bump to v4.6.1

This reverts commit 381930e547.

.github/workflows/build.yml

@@ -1,6 +1,8 @@
 name: Build
 run-name: Build the project
-on: [push]
+on:
+  workflow_dispatch:
+  push:
 jobs:
   build:
     runs-on: ubuntu-latest

.vscode/ltex.dictionary.en-US.txt

@@ -0,0 +1,7 @@
+GameSkeleton
+HiddenTactic
+subgoals
+KaTex
+gameserver
+lakefile
+Zulip

README.md

@@ -9,6 +9,7 @@ Please follow the tutorial [Creating a Game](doc/create_game.md). In particular,
 * Step 5: [How to Run Games Locally](doc/running_locally.md)
 * Step 7: [How to Update an existing Game](doc/update_game.md)
 * Step 8: [How to Publishing a Game](doc/publish_game.md)
+* [Troubleshooting](doc/troubleshoot.md)
 
 ## Documentation
 

client/src/app.tsx

@@ -8,40 +8,24 @@ import '@fontsource/roboto/700.css';
 
 import './css/reset.css';
 import './css/app.css';
-import { MobileContext } from './components/infoview/context';
+import { PreferencesContext} from './components/infoview/context';
-import { useMobile } from './hooks';
+import UsePreferences from "./state/hooks/use_preferences"
-import { AUTO_SWITCH_THRESHOLD, getWindowDimensions} from './state/preferences';
 
 export const GameIdContext = React.createContext<string>(undefined);
 
 function App() {
-  const { mobile, setMobile, lockMobile, setLockMobile } = useMobile();
 
   const params = useParams()
   const gameId = "g/" + params.owner + "/" + params.repo
 
-  const automaticallyAdjustLayout = () => {
+  const {mobile, layout, isSavePreferences, setLayout, setIsSavePreferences} = UsePreferences()
-    const {width} = getWindowDimensions()
-    setMobile(width < AUTO_SWITCH_THRESHOLD)
-  }
-
-  React.useEffect(()=>{
-    if (!lockMobile){
-      void automaticallyAdjustLayout()
-      window.addEventListener('resize', automaticallyAdjustLayout)
-
-      return () => {
-        window.removeEventListener('resize', automaticallyAdjustLayout)
-      }
-    }
-  }, [lockMobile])
 
   return (
     <div className="app">
       <GameIdContext.Provider value={gameId}>
-        <MobileContext.Provider value={{mobile, setMobile, lockMobile, setLockMobile}}>
+          <PreferencesContext.Provider value={{mobile, layout, isSavePreferences, setLayout, setIsSavePreferences}}>
-          <Outlet />
+            <Outlet />
-        </MobileContext.Provider>
+          </PreferencesContext.Provider>
       </GameIdContext.Provider>
     </div>
   )

client/src/components/app_bar.tsx

@@ -7,7 +7,7 @@ import { faDownload, faUpload, faEraser, faBook, faBookOpen, faGlobe, faHome,
   faArrowRight, faArrowLeft, faXmark, faBars, faCode,
   faCircleInfo, faTerminal, faMobileScreenButton, faDesktop, faGear } from '@fortawesome/free-solid-svg-icons'
 import { GameIdContext } from "../app"
-import { InputModeContext, MobileContext, WorldLevelIdContext } from "./infoview/context"
+import { InputModeContext, PreferencesContext, WorldLevelIdContext } from "./infoview/context"
 import { GameInfo, useGetGameInfoQuery } from '../state/api'
 import { changedOpenedIntro, selectCompleted, selectDifficulty, selectProgress } from '../state/progress'
 import { useAppDispatch, useAppSelector } from '../hooks'
@@ -162,7 +162,7 @@ export function WelcomeAppBar({pageNumber, setPageNumber, gameInfo, toggleImpres
 }) {
   const gameId = React.useContext(GameIdContext)
   const gameProgress = useAppSelector(selectProgress(gameId))
-  const {mobile, setMobile} = React.useContext(MobileContext)
+  const {mobile} = React.useContext(PreferencesContext)
   const [navOpen, setNavOpen] = React.useState(false)
 
   return <div className="app-bar">
@@ -212,7 +212,7 @@ export function LevelAppBar({isLoading, levelTitle, toggleImpressum, pageNumber=
 }) {
   const gameId = React.useContext(GameIdContext)
   const {worldId, levelId} = React.useContext(WorldLevelIdContext)
-  const {mobile} = React.useContext(MobileContext)
+  const {mobile} = React.useContext(PreferencesContext)
   const [navOpen, setNavOpen] = React.useState(false)
   const gameInfo = useGetGameInfoQuery({game: gameId})
   const completed = useAppSelector(selectCompleted(gameId, worldId, levelId))

client/src/components/hints.tsx

@@ -1,22 +1,42 @@
-import { GameHint } from "./infoview/rpc_api";
+import { GameHint, InteractiveGoalsWithHints, ProofState } from "./infoview/rpc_api";
 import * as React from 'react';
 import Markdown from './markdown';
-import { ProofStep } from "./infoview/context";
+import { DeletedChatContext, ProofContext } from "./infoview/context";
+import { lastStepHasErrors } from "./infoview/goals";
+import { Button } from "./button";
+
+/** Plug-in the variable names in a hint. We do this client-side to prepare
+ * for i18n in the future. i.e. one should be able translate the `rawText`
+ * and have the variables substituted just before displaying.
+ */
+function getHintText(hint: GameHint): string {
+  if (hint.rawText) {
+    // Replace the variable names used in the hint with the ones used by the player
+    // variable names are marked like `«{g}»` inside the text.
+    return hint.rawText.replaceAll(/«\{(.*?)\}»/g, ((_, v) =>
+      // `hint.varNames` contains tuples `[oldName, newName]`
+      (hint.varNames.find(x => x[0] == v))[1]))
+  } else {
+    // hints created in the frontend do not have a `rawText`
+    // TODO: `hint.text` could be removed in theory.
+    return hint.text
+  }
+}
 
 export function Hint({hint, step, selected, toggleSelection, lastLevel} : {hint: GameHint, step: number, selected: number, toggleSelection: any, lastLevel?: boolean}) {
   return <div className={`message information step-${step}` + (step == selected ? ' selected' : '') + (lastLevel ? ' recent' : '')} onClick={toggleSelection}>
-    <Markdown>{hint.text}</Markdown>
+    <Markdown>{getHintText(hint)}</Markdown>
   </div>
 }
 
 export function HiddenHint({hint, step, selected, toggleSelection, lastLevel} : {hint: GameHint, step: number, selected: number, toggleSelection: any, lastLevel?: boolean}) {
   return <div className={`message warning step-${step}` + (step == selected ? ' selected' : '') + (lastLevel ? ' recent' : '')} onClick={toggleSelection}>
-    <Markdown>{hint.text}</Markdown>
+    <Markdown>{getHintText(hint)}</Markdown>
   </div>
 }
 
 export function Hints({hints, showHidden, step, selected, toggleSelection, lastLevel} : {hints: GameHint[], showHidden: boolean, step: number, selected: number, toggleSelection: any, lastLevel?: boolean}) {
-
+  if (!hints) {return <></>}
   const openHints = hints.filter(hint => !hint.hidden)
   const hiddenHints = hints.filter(hint => hint.hidden)
 
