XQuery Language Server

XQuery language support for VS Code via the xq-lsp language server.

Features

• Syntax highlighting — keywords, types, variables, operators, comments, and XQuery 4.0 tokens
• 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 highlighted as you type
• Formatting — format XQuery files with Prettier via Shift+Alt+F (Format Document)

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

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

Supported file extensions

.xq, .xql, .xqm, .xqy, .xquery

Configuration

Summary: Fonto development

Place an lsp-config.xq file in the Fonto root folder (the one that holds the manifest.json) with the following content:

map {
	'lib': 'fonto',
	'glob': 'packages/**/*.xqm',
	'import': map {
		'generateLocationHints': false()
	}
}

General configuration

Place an lsp-config.xq file in your project root to enable glob-based import resolution. The server walks up from the current file's directory to find it.

map {"glob": "src/**/*.xq"}

Multiple patterns are written as an XPath sequence:

map {"glob": ("src/**/*.xq", "lib/**/*.xq")}

The server indexes all matched files by their declared namespace URI, so imports without an at clause resolve automatically:

(: no "at" path needed :)
import module namespace util="http://example.com/util";

Runtime built-ins

Use the lib key to load built-in definitions for a specific runtime:

map {"glob": "src/**/*.xq", "lib": "fonto"}

Then import the namespace in your XQuery files as usual — the server resolves completions, hover, and go-to-definition against the bundled definitions:

import module namespace fonto="http://www.fontoxml.com/functions";

Multiple libs use an XPath sequence:

map {"glob": "src/**/*.xq", "lib": ("fonto", "other")}

Strict mode

The type checker only reports certain static errors by default. Opt in to stricter checking — e.g. warnings (XPTY0004) when an argument's cardinality may not fit the parameter's occurrence indicator, such as passing item()* where item() is expected:

map {
	"glob": "src/**/*.xq",
	"strict": map {
		"cardinality": true()
	}
}

See the main README for details.

Formatting

XQuery formatting is provided by prettier-plugin-xquery, bundled directly in the extension. No separate install is required.

Trigger formatting with Format Document (Shift+Alt+F on Windows/Linux, Shift+Option+F on macOS), or enable format-on-save in your VS Code settings:

"[xquery]": {
  "editor.defaultFormatter": "elliat.xquery-lsp-vscode",
  "editor.formatOnSave": true
}

Prettier options (print width, tab width, etc.) are read from your project's Prettier config file if one exists.

Requirements

Node.js must be installed and available on your PATH.

Pre-release versions

Every change to the language server or extension on main is published as a pre-release. To try it, open the extension in VS Code and click Switch to Pre-Release Version; click Switch to Release Version to go back. Pre-releases use the next minor version with the CI run number as patch (e.g. 0.9.57), so they always sort above the current stable release.

To test a specific build without the Marketplace, download the .vsix from the "VS Code pre-release" workflow run and install it with code --install-extension <file>.vsix.