
             self.readline = readline
         else:
             self.readline = None
 
         # _greedy_changed() depends on splitter and readline being defined:
         Completer.__init__(self, namespace=namespace, global_namespace=global_namespace,
                             config=config, **kwargs)
 
         # List where completion matches will be stored
         self.matches = []
         self.shell = shell
         # 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
 
         #regexp to parse docstring for function signature
         self.docstring_sig_re = re.compile(r'^[\w|\s.]+\(([^)]*)\).*')
         self.docstring_kwd_re = re.compile(r'[\s|\[]*(\w+)(?:\s*=\s*.*)')
         #use this if positional argument name is also needed
         #= re.compile(r'[\s|\[]*(\w+)(?:\s*=?\s*.*)')
 
         # All active matcher routines for completion
         self.matchers = [
                          self.python_matches,
                          self.file_matches,
                          self.magic_matches,
                          self.python_func_kw_matches,
                          self.dict_key_matches,
                          ]
 
         # This is set externally by InteractiveShell
         self.custom_completers = None
 
     def all_completions(self, text):
         """
         Wrapper around the complete method for the benefit of emacs.
         """
         return self.complete(text)[1]
 
     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."""
 
         # 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 text.startswith('!'):
             text = text[1:]
             text_prefix = u'!'
         else:
             text_prefix = u''
 
         text_until_cursor = self.text_until_cursor
         # track strings with open quotes
         open_quotes = has_open_quotes(text_until_cursor)
 
         if '(' in text_until_cursor or '[' in text_until_cursor:
             lsplit = text
         else:
             try:
                 # arg_split ~ shlex.split, but with unicode bugs fixed by us
                 lsplit = arg_split(text_until_cursor)[-1]
             except ValueError:
                 # typically an unmatched ", or backslash without escaped char.
                 if open_quotes:
                     lsplit = text_until_cursor.split(open_quotes)[-1]
                 else:
                     return []
             except IndexError:
                 # tab pressed on empty line
                 lsplit = ""
 
         if not open_quotes and lsplit != protect_filename(lsplit):
             # if protectables are found, do matching on the whole escaped name
             has_protectables = True
             text0,text = text,lsplit
         else:
             has_protectables = False
             text = os.path.expanduser(text)
 
         if text == "":
             return [text_prefix + cast_unicode_py2(protect_filename(f)) for f in self.glob("*")]
 
         # Compute the matches from the filesystem
         if sys.platform == 'win32':
             m0 = self.clean_glob(text)
         else:
             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]
 
         # Mark directories in input list by appending '/' to their names.
         return [cast_unicode_py2(x+'/') if os.path.isdir(x) else x for x in matches]
 
     def magic_matches(self, text):
         """Match magics"""
         # Get all shell magics now rather than statically, so magics loaded at
         # runtime show up too.
         lsm = self.shell.magics_manager.lsmagic()
         line_magics = lsm['line']
         cell_magics = lsm['cell']
         pre = self.magic_escape
         pre2 = pre+pre
         
         # Completion logic:
         # - user gives %%: only do cell magics
         # - user gives %: do both line and cell magics
         # - no prefix: do both
         # In other words, line magics are skipped if the user gives %% explicitly
         bare_text = text.lstrip(pre)
         comp = [ pre2+m for m in cell_magics if m.startswith(bare_text)]
         if not text.startswith(pre2):
             comp += [ pre+m for m in line_magics if m.startswith(bare_text)]
         return [cast_unicode_py2(c) for c in comp]
 
 
     def python_matches(self, text):
         """Match attributes or global python names"""
         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[txt.rindex('.'):]) is None)
                     matches = filter(no__name, matches)
             except NameError:
                 # catches <undefined attributes>.<tab>
                 matches = []
         else:
             matches = self.global_matches(text)
         return matches
 
     def _default_arguments_from_docstring(self, doc):
         """Parse the first line of docstring for call signature.
 
