nvim-cmp/README.md

nvim-cmp

A completion plugin for neovim written in Lua.

Status

not yet stable but ok to use (for testing).

Configuration

First, You should install core and sources by your favorite plugin manager.

The nvim-cmp sources can be found in here.

Plug 'hrsh7th/nvim-cmp'
Plug 'hrsh7th/cmp-buffer'

Then setup configuration.

" Setup global configuration
lua <<EOF
  require'cmp'.setup {
    -- You should change this example to your chosen snippet engine.
    snippet = {
      expand = function(args)
        -- You must install `vim-vsnip` if you set up as same as the following.
        vim.fn['vsnip#anonymous'](args.body)
      end
    },
  
    -- You should specify your *installed* sources.
    sources = {
      { name = 'buffer' }
    },
  }
EOF

" Setup buffer configuration
autocmd FileType markdown lua require'cmp'.setup.buffer {
\   sources = {
\     { name = 'buffer' },
\   },
\ }

Configuration

The default configuration can be found in here

completion.autocomplete (type: cmp.TriggerEvent[])

The autocompletion trigger events.

If you specify an empty table, nvim-cmp does not perform completion automatically.

But you can still use manual completion. It is similar to omni-completion.

completion.keyword_pattern (type: string)

A default keyword pattern. This value will be used if the source has no source specific pattern.

completion.keyword_length (type: number)

A minimum keyword length to completion.

completion.completeopt (type: string)

A vim's completeopt setting. Warning: Be careful when changing this value.

sorting.priority_weight (type: number)

A the source priority for sorting.

score + ((#sources - (source_index - 1)) * sorting.priority_weight)

sorting.comparators (type: function[])

A comparator function list. The function must return boolean|nil.

Source creation

If you publish nvim-cmp source to GitHub, please add nvim-cmp topic for the repo.

You should read cmp types and LSP spec to create sources.

• The complete function is required but others can be omitted.
• The callback argument must always be called.
• The custom source only can use require('cmp').
• The custom source can specify word property to CompletionItem. (It isn't an LSP specification but supported as a special case.)

local source = {}

---Source constructor.
source.new = function()
  local self = setmetatable({}, { __index = source })
  self.your_awesome_variable = 1
  return self
end

---Return keyword pattern which will be used...
---  1. Trigger keyword completion
---  2. Detect menu start offset
---  3. Reset completion state
---@return string
function source:get_keyword_pattern()
  return '???'
end

---Return trigger characters.
---@return string[]
function source:get_trigger_characters()
  return { ??? }
end

---Invoke completion (required).
---  If you want to abort completion, just call the callback without arguments.
---@param request  cmp.CompletionRequest
---@param callback fun(response: lsp.CompletionResponse|nil)
function source:complete(request, callback)
  callback({
    { label = 'January' },
    { label = 'February' },
    { label = 'March' },
    { label = 'April' },
    { label = 'May' },
    { label = 'June' },
    { label = 'July' },
    { label = 'August' },
    { label = 'September' },
    { label = 'October' },
    { label = 'November' },
    { label = 'December' },
  })
end

---Resolve completion item that will be called when the item selected or before the item confirmation.
---@param completion_item lsp.CompletionItem
---@param callback fun(completion_item: lsp.CompletionItem|nil)
function source:resolve(completion_item, callback)
  callback(completion_item)
end

---Execute command that will be called when after the item confirmation.
---@param completion_item lsp.CompletionItem
---@param callback fun(completion_item: lsp.CompletionItem|nil)
function source:execute(completion_item, callback)
  callback(completion_item)
end

return source