Work in progress.

An attempt to write a Language Server Protocol server for and in XQuery 4.0. It tracks the draft specifications at https://qt4cg.org/ It written for BaseX 12.0 and uses the BaseX websocket feature.

Demo

The demos expect Docker or Podman on the local machine. This is only a requirement for the demos.

1 Clone this repo 2. Run docker compose up -d The LSP server shall now running on port 3000 (edit compose.yaml to change port) 3. In a browser navigate to http://localhost:3000/static/clients/codemirror/ to see the CodeMirror 6 demo.

In principle, the LSP can be used in any environment that can make use of a LSP server accessed via a websocket.

LSP Server

• webapp/lsp The LSP implementation in XQuery using WebSockets for transport and the JSON-RPC 2.0 API for data format.

Sample html clients

Samples using common browser based code editors are available. The CodeMirror 6 sample is the most functional.

These examples are self contained (no internet access required). Some make use of recent html features, for instance popovertarget

CodeMirror6 https://codemirror.net/

• webapp/static/codemirror A test html page using the CodeMirror6 editor that connects to the BaseX LSP instance

uses

• https://codemirror.net/docs/ref/#lsp-client
• https://github.com/codemirror/legacy-modes/ xquery mode provides browser based syntax highlighting (XQuery 3.1?)

alternative LSP interfaces

• https://github.com/FurqanSoftware/codemirror-languageserver
• https://hjr265.me/blog/codemirror-lsp/

Ace Editor

• webapp/static/ace A test html page using the Ace editor that connects to the BaseX LSP instance @TODO fix

Uses

• https://github.com/mkslanc/ace-linters https://mkslanc.github.io/ace-linters/

Make a websocket server for lsp on port 3000 https://mkslanc.github.io/ace-linters/websocket.html

http://localhost:3000/exampleServer

c1b317e012/packages/demo/websockets-lsp/server/server.ts I needed set NODE_OPTIONS=--max_old_space_size=8192 for build to complete

Or node --max-old-space-size=8192 node_modules/webpack-dev-serve r/bin/webpack-dev-server.js

Monaco editor

@TODO create https://socket.dev/npm/package/monaco-editor

Server dev notes

State is held in websocket attributes.

Name	Use
client	the client initialize message
initialized	set true after client sends initialized message
files	A map whose keys are open uris, values are maps (doctype-> attribute name where doctype is stored
file-{uuid}	name of websocket attribute containing the textDocument
parse-{uuid}	name of websocket attribute containing parse tree XML

sequenceDiagram
    WS->>lsp-ws: message
    lsp-ws->>rpc: reply
    rpc->>+John: John, can you hear me?
   

XQuery 4.0 parser

The ebnf is taken from Gunther Rademacher's rex-parser-generator XQuery-40.ebnf

The script scripts/rex.xq can generate XQuery or Java parser code from this. The npm package.json script javac can create a jar file from the Java source.

Related links

java -cp org.eclipse.lemminx-uber.jar org.eclipse.lemminx.XMLServerSocketLauncher`