<C-space> does nothing in YouCompleteMe

Question

I'm on my 4th clean install of YouCompleteMe. I am trying to get to work with a Python file after a . (such as foo....Then I hit <C-space> and would hope to see a list of options to complete with), but so far, nothing seems to be getting through.

This is the situation:

i  <C-Space>   * <C-X><C-O><C-P>
    Last set from ~/dotfiles/vim/.vim/bundle/youcompleteme/autoload/youcompleteme.vim

From .vimrc:

let g:ycm_python_binary_path = '/usr/bin/python'
let g:ycm_server_python_interpreter = '/usr/bin/python2'
let g:ycm_min_num_of_chars_for_completion = 2

And I've got no errors or warnings from the YcmDiags or any other YCM logs.

If I go ahead and type 2 characters (assuming they match a possible completion), the completions appear very quickly, so I believe the call is being made and serviced properly in that context. It's just calling it up manually with the key-binding is unresponsive.

I'm running xfce4-terminal and using zsh with oh-my-zsh, but I hope nothing there would be the culprit, like for example the terminal is blocking <C-space> from getting to Vim.

Oh, and I'm running Vim 8.0 on Arch Linux.

Answer 1

You actaully need to map to <Nul>, not to <C-Space> - looks strange I know, but I learned that recently trying to map to <C-Space>. I looked how it's done in CtrlSpace plugin, and it's using <Nul> for that. The reason is that your terminal probably send's ^@ (Nul character/sign) on Ctrl-Space - you can check that in Insert Mode by pressing Ctrl-v Ctrl-Space. The downside is that <Nul> can be triggered from other key sequences, not only Ctrl-Space.

Edit: Here's a related SO answer with a bit different approach. It maps <Nul> directly to <C-Space>