Support selecting the first completion option / Remove 'noselect' from completeopts

[rouge8]

This patch removes noselect from the default completeopts. This should no longer be necessary thanks to 25b572b, because the <C-p> added to the map will deselect the first entry.

Combined with something like this in your ~/.vimrc:

function! RemapAleCompletion()
  iunmap <Plug>(ale_show_completion_menu)
  inoremap <silent> <Plug>(ale_show_completion_menu) <C-x><C-o>
endfunction

augroup remap_ale_completion
  autocmd!
  autocmd VimEnter * call RemapAleCompletion()
augroup END

This can address #3433.

[MeTheFlea]

function! RemapAleCompletion()
  iunmap <Plug>(ale_show_completion_menu)
  inoremap <silent> <Plug>(ale_show_completion_menu) <C-x><C-o>
endfunction

augroup remap_ale_completion
  autocmd!
  autocmd VimEnter * call RemapAleCompletion()
augroup END

I'm a bit of a vimscript novice but this snippet doesn't seem to work, since <Plug>(ale_show_completion_menu) doesn't seem to be set by the time VimEnter * call RemapAleCompletion() is executed. It seems like <Plug>(ale_show_completion_menu) is only set after the first time ALEComplete is called, and I'm not sure if there's an autocmd moment where I can automatically override it once it gets set. However, calling RemapAleCompletion() manually after doing :ALEComplete once does seem to provide the behaviour I originally wanted in #3433 for the rest of the vim session.

[rouge8]

I'm a bit of a vimscript novice but this snippet doesn't seem to work, since <Plug>(ale_show_completion_menu) doesn't seem to be set by the time VimEnter * call RemapAleCompletion() is executed. It seems like <Plug>(ale_show_completion_menu) is only set after the first time ALEComplete is called, and I'm not sure if there's an autocmd moment where I can automatically override it once it gets set. However, calling RemapAleCompletion() manually after doing :ALEComplete once does seem to provide the behaviour I originally wanted in #3433 for the rest of the vim session.

I think I can reproduce what you're seeing when I don't use let g:ale_completion_enabled = 1. In that case, I believe this PR plus this function fixes #3433:

function! RemapAleCompletion()
  " Load autoload/ale/completion.vim and the <Plug>(ale_show_completion_menu) mapping
  ALEComplete
  " or:
  " call ale#completion#GetCompletions('ale-manual')

  iunmap <Plug>(ale_show_completion_menu)
  inoremap <silent> <Plug>(ale_show_completion_menu) <C-x><C-o>
endfunction

augroup remap_ale_completion
  autocmd!
  autocmd VimEnter * call RemapAleCompletion()
augroup END

[w0rp]

I think instead of this change, we need a separate Plug mapping for manual completion (ale-manual) so we don't send C-p to back out of selecting the first item. This can be done by adding an argument to s:OpenCompletionMenu to change which Plug key it sends. We can't select the first item from automatic completion as it will interrupt typing, but we can when you open the completion menu through a keybind.

[rouge8]

I think instead of this change, we need a separate Plug mapping for manual completion (ale-manual) so we don't send C-p to back out of selecting the first item. This can be done by adding an argument to s:OpenCompletionMenu to change which Plug key it sends. We can't select the first item from automatic completion as it will interrupt typing, but we can when you open the completion menu through a keybind.

I actually use this with automatic completion. The noinsert ensures it doesn't insert the selected item unless I request it with C-y.

[w0rp]

I'm gonna replace this with an alternate patch which respects the value of completeopt, so you'll get noselect if you have your options configured that way, otherwise you won't.