         Docstring should be of the form 'min(iterable[, key=func])\n'.
         It can also parse cython docstring of the form
         'Minuit.migrad(self, int ncall=10000, resume=True, int nsplit=1)'.
         """
         if doc is None:
             return []
 
         #care only the firstline
         line = doc.lstrip().splitlines()[0]
 
         #p = re.compile(r'^[\w|\s.]+\(([^)]*)\).*')
         #'min(iterable[, key=func])\n' -> 'iterable[, key=func]'
         sig = self.docstring_sig_re.search(line)
         if sig is None:
             return []
         # iterable[, key=func]' -> ['iterable[' ,' key=func]']
         sig = sig.groups()[0].split(',')
         ret = []
         for s in sig:
             #re.compile(r'[\s|\[]*(\w+)(?:\s*=\s*.*)')
             ret += self.docstring_kwd_re.findall(s)
         return ret
 
     def _default_arguments(self, obj):
         """Return the list of default arguments of obj if it is callable,
         or empty list otherwise."""
         call_obj = obj
         ret = []
         if inspect.isbuiltin(obj):
             pass
         elif not (inspect.isfunction(obj) or inspect.ismethod(obj)):
             if inspect.isclass(obj):
                 #for cython embededsignature=True the constructor docstring
                 #belongs to the object itself not __init__
                 ret += self._default_arguments_from_docstring(
                             getattr(obj, '__doc__', ''))
                 # for classes, check for __init__,__new__
                 call_obj = (getattr(obj, '__init__', None) or
                        getattr(obj, '__new__', None))
             # for all others, check if they are __call__able
             elif hasattr(obj, '__call__'):
                 call_obj = obj.__call__
         ret += self._default_arguments_from_docstring(
                  getattr(call_obj, '__doc__', ''))
 
         if PY3:
             _keeps = (inspect.Parameter.KEYWORD_ONLY,
                       inspect.Parameter.POSITIONAL_OR_KEYWORD)
             signature = inspect.signature
         else:
             import IPython.utils.signatures
             _keeps = (IPython.utils.signatures.Parameter.KEYWORD_ONLY,
                       IPython.utils.signatures.Parameter.POSITIONAL_OR_KEYWORD)
             signature = IPython.utils.signatures.signature
 
         try:
             sig = signature(call_obj)
             ret.extend(k for k, v in sig.parameters.items() if
                        v.kind in _keeps)
         except ValueError:
             pass
 
         return list(set(ret))
 
     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 before the cursor
         # e.g. for "foo (1+bar(x), pa<cursor>,a=1)", the candidate is "foo"
         tokens = regexp.findall(self.text_until_cursor)
         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(next(iterTokens))
                 if not isId(ids[-1]):
                     ids.pop(); break
                 if not next(iterTokens) == '.':
                     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(u"%s=" %namedArg)
         return argMatches
 
     def dict_key_matches(self, text):
         "Match string keys in a dictionary, after e.g. 'foo[' "
         def get_keys(obj):
             # Objects can define their own completions by defining an
             # _ipy_key_completions_() method.
             method = get_real_method(obj, '_ipython_key_completions_')
             if method is not None:
                 return method()
 
             # Special case some common in-memory dict-like types
             if isinstance(obj, dict) or\
                _safe_isinstance(obj, 'pandas', 'DataFrame'):
                 try:
                     return list(obj.keys())
                 except Exception:
                     return []
             elif _safe_isinstance(obj, 'numpy', 'ndarray') or\
                  _safe_isinstance(obj, 'numpy', 'void'):
                 return obj.dtype.names or []
             return []
 
         try:
             regexps = self.__dict_key_regexps
         except AttributeError:
             dict_key_re_fmt = r'''(?x)
             (  # match dict-referring expression wrt greedy setting
                 %s
             )
             \[   # open bracket
             \s*  # and optional whitespace
             ([uUbB]?  # string prefix (r not handled)
                 (?:   # unclosed string
                     '(?:[^']|(?<!\\)\\')*
                 |
                     "(?:[^"]|(?<!\\)\\")*
                 )
             )?
             $
             '''
             regexps = self.__dict_key_regexps = {
                 False: re.compile(dict_key_re_fmt % '''
                                   # identifiers separated by .
                                   (?!\d)\w+
                                   (?:\.(?!\d)\w+)*
                                   '''),
                 True: re.compile(dict_key_re_fmt % '''
                                  .+
                                  ''')
             }
 