@@ -29,7 +49,7 @@ export function Hints({hints, showHidden, step, selected, toggleSelection, lastL
 
 export function DeletedHint({hint} : {hint: GameHint}) {
   return <div className="message information deleted-hint">
-    <Markdown>{hint.text}</Markdown>
+    <Markdown>{getHintText(hint)}</Markdown>
   </div>
 }
 
@@ -46,22 +66,54 @@ export function DeletedHints({hints} : {hints: GameHint[]}) {
 }
 
 /** Filter hints to not show consequtive identical hints twice.
- *
+ * Hidden hints are not filtered.
- * This function takes a `ProofStep[]` and extracts the hints in form of an
- * element of type `GameHint[][]` where it removes hints that are identical to hints
- * appearing in the previous step. Hidden hints are not filtered.
- *
- * This effectively means we prevent consequtive identical hints from being shown.
  */
-export function filterHints(proof: ProofStep[]): GameHint[][] {
+export function filterHints(hints: GameHint[], prevHints: GameHint[]): GameHint[] {
-  return proof.map((step, i) => {
+  if (!hints) {
-    if (i == 0){
+    return []}
-      return step.hints
+  else if (!prevHints) {
-    } else {
+    return hints }
-      // TODO: Writing all fields explicitely is somewhat fragile to changes, is there a
+  else {
-      // good way to shallow-compare objects?
+    return hints.filter((hint) => hint.hidden ||
-      return step.hints.filter((hint) => hint.hidden ||
+    (prevHints.find(x => (x.text == hint.text && x.hidden == hint.hidden)) === undefined)
-        (proof[i-1].hints.find((x) => (x.text == hint.text && x.hidden == hint.hidden)) === undefined))
+    )
-    }
+  }
-  })
+}
+
+
+function hasHiddenHints(step: InteractiveGoalsWithHints): boolean {
+  return step?.goals[0]?.hints.some((hint) => hint.hidden)
+}
+
+
+export function MoreHelpButton({selected=null} : {selected?: number}) {
+
+  const {proof, setProof} = React.useContext(ProofContext)
+  const {deletedChat, setDeletedChat, showHelp, setShowHelp} = React.useContext(DeletedChatContext)
+
+  let k = proof?.steps.length ?
+    ((selected === null) ? (proof?.steps.length - (lastStepHasErrors(proof) ? 2 : 1)) : selected)
+    : 0
+
+  const activateHiddenHints = (ev) => {
+    // If the last step (`k`) has errors, we want the hidden hints from the
+    // second-to-last step to be affected
+    if (!(proof?.steps.length)) {return}
+
+    // state must not be mutated, therefore we need to clone the set
+    let tmp = new Set(showHelp)
+    if (tmp.has(k)) {
+      tmp.delete(k)
+    } else {
+      tmp.add(k)
+    }
+    setShowHelp(tmp)
+    console.debug(`help: ${Array.from(tmp.values())}`)
+  }
+
+  if (hasHiddenHints(proof?.steps[k]) && !showHelp.has(k)) {
+    return <Button to="" onClick={activateHiddenHints}>
+      Show more help!
+    </Button>
+  }
 }

client/src/components/infoview/context.ts

@@ -3,45 +3,59 @@
  */
 import * as React from 'react';
 import * as monaco from 'monaco-editor/esm/vs/editor/editor.api.js'
-import { InteractiveDiagnostic, InteractiveTermGoal } from '@leanprover/infoview-api';
+import { InteractiveDiagnostic } from '@leanprover/infoview-api';
-import { GameHint, InteractiveGoal, InteractiveGoals } from './rpc_api';
+import { Diagnostic } from 'vscode-languageserver-types'
+import { GameHint, InteractiveGoal, InteractiveTermGoal,InteractiveGoalsWithHints, ProofState } from './rpc_api';
+import { PreferencesState } from '../../state/preferences';
 
 export const MonacoEditorContext = React.createContext<monaco.editor.IStandaloneCodeEditor>(
   null as any)
 
 export type InfoStatus = 'updating' | 'error' | 'ready';
 
-/** One step of the proof */
+// /** One step of the proof */
-export type ProofStep = {
+// export type ProofStep = {
-  /** The command in this step */
+//   /** The command in this step */
-  command : string
+//   command : string
-  /** List of goals *after* this command */
+//   /** List of goals *after* this command */
-  goals: InteractiveGoal[]     // TODO: Add correct type
+//   goals: InteractiveGoal[]     // TODO: Add correct type
-  /** Story relevant messages */
+//   /** Story relevant messages */
-  hints: GameHint[]        // TODO: Add correct type
+//   hints: GameHint[]        // TODO: Add correct type
-  /** Errors and warnings */
+//   /** Errors and warnings */
-  errors: InteractiveDiagnostic[]       // TODO: Add correct type
+//   errors: InteractiveDiagnostic[]       // TODO: Add correct type
-}
+// }
 
 /** The context storing the proof step-by-step for the command line mode */
 export const ProofContext = React.createContext<{
   /** The proof consists of multiple steps that are processed one after the other.
    * In particular multi-line terms like `match`-statements will not be supported.
    *
-   * Note that the first step will always have `null` as command
+   * Note that the first step will always have "" as command
    */
-  proof: ProofStep[],
+  proof: ProofState,
-  setProof: React.Dispatch<React.SetStateAction<Array<ProofStep>>>
+  setProof: React.Dispatch<React.SetStateAction<ProofState>>
+  /** TODO: Workaround to capture a crash of the gameserver. */
+  interimDiags: Diagnostic[],
+  setInterimDiags: React.Dispatch<React.SetStateAction<Array<Diagnostic>>>
+  /** TODO: Workaround to capture a crash of the gameserver. */
+  crashed: Boolean,
+  setCrashed: React.Dispatch<React.SetStateAction<Boolean>>
 }>({
-  proof: [],
+  proof: {steps: [], diagnostics: [], completed: false, completedWithWarnings: false},
-  setProof: () => {} // TODO: implement me
+  setProof: () => {},
+  interimDiags: [],
+  setInterimDiags: () => {},
+  crashed: false,
+  setCrashed: () => {}
 })
 
