#!/usr/bin/env python # # Copyright (C) 2011, 2012, 2013 Strahinja Val Markovic # # 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 . import abc import ycm_core from ycm import vimsupport from ycm.completers.completer_utils import TriggersForFiletype 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. CandidatesForQueryAsync() 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. The job of CandidatesForQueryAsync() is to merely initiate this request, which will hopefully be processed in a background thread. You may want to subclass ThreadedCompleter instead of Completer directly. AsyncCandidateRequestReady() is the function that is repeatedly polled until it returns True. If CandidatesForQueryAsync() started a background task of collecting the required completions, AsyncCandidateRequestReady() would check the state of that task and return False until it was completed. CandidatesFromStoredRequest() should return the list of candidates. This is what YCM calls after AsyncCandidateRequestReady() returns True. The format of the result can be a list of strings or a more complicated list of dictionaries. See ':h complete-items' for the format, and clang_completer.py to see how its used in practice. 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 that maintains its own internal cache and therefore directly overrides the "main" functions in the API instead of the *Inner versions. A good example of a simple completer that does not do this is omni_completer.py. If you're confident your completer doesn't need a background task (think again, you probably do) because you can "certainly" furnish a response in under 10ms, then you can perform your backend processing in a synchronous fashion. You may also need to do this because of technical restrictions (much like omni_completer.py has to do it because accessing Vim internals is not thread-safe). But even if you're certain, still try to do the processing in a background thread. Your completer is unlikely to be merged if it does not, because synchronous processing will block Vim's GUI thread and that's a very, VERY bad thing (so try not to do it!). Again, you may want to subclass ThreadedCompleter instead of Completer directly; ThreadedCompleter will abstract away the use of a background thread for you. See threaded_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.""" __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() self.completions_future = None self.completions_cache = None self.completion_start_column = None # It's highly likely you DON'T want to override this function but the *Inner # version of it. def ShouldUseNow( self, start_column, current_line ): inner_says_yes = self.ShouldUseNowInner( start_column, current_line ) if not inner_says_yes: self.completions_cache = None previous_results_were_empty = ( self.completions_cache and self.completions_cache.CacheValid( start_column ) and not self.completions_cache.raw_completions ) return inner_says_yes and not previous_results_were_empty def ShouldUseNowInner( self, start_column, current_line ): line_length = len( current_line ) if not line_length or start_column - 1 >= line_length: return False filetype = self._CurrentFiletype() 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, start_column ): query_length = vimsupport.CurrentColumn() - 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 CandidatesForQueryAsync( self, query, start_column ): self.completion_start_column = start_column if query and self.completions_cache and self.completions_cache.CacheValid( start_column ): self.completions_cache.filtered_completions = ( self.FilterAndSortCandidates( self.completions_cache.raw_completions, query ) ) else: self.completions_cache = None self.CandidatesForQueryAsyncInner( query, start_column ) def DefinedSubcommands( self ): return [] def EchoUserCommandsHelpMessage( self ): subcommands = self.DefinedSubcommands() if subcommands: vimsupport.EchoText( 'Supported commands are:\n' + '\n'.join( subcommands ) + '\nSee the docs for information on what they do.' ) else: vimsupport.EchoText( 'No supported subcommands' ) def FilterAndSortCandidates( self, candidates, query ): if not candidates: return [] if hasattr( candidates, 'words' ): candidates = candidates.words items_are_objects = 'word' in candidates[ 0 ] matches = ycm_core.FilterAndSortCandidates( candidates, 'word' if items_are_objects else '', query ) return matches def CandidatesForQueryAsyncInner( self, query, start_column ): pass # It's highly likely you DON'T want to override this function but the *Inner # version of it. def AsyncCandidateRequestReady( self ): if self.completions_cache: return True else: return self.AsyncCandidateRequestReadyInner() def AsyncCandidateRequestReadyInner( self ): if not self.completions_future: # We return True so that the caller can extract the default value from the # future return True return self.completions_future.ResultsReady() # It's highly likely you DON'T want to override this function but the *Inner # version of it. def CandidatesFromStoredRequest( self ): if self.completions_cache: return self.completions_cache.filtered_completions else: self.completions_cache = CompletionsCache() self.completions_cache.raw_completions = self.CandidatesFromStoredRequestInner() self.completions_cache.line, _ = vimsupport.CurrentLineAndColumn() self.completions_cache.column = self.completion_start_column return self.completions_cache.raw_completions def CandidatesFromStoredRequestInner( self ): if not self.completions_future: return [] return self.completions_future.GetResults() def OnFileReadyToParse( self ): pass def OnBufferVisit( self ): pass def OnBufferUnload( self, deleted_buffer_file ): pass def OnInsertLeave( self ): pass def OnVimLeave( self ): pass def OnUserCommand( self, arguments ): vimsupport.PostVimMessage( NO_USER_COMMANDS ) def OnCurrentIdentifierFinished( self ): pass def DiagnosticsForCurrentFileReady( self ): return False def GetDiagnosticsForCurrentFile( self ): return [] def ShowDetailedDiagnostic( self ): pass def GettingCompletions( self ): return False def _CurrentFiletype( self ): filetypes = vimsupport.CurrentFiletypes() 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 ): return '' class CompletionsCache( object ): def __init__( self ): self.line = -1 self.column = -1 self.raw_completions = [] self.filtered_completions = [] def CacheValid( self, start_column ): completion_line, _ = vimsupport.CurrentLineAndColumn() completion_column = start_column return completion_line == self.line and completion_column == self.column