         match = regexps[self.greedy].search(self.text_until_cursor)
         if match is None:
             return []
 
         expr, prefix = match.groups()
         try:
             obj = eval(expr, self.namespace)
         except Exception:
             try:
                 obj = eval(expr, self.global_namespace)
             except Exception:
                 return []
 
         keys = get_keys(obj)
         if not keys:
             return keys
         closing_quote, token_offset, matches = match_dict_keys(keys, prefix, self.splitter.delims)
         if not matches:
             return matches
         
         # get the cursor position of
         # - the text being completed
         # - the start of the key text
         # - the start of the completion
         text_start = len(self.text_until_cursor) - len(text)
         if prefix:
             key_start = match.start(2)
             completion_start = key_start + token_offset
         else:
             key_start = completion_start = match.end()
         
         # grab the leading prefix, to make sure all completions start with `text`
         if text_start > key_start:
             leading = ''
         else:
             leading = text[text_start:completion_start]
         
         # the index of the `[` character
         bracket_idx = match.end(1)
 
         # append closing quote and bracket as appropriate
         # this is *not* appropriate if the opening quote or bracket is outside
         # the text given to this method
         suf = ''
         continuation = self.line_buffer[len(self.text_until_cursor):]
         if key_start > text_start and closing_quote:
             # quotes were opened inside text, maybe close them
             if continuation.startswith(closing_quote):
                 continuation = continuation[len(closing_quote):]
             else:
                 suf += closing_quote
         if bracket_idx > text_start:
             # brackets were opened inside text, maybe close them
             if not continuation.startswith(']'):
                 suf += ']'
         
         return [leading + k + suf for k in matches]
 
     def unicode_name_matches(self, text):
         u"""Match Latex-like syntax for unicode characters base 
         on the name of the character.
         
         This does  \\GREEK SMALL LETTER ETA -> η
 
         Works only on valid python 3 identifier, or on combining characters that 
         will combine to form a valid identifier.
         
         Used on Python 3 only.
         """
         slashpos = text.rfind('\\')
         if slashpos > -1:
             s = text[slashpos+1:]
             try :
                 unic = unicodedata.lookup(s)
                 # allow combining chars
                 if ('a'+unic).isidentifier():
                     return '\\'+s,[unic]
             except KeyError:
                 pass
         return u'', []
 
 
 
 
     def latex_matches(self, text):
         u"""Match Latex syntax for unicode characters.
         
         This does both \\alp -> \\alpha and \\alpha -> α
         
         Used on Python 3 only.
         """
         slashpos = text.rfind('\\')
         if slashpos > -1:
             s = text[slashpos:]
             if s in latex_symbols:
                 # Try to complete a full latex symbol to unicode
                 # \\alpha -> α
                 return s, [latex_symbols[s]]
             else:
                 # If a user has partially typed a latex symbol, give them
                 # a full list of options \al -> [\aleph, \alpha]
                 matches = [k for k in latex_symbols if k.startswith(s)]
                 return s, matches
         return u'', []
 
     def dispatch_custom_completer(self, text):
         if not self.custom_completers:
             return
 
         line = self.line_buffer
         if not line.strip():
             return None
 
         # Create a little structure to pass all the relevant information about
         # the current completion to any custom completer.
         event = Bunch()
         event.line = line
         event.symbol = text
         cmd = line.split(None,1)[0]
         event.command = cmd
         event.text_until_cursor = self.text_until_cursor
 
         # 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.text_until_cursor)):
             try:
                 res = c(event)
                 if res:
                     # first, try case sensitive match
                     withcase = [cast_unicode_py2(r) for r in res if r.startswith(text)]
                     if withcase:
                         return withcase
                     # if none, then case insensitive ones are ok too
                     text_low = text.lower()
                     return [cast_unicode_py2(r) for r in res if r.lower().startswith(text_low)]
             except TryNext:
                 pass
 
         return None
 
     def complete(self, text=None, line_buffer=None, cursor_pos=None):
         """Find completions for the given text and line context.
 
