$/game/setInventory no longer needed

client/src/app.tsx

@@ -11,7 +11,6 @@ import './css/app.css';
 import { MobileContext } from './components/infoview/context';
 import { useMobile } from './hooks';
 import { AUTO_SWITCH_THRESHOLD, getWindowDimensions} from './state/preferences';
-import { connection } from './connection';
 
 export const GameIdContext = React.createContext<string>(undefined);
 
@@ -37,10 +36,6 @@ function App() {
     }
   }, [lockMobile])
 
-  React.useEffect(() => {
-    connection.startLeanClient(gameId);
-  }, [gameId])
-
   return (
     <div className="app">
       <GameIdContext.Provider value={gameId}>

client/src/components/level.tsx

@@ -18,7 +18,6 @@ import { EditorConnection, EditorEvents } from '../../../node_modules/lean4-info
 import { EventEmitter } from '../../../node_modules/lean4-infoview/src/infoview/event'
 
 import { GameIdContext } from '../app'
-import { ConnectionContext, connection, useLeanClient } from '../connection'
 import { useAppDispatch, useAppSelector } from '../hooks'
 import { useGetGameInfoQuery, useLoadInventoryOverviewQuery, useLoadLevelQuery } from '../state/api'
 import { changedSelection, codeEdited, selectCode, selectSelections, selectCompleted, helpEdited,
@@ -44,6 +43,15 @@ import 'lean4web/client/src/editor/infoview.css'
 import 'lean4web/client/src/editor/vscode.css'
 import '../css/level.css'
 import { LevelAppBar } from './app_bar'
+import { LeanClient } from 'lean4web/client/src/editor/leanclient'
+import { DisposingWebSocketMessageReader } from 'lean4web/client/src/reader'
+import { WebSocketMessageWriter, toSocket } from 'vscode-ws-jsonrpc'
+import { IConnectionProvider } from 'monaco-languageclient'
+import { monacoSetup } from 'lean4web/client/src/monacoSetup'
+import { onigasmH } from 'onigasm/lib/onigasmH'
+
+
+monacoSetup()
 
 function Level() {
   const params = useParams()
@@ -211,10 +219,8 @@ function PlayableLevel({impressum, setImpressum}) {
 
   const dispatch = useAppDispatch()
 
-  const difficulty = useSelector(selectDifficulty(gameId))
   const initialCode = useAppSelector(selectCode(gameId, worldId, levelId))
   const initialSelections = useAppSelector(selectSelections(gameId, worldId, levelId))
-  const inventory: Array<String> = useSelector(selectInventory(gameId))
 
   const typewriterMode = useSelector(selectTypewriterMode(gameId))
   const setTypewriterMode = (newTypewriterMode: boolean) => dispatch(changeTypewriterMode({game: gameId, typewriterMode: newTypewriterMode}))
@@ -293,12 +299,6 @@ function PlayableLevel({impressum, setImpressum}) {
   // a hint at the beginning of the proof...
   const [selectedStep, setSelectedStep] = useState<number>()
 
-  // if the user inventory changes, notify the server
-  useEffect(() => {
-    let leanClient = connection.getLeanClient(gameId)
-    leanClient.sendNotification('$/game/setInventory', {inventory: inventory, difficulty: difficulty})
-  }, [inventory])
-
   useEffect (() => {
     // Lock editor mode
     if (level?.data?.template) {
@@ -372,7 +372,7 @@ function PlayableLevel({impressum, setImpressum}) {
 
   // Effect when command line mode gets enabled
   useEffect(() => {
-    if (editor && typewriterMode) {
+    if (onigasmH && editor && typewriterMode) {
       let code = editor.getModel().getLinesContent().filter(line => line.trim())
       editor.executeEdits("typewriter", [{
         range: editor.getModel().getFullModelRange(),
@@ -395,7 +395,7 @@ function PlayableLevel({impressum, setImpressum}) {
       //   editor.setSelection(monaco.Selection.fromPositions(endPos, endPos))
       // }
     }
-  }, [editor, typewriterMode])
+  }, [editor, typewriterMode, onigasmH == null])
 
   return <>
     <div style={level.isLoading ? null : {display: "none"}} className="app-content loading"><CircularProgress /></div>
@@ -531,21 +531,32 @@ function Introduction({impressum, setImpressum}) {
 
 function useLevelEditor(codeviewRef, initialCode, initialSelections, onDidChangeContent, onDidChangeSelection) {
 
-  const connection = React.useContext(ConnectionContext)
   const gameId = React.useContext(GameIdContext)
   const {worldId, levelId} = useContext(WorldLevelIdContext)
 
-
   const [editor, setEditor] = useState<monaco.editor.IStandaloneCodeEditor|null>(null)
   const [infoProvider, setInfoProvider] = useState<null|InfoProvider>(null)
-  const [infoviewApi, setInfoviewApi] = useState<null|InfoviewApi>(null)
   const [editorConnection, setEditorConnection] = useState<null|EditorConnection>(null)
 
-  // Create Editor
+  const uriStr = `file:///${worldId}/${levelId}`
+  const uri = monaco.Uri.parse(uriStr)
+
+  const inventory: Array<String> = useSelector(selectInventory(gameId))
+  const difficulty: number = useSelector(selectDifficulty(gameId))
+
   useEffect(() => {
+    const model = monaco.editor.createModel(initialCode ?? '', 'lean4', uri)
+    if (onDidChangeContent) {
+      model.onDidChangeContent(() => onDidChangeContent(model.getValue()))
+    }
+
     const editor = monaco.editor.create(codeviewRef.current!, {
+      model,
       glyphMargin: true,
       quickSuggestions: false,
+      lineDecorationsWidth: 5,
+      folding: false,
+      lineNumbers: 'on',
       lightbulb: {
         enabled: true
       },
@@ -557,11 +568,61 @@ function useLevelEditor(codeviewRef, initialCode, initialSelections, onDidChange
         enabled: false
       },
       lineNumbersMinChars: 3,
+      tabSize: 2,
       'semanticHighlighting.enabled': true,
       theme: 'vs-code-theme-converted'
     })
+    if (onDidChangeSelection) {
+      editor.onDidChangeCursorSelection(() => onDidChangeSelection(editor.getSelections()))
+    }
+    if (initialSelections) {
+      console.debug("Initial Selection: ", initialSelections)
+      // BUG: Somehow I get an `invalid arguments` bug here
+      // editor.setSelections(initialSelections)
+    }
+    setEditor(editor)
+    const abbrevRewriter = new AbbreviationRewriter(new AbbreviationProvider(), model, editor)
+
+    const socketUrl = ((window.location.protocol === "https:") ? "wss://" : "ws://") + window.location.host + '/websocket/' + gameId
+
+    const connectionProvider : IConnectionProvider = {
+      get: async () => {
+        return await new Promise((resolve, reject) => {
+          console.log(`connecting ${socketUrl}`)
+          const websocket = new WebSocket(socketUrl)
+          websocket.addEventListener('error', (ev) => {
+            reject(ev)
+          })
+          websocket.addEventListener('message', (msg) => {
+            // console.log(msg.data)
+          })
+          websocket.addEventListener('open', () => {
+            const socket = toSocket(websocket)
+            const reader = new DisposingWebSocketMessageReader(socket)
+            const writer = new WebSocketMessageWriter(socket)
+            resolve({
+              reader,
+              writer
+            })
+          })
+        })
+      }
+    }
 