+
+// TODO: Do we still need that?
 export interface ProofStateProps {
   // pos: DocumentPosition;
   status: InfoStatus;
   messages: InteractiveDiagnostic[];
-  goals?: InteractiveGoals;
+  goals?: InteractiveGoalsWithHints;
   termGoal?: InteractiveTermGoal;
   error?: string;
   // userWidgets: UserWidgetInstance[];
@@ -49,31 +63,31 @@ export interface ProofStateProps {
   // triggerUpdate: () => Promise<void>;
 }
 
-export const ProofStateContext = React.createContext<{
+// export const ProofStateContext = React.createContext<{
-  proofState : ProofStateProps,
+//   proofState : ProofStateProps,
-  setProofState: React.Dispatch<React.SetStateAction<ProofStateProps>>
+//   setProofState: React.Dispatch<React.SetStateAction<ProofStateProps>>
-}>({
+// }>({
-  proofState : {
+//   proofState : {
-    status: 'updating',
+//     status: 'updating',
-    messages: [],
+//     messages: [],
-    goals: undefined,
+//     goals: undefined,
-    termGoal: undefined,
+//     termGoal: undefined,
-    error: undefined},
+//     error: undefined},
-  setProofState: () => {},
+//   setProofState: () => {},
-})
+// })
 
-export interface IMobileContext {
+export interface IPreferencesContext extends PreferencesState{
-  mobile : boolean,
+  mobile: boolean, // The variables that actually control the page 'layout' can only be changed through layout.
-  setMobile: React.Dispatch<React.SetStateAction<Boolean>>,
+  setLayout: React.Dispatch<React.SetStateAction<PreferencesState["layout"]>>;
-  lockMobile: boolean,
+  setIsSavePreferences: React.Dispatch<React.SetStateAction<Boolean>>;
-  setLockMobile: React.Dispatch<React.SetStateAction<Boolean>>,
 }
 
-export const MobileContext = React.createContext<IMobileContext>({
+export const PreferencesContext = React.createContext<IPreferencesContext>({
   mobile: false,
-  setMobile: () => {},
+  layout: "auto",
-  lockMobile: false,
+  isSavePreferences: false,
-  setLockMobile: () => {}
+  setLayout: () => {},
+  setIsSavePreferences: () => {}
 })
 
 export const WorldLevelIdContext = React.createContext<{

client/src/components/infoview/goals.tsx

@@ -10,7 +10,10 @@ import { Locations, LocationsContext, SelectableLocation } from '../../../../nod
 import { InteractiveCode } from '../../../../node_modules/lean4-infoview/src/infoview/interactiveCode'
 import { WithTooltipOnHover } from '../../../../node_modules/lean4-infoview/src/infoview/tooltips';
 import { InputModeContext } from './context';
-import { InteractiveGoal, InteractiveGoals, InteractiveHypothesisBundle } from './rpc_api';
+import { InteractiveGoal, InteractiveGoals, InteractiveGoalsWithHints, InteractiveHypothesisBundle, ProofState } from './rpc_api';
+import { RpcSessionAtPos } from '@leanprover/infoview/*';
+import { DocumentPosition } from '../../../../node_modules/lean4-infoview/src/infoview/util';
+import { DiagnosticSeverity } from 'vscode-languageserver-protocol';
 
 /** Returns true if `h` is inaccessible according to Lean's default name rendering. */
 function isInaccessibleName(h: string): boolean {
@@ -39,7 +42,11 @@ function goalToString(g: InteractiveGoal): string {
 }
 
 export function goalsToString(goals: InteractiveGoals): string {
-    return goals.goals.map(goalToString).join('\n\n')
+    return goals.goals.map(g => goalToString(g)).join('\n\n')
+}
+
+export function goalsWithHintsToString(goals: InteractiveGoalsWithHints): string {
+    return goals.goals.map(g => goalToString(g.goal)).join('\n\n')
 }
 
 interface GoalFilterState {
@@ -255,16 +262,16 @@ export const ProofDisplay = React.memo((props : ProofDisplayProps) => {
 })
 
 interface GoalsProps {
-    goals: InteractiveGoals
+    goals: InteractiveGoalsWithHints
     filter: GoalFilterState
 }
 
 export function Goals({ goals, filter }: GoalsProps) {
     if (goals.goals.length === 0) {
-        return <>No goals</>
+        return <></>
     } else {
         return <>
-          {goals.goals.map((g, i) => <Goal typewriter={false} key={i} goal={g} filter={filter} />)}
+          {goals.goals.map((g, i) => <Goal typewriter={false} key={i} goal={g.goal} filter={filter} />)}
         </>
     }
 }
@@ -276,7 +283,7 @@ interface FilteredGoalsProps {
      * When this is `undefined`, the component will not appear at all but will remember its state
      * by virtue of still being mounted in the React tree. When it does appear again, the filter
      * settings and collapsed state will be as before. */
-    goals?: InteractiveGoals
+    goals?: InteractiveGoalsWithHints
 }
 
 /**
@@ -291,7 +298,7 @@ export const FilteredGoals = React.memo(({ headerChildren, goals }: FilteredGoal
             data-id="copy-goal-to-comment"
             onClick={e => {
                 e.preventDefault();
-                if (goals) void ec.copyToComment(goalsToString(goals))
+                if (goals) void ec.copyToComment(goalsWithHintsToString(goals))
             }}
             title="copy state to comment" />
 
@@ -336,3 +343,45 @@ export const FilteredGoals = React.memo(({ headerChildren, goals }: FilteredGoal
         </details>
     </div>
 })
+
+export function loadGoals(
+  rpcSess: RpcSessionAtPos,
+  uri: string,
+  setProof: React.Dispatch<React.SetStateAction<ProofState>>,
+  setCrashed: React.Dispatch<React.SetStateAction<Boolean>>) {
+console.info('sending rpc request to load the proof state')
+
+rpcSess.call('Game.getProofState', DocumentPosition.toTdpp({line: 0, character: 0, uri: uri})).then(
+  (proof : ProofState) => {
+    if (typeof proof !== 'undefined') {
+      console.info(`received a proof state!`)
+      console.log(proof)
+      setProof(proof)
+      setCrashed(false)
+    } else {
+      console.warn('received undefined proof state!')
+      setCrashed(true)
+      // setProof(undefined)
+    }
+  }
+).catch((error) => {
+  setCrashed(true)
+  console.warn(error)
+})
+}
+
+
+export function lastStepHasErrors (proof : ProofState): boolean {
+  if (!proof?.steps.length) {return false}
+
+  let diags = [...proof.steps[proof.steps.length - 1].diags, ...proof.diagnostics]
+
+  return diags.some(
+    (d) => (d.severity == DiagnosticSeverity.Error ) // || d.severity == DiagnosticSeverity.Warning
+  )
+}
+
+export function isLastStepWithErrors (proof : ProofState, i: number): boolean {
+  if (!proof?.steps.length) {return false}
+  return (i == proof.steps.length - 1) && lastStepHasErrors(proof)
+}