         Note that both the text and the line_buffer are optional, but at least
         one of them must be given.
 
         Parameters
         ----------
           text : string, optional
             Text to perform the completion on.  If not given, the line buffer
             is split using the instance's CompletionSplitter object.
 
           line_buffer : string, optional
             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.
 
           cursor_pos : int, optional
             Index of the cursor in the full line buffer.  Should be provided by
             remote frontends where kernel has no access to frontend state.
 
         Returns
         -------
         text : str
           Text that was actually used in the completion.
 
         matches : list
           A list of completion matches.
         """
         # if the cursor position isn't given, the only sane assumption we can
         # make is that it's at the end of the line (the common case)
         if cursor_pos is None:
             cursor_pos = len(line_buffer) if text is None else len(text)
 
         if self.use_main_ns:
             self.namespace = __main__.__dict__
 
-        if PY3:
+        if PY3 and self.backslash_combining_completions:
 
             base_text = text if not line_buffer else line_buffer[:cursor_pos]
             latex_text, latex_matches = self.latex_matches(base_text)
             if latex_matches:
                  return latex_text, latex_matches
             name_text = ''
             name_matches = []
             for meth in (self.unicode_name_matches, back_latex_name_matches, back_unicode_name_matches):
                 name_text, name_matches = meth(base_text)
                 if name_text:
                     return name_text, name_matches
         
         # if text is either None or an empty string, rely on the line buffer
         if not text:
             text = self.splitter.split_line(line_buffer, cursor_pos)
 
         # If no line buffer is given, assume the input text is all there was
         if line_buffer is None:
             line_buffer = text
 
         self.line_buffer = line_buffer
         self.text_until_cursor = self.line_buffer[:cursor_pos]
 
         # Start with a clean slate of completions
         self.matches[:] = []
         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:
                     try:
                         self.matches.extend(matcher(text))
                     except:
                         # Show the ugly traceback if the matcher causes an
                         # exception, but do NOT crash the kernel!
                         sys.excepthook(*sys.exc_info())
             else:
                 for matcher in self.matchers:
                     self.matches = matcher(text)
                     if self.matches:
                         break
         # FIXME: we should extend our api to return a dict with completions for
         # different types of objects.  The rlcomplete() method could then
         # simply collapse the dict into a list for readline, but we'd have
         # richer completion semantics in other evironments.
         self.matches = sorted(set(self.matches), key=completions_sorting_key)
 
         return text, self.matches

docs/source/whatsnew/version5.rst

@@ -1,298 +1,302 b''
 ============
  5.x Series
 ============
 
 IPython 5.4
 ===========
 
 Configurable TerminalInteractiveShell
 -------------------------------------
 
 Backported from the 6.x branch as an exceptional new feature. See
 :ghpull:`10373` and :ghissue:`10364`
 
 IPython gained a new ``c.TerminalIPythonApp.interactive_shell_class`` option
 that allow to customize the class used to start the terminal frontend. This
 should allow user to use custom interfaces, like reviving the former readline
 interface which is now a separate package not maintained by the core team.
 
+
+* added ``Completer.backslash_combining_completions`` boolean option to
+  deactivate backslash-tab completion that may conflict with windows path. 
+
 IPython 5.3
 ===========
 
 Released on February 24th, 2017. Remarkable changes and fixes:
 