-    const infoProvider = new InfoProvider(connection.getLeanClient(gameId))
+    // Following `vscode-lean4/webview/index.ts`
+    const client = new LeanClient(connectionProvider, showRestartMessage, {inventory, difficulty})
+    const infoProvider = new InfoProvider(client)
+    // const div: HTMLElement = infoviewRef.current!
+    const imports = {
+      '@leanprover/infoview': `${window.location.origin}/index.production.min.js`,
+      'react': `${window.location.origin}/react.production.min.js`,
+      'react/jsx-runtime': `${window.location.origin}/react-jsx-runtime.production.min.js`,
+      'react-dom': `${window.location.origin}/react-dom.production.min.js`,
+      'react-popper': `${window.location.origin}/react-popper.production.min.js`
+    }
+    // loadRenderInfoview(imports, [infoProvider.getApi(), div], setInfoviewApi)
+    setInfoProvider(infoProvider)
+    client.restart()
 
     const editorApi = infoProvider.getApi()
 
@@ -606,54 +667,27 @@ function useLevelEditor(codeviewRef, initialCode, initialSelections, onDidChange
 
     setEditor(editor)
     setInfoProvider(infoProvider)
-    setInfoviewApi(infoviewApi)
-
-    return () => { infoProvider.dispose(); editor.dispose() }
-  }, [])
-
-  const {leanClient, leanClientStarted} = useLeanClient(gameId)
-  const uriStr = `file:///${worldId}/${levelId}`
-  const uri = monaco.Uri.parse(uriStr)
 
-  // Create model when level changes
+    infoProvider.openPreview(editor, infoviewApi)
-  useEffect(() => {
+    const taskgutter = new LeanTaskGutter(infoProvider.client, editor)
-    if (editor && leanClientStarted) {
 
-      let model = monaco.editor.getModel(uri)
+    // TODO:
-      if (!model) {
+    // setRestart(() => restart)
-        model = monaco.editor.createModel(initialCode, 'lean4', uri)
-      }
-      model.onDidChangeContent(() => onDidChangeContent(model.getValue()))
-      editor.onDidChangeCursorSelection(() => onDidChangeSelection(editor.getSelections()))
-      editor.setModel(model)
-      if (initialSelections) {
-        console.debug("Initial Selection: ", initialSelections)
-        // BUG: Somehow I get an `invalid arguments` bug here
-        // editor.setSelections(initialSelections)
-      }
 
-      return () => {
+    return () => {
-        editorConnection.api.sendClientNotification(uriStr, "textDocument/didClose", {textDocument: {uri: uriStr}})
+      editor.dispose();
-        model.dispose();
+      model.dispose();
-      }
+      abbrevRewriter.dispose();
+      taskgutter.dispose();
+      infoProvider.dispose();
+      client.dispose();
     }
-  }, [editor, levelId, connection, leanClientStarted])
+  }, [gameId, worldId, levelId])
-
-
-  useEffect(() => {
-    if (editor && leanClientStarted) {
-
-      let model = monaco.editor.getModel(uri)
-      infoviewApi.serverRestarted(leanClient.initializeResult)
-
-      infoProvider.openPreview(editor, infoviewApi)
-
-      const taskGutter = new LeanTaskGutter(infoProvider.client, editor)
-      const abbrevRewriter = new AbbreviationRewriter(new AbbreviationProvider(), model, editor)
 
-      return () => { abbrevRewriter.dispose(); taskGutter.dispose(); }
+  const showRestartMessage = () => {
-    }
+    // setRestartMessage(true)
-  }, [editor, connection, leanClientStarted])
+    console.log("TODO: SHOW RESTART MESSAGE")
+  }
 
   return {editor, infoProvider, editorConnection}
 }

client/src/connection.ts

@@ -1,68 +0,0 @@
-/**
- *  @fileOverview todo
- */
-
-import * as React from 'react';
-import * as monaco from 'monaco-editor/esm/vs/editor/editor.api.js'
-import { LeanClient } from 'lean4web/client/src/editor/leanclient';
-
-export class Connection {
-  private game: string = undefined // We only keep a connection to a single game at a time
-  private leanClient: LeanClient = null
-
-  getLeanClient(game): LeanClient {
-    if (this.game !== game) {
-      if (this.leanClient) {
-        this.leanClient.stop() // Stop previous Lean client
-      }
-      this.game = game
-      // Start a new Lean client for the new `gameId`.
-      const socketUrl = ((window.location.protocol === "https:") ? "wss://" : "ws://") + window.location.host + '/websocket/' + game
-      const uri = monaco.Uri.parse('file:///')
-      this.leanClient = new LeanClient(socketUrl, undefined, uri, () => {})
-    }
-
-    return this.leanClient
-  }
-
-  /** If not already started, starts the Lean client. resolves the returned promise as soon as a
-   * Lean client is running.
-   */
-  startLeanClient = (game) => {
-    return new Promise<LeanClient>((resolve) => {
-      const leanClient = this.getLeanClient(game)
-      if (leanClient.isRunning()) {
-        resolve(leanClient)
-      } else {
-        if (!leanClient.isStarted()) {
-          leanClient.start()
-        }
-        leanClient.restarted(() => {
-          // This keep alive message is not recognized by the server,
-          // but it makes sure that the websocket connection does not
-          // time out after 60 seconds.
-          setInterval(() => {leanClient.sendNotification('$/keepAlive', {}) }, 5000)
-          resolve(leanClient)
-        })
-      }
-    })
-  }
-}
-
-export const connection = new Connection()
-
-export const ConnectionContext = React.createContext(null);
-
-export const useLeanClient = (gameId) => {
-  const leanClient = connection.getLeanClient(gameId)
-  const [leanClientStarted, setLeanClientStarted] = React.useState(leanClient.isStarted())
-
-  React.useEffect(() => {
-    const t1 = leanClient.restarted(() => { console.log("START"); setLeanClientStarted(true) })
-    const t2 = leanClient.stopped(() => { console.log("STOP"); setLeanClientStarted(false) })
-
-    return () => {t1.dispose(); t2.dispose()}
-  }, [leanClient, setLeanClientStarted])
-
-  return {leanClientStarted, leanClient}
-}

client/src/index.tsx

@@ -1,7 +1,6 @@
 import * as React from 'react'
 import { createRoot } from 'react-dom/client'
 import App from './app'
-import { ConnectionContext, connection } from './connection'
 import { store } from './state/store'
 import { Provider } from 'react-redux'
 import type { RouteObject } from "react-router"
@@ -10,11 +9,8 @@ import ErrorPage from './components/error_page'
 import Welcome from './components/welcome'
 import LandingPage from './components/landing_page'
 import Level from './components/level'
-import { monacoSetup } from 'lean4web/client/src/monacoSetup'
 
