Blink Completion (blink.cmp)

blink.cmp provides a completion plugin with support for LSPs and external sources while updating on every keystroke with minimal overhead (0.5-4ms async). It achieves this by writing the fuzzy searching in SIMD to easily handle >20k items. It provides extensibility via hooks into the trigger, sources and rendering pipeline. Plenty of work has been put into making each stage of the pipeline as intelligent as possible, such as frecency and proximity bonus on fuzzy matching, and this work is on-going. nvim-cmp sources are supported out of the box but migration to the blink.cmp style source is highly encouraged.

Features

• Works out of the box with no additional configuration
• Simple hackable codebase
• Updates on every keystroke (0.5-4ms non-blocking, single core)
• Typo resistant fuzzy with frecency and proximity bonus
• Extensive LSP support (tracker)
• Snippet support (including friendly-snippets)
• TODO: Cmdline support
• External sources support (including nvim-cmp compatibility layer)
• Comparison with nvim-cmp

Installation

lazy.nvim

{
  'saghen/blink.nvim',
  -- note: requires nightly
  build = 'cargo build --release',
  -- todo: should handle lazy loading internally
  event = 'InsertEnter',
  dependencies = {
    {
      'garymjr/nvim-snippets',
      dependencies = { 'rafamadriz/friendly-snippets' },
      opts = { create_cmp_source = false, friendly_snippets = true },
    },
  },
  opts = {
    -- see lua/blink/cmp/config.lua for all options
    cmp = { enabled = true }
  }
}

How it works

The plugin use a 4 stage pipeline: trigger -> sources -> fuzzy -> render

Trigger: Controls when to request completion items from the sources and provides a context downstream with the current query (i.e. hello.wo|, the query would be wo) and the treesitter object under the cursor (i.e. for intelligently enabling/disabling sources). It respects trigger characters passed by the LSP (or any other source) and includes it in the context for sending to the LSP.

Sources: Provides a common interface for and merges the results of completion, trigger character, resolution of additional information and cancellation. It also provides a compatibility layer to nvim-cmp's sources. Many sources are builtin: LSP, buffer, treesitter, path, snippets

Fuzzy: Rust <-> Lua FFI which performs both filtering and sorting of the items

    Filtering: The fuzzy matching uses smith-waterman, same as FZF, but implemented in SIMD for ~6x the performance of FZF (todo: add benchmarks). Due to the SIMD's performance, the prefiltering phase on FZF was dropped to allow for typos. Similar to fzy/fzf, additional points are given to prefix matches, characters with capitals (to promote camelCase/PascalCase first char matching) and matches after delimiters (to promote snake_case first char matching)

    Sorting: Combines fuzzy matching score with frecency and proximity bonus. Each completion item may also include a score_offset which will be added to this score to demote certain sources. The buffer and snippets sources take advantage of this to avoid taking presedence over the LSP source. The paramaters here still need to be tuned and have been exposed, so please let me know if you find some magical parameters!

Render: Responsible for placing the autocomplete, documentation and function parameters windows. All of the rendering can be overriden following a syntax similar to incline.nvim. It uses the neovim window decoration provider to provide next to no overhead from highlighting.

Compared to nvim-cmp

Advantages

• Avoids the complexity of nvim-cmp's configuration by providing sensible defaults
• Updates on every keystroke, versus nvim-cmp's default debounce of 60ms
  • Setting nvim-cmp's deboucne to 0ms leads to visible stuttering. If you'd like to stick with nvim-cmp, try yioneko's fork
• Boosts completion item score via frecency and proximity bonus. nvim-cmp only boosts score via proximity bonus
• Typo-resistant fuzzy matching unlike nvim-cmp's fzf-style fuzzy matching
• Core sources (buffer, snippets, lsp) are built-in versus nvim-cmp's exclusively external sources
• Uses native snippets versus nvim-cmp's required snippet engine

Disadvantages

All of the following are planned, but not yet implemented.

• Less customizable across the board wrt matching, sources, sorting, filtering, etc
• Significantly less testing and documentation
• No support for cmdline completions
• No support for dynamic (i.e. per-filetype) sources
• Customizable rendering of completion window

Special Thanks

@redxtech Help with design, testing and helping me keep my sanity @aadityasahay Help with rust and design