 * Fix a bug in ``set_next_input`` leading to a crash of terminal IPython.
   :ghpull:`10231`, :ghissue:`10296`, :ghissue:`10229`
 * Always wait for editor inputhook for terminal IPython :ghpull:`10239`,
   :ghpull:`10240`
 * Disable ``_ipython_display_`` in terminal :ghpull:`10249`, :ghpull:`10274`
 * Update terminal colors to be more visible by default on windows
   :ghpull:`10260`, :ghpull:`10238`, :ghissue:`10281`
 * Add Ctrl-Z shortcut (suspend) in terminal debugger :ghpull:`10254`,
   :ghissue:`10273`
 * Indent on new line by looking at the text before the cursor :ghpull:`10264`,
   :ghpull:`10275`, :ghissue:`9283`
 * Update QtEventloop integration to fix some matplotlib integration issues
   :ghpull:`10201`, :ghpull:`10311`, :ghissue:`10201`
 * Respect completions display style in terminal debugger :ghpull:`10305`,
   :ghpull:`10313`
 * Add a config option ``TerminalInteractiveShell.extra_open_editor_shortcuts``
   to enable extra shortcuts to open the input in an editor. These are :kbd:`v`
   in vi mode, and :kbd:`C-X C-E` in emacs mode (:ghpull:`10330`).
   The :kbd:`F2` shortcut is always enabled.
 
 IPython 5.2.2
 =============
 
 * Fix error when starting with ``IPCompleter.limit_to__all__`` configured.
 
 IPython 5.2.1
 =============
 
 * Fix tab completion in the debugger. :ghpull:`10223`
 
 IPython 5.2
 ===========
 
 Released on January 29th, 2017. Remarkable changes and fixes:
 
 * restore IPython's debugger to raise on quit. :ghpull:`10009`
 * The configuration value ``c.TerminalInteractiveShell.highlighting_style`` can
   now directly take a class argument for custom color style. :ghpull:`9848`
 * Correctly handle matplotlib figures dpi :ghpull:`9868`
 * Deprecate ``-e`` flag for the ``%notebook`` magic that had no effects.
   :ghpull:`9872`
 * You can now press F2 while typing at a terminal prompt to edit the contents
   in your favourite terminal editor. Set the :envvar:`EDITOR` environment
   variable to pick which editor is used. :ghpull:`9929`
 * sdists will now only be ``.tar.gz`` as per upstream PyPI requirements.
   :ghpull:`9925`
 * :any:`IPython.core.debugger` have gained a ``set_trace()`` method for
   convenience. :ghpull:`9947`
 * The 'smart command mode' added to the debugger in 5.0 was removed, as more
   people preferred the previous behaviour. Therefore, debugger commands such as
   ``c`` will act as debugger commands even when ``c`` is defined as a variable.
   :ghpull:`10050`
 * Fixes OS X event loop issues at startup, :ghpull:`10150`
 * Deprecate the ``%autoindent`` magic. :ghpull:`10176`
 * Emit a :any:`DeprecationWarning` when setting the deprecated
   ``limit_to_all`` option of the completer. :ghpull:`10198`
 * The :cellmagic:`capture` magic can now capture the result of a cell (from an
   expression on the last line), as well as printed and displayed output.
   :ghpull:`9851`.
 
 
 Changes of behavior to :any:`InteractiveShellEmbed`.
 
 :any:`InteractiveShellEmbed` interactive behavior have changed a bit in between
 5.1 and 5.2. By default ``%kill_embedded`` magic will prevent further invocation
 of the current ``call location`` instead of preventing further invocation of
 the current instance creation location. For most use case this will not change
 much for you, though previous behavior was confusing and less consistent with
 previous IPython versions.
 
 You can now deactivate instances by using ``%kill_embedded --instance`` flag,
 (or ``-i`` in short). The ``%kill_embedded`` magic also gained a
 ``--yes``/``-y`` option which skip confirmation step, and  ``-x``/``--exit``
 which also exit the current embedded call without asking for confirmation.
 
 See :ghpull:`10207`.
 
