如何配置Vim通过ctags实现非前缀部分匹配自动补全

Absolutely, you can make Vim do non-prefix (substring-based) autocompletion—either by tweaking its built-in features with a custom function, or leveraging ctags. Let’s walk through both approaches clearly:

方法1：自定义内置补全函数实现子串匹配 #

Vim’s default <C-n>/<C-p> uses prefix matching, but we can build a simple custom completion function to handle substring matches instead. Add this to your .vimrc:

function! SubstringComplete(findstart, base)
    if a:findstart
        " Locate the start of the current word under the cursor
        let line = getline('.')
        let start = col('.') - 1
        while start > 0 && line[start-1] =~ '\w'
            let start -= 1
        endwhile
        return start
    else
        " Gather keywords from buffers and tags
        let keywords = []
        call extend(keywords, getcompletion(a:base, 'buffer'))
        call extend(keywords, getcompletion(a:base, 'tags'))
        " Filter to keep only keywords containing our substring
        let matches = filter(keywords, 'stridx(v:val, a:base) != -1')
        " Deduplicate and sort the results
        let matches = sort(uniq(matches))
        return matches
    endif
endfunction

" Set our custom function as the completion handler
set completefunc=SubstringComplete
" Bind <C-n> to trigger substring completion (replace with your preferred key)
inoremap <C-n> <C-x><C-u>

Now when you type test_gener and hit <C-n>, Vim will pull up all keywords (including _generator_function_1) that contain the substring gener. Select the one you want, and it’ll auto-complete to test_generator_function_1.

方法2：结合ctags实现智能补全 #

If you prefer using ctags, here’s how to set it up for flexible matching:

1. Generate your tags file:
   Navigate to your project root and run:

   ctags -R --extra=+q .
   

   The --extra=+q flag adds extra metadata to tags, making them easier to work with.

2. Configure Vim to use tags:
   Add these lines to your .vimrc:

   set tags=./tags; " Recursively look for tags files upwards from the current directory
   set complete+=t " Include tags in Vim's default completion sources
   

3. Use substring completion with tags:
   For substring matches, pair this with the custom completion function from Method 1—it already includes tags as a source. Alternatively, if you want to stick to Vim’s native tag completion (<C-x><C-]>), you can tweak your workflow to search for the middle substring (e.g., type gener then hit <C-x><C-]>) and manually prepend test_ if needed, but the custom function is more seamless.

Extra Tips #

• Add these settings to make completion case-insensitive (but still respect uppercase when you type it):

  set ignorecase
  set smartcase
  

• Feel free to rebind the completion shortcut to whatever you prefer—swap <C-n> with <C-p> or another key if that fits your workflow better.

内容的提问来源于stack exchange，提问作者Leeren