client/src/components/infoview/info.tsx

@@ -4,7 +4,7 @@ import * as React from 'react'
 import { CircularProgress } from '@mui/material'
 import type { Location, Diagnostic } from 'vscode-languageserver-protocol'
 import { getInteractiveTermGoal, InteractiveDiagnostic, UserWidgetInstance, Widget_getWidgets, RpcSessionAtPos, isRpcError,
-  RpcErrorCode, getInteractiveDiagnostics, InteractiveTermGoal } from '@leanprover/infoview-api'
+  RpcErrorCode, getInteractiveDiagnostics } from '@leanprover/infoview-api'
 import { basename, DocumentPosition, RangeHelpers, useEvent, usePausableState, discardMethodNotFound,
   mapRpcError, useAsyncWithTrigger, PausableProps } from '../../../../node_modules/lean4-infoview/src/infoview/util'
 import { ConfigContext, EditorContext, LspDiagnosticsContext, ProgressContext } from '../../../../node_modules/lean4-infoview/src/infoview/contexts'
@@ -14,7 +14,7 @@ import { GoalsLocation, Locations, LocationsContext } from '../../../../node_mod
 
 import { AllMessages, lspDiagToInteractive } from './messages'
 import { goalsToString, Goal, MainAssumptions, OtherGoals, ProofDisplay } from './goals'
-import { InteractiveGoals } from './rpc_api'
+import { InteractiveTermGoal, InteractiveGoalsWithHints, InteractiveGoals, ProofState } from './rpc_api'
 import { MonacoEditorContext, ProofStateProps, InfoStatus, ProofContext } from './context'
 
 // TODO: All about pinning could probably be removed
@@ -83,11 +83,11 @@ interface InfoDisplayContentProps extends PausableProps {
   error?: string
   userWidgets: UserWidgetInstance[]
   triggerUpdate: () => Promise<void>
-  proof? : string
+  proofString? : string
 }
 
 const InfoDisplayContent = React.memo((props: InfoDisplayContentProps) => {
-    const {pos, messages, goals, termGoal, error, userWidgets, triggerUpdate, isPaused, setPaused, proof} = props
+    const {pos, messages, goals, termGoal, error, userWidgets, triggerUpdate, isPaused, setPaused, proofString} = props
 
     const hasWidget = userWidgets.length > 0
     const hasError = !!error
@@ -114,7 +114,8 @@ const InfoDisplayContent = React.memo((props: InfoDisplayContentProps) => {
 
     const goalFilter = { reverse: false, showType: true, showInstance: true, showHiddenAssumption: true, showLetValue: true }
     /* Adding {' '} to manage string literals properly: https://reactjs.org/docs/jsx-in-depth.html#string-literals-1 */
-    return <>
+
+   return <>
         {hasError &&
             <div className='error' key='errors'>
                 Error updating:{' '}{error}.
@@ -137,7 +138,7 @@ const InfoDisplayContent = React.memo((props: InfoDisplayContentProps) => {
         {userWidgets.map(widget =>
           <details key={`widget::${widget.id}::${widget.range?.toString()}`} open>
             <summary className='mv2 pointer'>{widget.name}</summary>
-            <PanelWidgetDisplay pos={pos} goals={goals ? goals.goals.map (goal => goal) : []}
+            <PanelWidgetDisplay pos={pos} goals={goals ? goals.goals : []}
               termGoal={termGoal} selectedLocations={selectedLocs} widget={widget}/>
           </details>
         )}
@@ -166,6 +167,7 @@ interface InfoDisplayProps {
   pos: DocumentPosition,
   status: InfoStatus,
   messages: InteractiveDiagnostic[],
+  proof?: ProofState,
   goals?: InteractiveGoals,
   termGoal?: InteractiveTermGoal,
   error?: string,
@@ -175,7 +177,7 @@ interface InfoDisplayProps {
 }
 
 /** Displays goal state and messages. Can be paused. */
-function InfoDisplay(props0: ProofStateProps & InfoDisplayProps & InfoPinnable) {
+function InfoDisplay(props0: InfoDisplayProps & InfoPinnable) {
     // Used to update the paused state *just once* if it is paused,
     // but a display update is triggered
     const [shouldRefresh, setShouldRefresh] = React.useState<boolean>(false)
@@ -214,7 +216,7 @@ function InfoDisplay(props0: ProofStateProps & InfoDisplayProps & InfoPinnable)
     {/* <details open> */}
         {/* <InfoStatusBar {...props} triggerUpdate={triggerDisplayUpdate} isPaused={isPaused} setPaused={setPaused} /> */}
         <div className="vscode-light">
-            <InfoDisplayContent {...props} proof={editor.getValue()} triggerUpdate={triggerDisplayUpdate} isPaused={isPaused} setPaused={setPaused} />
+            <InfoDisplayContent {...props} proofString={editor.getValue()} triggerUpdate={triggerDisplayUpdate} isPaused={isPaused} setPaused={setPaused} />
         </div>
     {/* </details> */}
     </RpcContext.Provider>
@@ -252,7 +254,7 @@ function useIsProcessingAt(p: DocumentPosition): boolean {
 
 function InfoAux(props: InfoProps) {
 
-    const proofContext = React.useContext(ProofContext)
+    const { setProof } = React.useContext(ProofContext)
 
     const config = React.useContext(ConfigContext)
 
@@ -290,6 +292,10 @@ function InfoAux(props: InfoProps) {
     // with e.g. a new `pos`.
     type InfoRequestResult = Omit<InfoDisplayProps, 'triggerUpdate'>
     const [state, triggerUpdateCore] = useAsyncWithTrigger(() => new Promise<InfoRequestResult>((resolve, reject) => {
+
+        const proofReq = rpcSess.call('Game.getProofState', DocumentPosition.toTdpp(pos)).catch((error) => {
+            console.warn(error)
+          })
         const goalsReq = rpcSess.call('Game.getInteractiveGoals', DocumentPosition.toTdpp(pos))
         const termGoalReq = getInteractiveTermGoal(rpcSess, DocumentPosition.toTdpp(pos))
         const widgetsReq = Widget_getWidgets(rpcSess, pos).catch(discardMethodNotFound)
@@ -308,6 +314,7 @@ function InfoAux(props: InfoProps) {
                 pos,
                 status: 'updating',
                 messages: lspDiagsHere.map(lspDiagToInteractive),
+                proof: undefined,
                 goals: undefined,
                 termGoal: undefined,
                 error: undefined,
@@ -318,11 +325,12 @@ function InfoAux(props: InfoProps) {
 
