Use ALE completion

config/ale.vim

@@ -87,7 +87,7 @@ let g:ale_go_langserver_executable = 'gopls'
 
 let g:airline#extensions#ale#enabled = 1
 
-let g:ale_completion_enabled = 0
+let g:ale_completion_enabled = 1
 let g:ale_lint_on_enter = 0
 let g:ale_lint_on_text_changed = 'never'
 highlight ALEErrorSign ctermbg=NONE ctermfg=red
@@ -96,3 +96,9 @@ let g:ale_linters_explicit = 1
 let g:ale_lint_on_save = 1
 let g:ale_fix_on_save = 1
 
+" let g:ale_set_balloons = 1
+let g:ale_hover_to_preview = 1
+let g:ale_float_preview = 1
+let g:ale_floating_window_border = ['│', '─', '╭', '╮', '╯', '╰']
+
+set omnifunc=ale#completion#OmniFunc