vimrc: autocomplete improvements

vimrc

@@ -128,6 +128,10 @@ map <Leader>8 :call RequestGrep()<CR>
 packadd! deoplete.nvim
 let g:deoplete#enable_at_startup = 1
 call deoplete#custom#option('num_processes', 6)
+" https://github.com/Shougo/deoplete.nvim/issues/965#issuecomment-482925193
+call deoplete#custom#option('omni_patterns', {
+\ 'go': '[^. *\t]\.\w*',
+\})
 " <TAB>: completion.
 inoremap <expr><TAB>  pumvisible() ? "\<C-n>" : "\<TAB>"
 inoremap <expr><s-TAB>  pumvisible() ? "\<C-p>" : "\<s-TAB>"
@@ -169,7 +173,6 @@ let g:rustfmt_autosave = 1
 " ALE configuration:
 " Note: needs https://github.com/dense-analysis/ale/issues/3373
 " to avoid "json decode error" during deoplete resolution.
-set omnifunc=ale#completion#OmniFunc
 function SymbolSearch()
   call inputsave()
   let s:pattern = trim(input("symbol search: "))
@@ -216,7 +219,7 @@ let g:ale_rust_analyzer_config = {
 let g:ale_go_goimports_options = '-local github.com/sensiblecodeio/cantabular'
 let g:ale_go_gopls_options = '' " TODO: composite keys?
 let g:ale_command_wrapper = 'nice -n5'
-let g:ale_completion_enabled = 1
+let g:ale_completion_enabled = 0
 let g:ale_close_preview_on_insert = 1
 let g:ale_hover_to_preview = 1
 let g:ale_sign_column_always = 1
@@ -245,6 +248,7 @@ packadd! ale
 
 " load other plugins:
 packadd! lightline.vim
+packadd! tmux-complete.vim
 packadd! vim-commentary
 packadd! vim-surround
 packadd! vim-yaml-folds