 
 
 IPython 5.1
 ===========
 
 * Broken ``%timeit`` on Python2 due to the use of ``__qualname__``. :ghpull:`9804`
 * Restore ``%gui qt`` to create and return a ``QApplication`` if necessary. :ghpull:`9789`
 * Don't set terminal title by default. :ghpull:`9801`
 * Preserve indentation when inserting newlines with ``Ctrl-O``. :ghpull:`9770`
 * Restore completion in debugger. :ghpull:`9785`
 * Deprecate ``IPython.core.debugger.Tracer()`` in favor of simpler, newer, APIs. :ghpull:`9731`
 * Restore ``NoOpContext`` context manager removed by mistake, and add `DeprecationWarning`. :ghpull:`9765`
 * Add option allowing ``Prompt_toolkit`` to use 24bits colors. :ghpull:`9736`
 * Fix for closing interactive matplotlib windows on OS X. :ghpull:`9854`
 * An embedded interactive shell instance can be used more than once. :ghpull:`9843`
 * More robust check for whether IPython is in a terminal. :ghpull:`9833`
 * Better pretty-printing of dicts on PyPy. :ghpull:`9827`
 * Some coloured output now looks better on dark background command prompts in Windows.
   :ghpull:`9838`
 * Improved tab completion of paths on Windows . :ghpull:`9826`
 * Fix tkinter event loop integration on Python 2 with ``future`` installed. :ghpull:`9824`
 * Restore ``Ctrl-\`` as a shortcut to quit IPython.
 * Make ``get_ipython()`` accessible when modules are imported by startup files. :ghpull:`9818`
 * Add support for running directories containing a ``__main__.py`` file with the
   ``ipython`` command. :ghpull:`9813`
 
 
 True Color feature
 ------------------
 
 ``prompt_toolkit`` uses pygments styles for syntax highlighting. By default, the
 colors specified in the style are approximated using a standard 256-color
 palette. ``prompt_toolkit`` also supports 24bit, a.k.a. "true", a.k.a. 16-million
 color escape sequences which enable compatible terminals to display the exact
 colors specified instead of an approximation. This true_color option exposes
 that capability in prompt_toolkit to the IPython shell.
 
 Here is a good source for the current state of true color support in various
 terminal emulators and software projects: https://gist.github.com/XVilka/8346728
 
 
 
 IPython 5.0
 ===========
 
 Released July 7, 2016
 
 New terminal interface
 ----------------------
 
 IPython 5 features a major upgrade to the terminal interface, bringing live
 syntax highlighting as you type, proper multiline editing and multiline paste,
 and tab completions that don't clutter up your history.
 
 .. image:: ../_images/ptshell_features.png
     :alt: New terminal interface features
     :align: center
     :target: ../_images/ptshell_features.png
 
 These features are provided by the Python library `prompt_toolkit
 <http://python-prompt-toolkit.readthedocs.io/en/stable/>`__, which replaces
 ``readline`` throughout our terminal interface.
 
 Relying on this pure-Python, cross platform module also makes it simpler to
 install IPython. We have removed dependencies on ``pyreadline`` for Windows and
 ``gnureadline`` for Mac.
 
 Backwards incompatible changes
 ------------------------------
 
 - The ``%install_ext`` magic function, deprecated since 4.0, has now been deleted.
   You can distribute and install extensions as packages on PyPI.
 - Callbacks registered while an event is being handled will now only be called
   for subsequent events; previously they could be called for the current event.
   Similarly, callbacks removed while handling an event *will* always get that
   event. See :ghissue:`9447` and :ghpull:`9453`.
 - Integration with pydb has been removed since pydb development has been stopped
   since 2012, and pydb is not installable from PyPI.
 - The ``autoedit_syntax`` option has apparently been broken for many years.
   It has been removed.
 