 
-monacoSetup()
-
 
 // If `VITE_LEAN4GAME_SINGLE` is set to true, then `/` should be redirected to
 // `/g/local/game`. This is used for the devcontainer setup
@@ -61,9 +57,7 @@ const root = createRoot(container!);
 root.render(
   <React.StrictMode>
     <Provider store={store}>
-      <ConnectionContext.Provider value={connection}>
+      <RouterProvider router={router} />
-        <RouterProvider router={router} />
-      </ConnectionContext.Provider>
     </Provider>
   </React.StrictMode>
 );

client/src/state/store.ts

@@ -19,11 +19,7 @@ export const store = configureStore({
   },
   // Make connection available in thunks:
   middleware: getDefaultMiddleware =>
-    getDefaultMiddleware({
+    getDefaultMiddleware().concat(apiSlice.middleware),
-      thunk: {
-        extraArgument: { connection }
-      }
-    }).concat(apiSlice.middleware),
 });
 
 /**

package-lock.json

@@ -31,7 +31,7 @@
         "debounce": "^1.2.1",
         "express": "^4.18.2",
         "lean4-infoview": "https://gitpkg.now.sh/leanprover/vscode-lean4/lean4-infoview?de0062c",
-        "lean4web": "github:hhu-adam/lean4web",
+        "lean4web": "github:hhu-adam/lean4web#b91645a7b88814675ba9f99817436d0a2ce3a0ec",
         "octokit": "^2.0.14",
         "path-browserify": "^1.0.1",
         "react": "^18.2.0",
@@ -2539,9 +2539,9 @@
       }
     },
     "node_modules/@leanprover/infoview": {
-      "version": "0.4.3",
+      "version": "0.4.4",
-      "resolved": "https://registry.npmjs.org/@leanprover/infoview/-/infoview-0.4.3.tgz",
+      "resolved": "https://registry.npmjs.org/@leanprover/infoview/-/infoview-0.4.4.tgz",
-      "integrity": "sha512-SufdOr2myHAbZNUmobfQdAhsEC5H9ddi3KS0z1v/8riWSMm+yJk3u4LxVuzCmmSmV2QxFqtFzn5z+HQqj1Vo7g==",
+      "integrity": "sha512-OxHffFaHcEudLyBEWpicOl7TfXuTYxW5Sz1RkHdUINWJpQsQn60YDF5fNRKmSb0d/fm7p+LVeBvM273jvfR5wQ==",
       "dependencies": {
         "@leanprover/infoview-api": "~0.2.1",
         "@vscode/codicons": "^0.0.32",
@@ -10081,7 +10081,8 @@
     },
     "node_modules/lean4web": {
       "version": "0.1.0",
-      "resolved": "git+ssh://git@github.com/hhu-adam/lean4web.git#6fc9c11179934cce7ca1f78140c57b6931186b42",
+      "resolved": "git+ssh://git@github.com/hhu-adam/lean4web.git#b91645a7b88814675ba9f99817436d0a2ce3a0ec",
+      "integrity": "sha512-s9qYeXuMNBGDPKC5IuFTjV/j8tQCRkZr+poYKEWljrM95rsz4JHIvjdEt891fE9JhPDLSN+iXNRXwIOCT6FlMg==",
       "dependencies": {
         "@emotion/react": "^11.11.1",
         "@emotion/styled": "^11.11.0",
@@ -10090,7 +10091,7 @@
         "@fortawesome/fontawesome-svg-core": "^6.2.0",
         "@fortawesome/free-solid-svg-icons": "^6.2.0",
         "@fortawesome/react-fontawesome": "^0.2.0",
-        "@leanprover/infoview": "^0.4.3",
+        "@leanprover/infoview": "^0.4.4",
         "@mui/material": "^5.13.7",
         "@vitejs/plugin-react-swc": "^3.4.0",
         "express": "^4.18.2",

package.json

@@ -28,7 +28,7 @@
     "debounce": "^1.2.1",
     "express": "^4.18.2",
     "lean4-infoview": "https://gitpkg.now.sh/leanprover/vscode-lean4/lean4-infoview?de0062c",
-    "lean4web": "github:hhu-adam/lean4web",
+    "lean4web": "github:hhu-adam/lean4web#b91645a7b88814675ba9f99817436d0a2ce3a0ec",
     "octokit": "^2.0.14",
     "path-browserify": "^1.0.1",
     "react": "^18.2.0",

server/GameServer.lean

@@ -1,5 +1,4 @@
 import GameServer.FileWorker
-import GameServer.Watchdog
 import GameServer.Commands
 
 -- TODO: The only reason we import `Commands` is so that it gets built to on `lake build`
@@ -10,13 +9,9 @@ unsafe def main : List String → IO UInt32 := fun args => do
 
   Lean.enableInitializersExecution
 
+  -- TODO: remove this argument
   if args[0]? == some "--server" then
-    MyServer.Watchdog.watchdogMain args
+    MyServer.FileWorker.workerMain {} args
-  else if args[0]? == some "--worker" then
-    MyServer.FileWorker.workerMain {}
   else
-    e.putStrLn s!"Expected `--server` or `--worker`"
+    e.putStrLn s!"Expected `--server`"
     return 1
-
-
--- TODO: Potentially it could be useful to pass in the `gameName` via the websocket connection

server/GameServer/EnvExtensions.lean

@@ -293,6 +293,7 @@ structure LevelInfo where
   descrText : Option String := none
   descrFormat : String := ""
   lemmaTab : Option String
+  module : Name
   displayName : Option String
   statementName : Option String
   template : Option String
@@ -317,6 +318,7 @@ def GameLevel.toInfo (lvl : GameLevel) (env : Environment) : LevelInfo :=
       | some tile => tile.category
       | none => none
     statementName := lvl.statementName.toString
+    module := lvl.module
     displayName := match lvl.statementName with
       | .anonymous => none
       | name => match (inventoryExt.getState env).find?
@@ -381,7 +383,7 @@ structure GameTile where
 
