YouCompleteMe/python/ycm/completers/completer.py
Strahinja Val Markovic e424d75c42 Preventing traceback for detailed diagnostic
Previously we'd show a Python traceback if the user asked for a detailed
diagnostic in a file that wasn't supported by Clang (something written in Python
perhaps). Now we show an nice, far less scary message informing the user of
this.

Fixes #748.
2014-01-02 14:24:17 -08:00

291 lines
10 KiB
Python

#!/usr/bin/env python
#
# Copyright (C) 2011, 2012, 2013 Strahinja Val Markovic <val@markovic.io>
#
# This file is part of YouCompleteMe.
#
# YouCompleteMe is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# YouCompleteMe is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with YouCompleteMe. If not, see <http://www.gnu.org/licenses/>.
import abc
from collections import defaultdict
from ycm.utils import ToUtf8IfNeeded, ForceSemanticCompletion, RunningInsideVim
if RunningInsideVim():
from ycm_client_support import FilterAndSortCandidates
else:
from ycm_core import FilterAndSortCandidates
from ycm.completers.completer_utils import TriggersForFiletype
from ycm.server.responses import NoDiagnosticSupport
NO_USER_COMMANDS = 'This completer does not define any commands.'
class Completer( object ):
"""A base class for all Completers in YCM.
Here's several important things you need to know if you're writing a custom
Completer. The following are functions that the Vim part of YCM will be
calling on your Completer:
ShouldUseNow() is called with the start column of where a potential completion
string should start and the current line (string) the cursor is on. For
instance, if the user's input is 'foo.bar' and the cursor is on the 'r' in
'bar', start_column will be the 0-based index of 'b' in the line. Your
implementation of ShouldUseNow() should return True if your semantic completer
should be used and False otherwise.
This is important to get right. You want to return False if you can't provide
completions because then the identifier completer will kick in, and that's
better than nothing.
Note that it's HIGHLY likely that you want to override the ShouldUseNowInner()
function instead of ShouldUseNow() directly (although chances are that you
probably won't have any need to override either). ShouldUseNow() will call
your *Inner version of the function and will also make sure that the
completion cache is taken into account. You'll see this pattern repeated
throughout the Completer API; YCM calls the "main" version of the function and
that function calls the *Inner version while taking into account the cache.
The cache is important and is a nice performance boost. When the user types in
"foo.", your completer will return a list of all member functions and
variables that can be accessed on the "foo" object. The Completer API caches
this list. The user will then continue typing, let's say "foo.ba". On every
keystroke after the dot, the Completer API will take the cache into account
and will NOT re-query your completer but will in fact provide fuzzy-search on
the candidate strings that were stored in the cache.
ComputeCandidates() is the main entry point when the user types. For
"foo.bar", the user query is "bar" and completions matching this string should
be shown. It should return the list of candidates. The format of the result
can be a list of strings or a more complicated list of dictionaries. Use
ycm.server.responses.BuildCompletionData to build the detailed response. See
clang_completer.py to see how its used in practice.
Again, you probably want to override ComputeCandidatesInner().
You also need to implement the SupportedFiletypes() function which should
return a list of strings, where the strings are Vim filetypes your completer
supports.
clang_completer.py is a good example of a "complicated" completer. A good
example of a simple completer is ultisnips_completer.py.
The On* functions are provided for your convenience. They are called when
their specific events occur. For instance, the identifier completer collects
all the identifiers in the file in OnFileReadyToParse() which gets called when
the user stops typing for 2 seconds (Vim's CursorHold and CursorHoldI events).
One special function is OnUserCommand. It is called when the user uses the
command :YcmCompleter and is passed all extra arguments used on command
invocation (e.g. OnUserCommand(['first argument', 'second'])). This can be
used for completer-specific commands such as reloading external configuration.
When the command is called with no arguments you should print a short summary
of the supported commands or point the user to the help section where this
information can be found.
