Documentation for ncm2

[languitar]

neovim-completion-manager got replaced by ncm2. Some calls to register custom completions have changed with this. I am still struggling to get vimtex completion working here. Some documentation would be nice.

[lervag]

Interesting! I've noticed that ncm2 has been announced, but I'm currently using deoplete and will probably not change again very soon as I'm happy for now. As such, I don't really have the time to investigate the necessary configuration. I would be very happy if you/someone could help me by proposing text for the docs.

[clason]

The following (stolen from reddit) works for me:

" include the following plugins (here using junnegun/vim-plug)
Plug 'roxma/nvim-yarp'                                                    
Plug 'ncm2/ncm2'     

au User Ncm2Plugin call ncm2#register_source({                                
        \ 'name' : 'vimtex',                                                      
        \ 'priority': 9,                                                          
        \ 'subscope_enable': 1,                                                   
        \ 'complete_length': 1,                                                   
        \ 'scope': ['tex'],                                                       
        \ 'mark': 'tex',                                                          
        \ 'word_pattern': '\w+',                                                  
        \ 'complete_pattern': g:vimtex#re#ncm,                                    
        \ 'on_complete': ['ncm2#on_complete#omni', 'vimtex#complete#omnifunc'],   
        \ })                                                           
au BufEnter * call ncm2#enable_for_buffer()    
set completeopt=noinsert,menuone,noselect         

(there are other options for convenience; see https://github.com/ncm2/ncm2#optional-vimrc-tips)

It feels a bit snappier than deoplete (and less prone to race conditions, i.e., \de showing \dagger if the e is typed too quickly after d), although there are some (cosmetic) regressions regarding the (optional and still experimental) integration with UltiSnips (already fixed!).

(One difference is that ncm2 is opt-in rather than opt-out like deoplete, so every source has to be explicitly set up. E.g., for Ultisnips you have to add Plug 'ncm2/ncm2-ultisnips', but then it works without further configuration. There's a corresponding plugin for snipmate.)

[languitar]

@clason I tried exactly that code but I can't get completions for tex with this. Any idea?

[clason]

@languitar Here's a minimal vimrc that works for me:

call plug#begin('~/.vim/plugged')                                                 
Plug 'roxma/nvim-yarp'                                                            
Plug 'ncm2/ncm2'                                                                  
Plug 'lervag/vimtex'                                                              
call plug#end()                                                                   

au User Ncm2Plugin call ncm2#register_source({                                    
            \ 'name' : 'vimtex',                                                  
            \ 'priority': 1,                                                      
            \ 'subscope_enable': 1,                                               
            \ 'complete_length': 1,                                               
            \ 'scope': ['tex'],                                                   
            \ 'mark': 'tex',                                                      
            \ 'word_pattern': '\w+',                                              
            \ 'complete_pattern': g:vimtex#re#ncm,                                
            \ 'on_complete': ['ncm2#on_complete#omni',                            
            'vimtex#complete#omnifunc'],                                          
            \ })                                                           
au BufEnter * call ncm2#enable_for_buffer()                                       
set completeopt=noinsert,menuone,noselect

First thing is to check your neovim version (I'm on NVIM v0.3.1-172-g56065bbdc) and make sure that the python integration is working (:checkhealth, and if in doubt, pip3 install -U --force neovim). Another thought: Maybe your file is not recognized as tex (:se ft=tex to make sure)?

Or, more likely, something in your vimrc interferes with the ncm2#enable() call. If you manually call this function after the buffer is loaded, does it work then?

[lervag]

Thanks! I've added a section on this now. What do you think?

[clason]

Looks good!

[languitar]

@clason seems there was an update to ncm2 that I was missing. Now it works.

[clason]

Just a heads-up: Recent commits changed the sorting and matching algorithm to fuzzy matching; to get the old, prefix-based, behaviour, you have to add the following line to the custom source:

\ 'matcher': {'name': 'prefix', 'key': 'word'},

I'll make a pull request for the documentation.

[lervag]

Thanks!