Do not show exception w/ file completer when pressing tab after backslash

IPython/completer.py

@@ -1,644 +1,644 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 IPython.rlineimpl as readline    
 import itertools
 from IPython.ipstruct import Struct
 from IPython import ipapi
 
 import types
 
 # Python 2.4 offers sets as a builtin
 try:
     set([1,2])
 except NameError:
     from sets import Set as set
 
 from IPython.genutils import debugx
 
 __all__ = ['Completer','IPCompleter']
 
 def get_class_members(cls):
     ret = dir(cls)
     if hasattr(cls,'__bases__'):
         for base in cls.__bases__:
             ret.extend(get_class_members(base))
     return ret
 
 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)
         """
 
         # some minimal strict typechecks.  For some core data structures, I
         # want actual basic python types, not just anything that looks like
         # one.  This is especially true for namespaces.
         for ns in (namespace,global_namespace):
             if ns is not None and type(ns) != types.DictType:
                 raise TypeError,'namespace must be a dictionary'
 
         # 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:
             object = eval(expr, self.namespace)
         except:
             try:
                 object = eval(expr, self.global_namespace)
             except:
                 return []
                 
 
         # Start building the attribute list via dir(), and then complete it
         # with a few extra special-purpose calls.
         words = dir(object)
 
         if hasattr(object,'__class__'):
             words.append('__class__')
             words.extend(get_class_members(object.__class__))
 
         # this is the 'dir' function for objects with Enthought's traits
         if hasattr(object, 'trait_names'):
             try:
                 words.extend(object.trait_names())
                 # eliminate possible duplicates, as some traits may also
                 # appear as normal attributes in the dir() call.
                 words = set(words)
             except TypeError:
                 # This will happen if `object` is a class and not an instance.
                 pass
 
         # Support for PyCrust-style _getAttributeNames magic method.
         if hasattr(object, '_getAttributeNames'):
             try:
                 words.extend(object._getAttributeNames())
                 # Eliminate duplicates.
                 words = set(words)
             except TypeError:
                 # `object` is a class and not an instance.  Ignore
                 # this error.
                 pass
 
         # filter out non-string attributes which may be stuffed by dir() calls
         # and poor coding in third-party modules
         words = [w for w in words
                  if isinstance(w, basestring) and w != "__builtins__"]
         # Build match list to return
         n = len(attr)
         return ["%s.%s" % (expr, w) for w in words if w[:n] == attr ]
 
 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.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.omit__names = omit__names
         self.merge_completions = shell.rc.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
 
         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])
         
         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 None
+                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]
         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]
             
             matches = [ (d + '/' + p) for p in os.listdir(d) ]
             
         return 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
         if ' ' in self.lbuf:
             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)
                 return [r for r in res if r.lower().startswith(text.lower())]
             except ipapi.TryNext:
                 pass
             
         return None
         
     
     
     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'.  """
 
         #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).
 
         # don't apply this on 'dumb' terminals, such as emacs buffers, so we
         # don't interfere with their own tab-completion mechanism.
         self.full_lbuf = self.get_line_buffer()
         self.lbuf = self.full_lbuf[:self.readline.get_endidx()]
         if not (self.dumb_terminal or self.get_line_buffer().strip()):
             self.readline.insert_text('\t')
             return None
 
         
         magic_escape = self.magic_escape
         magic_prefix = self.magic_prefix
 
         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
 
             try:
                 return self.matches[state].replace(magic_prefix,magic_escape)
             except IndexError:
                 return None
         except:
             from IPython.ultraTB import AutoFormattedTB; # dbg
             tb=AutoFormattedTB('Verbose');tb() #dbg
 
             # If completion fails, don't annoy the user.
             return None