   TODO: What's the format? -/
   image: String := default
-deriving Inhabited, ToJson
+deriving Inhabited, ToJson, FromJson
 
 structure Game where
   /-- Internal name of the game. -/
@@ -401,7 +403,7 @@ structure Game where
   tile : GameTile := default
   /-- The path to the background image of the world. -/
   image : String := default
-deriving Inhabited, ToJson
+deriving Inhabited, ToJson, FromJson
 
 def getGameJson (game : «Game») : Json := Id.run do
   let gameJson : Json := toJson game

server/GameServer/FileWorker.lean

@@ -1,7 +1,8 @@
-/- This file is mostly copied from `Lean/Server/FileWorker.lean`. -/
+/- This file is adapted from `Lean/Server/FileWorker.lean`. -/
 import Lean.Server.FileWorker
 import GameServer.Game
 import GameServer.ImportModules
+import GameServer.SaveData
 
 namespace MyModule
 open Lean
@@ -17,7 +18,7 @@ private def mkEOI (pos : String.Pos) : Syntax :=
   mkNode ``Command.eoi #[atom]
 
 partial def parseTactic (inputCtx : InputContext) (pmctx : ParserModuleContext)
-  (mps : ModuleParserState) (messages : MessageLog) (couldBeEndSnap : Bool) :
+  (mps : ModuleParserState) (messages : MessageLog) :
     Syntax × ModuleParserState × MessageLog × String.Pos := Id.run do
   let mut pos := mps.pos
   let mut recovering := mps.recovering
@@ -56,6 +57,20 @@ open IO
 open Snapshots
 open JsonRpc
 
+structure GameWorkerState :=
+  inventory : Array String
+  /--
+  Check for tactics/theorems that are not unlocked.
+  0: no check
+  1: give warnings
+  2: give errors
+  -/
+  difficulty : Nat
+  levelInfo : LevelInfo
+  deriving ToJson, FromJson
+
+abbrev GameWorkerM := StateT GameWorkerState Server.FileWorker.WorkerM
+
 section Elab
 
 def addErrorMessage (info : SourceInfo) (inputCtx : Parser.InputContext) (s : MessageData) :
@@ -73,29 +88,30 @@ def addErrorMessage (info : SourceInfo) (inputCtx : Parser.InputContext) (s : Me
 /-- Find all tactics in syntax object that are forbidden according to a
 set `allowed` of allowed tactics. -/
 partial def findForbiddenTactics (inputCtx : Parser.InputContext)
-    (levelParams : Game.DidOpenLevelParams) (stx : Syntax) :
+    (gameWorkerState : GameWorkerState) (stx : Syntax) :
     Elab.Command.CommandElabM Unit := do
+  let levelInfo := gameWorkerState.levelInfo
   match stx with
   | .missing => return ()
   | .node _info _kind args =>
     for arg in args do
-      findForbiddenTactics inputCtx levelParams arg
+      findForbiddenTactics inputCtx gameWorkerState arg
   | .atom info val =>
     -- ignore syntax elements that do not start with a letter
     -- and ignore "with" keyword
     let allowed := ["with", "fun", "at", "only", "by", "to"]
     if 0 < val.length ∧ val.data[0]!.isAlpha ∧ not (allowed.contains val) then
       let val := val.dropRightWhile (fun c => c == '!' || c == '?') -- treat `simp?` and `simp!` like `simp`
-      match levelParams.tactics.find? (·.name.toString == val) with
+      match levelInfo.tactics.find? (·.name.toString == val) with
       | none =>
         -- Note: This case means that the tactic will never be introduced in the game.
-        match levelParams.inventory.find? (· == val) with
+        match gameWorkerState.inventory.find? (· == val) with
         | none =>
           addWarningMessage info s!"You have not unlocked the tactic '{val}' yet!"
         | some _ => pure () -- tactic is in the inventory, allow it.
       | some tac =>
         if tac.locked then
-          match levelParams.inventory.find? (· == val) with
+          match gameWorkerState.inventory.find? (· == val) with
           | none =>
             addWarningMessage info s!"You have not unlocked the tactic '{val}' yet!"
           | some _ => pure () -- tactic is in the inventory, allow it.
@@ -109,10 +125,10 @@ partial def findForbiddenTactics (inputCtx : Parser.InputContext)
         let some (.thmInfo ..) := (← getEnv).find? n
           | return () -- not a theorem -> ignore
         -- Forbid the theorem we are proving currently
-        if n = levelParams.statementName then
+        if some n = levelInfo.statementName then
           addErrorMessage info inputCtx s!"Structural recursion: you can't use '{n}' to proof itself!"
 
-        let lemmasAndDefs := levelParams.lemmas ++ levelParams.definitions
+        let lemmasAndDefs := levelInfo.lemmas ++ levelInfo.definitions
         match lemmasAndDefs.find? (fun l => l.name == n) with
         | none => addWarningMessage info s!"You have not unlocked the lemma/definition '{n}' yet!"
         | some lem =>
@@ -121,7 +137,7 @@ partial def findForbiddenTactics (inputCtx : Parser.InputContext)
           else if lem.disabled then
             addWarningMessage info s!"The lemma/definition '{n}' is disabled in this level!"
 where addWarningMessage (info : SourceInfo) (s : MessageData) :=
-  let difficulty := levelParams.difficulty
+  let difficulty := gameWorkerState.difficulty
   if difficulty > 0 then
     modify fun st => { st with
       messages := st.messages.add {
@@ -137,7 +153,7 @@ where addWarningMessage (info : SourceInfo) (s : MessageData) :=
 
 open Elab Meta Expr in
 def compileProof (inputCtx : Parser.InputContext) (snap : Snapshot) (hasWidgets : Bool)
-    (couldBeEndSnap : Bool) (levelParams : Game.DidOpenLevelParams)
+    (couldBeEndSnap : Bool) (gameWorkerState : GameWorkerState)
     (initParams : Lsp.InitializeParams) : IO Snapshot := do
   -- Recognize end snap
   if inputCtx.input.atEnd snap.mpState.pos ∧ couldBeEndSnap then
@@ -168,7 +184,7 @@ def compileProof (inputCtx : Parser.InputContext) (snap : Snapshot) (hasWidgets
     Elab.Command.catchExceptions
       (getResetInfoTrees *> do
         let some level ← GameServer.getLevelByFileName? initParams inputCtx.fileName
-          | throwError "Level not found: {inputCtx.fileName}"
+          | panic! s!"Level not found: {inputCtx.fileName} / {GameServer.levelIdFromFileName? initParams inputCtx.fileName}"
         let scope := level.scope
 
         -- use open namespaces and options as in the level file
@@ -186,12 +202,12 @@ def compileProof (inputCtx : Parser.InputContext) (snap : Snapshot) (hasWidgets
             currNamespace := scope.currNamespace,
             openDecls := scope.openDecls }
           let (tacticStx, cmdParserState, msgLog, endOfWhitespace) :=
-            MyModule.parseTactic inputCtx pmctx snap.mpState snap.msgLog couldBeEndSnap
+            MyModule.parseTactic inputCtx pmctx snap.mpState snap.msgLog
           modify (fun s => { s with messages := msgLog })
           parseResultRef.set (tacticStx, cmdParserState)
 