         // NB: it is important to await await reqs at once, otherwise
         // if both throw then one exception becomes unhandled.
-        Promise.all([goalsReq, termGoalReq, widgetsReq, messagesReq]).then(
+        Promise.all([proofReq, goalsReq, termGoalReq, widgetsReq, messagesReq]).then(
-            ([goals, termGoal, userWidgets, messages]) => resolve({
+            ([proof, goals, termGoal, userWidgets, messages]) => resolve({
                 pos,
                 status: 'ready',
                 messages,
+                proof : proof as any,
                 goals: goals as any,
                 termGoal,
                 error: undefined,
@@ -353,6 +361,7 @@ function InfoAux(props: InfoProps) {
                     pos,
                     status: 'error',
                     messages: lspDiagsHere.map(lspDiagToInteractive),
+                    proof: undefined,
                     goals: undefined,
                     termGoal: undefined,
                     error: `Error fetching goals: ${errorString}`,
@@ -389,6 +398,7 @@ function InfoAux(props: InfoProps) {
         pos,
         status: 'updating',
         messages: [],
+        proof: undefined,
         goals: undefined,
         termGoal: undefined,
         error: undefined,
@@ -412,6 +422,11 @@ function InfoAux(props: InfoProps) {
           //   hintContext.setHints(state.value.goals.goals[0].hints)
           // }
           setDisplayProps({ ...state.value, triggerUpdate })
+
+          // Update the game's proof state
+          console.info('updating proof from editor mode.')
+          setProof(state.value.proof)
+
         } else if (state.state === 'rejected' && state.error !== 'retry') {
             // The code inside `useAsyncWithTrigger` may only ever reject with a `retry` exception.
             console.warn('Unreachable code reached with error: ', state.error)

client/src/components/infoview/main.tsx

@@ -26,15 +26,17 @@ import Markdown from '../markdown';
 
 import { Infos } from './infos';
 import { AllMessages, Errors, WithLspDiagnosticsContext } from './messages';
-import { Goal } from './goals';
+import { Goal, isLastStepWithErrors, lastStepHasErrors, loadGoals } from './goals';
-import { DeletedChatContext, InputModeContext, MobileContext, MonacoEditorContext, ProofContext, ProofStep, SelectionContext, WorldLevelIdContext } from './context';
+import { DeletedChatContext, InputModeContext, PreferencesContext, MonacoEditorContext, ProofContext, SelectionContext, WorldLevelIdContext } from './context';
-import { Typewriter, hasErrors, hasInteractiveErrors } from './typewriter';
+import { Typewriter, getInteractiveDiagsAt, hasErrors, hasInteractiveErrors } from './typewriter';
 import { InteractiveDiagnostic } from '@leanprover/infoview/*';
 import { Button } from '../button';
 import { CircularProgress } from '@mui/material';
-import { GameHint } from './rpc_api';
+import { GameHint, InteractiveGoalsWithHints, ProofState } from './rpc_api';
 import { store } from '../../state/store';
-import { Hints, filterHints } from '../hints';
+import { Hints, MoreHelpButton, filterHints } from '../hints';
+import { DocumentPosition } from '../../../../node_modules/lean4-infoview/src/infoview/util';
+import { DiagnosticSeverity } from 'vscode-languageclient';
 
 /** Wrapper for the two editors. It is important that the `div` with `codeViewRef` is
  * always present, or the monaco editor cannot start.
@@ -61,36 +63,35 @@ function DualEditorMain({ worldId, levelId, level, worldSize }: { worldId: strin
   const gameId = React.useContext(GameIdContext)
   const { typewriterMode } = React.useContext(InputModeContext)
 
-  // Mark level as completed when server gives notification
+  const {proof, setProof} = React.useContext(ProofContext)
+
   const dispatch = useAppDispatch()
-  useServerNotificationEffect(
-    '$/game/completed',
-    (params: any) => {
-      if (ec.events.changedCursorLocation.current &&
-          ec.events.changedCursorLocation.current.uri === params.uri) {
-        dispatch(levelCompleted({ game: gameId, world: worldId, level: levelId }))
 
-        // On completion, add the names of all new items to the local storage
+  React.useEffect(() => {
-        let newTiles = [
+    if (proof?.completed) {
-          ...level?.tactics,
+      dispatch(levelCompleted({ game: gameId, world: worldId, level: levelId }))
-          ...level?.lemmas,
-          ...level?.definitions
-        ].filter((tile) => tile.new).map((tile) => tile.name)
 
-        // Add the proven statement to the local storage as well.
+      // On completion, add the names of all new items to the local storage
-        if (level?.statementName != null) {
+      let newTiles = [
-          newTiles.push(level?.statementName)
+        ...level?.tactics,
-        }
+        ...level?.lemmas,
+        ...level?.definitions
+      ].filter((tile) => tile.new).map((tile) => tile.name)
 
-        let inv: string[] = selectInventory(gameId)(store.getState())
+      // Add the proven statement to the local storage as well.
-
+      if (level?.statementName != null) {
-        // add new items and remove duplicates
+        newTiles.push(level?.statementName)
-        let newInv = [...inv, ...newTiles].filter((item, i, array) => array.indexOf(item) == i)
-
-        dispatch(changedInventory({ game: gameId, inventory: newInv }))
       }
-    }, [level]
+
-  )
+      let inv: string[] = selectInventory(gameId)(store.getState())
+
+      // add new items and remove duplicates
+      let newInv = [...inv, ...newTiles].filter((item, i, array) => array.indexOf(item) == i)
+
+      dispatch(changedInventory({ game: gameId, inventory: newInv }))
+
+    }
+  }, [proof, level])
 
   /* Set up updates to the global infoview state on editor events. */
   const config = useEventResult(ec.events.changedInfoviewConfig) ?? defaultInfoviewConfig;
@@ -154,8 +155,21 @@ export function Main(props: { world: string, level: number, data: LevelInfo}) {
   const gameId = React.useContext(GameIdContext)
   const {worldId, levelId} = React.useContext(WorldLevelIdContext)
 
-  const completed = useAppSelector(selectCompleted(gameId, props.world, props.level))
+  const { proof, setProof } = React.useContext(ProofContext)
+  const {selectedStep, setSelectedStep} = React.useContext(SelectionContext)
+  const { setDeletedChat, showHelp, setShowHelp } = React.useContext(DeletedChatContext)
 
+
+  function toggleSelection(line: number) {
+    return (ev) => {
+      console.debug('toggled selection')
+      if (selectedStep == line) {
+        setSelectedStep(undefined)
+      } else {
+        setSelectedStep(line)
+      }
+    }
+  }
   console.debug(`template: ${props.data?.template}`)
 
