Provide tag completions for asyncomplete.vim

Plug 'prabirshrestha/asyncomplete.vim'
Plug 'prabirshrestha/asyncomplete-tags.vim'

asyncomplete-tags.vim is not responsible for creating tag files. You should create tagfiles on your own or use plugins to help you generate tags files. If you are using a plugin to generate tags make sure it is async so it doesn't block vim.

Here is an example configured with ctags and vim-gutentags. vim-gutentags generates tags asynchronously using job.

Plug 'prabirshrestha/asyncomplete.vim'
if executable('ctags')
    Plug 'prabirshrestha/asyncomplete-tags.vim'
    Plug 'ludovicchabant/vim-gutentags'
endif

au User asyncomplete_setup call asyncomplete#register_source(asyncomplete#sources#tags#get_source_options({
    \ 'name': 'tags',
    \ 'allowlist': ['c'],
    \ 'completor': function('asyncomplete#sources#tags#completor'),
    \ 'config': {
    \    'max_file_size': 50000000,
    \  },
    \ }))

Note: config is optional. max_file_size defaults to 50000000 (50mb). If the tag file size exceeds max_file_size it is ignored. Set max_file_size to -1 for unlimited file size.

It will try to use grep or findstr (findstr ships with Windows) asynchronously. If those executables are not found it will fallback to using vimscript which could be slow for large tag files.