           -- Check for forbidden tactics
-          findForbiddenTactics inputCtx levelParams tacticStx
+          findForbiddenTactics inputCtx gameWorkerState tacticStx
 
           -- Insert invisible `skip` command to make sure we always display the initial goal
           let skip := Syntax.node (.original default 0 default endOfWhitespace) ``Lean.Parser.Tactic.skip #[]
@@ -219,6 +235,7 @@ def compileProof (inputCtx : Parser.InputContext) (snap : Snapshot) (hasWidgets
     }
 
   let (tacticStx, cmdParserState) ← parseResultRef.get
+  if tacticStx.isMissing then throwServerError "Tactic execution went wrong. No stx found."
 
   let postCmdSnap : Snapshot := {
     beginPos := tacticStx.getPos?.getD 0
@@ -270,7 +287,7 @@ where
 
   /-- Elaborates the next command after `parentSnap` and emits diagnostics into `hOut`. -/
   private def nextSnap (ctx : WorkerContext) (m : DocumentMeta) (cancelTk : CancelToken)
-      (levelParams : Game.DidOpenLevelParams) (initParams : Lsp.InitializeParams)
+      (gameWorkerState : GameWorkerState) (initParams : Lsp.InitializeParams)
       : AsyncElabM (Option Snapshot) := do
     cancelTk.check
     let s ← get
@@ -288,7 +305,7 @@ where
     -- we can see the current goal even on an empty document
     let couldBeEndSnap := s.snaps.size > 1
     let snap ← compileProof m.mkInputContext lastSnap ctx.clientHasWidgets couldBeEndSnap
-      levelParams initParams
+      gameWorkerState initParams
     set { s with snaps := s.snaps.push snap }
     -- TODO(MH): check for interrupt with increased precision
     cancelTk.check
@@ -310,7 +327,7 @@ where
 
   /-- Elaborates all commands after the last snap (at least the header snap is assumed to exist), emitting the diagnostics into `hOut`. -/
   def unfoldSnaps (m : DocumentMeta) (snaps : Array Snapshot) (cancelTk : CancelToken)
-      (startAfterMs : UInt32) (levelParams : Game.DidOpenLevelParams)
+      (startAfterMs : UInt32) (gameWorkerState : GameWorkerState)
       : ReaderT WorkerContext IO (AsyncList ElabTaskError Snapshot) := do
     let ctx ← read
     let some headerSnap := snaps[0]? | panic! "empty snapshots"
@@ -326,21 +343,15 @@ where
       publishIleanInfoUpdate m ctx.hOut snaps
       return AsyncList.ofList snaps.toList ++ AsyncList.delayed (← EIO.asTask (ε := ElabTaskError) (prio := .dedicated) do
         IO.sleep startAfterMs
-        AsyncList.unfoldAsync (nextSnap ctx m cancelTk levelParams ctx.initParams) { snaps })
+        AsyncList.unfoldAsync (nextSnap ctx m cancelTk gameWorkerState ctx.initParams) { snaps })
 
 end Elab
 
-structure GameWorkerState :=
-(levelParams : Game.DidOpenLevelParams)
-
-abbrev GameWorkerM := StateT GameWorkerState Server.FileWorker.WorkerM
-
 section Updates
 
 /-- Given the new document, updates editable doc state. -/
   def updateDocument (newMeta : DocumentMeta) : GameWorkerM Unit := do
     let s ← get
-    let levelParams := s.levelParams
     let ctx ← read
     let oldDoc := (← StateT.lift get).doc
     oldDoc.cancelTk.set
@@ -382,7 +393,7 @@ section Updates
           validSnaps := validSnaps.dropLast
       -- wait for a bit, giving the initial `cancelTk.check` in `nextCmdSnap` time to trigger
       -- before kicking off any expensive elaboration (TODO: make expensive elaboration cancelable)
-      unfoldSnaps newMeta validSnaps.toArray cancelTk levelParams ctx
+      unfoldSnaps newMeta validSnaps.toArray cancelTk s ctx
         (startAfterMs := ctx.initParams.editDelay.toUInt32)
     StateT.lift <| modify fun st => { st with
       doc := { meta := newMeta, cmdSnaps := AsyncList.delayed newSnaps, cancelTk }}
@@ -397,24 +408,23 @@ section Initialization
     fileMap  := default
 
   def compileHeader (m : DocumentMeta) (hOut : FS.Stream) (opts : Options) (hasWidgets : Bool)
-      (levelParams : Game.DidOpenLevelParams) (initParams : InitializeParams) :
+      (gameDir : String) (module : Name):
       IO (Syntax × Task (Except Error (Snapshot × SearchPath))) := do
     -- Determine search paths of the game project by running `lake env printenv LEAN_PATH`.
     let out ← IO.Process.output
-      { cwd := levelParams.gameDir, cmd := "lake", args := #["env","printenv","LEAN_PATH"] }
+      { cwd := gameDir, cmd := "lake", args := #["env","printenv","LEAN_PATH"] }
     if out.exitCode != 0 then
       throwServerError s!"Error while running Lake: {out.stderr}"
 
     -- Make the paths relative to the current directory
     let paths : List System.FilePath := System.SearchPath.parse out.stdout.trim
     let currentDir ← IO.currentDir
-    let paths := paths.map fun p => currentDir / (levelParams.gameDir : System.FilePath) / p
+    let paths := paths.map fun p => currentDir / (gameDir : System.FilePath) / p
 
     -- Set the search path
     Lean.searchPathRef.set paths
 
-    let env ← importModules' #[{ module := `Init : Import }, { module := levelParams.levelModule : Import }]
+    let env ← importModules' #[{ module := `Init : Import }, { module := module : Import }]
-    -- return (env, paths)
 
     -- use empty header
     let (headerStx, headerParserState, msgLog) ← Parser.parseHeader
@@ -458,10 +468,11 @@ section Initialization
       return (headerSnap, srcSearchPath)
 