   // React.useEffect (() => {
@@ -182,6 +196,19 @@ export function Main(props: { world: string, level: number, data: LevelInfo}) {
 
   const curUri = useEventResult(ec.events.changedCursorLocation, loc => loc?.uri);
 
+  const curPos: DocumentPosition | undefined =
+    useEventResult(ec.events.changedCursorLocation, loc => loc ? { uri: loc.uri, ...loc.range.start } : undefined)
+
+  // Effect when the cursor changes in the editor
+  React.useEffect(() => {
+    // TODO: this is a bit of a hack and will yield unexpected behaviour if lines
+    // are indented.
+    let newPos = curPos?.line + (curPos?.character == 0 ? 0 : 1)
+
+    // scroll the chat along
+    setSelectedStep(newPos)
+  }, [curPos])
+
   useClientNotificationEffect(
     'textDocument/didClose',
     (params: DidCloseTextDocumentParams) => {
@@ -206,8 +233,17 @@ export function Main(props: { world: string, level: number, data: LevelInfo}) {
     ret = <div><p>{serverStoppedResult.message}</p><p className="error">{serverStoppedResult.reason}</p></div>
   } else {
     ret = <div className="infoview vscode-light">
-      {completed && <div className="level-completed">Level completed! 🎉</div>}
+      {proof?.completedWithWarnings &&
+        <div className="level-completed">
+          {proof?.completed ? "Level completed! 🎉" : "Level completed with warnings 🎭"}
+        </div>
+      }
       <Infos />
+      <Hints hints={proof?.steps[curPos?.line]?.goals[0]?.hints}
+        showHidden={showHelp.has(curPos?.line)} step={curPos?.line}
+        selected={selectedStep} toggleSelection={toggleSelection(curPos?.line)}
+        lastLevel={curPos?.line == proof?.steps.length - 1}/>
+      <MoreHelpButton selected={curPos?.line}/>
     </div>
   }
 
@@ -223,15 +259,24 @@ const goalFilter = {
 }
 
 /** The display of a single entered lean command */
-function Command({ command, deleteProof }: { command: string, deleteProof: any }) {
+function Command({ proof, i, deleteProof }: { proof: ProofState, i: number, deleteProof: any }) {
   // The first step will always have an empty command
-  if (!command) { return <></> }
+  if (!proof?.steps[i]?.command) { return <></> }
-  return <div className="command">
+
-    <div className="command-text">{command}</div>
+  if (isLastStepWithErrors(proof, i)) {
-    <Button to="" className="undo-button btn btn-inverted" title="Retry proof from here" onClick={deleteProof}>
+    // If the last step has errors, we display the command in a different style
-      <FontAwesomeIcon icon={faDeleteLeft} />&nbsp;Retry
+    // indicating that it will be removed on the next try.
-    </Button>
+    return <div className="failed-command">
-  </div>
+      <i>Failed command</i>: {proof?.steps[i].command}
+    </div>
+  } else {
+    return <div className="command">
+      <div className="command-text">{proof?.steps[i].command}</div>
+      <Button to="" className="undo-button btn btn-inverted" title="Retry proof from here" onClick={deleteProof}>
+        <FontAwesomeIcon icon={faDeleteLeft} />&nbsp;Retry
+      </Button>
+    </div>
+  }
 }
 
 // const MessageView = React.memo(({uri, diag}: MessageViewProps) => {
@@ -286,10 +331,14 @@ function Command({ command, deleteProof }: { command: string, deleteProof: any }
 // }, fastIsEqual)
 
 /** The tabs of goals that lean ahs after the command of this step has been processed */
-function GoalsTabs({ proofStep, last, onClick, onGoalChange=(n)=>{}}: { proofStep: ProofStep, last : boolean, onClick? : any, onGoalChange?: (n?: number) => void }) {
+function GoalsTabs({ proofStep, last, onClick, onGoalChange=(n)=>{}}: { proofStep: InteractiveGoalsWithHints, last : boolean, onClick? : any, onGoalChange?: (n?: number) => void }) {
 
   const [selectedGoal, setSelectedGoal] = React.useState<number>(0)
 
+  if (proofStep.goals.length == 0) {
+    return <></>
+  }
+
   return <div className="goal-tabs" onClick={onClick}>
     <div className={`tab-bar ${last ? 'current' : ''}`}>
       {proofStep.goals.map((goal, i) => (
@@ -300,7 +349,7 @@ function GoalsTabs({ proofStep, last, onClick, onGoalChange=(n)=>{}}: { proofSte
       ))}
     </div>
     <div className="goal-tab vscode-light">
-      <Goal typewriter={false} filter={goalFilter} goal={proofStep.goals[selectedGoal]} />
+      <Goal typewriter={false} filter={goalFilter} goal={proofStep.goals[selectedGoal]?.goal} />
     </div>
   </div>
 }
@@ -349,13 +398,12 @@ export function TypewriterInterface({props}) {
   const [disableInput, setDisableInput] = React.useState<boolean>(false)
   const [loadingProgress, setLoadingProgress] = React.useState<number>(0)
   const { setDeletedChat, showHelp, setShowHelp } = React.useContext(DeletedChatContext)
-  const {mobile} = React.useContext(MobileContext)
+  const {mobile} = React.useContext(PreferencesContext)
-  const { proof } = React.useContext(ProofContext)
+  const { proof, setProof, crashed, setCrashed, interimDiags } = React.useContext(ProofContext)
   const { setTypewriterInput } = React.useContext(InputModeContext)
   const { selectedStep, setSelectedStep } = React.useContext(SelectionContext)
 
   const proofPanelRef = React.useRef<HTMLDivElement>(null)
-  const completed = useAppSelector(selectCompleted(gameId, props.world, props.level))
   // const config = useEventResult(ec.events.changedInfoviewConfig) ?? defaultInfoviewConfig;
   // const curUri = useEventResult(ec.events.changedCursorLocation, loc => loc?.uri);
 
@@ -367,9 +415,11 @@ export function TypewriterInterface({props}) {
   function deleteProof(line: number) {
     return (ev) => {
       let deletedChat: Array<GameHint> = []
-      filterHints(proof).slice(line).map((hintsAtStep, i) => {
+      proof?.steps.slice(line).map((step, i) => {
+        let filteredHints = filterHints(step.goals[0]?.hints, proof?.steps[i-1]?.goals[0]?.hints)
+
         // Only add these hidden hints to the deletion stack which were visible
-        deletedChat = [...deletedChat, ...hintsAtStep.filter(hint => (!hint.hidden || showHelp.has(line + i)))]
+        deletedChat = [...deletedChat, ...filteredHints.filter(hint => (!hint.hidden || showHelp.has(line + i)))]
       })
       setDeletedChat(deletedChat)
 
