Editor Setup

BioLang ships with a built-in language server (bl lsp) that provides real-time diagnostics, completions, hover documentation, and more. This page covers how to configure it for the most popular editors.

Language Server Features

The BioLang LSP supports the following capabilities:

VS Code

The official BioLang extension for Visual Studio Code provides the best out-of-the-box experience with syntax highlighting, LSP integration, and snippet support.

Installation

1. Open VS Code
2. Go to Extensions (Ctrl+Shift+X / Cmd+Shift+X)
3. Search for "BioLang"
4. Click Install

Or install from the command line:

code --install-extension biolang.biolang-vscode

Configuration

The extension automatically detects the bl binary from your PATH. To use a custom binary path or pass additional LSP flags, add these settings to your settings.json:

{
  "biolang.serverPath": "/usr/local/bin/bl",
  "biolang.lsp.args": ["lsp", "--log-level", "info"],
  "biolang.formatOnSave": true,
  "biolang.trace.server": "messages"
}

Recommended Companion Extensions

• Error Lens — inline diagnostic messages
• indent-rainbow — visualize indentation levels
• Bracket Pair Colorizer — matching bracket colors

Snippets

The extension includes built-in snippets for common patterns:

Neovim

Neovim users can configure the BioLang LSP via nvim-lspconfig.

Basic Setup

Add the following to your init.lua:

-- Register BioLang file type
vim.filetype.add({
  extension = {
    bl = "biolang",
  },
})

-- Configure LSP
local lspconfig = require("lspconfig")
local configs = require("lspconfig.configs")

if not configs.biolang then
  configs.biolang = {
    default_config = {
      cmd = { "bl", "lsp" },
      filetypes = { "biolang" },
      root_dir = lspconfig.util.root_pattern(".git", "biolang.toml"),
      settings = {},
    },
  }
end

lspconfig.biolang.setup({
  on_attach = function(client, bufnr)
    -- Format on save
    if client.supports_method("textDocument/formatting") then
      vim.api.nvim_create_autocmd("BufWritePre", {
        buffer = bufnr,
        callback = function()
          vim.lsp.buf.format({ async = false })
        end,
      })
    end
  end,
})

Tree-sitter Grammar

For enhanced syntax highlighting, install the BioLang Tree-sitter grammar via nvim-treesitter:

require("nvim-treesitter.configs").setup({
  ensure_installed = { "biolang" },
  highlight = { enable = true },
})

Telescope Integration

Use Telescope for fuzzy-finding BioLang symbols:

vim.keymap.set("n", "<leader>bs", function()
  require("telescope.builtin").lsp_document_symbols({
    symbols = { "function", "variable" },
  })
end, { desc = "BioLang symbols" })

Emacs

Emacs users can configure BioLang via lsp-mode or eglot.

lsp-mode Setup

;; Define BioLang major mode
(define-derived-mode biolang-mode prog-mode "BioLang"
  "Major mode for editing BioLang files."
  (setq-local comment-start "# ")
  (setq-local comment-end ""))

(add-to-list 'auto-mode-alist '("\\.bl\\'" . biolang-mode))

;; LSP configuration
(with-eval-after-load 'lsp-mode
  (add-to-list 'lsp-language-id-configuration '(biolang-mode . "biolang"))
  (lsp-register-client
   (make-lsp-client
    :new-connection (lsp-stdio-connection '("bl" "lsp"))
    :activation-fn (lsp-activate-on "biolang")
    :server-id 'biolang-lsp)))

(add-hook 'biolang-mode-hook #'lsp-deferred)

eglot Setup

(add-to-list 'eglot-server-programs
             '(biolang-mode . ("bl" "lsp")))
(add-hook 'biolang-mode-hook #'eglot-ensure)

Other Editors

Any editor that supports the Language Server Protocol can work with BioLang. The LSP server is started with:

bl lsp

It communicates over stdin/stdout using the standard LSP JSON-RPC protocol. Common editors with LSP support include:

• Sublime Text — via the LSP package
• Helix — add to languages.toml
• Zed — custom language server configuration
• Kate — via built-in LSP client

Helix Example

Add to ~/.config/helix/languages.toml:

[[language]]
name = "biolang"
scope = "source.biolang"
file-types = ["bl"]
roots = ["biolang.toml"]
language-servers = ["biolang-lsp"]
comment-token = "#"
indent = { tab-width = 2, unit = "  " }

[language-server.biolang-lsp]
command = "bl"
args = ["lsp"]

Verifying the Setup

To confirm everything is working, create a test file test.bl:

# test.bl — verify editor integration
let seq = dna"ATCGATCG"
let gc = gc_content(seq)
print("GC content: {gc}")

You should see:

• Syntax highlighting for keywords, strings, DNA literals, and comments
• Completions when typing seq |> (offering gc_content, reverse_complement, etc.)
• Hover information when hovering over gc_content
• No diagnostic errors (red squiggles)

Next Steps

With your editor configured, explore the REPL Tour to learn about BioLang's interactive mode.