   def initializeWorker (meta : DocumentMeta) (i o e : FS.Stream) (initParams : InitializeParams) (opts : Options)
-       (levelParams : Game.DidOpenLevelParams) : IO (WorkerContext × WorkerState) := do
+      (gameDir : String) (gameWorkerState : GameWorkerState) : IO (WorkerContext × WorkerState) := do
     let clientHasWidgets := initParams.initializationOptions?.bind (·.hasWidgets?) |>.getD false
+
     let (headerStx, headerTask) ← compileHeader meta o opts (hasWidgets := clientHasWidgets)
-      levelParams initParams
+      gameDir gameWorkerState.levelInfo.module
     let cancelTk ← CancelToken.new
     let ctx :=
       { hIn  := i
@@ -472,7 +483,7 @@ section Initialization
         clientHasWidgets
       }
     let cmdSnaps ← EIO.mapTask (t := headerTask) (match · with
-      | Except.ok (s, _) => unfoldSnaps meta #[s] cancelTk levelParams ctx (startAfterMs := 0)
+      | Except.ok (s, _) => unfoldSnaps meta #[s] cancelTk gameWorkerState ctx (startAfterMs := 0)
       | Except.error e   => throw (e : ElabTaskError))
     let doc : EditableDocument := { meta, cmdSnaps := AsyncList.delayed cmdSnaps, cancelTk }
     return (ctx,
@@ -509,6 +520,7 @@ section MessageHandling
     match method with
     | "textDocument/didChange" => handle DidChangeTextDocumentParams (handleDidChange)
     | "$/cancelRequest"        => handle CancelParams (handleCancelRequest ·)
+    | "$/setTrace"        => pure ()
     | "$/lean/rpc/release"     => handle RpcReleaseParams (handleRpcRelease ·)
     | "$/lean/rpc/keepAlive"   => handle RpcKeepAliveParams (handleRpcKeepAlive ·)
     | _                        => throwServerError s!"Got unsupported notification method: {method}"
@@ -547,26 +559,32 @@ section MainLoop
       let doc := st.doc
       doc.cancelTk.set
       return ()
-    | Message.notification "$/game/setInventory" params =>
+    | Message.request id "shutdown" none =>
-      let p := (← parseParams Game.SetInventoryParams (toJson params))
+      ctx.hOut.writeLspResponse ⟨id, Json.null⟩
-      let s ← get
-
-      set {s with levelParams := {s.levelParams with
-        inventory := p.inventory,
-        difficulty := p.difficulty}}
       mainLoop
     | Message.notification method (some params) =>
       handleNotification method (toJson params)
       mainLoop
-    | _ => throwServerError "Got invalid JSON-RPC message"
+    | _ => throwServerError s!"Got invalid JSON-RPC message: {toJson msg}"
 end MainLoop
 
-def initAndRunWorker (i o e : FS.Stream) (opts : Options) : IO UInt32 := do
+def initAndRunWorker (i o e : FS.Stream) (opts : Options) (gameDir : String) : IO UInt32 := do
   let i ← maybeTee "fwIn.txt" false i
   let o ← maybeTee "fwOut.txt" true o
-  let initParams ← i.readLspRequestAs "initialize" InitializeParams
+  let initRequest ← i.readLspRequestAs "initialize" Game.InitializeParams
+  o.writeLspResponse {
+    id     := initRequest.id
+    result := {
+      capabilities := Watchdog.mkLeanServerCapabilities
+      serverInfo?  := some {
+        name     := "Lean 4 Game Server"
+        version? := "0.1.1"
+      }
+      : InitializeResult
+    }
+  }
+  discard $ i.readLspNotificationAs "initialized" InitializedParams
   let ⟨_, param⟩ ← i.readLspNotificationAs "textDocument/didOpen" DidOpenTextDocumentParams
-  let ⟨_, levelParams⟩ ← i.readLspNotificationAs "$/game/didOpenLevel" Game.DidOpenLevelParams
 
   let doc := param.textDocument
   /- NOTE(WN): `toFileMap` marks line beginnings as immediately following
@@ -578,9 +596,24 @@ def initAndRunWorker (i o e : FS.Stream) (opts : Options) : IO UInt32 := do
   let e := e.withPrefix s!"[{param.textDocument.uri}] "
   let _ ← IO.setStderr e
   try
-    let (ctx, st) ← initializeWorker meta i o e initParams.param opts levelParams
+    let game ← loadGameData gameDir
+    -- TODO: We misuse the `rootUri` field to the gameName
+    let rootUri? : Option String := some (toString game.name)
+    let initParams := {initRequest.param.toLeanInternal with rootUri?}
+    let some (levelId : LevelId) := GameServer.levelIdFromFileName?
+        initParams meta.mkInputContext.fileName
+      | throwServerError s!"Could not determine level ID: {meta.mkInputContext.fileName}"
+    let levelInfo ← loadLevelData gameDir levelId.world levelId.level
+    let some initializationOptions := initRequest.param.initializationOptions?
+      | throwServerError "no initialization options found"
+    let gameWorkerState : GameWorkerState:= {
+      inventory := initializationOptions.inventory
+      difficulty := initializationOptions.difficulty
+      levelInfo
+    }
+    let (ctx, st) ← initializeWorker meta i o e initParams opts gameDir gameWorkerState
     let _ ← StateRefT'.run (s := st) <| ReaderT.run (r := ctx) <|
-      StateT.run (s := {levelParams := levelParams}) <| (mainLoop)
+      StateT.run (s := gameWorkerState) <| (mainLoop)
     return (0 : UInt32)
   catch e =>
     IO.eprintln e
@@ -590,12 +623,13 @@ def initAndRunWorker (i o e : FS.Stream) (opts : Options) : IO UInt32 := do
       message := e.toString }] o
     return (1 : UInt32)
 
-def workerMain (opts : Options) : IO UInt32 := do
+def workerMain (opts : Options) (args : List String): IO UInt32 := do
   let i ← IO.getStdin
   let o ← IO.getStdout
   let e ← IO.getStderr
   try
-    let exitCode ← initAndRunWorker i o e opts
+    let some gameDir := args[1]? | throwServerError "Expected second argument: gameDir"
+    let exitCode ← initAndRunWorker i o e opts gameDir
     -- HACK: all `Task`s are currently "foreground", i.e. we join on them on main thread exit, but we definitely don't
     -- want to do that in the case of the worker processes, which can produce non-terminating tasks evaluating user code
     o.flush

server/GameServer/Game.lean

@@ -25,75 +25,56 @@ open Lsp
 open JsonRpc
 open IO
 
-structure DidOpenLevelParams where
+/- Game-specific version of `InitializeParams` that allows for extra options: -/
-  uri : String
-  gameDir : String
-  levelModule : Name
-  tactics : Array InventoryTile
-  lemmas : Array InventoryTile
-  definitions : Array InventoryTile
-  inventory : Array String
-  /--
-  Check for tactics/theorems that are not unlocked.
-  0: no check
-  1: give warnings
-  2: give errors
-  -/
-  difficulty : Nat
-  /-- The name of the theorem to be proven in this level. -/
-  statementName : Name
-  deriving ToJson, FromJson
 
-structure SetInventoryParams where
+structure InitializationOptions extends Lean.Lsp.InitializationOptions :=
-  inventory : Array String
   difficulty : Nat
-deriving ToJson, FromJson
+  inventory : Array String
+  deriving ToJson, FromJson
 