@@ -382,7 +432,9 @@ export function TypewriterInterface({props}) {
         forceMoveMarkers: false
       }])
       setSelectedStep(undefined)
-      setTypewriterInput(proof[line].command)
+      setTypewriterInput(proof?.steps[line].command)
+      // Reload proof on deleting
+      loadGoals(rpcSess, uri, setProof, setCrashed)
       ev.stopPropagation()
     }
   }
@@ -402,7 +454,7 @@ export function TypewriterInterface({props}) {
 
    // Scroll to the end of the proof if it is updated.
    React.useEffect(() => {
-    if (proof?.length > 1) {
+    if (proof?.steps.length > 1) {
       proofPanelRef.current?.lastElementChild?.scrollIntoView() //scrollTo(0,0)
     } else {
       proofPanelRef.current?.scrollTo(0,0)
@@ -423,38 +475,8 @@ export function TypewriterInterface({props}) {
     }
   }, [selectedStep])
 
-  // TODO: This about hidden hints is all copied from `level.tsx`. Can we move that into `hints.tsx`?
+  // TODO: superfluous, can be replaced with `withErr` from above
-
+  let lastStepErrors = proof?.steps.length ? hasInteractiveErrors(getInteractiveDiagsAt(proof, proof?.steps.length)) : false
-  // If the last step has errors, we want to treat it as if it is part of the second-to-last step
-  let k = proof.length - 1
-  let withErr = hasInteractiveErrors(proof[k]?.errors) ? 1 : 0
-
-  const activateHiddenHints = (ev) => {
-    // If the last step (`k`) has errors, we want the hidden hints from the
-    // second-to-last step to be affected
-    if (!(proof.length)) {return}
-
-    // state must not be mutated, therefore we need to clone the set
-    let tmp = new Set(showHelp)
-    if (tmp.has(k - withErr)) {
-      tmp.delete(k - withErr)
-    } else {
-      tmp.add(k - withErr)
-    }
-    setShowHelp(tmp)
-    console.debug(`help: ${Array.from(tmp.values())}`)
-  }
-
-  function hasHiddenHints(i : number): boolean {
-    let step = proof[i]
-
-    // For example if the proof isn't loaded yet
-    if(!step) {return false}
-
-    return step.hints.some((hint) => hint.hidden)
-  }
-
-  let lastStepErrors = proof.length ? hasInteractiveErrors(proof[proof.length - 1].errors) : false
 
 
   useServerNotificationEffect("$/game/loading", (params : any) => {
@@ -474,20 +496,43 @@ export function TypewriterInterface({props}) {
       </div>
       <div className='proof' ref={proofPanelRef}>
         <ExerciseStatement data={props.data} />
-        {proof.length ?
+        {crashed ? <div>
-          <>
+          <p className="crashed_message">Crashed! Go to editor mode and fix your proof!
-            {proof.map((step, i) => {
+          Last server response:</p>
-              if (i == proof.length - 1 && lastStepErrors) {
+          {interimDiags.map(diag => {
-                // if the last command contains an error, we only display the errors but not the
+            const severityClass = diag.severity ? {
-                // entered command as it is still present in the command line.
+              [DiagnosticSeverity.Error]: 'error',
-                // TODO: Should not use index as key.
+              [DiagnosticSeverity.Warning]: 'warning',
-                return <div key={`proof-step-${i}`}>
+              [DiagnosticSeverity.Information]: 'information',
-                  <Errors errors={step.errors} typewriterMode={true} />
+              [DiagnosticSeverity.Hint]: 'hint',
+            }[diag.severity] : '';
+
+            return <div>
+              <div className={`${severityClass} ml1 message`}>
+                <p className="mv2">Line {diag.range.start.line}, Character {diag.range.start.character}</p>
+                <pre className="font-code pre-wrap">
+                  {diag.message}
+                </pre>
                 </div>
-              } else {
+            </div>
+          })}
+
+        </div> : proof?.steps.length ?
+          <>
+            {proof?.steps.map((step, i) => {
+              let filteredHints = filterHints(step.goals[0]?.hints, proof?.steps[i-1]?.goals[0]?.hints)
+
+              // if (i == proof?.steps.length - 1 && hasInteractiveErrors(step.diags)) {
+              //   // if the last command contains an error, we only display the errors but not the
+              //   // entered command as it is still present in the command line.
+              //   // TODO: Should not use index as key.
+              //   return <div key={`proof-step-${i}`} className={`step step-${i}`}>
+              //     <Errors errors={step.diags} typewriterMode={true} />
+              //   </div>
+              // } else {
                 return <div key={`proof-step-${i}`} className={`step step-${i}` + (selectedStep == i ? ' selected' : '')}>
-                  <Command command={step.command} deleteProof={deleteProof(i)} />
+                  <Command proof={proof} i={i} deleteProof={deleteProof(i)} />
-                  <Errors errors={step.errors} typewriterMode={true} />
+                  <Errors errors={step.diags} typewriterMode={true} />
                   {mobile && i == 0 && props.data?.introduction &&
                     <div className={`message information step-0${selectedStep === 0 ? ' selected' : ''}`} onClick={toggleSelectStep(0)}>
                       <Markdown>{props.data?.introduction}</Markdown>
@@ -495,22 +540,21 @@ export function TypewriterInterface({props}) {
                   }
                   {mobile &&
                     <Hints key={`hints-${i}`}
-                      hints={step.hints} showHidden={showHelp.has(i)} step={i}
+                      hints={filteredHints} showHidden={showHelp.has(i)} step={i}
                       selected={selectedStep} toggleSelection={toggleSelectStep(i)}/>
                   }
-                  <GoalsTabs proofStep={step} last={i == proof.length - (lastStepErrors ? 2 : 1)} onClick={toggleSelectStep(i)} onGoalChange={i == proof.length - 1 - withErr ? (n) => setDisableInput(n > 0) : (n) => {}}/>
+                  {/* <GoalsTabs proofStep={step} last={i == proof?.steps.length - (lastStepErrors ? 2 : 1)} onClick={toggleSelectStep(i)} onGoalChange={i == proof?.steps.length - 1 - withErr ? (n) => setDisableInput(n > 0) : (n) => {}}/> */}
-
+                  {!(isLastStepWithErrors(proof, i)) &&
-                  {mobile && i == proof.length - 1 &&
+                    <GoalsTabs proofStep={step} last={i == proof?.steps.length - (lastStepHasErrors(proof) ? 2 : 1)} onClick={toggleSelectStep(i)} onGoalChange={i == proof?.steps.length - (lastStepHasErrors(proof) ? 2 : 1) ? (n) => setDisableInput(n > 0) : (n) => {}}/>
-                    hasHiddenHints(proof.length - 1) && !showHelp.has(k - withErr) &&
+                  }
-                    <Button className="btn btn-help" to="" onClick={activateHiddenHints}>
+                  {mobile && i == proof?.steps.length - 1 &&
-                      Show more help!
+                    <MoreHelpButton />
-                    </Button>
                   }
 
