nvim-cmp/README.md

nvim-cmp

A completion plugin for neovim written in Lua.

Status

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

Development

You should read type definitions and LSP spec to develop core or sources.

Overview

nvim-cmp emphasizes compatibility with the VSCode behavior and the LSP specification but there are some little differences.

1. In nvim-cmp, the CompletionItem can have word and dup property that introduced by vim's completion mechanism.

Create custom source

The example source is here.

• The complete function is required but others can be omitted.
• The callback argument must always be called.

local source = {}

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

---Return keyword pattern which will be used by the followings.
---  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.
---@param request  cmp.CompletionRequest
---@param callback fun(response: lsp.CompletionResponse|nil)
---NOTE: This method is required.
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