-def handleDidOpenLevel (params : Json) : GameServerM Unit := do
+structure InitializeParams where
-  let p ← parseParams _ params
+  processId? : Option Int := none
-  let m := p.textDocument
+  clientInfo? : Option ClientInfo := none
-  -- Execute the regular handling of the `didOpen` event
+  /- We don't support the deprecated rootPath
-  handleDidOpen p
+  (rootPath? : Option String) -/
-  let fw ← findFileWorker! m.uri
+  rootUri? : Option String := none
-  -- let s ← get
+  initializationOptions? : Option InitializationOptions := none
-  let c ← read
+  capabilities : ClientCapabilities
-  let some lvl ← GameServer.getLevelByFileName? c.initParams ((System.Uri.fileUriToPath? m.uri).getD m.uri |>.toString)
+  /-- If omitted, we default to off. -/
-    | do
+  trace : Trace := Trace.off
-      c.hLog.putStr s!"Level not found: {m.uri} {c.initParams.rootUri?}"
+  workspaceFolders? : Option (Array WorkspaceFolder) := none
-      c.hLog.flush
+  deriving ToJson
-  -- Send an extra notification to the file worker to inform it about the level data
-  let s ← get
-  fw.stdin.writeLspNotification {
-    method := "$/game/didOpenLevel"
-    param  := {
-      uri := m.uri
-      gameDir := s.gameDir
-      levelModule := lvl.module
-      tactics := lvl.tactics.tiles
-      lemmas := lvl.lemmas.tiles
-      definitions := lvl.definitions.tiles
-      inventory := s.inventory
-      difficulty := s.difficulty
-      statementName := lvl.statementName
-      : DidOpenLevelParams
-    }
-  }
 
-partial def handleServerEvent (ev : ServerEvent) : GameServerM Bool := do
+instance : FromJson InitializeParams where
-  match ev with
+  fromJson? j := do
-  | ServerEvent.clientMsg msg =>
+    let processId? := j.getObjValAs? Int "processId"
-    match msg with
+    let clientInfo? := j.getObjValAs? ClientInfo "clientInfo"
-    | Message.notification "$/game/setInventory" params =>
+    let rootUri? := j.getObjValAs? String "rootUri"
-      let p := (← parseParams SetInventoryParams (toJson params))
+    let initializationOptions? := j.getObjValAs? InitializationOptions "initializationOptions"
-      let s ← get
+    let capabilities ← j.getObjValAs? ClientCapabilities "capabilities"
-      set {s with inventory := p.inventory, difficulty := p.difficulty}
+    let trace := (j.getObjValAs? Trace "trace").toOption.getD Trace.off
-      let st ← read
+    let workspaceFolders? := j.getObjValAs? (Array WorkspaceFolder) "workspaceFolders"
-      let workers ← st.fileWorkersRef.get
+    return ⟨
-      for (_, fw) in workers do
+      processId?.toOption,
-        fw.stdin.writeLspMessage msg
+      clientInfo?.toOption,
+      rootUri?.toOption,
+      initializationOptions?.toOption,
+      capabilities,
+      trace,
+      workspaceFolders?.toOption⟩
 
-      return true
+def InitializeParams.toLeanInternal (p : InitializeParams) : Lean.Lsp.InitializeParams :=
-    | _ => return false
+{
-  | _ => return false
+  processId? := p.processId?
+  clientInfo? := p.clientInfo?
+  rootUri? := p.rootUri?
+  initializationOptions? := p.initializationOptions?.map fun o => {
+    editDelay? := o.editDelay?
+    hasWidgets? := o.hasWidgets?
+  }
+  capabilities := p.capabilities
+  trace := p.trace
+  workspaceFolders? := p.workspaceFolders?
+}
 
 end Game

server/GameServer/Graph.lean

@@ -18,6 +18,14 @@ instance [ToJson β] : ToJson (Graph Name β) := {
   ]
 }
 
+-- Just a dummy implementation for now:
+instance : FromJson (Graph Name β) := {
+  fromJson? := fun _ => .ok {
+    nodes := {}
+    edges := {}
+  }
+}
+
 instance  : EmptyCollection (Graph α β) := ⟨default⟩
 
 def Graph.insertNode (g : Graph α β) (a : α) (b : β) :=

server/GameServer/SaveData.lean

@@ -22,16 +22,21 @@ def copyImages : IO Unit := do
         let content ← readBinFile file
         writeBinFile outFile content
 
+namespace GameData
+  def gameDataPath : System.FilePath := ".lake" / "gamedata"
+  def gameFileName := s!"game.json"
+  def docFileName := fun (inventoryType : InventoryType) (name : Name) => s!"doc__{inventoryType}__{name}.json"
+  def levelFileName := fun (worldId : Name) (levelId : Nat) => s!"level__{worldId}__{levelId}.json"
+  def inventoryFileName := s!"inventory.json"
+end GameData
 
--- TODO: I'm not sure this should be happening here...
+open GameData in
-#eval IO.FS.createDirAll ".lake/gamedata/"
-
 -- TODO: register all of this as ToJson instance?
 def saveGameData (allItemsByType : HashMap InventoryType (HashSet Name))
     (inventory : InventoryOverview): CommandElabM Unit := do
   let game ← getCurGame
   let env ← getEnv
-  let path : System.FilePath := s!"{← IO.currentDir}" / ".lake" / "gamedata"
+  let path := (← IO.currentDir) / gameDataPath
 
   if ← path.isDir then
     IO.FS.removeDirAll path
@@ -42,14 +47,32 @@ def saveGameData (allItemsByType : HashMap InventoryType (HashSet Name))
 
   for (worldId, world) in game.worlds.nodes.toArray do
     for (levelId, level) in world.levels.toArray do
-      IO.FS.writeFile (path / s!"level__{worldId}__{levelId}.json") (toString (toJson (level.toInfo env)))
+      IO.FS.writeFile (path / levelFileName worldId levelId) (toString (toJson (level.toInfo env)))
 
-  IO.FS.writeFile (path / s!"game.json") (toString (getGameJson game))
+  IO.FS.writeFile (path / gameFileName) (toString (getGameJson game))
 
   for inventoryType in [InventoryType.Lemma, .Tactic, .Definition] do
     for name in allItemsByType.findD inventoryType {} do
       let some item ← getInventoryItem? name inventoryType
         | throwError "Expected item to exist: {name}"
-      IO.FS.writeFile (path / s!"doc__{inventoryType}__{name}.json") (toString (toJson item))
+      IO.FS.writeFile (path / docFileName inventoryType name) (toString (toJson item))
+
+  IO.FS.writeFile (path / inventoryFileName) (toString (toJson inventory))
+
+open GameData
+
+def loadData (f : System.FilePath) (α : Type) [FromJson α] : IO α := do
+  let str ← IO.FS.readFile f
+  let json ← match Json.parse str with
+  | .ok v => pure v
+  | .error e => throw (IO.userError e)
+  let data ← match fromJson? json with
+  | .ok v => pure v
+  | .error e => throw (IO.userError e)
+  return data
+
+def loadGameData (gameDir : System.FilePath) : IO Game :=
+  loadData (gameDir / gameDataPath / gameFileName) Game
 
