xq-lsp

Language Server Protocol implementation for XQuery, providing autocompletion, hover documentation, signature help, go-to-definition, and diagnostics.

Features

• Completion — functions declared in the current file, imported modules, and variables in scope
• Hover — function signatures on hover
• Signature help — active parameter hints inside function calls
• Go to definition — jump to function or variable declarations, including across imported files
• Document symbols — file outline of all declared functions and variables
• Diagnostics — syntax errors as you type

Imports written as import module namespace prefix="uri" at "./other-file.xq" are followed automatically; symbols from imported files are included in completions.

For files with syntax errors (common while editing), the server falls back to regex-based extraction so completions keep working.

Emacs

With eglot (built-in since Emacs 29)

Install xquery-mode from MELPA:

M-x package-install RET xquery-mode RET

Add to your init.el:

(with-eval-after-load 'eglot
  (add-to-list 'eglot-server-programs
               '(xquery-mode . ("npx" "xq-lsp" "--stdio"))))

(add-hook 'xquery-mode-hook #'eglot-ensure)

Open any .xq file and eglot starts the server automatically. Run M-x eglot to start it manually.

Key bindings:

| Action | Key | |---|---| | Completion | C-M-i | | Hover / docs | C-c C-d | | Signature help | automatic in minibuffer | | Go to definition | M-. | | Go back | M-, | | Document symbols | M-x imenu | | Diagnostics | M-x flymake-show-buffer-diagnostics |

With lsp-mode

(with-eval-after-load 'lsp-mode
  (add-to-list 'lsp-language-id-configuration '(xquery-mode . "xquery"))

  (lsp-register-client
   (make-lsp-client
    :new-connection (lsp-stdio-connection '("npx" "xq-lsp" "--stdio"))
    :major-modes '(xquery-mode)
    :language-id "xquery"
    :server-id 'xquery-lsp)))

(add-hook 'xquery-mode-hook #'lsp)

VS Code

A minimal VS Code extension lives in editors/vscode/.

cd editors/vscode
npm install

Open the editors/vscode folder in VS Code and press F5 to launch a development host with the extension active. To install it permanently, package it with vsce:

npx vsce package
code --install-extension xquery-lsp-vscode-*.vsix

The extension registers .xq, .xql, .xqm, and .xqy files as XQuery and starts xq-lsp automatically when you open one.