Add config options for asyncomplete integration

'splitmode', 'filter_prefix', 'show_incomplete', 'sort_candidates'

See code comment below for details.

autoload/asyncomplete/sources/tmuxcomplete.vim

@@ -4,6 +4,32 @@ let s:defaultopts = {
             \ 'completor': function('asyncomplete#sources#tmuxcomplete#completor'),
             \ }
 
+" 'splitmode' can be 'words', 'lines', 'ilines', or 'linies,words'
+" 'ilines' is inner line, starting with a word character (ignoring special
+" chararcters in front)
+" 'ilines,words' completes both lines and words
+" more combinations can be added per request
+"
+" if 'filter_prefix' is enabled, we will filter candidates based on the entered
+" text, this usually gives faster results. for fuzzy matching this should be
+" disabled
+"
+" if there you are using many tmux windows with a lot of text in it completion
+" can be slow. that's why we start showing candidates as soon as they come in
+" if you prefer to only see candidates once the list is complete, you can
+" disable this 'show_incomplete'
+"
+" 'sort_candidates' controls whether we sort candidates from tmux externally.
+" if it's enabled we can't get early incomplete results. if you have
+" 'show_incomplete' disabled, this might get slightly quicker results and
+" potentially better sorted completions.
+let s:defaultconfig = {
+            \ 'splitmode':      'words',
+            \ 'filter_prefix':   1,
+            \ 'show_incomplete': 1,
+            \ 'sort_candidates': 0
+            \ }
+
 function! asyncomplete#sources#tmuxcomplete#register(opts)
     let l:opts = extend(copy(s:defaultopts), a:opts)
     call asyncomplete#register_source(l:opts)
@@ -18,10 +44,14 @@ function! asyncomplete#sources#tmuxcomplete#completor(opt, ctx)
     endif
     " echom '#completor for ' . l:kw
 
+    let l:config = extend(copy(s:defaultconfig), get(a:opt, 'config', {}))
+    " echom 'config ' . string(l:config)
+
     let l:params = {
                 \ 'name':     a:opt['name'],
                 \ 'ctx':      a:ctx,
                 \ 'startcol': a:ctx['col'] - l:kwlen,
+                \ 'config':   l:config,
                 \ 'kw':       l:kw,
                 \ 'raw':      [],
                 \ 'mapped':   []
@@ -31,7 +61,16 @@ function! asyncomplete#sources#tmuxcomplete#completor(opt, ctx)
     " completions later, even if the context changed in between.
     call s:complete(l:params, [''], 1)
 
-    let l:cmd = tmuxcomplete#getcommandlist(l:kw, 'words')
+    if !l:config['filter_prefix']
+        let l:kw = ''
+    endif
+
+    let l:cmd = tmuxcomplete#getcommandlist(l:kw, l:config['splitmode'])
+    if !l:config['sort_candidates']
+        call add(l:cmd, '-n')
+    endif
+    " echom 'cmd ' . string(l:cmd)
+
     let l:jobid = async#job#start(l:cmd, {
                 \ 'on_stdout': function('s:stdout', [l:params]),
                 \ 'on_exit':   function('s:exit',   [l:params]),
@@ -43,9 +82,11 @@ function! s:stdout(params, id, data, event) abort
 
     call extend(a:params['raw'], a:data) " to be mapped differently again on exit
 
-    " surround with pipes while incomplete
-    call extend(a:params['mapped'], map(copy(a:data), '{"word":v:val,"menu":"|' . a:params['name'] . '|"}'))
-    call s:complete(a:params, a:params['mapped'], 1)
+    if a:params['config']['show_incomplete']
+        " surround with pipes while incomplete
+        call extend(a:params['mapped'], map(copy(a:data), '{"word":v:val,"menu":"|' . a:params['name'] . '|"}'))
+        call s:complete(a:params, a:params['mapped'], 1)
+    endif
 endfunction
 
 function! s:exit(params, id, data, event) abort