Autocompletion and signature help plugin

• Async (with customizable 'debounce' delay) 'two-stage chain completion': first builtin LSP, then configurable fallback.
• Has functionality for completion item info and function signature (both in floating window appearing after customizable delay).

See more details in Features and help file.

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⦿ This is a part of mini.nvim library. Please use this link if you want to mention this module.

⦿ All contributions (issues, pull requests, discussions, etc.) are done inside of 'mini.nvim'.

⦿ See the repository page to learn about common design principles and configuration recipes.

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If you want to help this project grow but don't know where to start, check out contributing guides of 'mini.nvim' or leave a Github star for 'mini.nvim' project and/or any its standalone Git repositories.

Demo

demo-completion.mp4

Features

• Two-stage chain completion:
  • First stage is an LSP completion. Supports additionalTextEdits (like auto-import, etc.) and snippets (see "Snippets") (best results require 'mini.snippets' dependency).
  • If first stage is not set up or resulted into no candidates, fallback action is executed. The most tested actions are Neovim's built-in insert completion.
• Automatic display in floating window of completion item info (via 'completionItem/resolve' request) and signature help (with highlighting of active parameter if LSP server provides such information). Scrolling is possible in both info/signature window (<C-f> / <C-b> by default).
• Automatic actions are done after some configurable amount of delay. This reduces computational load and allows fast typing (completion and signature help) and item selection (item info)
• User can force two-stage/fallback completion (<C-Space> / <A-Space> by default).
• Highlighting of LSP kind (like "Function", "Keyword", etc.). Requires enabled 'mini.icons' (uses its "lsp" category) and Neovim>=0.11.

Dependencies

For full experience needs (still works without any of suggestions):

• Enabled 'mini.icons' module to highlight LSP kind (requires Neovim>=0.11). If absent, MiniCompletion.default_process_items() does not add highlighting. Also take a look at MiniIcons.tweak_lsp_kind().
• Enabled 'mini.snippets' module for better snippet handling (much recommended). If absent and custom snippet insert is not configured, vim.snippet.expand() is used on Neovim>=0.10 (nothing extra is done on earlier versions). See :h MiniCompletion.default_snippet_insert().

Snippets

As per LSP specification, some completion items can be supplied in the form of snippet - a template with both pre-defined text and places (called "tabstops") for user to interactively change/add text during snippet session.

In 'mini.completion' items that will insert snippet have "S" symbol shown in the popup. To actually insert a snippet:

• Select an item via <C-n> / <C-p>. This will insert item's label (usually not full snippet) first to reduce visual flicker. The full snippet text will be shown in info window if LSP server doesn't provide its own info for an item.

• Press <C-y> or attempt inserting a non-keyword character (like <CR>; new character will be removed). It will clear text from previous step, set cursor, and call lsp_completion.snippet_insert with snippet text.

• Press <C-e> to cancel snippet insert and properly end completion.

See :h MiniCompletion.default_snippet_insert() for overview of how to work with inserted snippets.

Installation

This plugin can be installed as part of 'mini.nvim' library (recommended) or as a standalone Git repository.

There are two branches to install from:

• main (default, recommended) will have latest development version of plugin. All changes since last stable release should be perceived as being in beta testing phase (meaning they already passed alpha-testing and are moderately settled).
• stable will be updated only upon releases with code tested during public beta-testing phase in main branch.

Here are code snippets for some common installation methods (use only one):

With mini.deps

Github repo	Branch	Code snippet
'mini.nvim' library	Main	Follow recommended 'mini.deps' installation
	Stable
Standalone plugin	Main	add('echasnovski/mini.completion')
	Stable	add({ source = 'echasnovski/mini.completion', checkout = 'stable' })

With folke/lazy.nvim

Github repo	Branch	Code snippet
'mini.nvim' library	Main	{ 'echasnovski/mini.nvim', version = false },
	Stable	{ 'echasnovski/mini.nvim', version = '*' },
Standalone plugin	Main	{ 'echasnovski/mini.completion', version = false },
	Stable	{ 'echasnovski/mini.completion', version = '*' },

With junegunn/vim-plug

Github repo	Branch	Code snippet
'mini.nvim' library	Main	Plug 'echasnovski/mini.nvim'
	Stable	Plug 'echasnovski/mini.nvim', { 'branch': 'stable' }
Standalone plugin	Main	Plug 'echasnovski/mini.completion'
	Stable	Plug 'echasnovski/mini.completion', { 'branch': 'stable' }

Important: don't forget to call require('mini.completion').setup() to enable its functionality.

Note: if you are on Windows, there might be problems with too long file paths (like error: unable to create file <some file name>: Filename too long). Try doing one of the following:

• Enable corresponding git global config value: git config --system core.longpaths true. Then try to reinstall.
• Install plugin in other place with shorter path.

Default config

-- No need to copy this inside `setup()`. Will be used automatically.
{
  -- Delay (debounce type, in ms) between certain Neovim event and action.
  -- This can be used to (virtually) disable certain automatic actions by
  -- setting very high delay time (like 10^7).
  delay = { completion = 100, info = 100, signature = 50 },

  -- Configuration for action windows:
  -- - `height` and `width` are maximum dimensions.
  -- - `border` defines border (as in `nvim_open_win()`).
  window = {
    info = { height = 25, width = 80, border = 'single' },
    signature = { height = 25, width = 80, border = 'single' },
  },

  -- Way of how module does LSP completion
  lsp_completion = {
    -- `source_func` should be one of 'completefunc' or 'omnifunc'.
    source_func = 'completefunc',

    -- `auto_setup` should be boolean indicating if LSP completion is set up
    -- on every `BufEnter` event.
    auto_setup = true,

    -- A function which takes LSP 'textDocument/completion' response items
    -- and word to complete. Output should be a table of the same nature as
    -- input items. Common use case is custom filter/sort.
    -- Default: `default_process_items`
    process_items = nil,

    -- A function which takes a snippet as string and inserts it at cursor.
    -- Default: `default_snippet_insert` which tries to use 'mini.snippets'
    -- and falls back to `vim.snippet.expand` (on Neovim>=0.10).
    snippet_insert = nil,
  },

  -- Fallback action as function/string. Executed in Insert mode.
  -- To use built-in completion (`:h ins-completion`), set its mapping as
  -- string. Example: set '<C-x><C-l>' for 'whole lines' completion.
  fallback_action = '<C-n>',

  -- Module mappings. Use `''` (empty string) to disable one. Some of them
  -- might conflict with system mappings.
  mappings = {
    -- Force two-step/fallback completions
    force_twostep = '<C-Space>',
    force_fallback = '<A-Space>',

    -- Scroll info/signature window down/up. When overriding, check for
    -- conflicts with built-in keys for popup menu (like `<C-u>`/`<C-o>`
    -- for 'completefunc'/'omnifunc' source function; or `<C-n>`/`<C-p>`).
    scroll_down = '<C-f>',
    scroll_up = '<C-b>',
  },

  -- Whether to set Vim's settings for better experience (modifies
  -- `shortmess` and `completeopt`)
  set_vim_settings = true,
}

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