-  IO.FS.writeFile (path / s!"inventory.json") (toString (toJson inventory))
+def loadLevelData (gameDir : System.FilePath) (worldId : Name) (levelId : Nat) : IO LevelInfo :=
+  loadData (gameDir / gameDataPath / levelFileName worldId levelId) LevelInfo

server/GameServer/Watchdog.lean

@@ -1,158 +0,0 @@
-/- This file is mostly copied from `Lean/Server/Watchdog.lean`. -/
-import Lean.Server.Watchdog
-import GameServer.Game
-
-namespace MyServer.Watchdog
-open Lean
-open Server
-open Watchdog
-open IO
-open Lsp
-open JsonRpc
-open System.Uri
-
-  partial def mainLoop (clientTask : Task ServerEvent) : GameServerM Unit := do
-    let st ← read
-    let workers ← st.fileWorkersRef.get
-    let mut workerTasks := #[]
-    for (_, fw) in workers do
-      if let WorkerState.running := fw.state then
-        workerTasks := workerTasks.push <| fw.commTask.map (ServerEvent.workerEvent fw)
-
-    let ev ← IO.waitAny (clientTask :: workerTasks.toList)
-
-    if ← Game.handleServerEvent ev then -- handle Game requests
-      mainLoop (←runClientTask)
-    else
-      match ev with
-      | ServerEvent.clientMsg msg =>
-        match msg with
-        | Message.request id "shutdown" _ =>
-          shutdown
-          st.hOut.writeLspResponse ⟨id, Json.null⟩
-        | Message.request id method (some params) =>
-          handleRequest id method (toJson params)
-          mainLoop (←runClientTask)
-        | Message.response .. =>
-          -- TODO: handle client responses
-          mainLoop (←runClientTask)
-        | Message.responseError _ _ e .. =>
-          throwServerError s!"Unhandled response error: {e}"
-        | Message.notification method (some params) =>
-          if method == "textDocument/didOpen" then
-            -- for lean4game, we need to pass in extra information when a level is opened:
-            Game.handleDidOpenLevel (← parseParams _ (toJson params))
-          else
-            handleNotification method (toJson params)
-          mainLoop (←runClientTask)
-        | _ => throwServerError "Got invalid JSON-RPC message"
-      | ServerEvent.clientError e => throw e
-      | ServerEvent.workerEvent fw ev =>
-        match ev with
-        | WorkerEvent.ioError e =>
-          throwServerError s!"IO error while processing events for {fw.doc.uri}: {e}"
-        | WorkerEvent.crashed _ =>
-          handleCrash fw.doc.uri #[]
-          mainLoop clientTask
-        | WorkerEvent.terminated =>
-          throwServerError "Internal server error: got termination event for worker that should have been removed"
-        | .importsChanged =>
-          startFileWorker fw.doc
-          mainLoop clientTask
-
-def initAndRunWatchdogAux : GameServerM Unit := do
-  let st ← read
-  try
-    discard $ st.hIn.readLspNotificationAs "initialized" InitializedParams
-    let clientTask ← runClientTask
-    mainLoop clientTask
-  catch err =>
-    shutdown
-    throw err
-  /- NOTE(WN): It looks like instead of sending the `exit` notification,
-  VSCode just closes the stream. In that case, pretend we got an `exit`. -/
-  let Message.notification "exit" none ←
-    try st.hIn.readLspMessage
-    catch _ => pure (Message.notification "exit" none)
-    | throwServerError "Got `shutdown` request, expected an `exit` notification"
-
-def createEnv (gameDir : String) (module : String) : IO Environment := do
-  -- Determine search paths of the game project by running `lake env printenv LEAN_PATH`.
-  let out ← IO.Process.output
-    { cwd := gameDir, cmd := "lake", args := #["env","printenv","LEAN_PATH"] }
-  if out.exitCode != 0 then
-    throwServerError s!"Error while running Lake: {out.stderr}"
-
-  -- Make the paths relative to the current directory
-  let paths : List System.FilePath := System.SearchPath.parse out.stdout.trim
-  let currentDir ← IO.currentDir
-  let paths := paths.map fun p => currentDir / (gameDir : System.FilePath) / p
-
-  -- Set the search path
-  Lean.searchPathRef.set paths
-
-  let env ← importModules #[{ module := `Init : Import }, { module := module : Import }] {} 0
-  return env
-
-def initAndRunWatchdog (args : List String) (i o e : FS.Stream) : IO Unit := do
-  if args.length < 2 then
-    throwServerError s!"Expected 1-3 command line arguments in addition to `--server`:
-      game directory, the name of the main module (optional), and the name of the game (optional)."
-  let gameDir := args[1]!
-  let module := if args.length < 3 then defaultGameModule else args[2]!
-  let gameName := if args.length < 4 then defaultGameName else args[3]!
-  let workerPath := "./gameserver"
-  -- TODO: Do the following commands slow us down?
-  let srcSearchPath ← initSrcSearchPath (← getBuildDir)
-  let references ← IO.mkRef (← loadReferences)
-  let fileWorkersRef ← IO.mkRef (RBMap.empty : FileWorkerMap)
-  let i ← maybeTee "wdIn.txt" false i
-  let o ← maybeTee "wdOut.txt" true o
-  let e ← maybeTee "wdErr.txt" true e
-  let state := {
-    env := ← createEnv gameDir module,
-    game := gameName,
-    gameDir := gameDir,
-    inventory := #[]
-    difficulty := 0
-    }
-  let initRequest ← i.readLspRequestAs "initialize" InitializeParams
-  -- We misuse the `rootUri` field to the gameName
-  let rootUri? := gameName
-  let initRequest := {initRequest with param := {initRequest.param with rootUri?}}
-  o.writeLspResponse {
-    id     := initRequest.id
-    result := {
-      capabilities := mkLeanServerCapabilities
-      serverInfo?  := some {
-        name     := "Lean 4 Game Server"
-        version? := "0.1.1"
-      }
-      : InitializeResult
-    }
-  }
-  let context : ServerContext := {
-    hIn            := i
-    hOut           := o
-    hLog           := e
-    args           := args
-    fileWorkersRef := fileWorkersRef
-    initParams     := initRequest.param
-    workerPath
-    srcSearchPath
-    references
-  }
-  discard $ ReaderT.run (StateT.run initAndRunWatchdogAux state) context
-
-def watchdogMain (args : List String) : IO UInt32 := do
-  let i ← IO.getStdin
-  let o ← IO.getStdout
-  let e ← IO.getStderr
-  try
-    initAndRunWatchdog args i o e
-    return 0
-  catch err =>
-    e.putStrLn s!"Watchdog error: {err}"
-    return 1
-
-end MyServer.Watchdog