prototype of autotrigger

autoload/UltiSnips.vim

@@ -144,3 +144,8 @@ endf
 function! UltiSnips#LeavingInsertMode()
     exec g:_uspy "UltiSnips_Manager._leaving_insert_mode()"
 endfunction
+
+function! UltiSnips#TrackChange()
+    exec g:_uspy "UltiSnips_Manager._track_change()"
+endfunction
+" }}}

pythonx/UltiSnips/snippet/source/_base.py

@@ -28,7 +28,7 @@ class SnippetSource(object):
         deep_extends = self.get_deep_extends(base_filetypes)
         return [ft for ft in deep_extends if ft in self._snippets]
 
-    def get_snippets(self, filetypes, before, possible):
+    def get_snippets(self, filetypes, before, possible, autotrigger_only):
         """Returns the snippets for all 'filetypes' (in order) and their
         parents matching the text 'before'. If 'possible' is true, a partial
         match is enough. Base classes can override this method to provide means
@@ -40,7 +40,7 @@ class SnippetSource(object):
         result = []
         for ft in self._get_existing_deep_extends(filetypes):
             snips = self._snippets[ft]
-            result.extend(snips.get_matching_snippets(before, possible))
+            result.extend(snips.get_matching_snippets(before, possible, autotrigger_only))
         return result
 
     def get_clear_priority(self, filetypes):

pythonx/UltiSnips/snippet/source/_snippet_dictionary.py

@@ -16,13 +16,16 @@ class SnippetDictionary(object):
         """Add 'snippet' to this dictionary."""
         self._snippets.append(snippet)
 
-    def get_matching_snippets(self, trigger, potentially):
+    def get_matching_snippets(self, trigger, potentially, autotrigger_only):
         """Returns all snippets matching the given trigger.
 
         If 'potentially' is true, returns all that could_match().
 
         """
         all_snippets = self._snippets
+        if autotrigger_only:
+            all_snippets = [s for s in all_snippets if s.has_option('A')]
+
         if not potentially:
             return [s for s in all_snippets if s.matches(trigger)]
         else:

pythonx/UltiSnips/snippet_manager.py

@@ -100,6 +100,8 @@ class SnippetManager(object):
         self._snip_expanded_in_action = False
         self._inside_action = False
 
+        self._last_inserted_char = ''
+
         self._added_snippets_source = AddedSnippetsSource()
         self.register_snippet_source('ultisnips_files', UltiSnipsFileSource())
         self.register_snippet_source('added', self._added_snippets_source)
@@ -363,6 +365,8 @@ class SnippetManager(object):
         _vim.command('autocmd!')
         _vim.command('autocmd CursorMovedI * call UltiSnips#CursorMoved()')
         _vim.command('autocmd CursorMoved * call UltiSnips#CursorMoved()')
+        _vim.command('autocmd InsertCharPre * call UltiSnips#TrackChange()')
+        _vim.command('autocmd TextChangedI * call UltiSnips#TrackChange()')
 
         _vim.command(
             'autocmd InsertLeave * call UltiSnips#LeavingInsertMode()')
@@ -541,7 +545,7 @@ class SnippetManager(object):
         elif feedkey:
             _vim.command('return %s' % _vim.escape(feedkey))
 
-    def _snips(self, before, partial):
+    def _snips(self, before, partial, autotrigger_only=False):
         """Returns all the snippets for the given text before the cursor.
 
         If partial is True, then get also return partial matches.
@@ -565,7 +569,14 @@ class SnippetManager(object):
                     cleared[key] = value
 
         for _, source in self._snippet_sources:
-            for snippet in source.get_snippets(filetypes, before, partial):
+            possible_snippets = source.get_snippets(
+                filetypes,
+                before,
+                partial,
+                autotrigger_only
+            )
+
+            for snippet in possible_snippets:
                 if ((clear_priority is None or snippet.priority > clear_priority)
                         and (snippet.trigger not in cleared or
                              snippet.priority > cleared[snippet.trigger])):
@@ -667,10 +678,10 @@ class SnippetManager(object):
                 self._snip_expanded_in_action = True
 
 
-    def _try_expand(self):
+    def _try_expand(self, autotrigger_only=False):
         """Try to expand a snippet in the current place."""
         before = _vim.buf.line_till_cursor
-        snippets = self._snips(before, False)
+        snippets = self._snips(before, False, autotrigger_only)
         if snippets:
             # prefer snippets with context if any
             snippets_with_context = [s for s in snippets if s.context]
@@ -765,6 +776,16 @@ class SnippetManager(object):
         finally:
             self._inside_action = old_flag
 
+    def _track_change(self):
+        inserted_char = _vim.eval('v:char')
+        if inserted_char == '':
+            before = _vim.buf.line_till_cursor
+            if before and before[-1] == self._last_inserted_char:
+                self._try_expand(autotrigger_only=True)
+        else:
+            self._last_inserted_char = inserted_char
+
+
 UltiSnips_Manager = SnippetManager(  # pylint:disable=invalid-name
     vim.eval('g:UltiSnipsExpandTrigger'),
     vim.eval('g:UltiSnipsJumpForwardTrigger'),

test/test_UltiSnipFunc.py

@@ -154,7 +154,7 @@ from UltiSnips.snippet.source import SnippetSource
 from UltiSnips.snippet.definition import UltiSnipsSnippetDefinition
 
 class MySnippetSource(SnippetSource):
-  def get_snippets(self, filetypes, before, possible):
+  def get_snippets(self, filetypes, before, possible, autotrigger_only):
     if before.endswith('blumba'):
       return [
           UltiSnipsSnippetDefinition(