Override the Shutdown() member function if your Completer subclass needs to do
custom cleanup logic on server shutdown."""
__metaclass__ = abc.ABCMeta
def __init__( self, user_options ):
self.user_options = user_options
self.min_num_chars = user_options[ 'min_num_of_chars_for_completion' ]
self.triggers_for_filetype = (
TriggersForFiletype( user_options[ 'semantic_triggers' ] )
if user_options[ 'auto_trigger' ] else defaultdict( set ) )
self.completions_future = None
self._completions_cache = None
# It's highly likely you DON'T want to override this function but the *Inner
# version of it.
def ShouldUseNow( self, request_data ):
inner_says_yes = self.ShouldUseNowInner( request_data )
if not inner_says_yes:
self._completions_cache = None
previous_results_were_empty = ( self._completions_cache and
self._completions_cache.CacheValid(
request_data[ 'line_num' ],
request_data[ 'start_column' ] ) and
not self._completions_cache.raw_completions )
return inner_says_yes and not previous_results_were_empty
def ShouldUseNowInner( self, request_data ):
current_line = request_data[ 'line_value' ]
start_column = request_data[ 'start_column' ]
line_length = len( current_line )
if not line_length or start_column - 1 >= line_length:
return False
filetype = self._CurrentFiletype( request_data[ 'filetypes' ] )
triggers = self.triggers_for_filetype[ filetype ]
for trigger in triggers:
index = -1
trigger_length = len( trigger )
while True:
line_index = start_column + index
if line_index < 0 or current_line[ line_index ] != trigger[ index ]:
break
if abs( index ) == trigger_length:
return True
index -= 1
return False
def QueryLengthAboveMinThreshold( self, request_data ):
query_length = request_data[ 'column_num' ] - request_data[ 'start_column' ]
return query_length >= self.min_num_chars
# It's highly likely you DON'T want to override this function but the *Inner
# version of it.
def ComputeCandidates( self, request_data ):
if ( not ForceSemanticCompletion( request_data ) and
not self.ShouldUseNow( request_data ) ):
return []
candidates = self._GetCandidatesFromSubclass( request_data )
if request_data[ 'query' ]:
candidates = self.FilterAndSortCandidates( candidates,
request_data[ 'query' ] )
return candidates
def _GetCandidatesFromSubclass( self, request_data ):
if ( self._completions_cache and
self._completions_cache.CacheValid( request_data[ 'line_num' ],
request_data[ 'start_column' ] ) ):
return self._completions_cache.raw_completions
else:
self._completions_cache = CompletionsCache()
self._completions_cache.raw_completions = self.ComputeCandidatesInner(
request_data )
self._completions_cache.line = request_data[ 'line_num' ]
self._completions_cache.column = request_data[ 'start_column' ]
return self._completions_cache.raw_completions
def ComputeCandidatesInner( self, request_data ):
pass
def DefinedSubcommands( self ):
return []
def UserCommandsHelpMessage( self ):
subcommands = self.DefinedSubcommands()
if subcommands:
return ( 'Supported commands are:\n' +
'\n'.join( subcommands ) +
'\nSee the docs for information on what they do.' )
else:
return 'This Completer has no supported subcommands.'
def FilterAndSortCandidates( self, candidates, query ):
if not candidates:
return []
# We need to handle both an omni_completer style completer and a server
# style completer
if 'words' in candidates:
candidates = candidates[ 'words' ]
sort_property = ''
if 'word' in candidates[ 0 ]:
sort_property = 'word'
elif 'insertion_text' in candidates[ 0 ]:
sort_property = 'insertion_text'
matches = FilterAndSortCandidates( candidates,
sort_property,
ToUtf8IfNeeded( query ) )
return matches
def OnFileReadyToParse( self, request_data ):
pass
def OnBufferVisit( self, request_data ):
pass
def OnBufferUnload( self, request_data ):
pass
def OnInsertLeave( self, request_data ):
pass
def OnUserCommand( self, arguments, request_data ):
raise NotImplementedError( NO_USER_COMMANDS )
def OnCurrentIdentifierFinished( self, request_data ):
pass
def GetDiagnosticsForCurrentFile( self, request_data ):
raise NoDiagnosticSupport
def GetDetailedDiagnostic( self, request_data ):
raise NoDiagnosticSupport
def _CurrentFiletype( self, filetypes ):
supported = self.SupportedFiletypes()
for filetype in filetypes:
if filetype in supported:
return filetype
return filetypes[0]
@abc.abstractmethod
def SupportedFiletypes( self ):
pass
def DebugInfo( self, request_data ):
return ''
def Shutdown( self ):
pass
class CompletionsCache( object ):
def __init__( self ):
self.line = -1
self.column = -1
self.raw_completions = []
self.filtered_completions = []
def CacheValid( self, current_line, start_column ):
return current_line == self.line and start_column == self.column