 New terminal interface
 ~~~~~~~~~~~~~~~~~~~~~~
 
 The overhaul of the terminal interface will probably cause a range of minor
 issues for existing users.
 This is inevitable for such a significant change, and we've done our best to
 minimise these issues.
 Some changes that we're aware of, with suggestions on how to handle them:
 
 IPython no longer uses readline configuration (``~/.inputrc``). We hope that
 the functionality you want (e.g. vi input mode) will be available by configuring
 IPython directly (see :doc:`/config/options/terminal`).
 If something's missing, please file an issue.
 
 The ``PromptManager`` class has been removed, and the prompt machinery simplified.
 See :ref:`custom_prompts` to customise prompts with the new machinery.
 
 :mod:`IPython.core.debugger` now provides a plainer interface.
 :mod:`IPython.terminal.debugger` contains the terminal debugger using
 prompt_toolkit.
 
 There are new options to configure the colours used in syntax highlighting.
 We have tried to integrate them with our classic  ``--colors`` option and
 ``%colors`` magic, but there's a mismatch in possibilities, so some configurations
 may produce unexpected results. See :ref:`termcolour` for more information.
 
 The new interface is not compatible with Emacs 'inferior-shell' feature. To
 continue using this, add the ``--simple-prompt`` flag to the command Emacs
 runs. This flag disables most IPython features, relying on Emacs to provide
 things like tab completion.
 
 Provisional Changes
 -------------------
 
 Provisional changes are experimental functionality that may, or may not, make
 it into a future version of IPython, and which API may change without warnings.
 Activating these features and using these API are at your own risk, and may have
 security implication for your system, especially if used with the Jupyter notebook,
 
 When running via the Jupyter notebook interfaces, or other compatible client,
 you can enable rich documentation experimental functionality:
 
 When the ``docrepr`` package is installed setting the boolean flag
 ``InteractiveShell.sphinxify_docstring`` to ``True``, will process the various
 object through sphinx before displaying them (see the ``docrepr`` package
 documentation for more information.
 
 You need to also enable the IPython pager display rich HTML representation
 using the ``InteractiveShell.enable_html_pager`` boolean configuration option.
 As usual you can set these configuration options globally in your configuration
 files, alternatively you can turn them on dynamically using the following
 snippet:
 
 .. code-block:: python
 
     ip = get_ipython()
     ip.sphinxify_docstring = True
     ip.enable_html_pager = True
 
 
 You can test the effect of various combinations of the above configuration in
 the Jupyter notebook, with things example like :
 
 .. code-block:: ipython
 
     import numpy as np
     np.histogram?
 
 
 This is part of an effort to make Documentation in Python richer and provide in
 the long term if possible dynamic examples that can contain math, images,
 widgets... As stated above this is nightly experimental feature with a lot of
 (fun) problem to solve. We would be happy to get your feedback and expertise on
 it.
 
 
 
 Deprecated Features
 -------------------
 
 Some deprecated features are listed in this section. Don't forget to enable
 ``DeprecationWarning`` as an error if you are using IPython in a Continuous
 Integration setup or in your testing in general:
 
 .. code-block:: python
 
     import warnings
     warnings.filterwarnings('error', '.*', DeprecationWarning, module='yourmodule.*')
 
 
 - ``hooks.fix_error_editor`` seems unused and is pending deprecation.
 - `IPython/core/excolors.py:ExceptionColors` is  deprecated.
 - `IPython.core.InteractiveShell:write()` is deprecated; use `sys.stdout` instead.
 - `IPython.core.InteractiveShell:write_err()` is deprecated; use `sys.stderr` instead.
 - The `formatter` keyword argument to `Inspector.info` in `IPython.core.oinspec` has no effect.
 - The `global_ns` keyword argument of IPython Embed was deprecated, and has no effect. Use `module` keyword argument instead.
 
 
 Known Issues:
 -------------
 
 - ``<Esc>`` Key does not dismiss the completer and does not clear the current
   buffer. This is an on purpose modification due to current technical
   limitation. Cf :ghpull:`9572`. Escape the control character which is used
   for other shortcut, and there is no practical way to distinguish. Use Ctr-G
   or Ctrl-C as an alternative.
 
 - Cannot use ``Shift-Enter`` and ``Ctrl-Enter`` to submit code in terminal. cf
   :ghissue:`9587` and :ghissue:`9401`. In terminal there is no practical way to
   distinguish these key sequences from a normal new line return.
 
 - ``PageUp`` and ``pageDown`` do not move through completion menu.
 
 - Color styles might not adapt to terminal emulator themes. This will need new
   version of Pygments to be released, and can be mitigated with custom themes.