                   {/* Show a message that there are no goals left */}
-                  {!step.goals.length && (
+                  {/* {!step.goals.length && (
                     <div className="message information">
-                      {completed ?
+                      {proof?.completed ?
                         <p>Level completed! 🎉</p> :
                         <p>
                           <b>no goals left</b><br />
@@ -518,11 +562,17 @@ export function TypewriterInterface({props}) {
                         </p>
                       }
                     </div>
-                  )}
+                  )} */}
                 </div>
               }
-            })}
+            //}
-            {mobile && completed &&
+            )}
+            {proof?.diagnostics.length > 0 &&
+              <div key={`proof-step-remaining`} className="step step-remaining">
+                <Errors errors={proof?.diagnostics} typewriterMode={true} />
+              </div>
+            }
+            {mobile && proof?.completed &&
               <div className="button-row mobile">
                 {props.level >= props.worldSize ?
                   <Button to={`/${gameId}`}>
@@ -535,11 +585,14 @@ export function TypewriterInterface({props}) {
                 }
               </div>
             }
-          </> : <CircularProgress variant="determinate" value={loadingProgress} />
+          </> : <CircularProgress variant="determinate" value={100*(1 - 1.024 ** (- loadingProgress))} />
+        // note: since we don't know the total number of files,
+        // we use a function which strictly monotonely increases towards `100` as `x → ∞`
+        // The base is chosen at random s.t. we get roughly 91% for `x = 100`.
         }
       </div>
     </div>
-    <Typewriter hidden={!withErr && proof[proof.length - 1]?.goals.length == 0} disabled={disableInput || !proof.length}/>
+    <Typewriter disabled={disableInput || !proof?.steps.length}/>
     </RpcContext.Provider>
   </div>
 }

client/src/components/infoview/messages.tsx

@@ -194,16 +194,24 @@ export function AllMessages() {
                 </a>
             </span>
         </summary> */}
-        <AllMessagesBody uri={curPos.uri} key={curPos.uri} messages={iDiags0} />
+        <AllMessagesBody uri={curPos.uri} key={curPos.uri} messages={iDiags0} curPos={curPos} />
     {/* </Details> */}
     </RpcContext.Provider>
     )
 }
 
 /** We factor out the body of {@link AllMessages} which lazily fetches its contents only when expanded. */
-function AllMessagesBody({uri, messages}: {uri: DocumentUri, messages: () => Promise<InteractiveDiagnostic[]>}) {
+function AllMessagesBody({uri, curPos, messages}: {uri: DocumentUri, curPos: DocumentPosition | undefined , messages: () => Promise<InteractiveDiagnostic[]>}) {
     const [msgs, setMsgs] = React.useState<InteractiveDiagnostic[] | undefined>(undefined)
-    React.useEffect(() => { void messages().then(setMsgs) }, [messages])
+    React.useEffect(() => { void messages().then(
+        msgs => setMsgs(msgs.filter(
+            (d)=>{
+                //console.log(`message start: ${d.range.start.line}. CurPos: ${curPos.line}`)
+
+                // Only show the messages from the line where the cursor is.
+                return d.range.start.line == curPos.line
+            }))
+    ) }, [messages, curPos])
     if (msgs === undefined) return <div>Loading messages...</div>
     else return <MessagesList uri={uri} messages={msgs}/>
 }

client/src/components/infoview/rpc_api.ts

@@ -3,46 +3,82 @@
  *
  * This file is based on `vscode-lean4/vscode-lean4/src/rpcApi.ts`
  */
-import { ContextInfo, FVarId, CodeWithInfos, MVarId } from '@leanprover/infoview-api';
+import type { Range } from 'vscode-languageserver-protocol';
-
+import type { ContextInfo, FVarId, CodeWithInfos, MVarId } from '@leanprover/infoview-api';
-export interface GameHint {
+import { InteractiveDiagnostic, TermInfo } from '@leanprover/infoview/*';
-  text: string;
+import type { Diagnostic } from 'vscode-languageserver-protocol';
-  hidden: boolean;
-}
 
 export interface InteractiveHypothesisBundle {
   /** The pretty names of the variables in the bundle. Anonymous names are rendered
    * as `"[anonymous]"` whereas inaccessible ones have a `✝` appended at the end.
    * Use `InteractiveHypothesisBundle_nonAnonymousNames` to filter anonymouse ones out. */
   names: string[];
-  /** Present since server version 1.1.2. */
   fvarIds?: FVarId[];
   type: CodeWithInfos;
   val?: CodeWithInfos;
   isInstance?: boolean;
   isType?: boolean;
-  isAssumption?: boolean;
   isInserted?: boolean;
   isRemoved?: boolean;
+  isAssumption?: boolean;
 }
 
 export interface InteractiveGoalCore {
   hyps: InteractiveHypothesisBundle[];
   type: CodeWithInfos;
-  /** Present since server version 1.1.2. */
   ctx?: ContextInfo;
 }
 
 export interface InteractiveGoal extends InteractiveGoalCore {
   userName?: string;
   goalPrefix?: string;
-  /** Present since server version 1.1.2. */
   mvarId?: MVarId;
   isInserted?: boolean;
   isRemoved?: boolean;
+}
+
+export interface InteractiveGoals extends InteractiveGoalCore {
+  goals: InteractiveGoals[];
+}
+
+export interface InteractiveTermGoal extends InteractiveGoalCore {
+  range?: Range;
+  term?: TermInfo;
+}
+
+export interface GameHint {
+  text: string;
+  hidden: boolean;
+  rawText: string;
+  varNames: string[][]; // in Lean: `Array (Name × Name)`
+}
+
+export interface InteractiveGoalWithHints {
+  goal: InteractiveGoal;
   hints: GameHint[];
 }
 
-export interface InteractiveGoals {
+export interface InteractiveGoalsWithHints {
-  goals: InteractiveGoal[];
+  goals: InteractiveGoalWithHints[];
+  command: string;
+  diags: InteractiveDiagnostic[];
+}
+
+/**
+ * The proof state as it is received from the server.
+ * Per proof step of the tactic proof, there is one `InteractiveGoalWithHints[]`.
+ */
+export interface ProofState {
+  /** The proof steps. step 0 is the state at the beginning of the proof. step one
+   * contains the goal after the first line has been evaluated.
+   *
+   * In particular `step[i]` is the proof step at the beginning of line `i` in vscode.
+   */
+  steps: InteractiveGoalsWithHints[];
+  /** The remaining diagnostics that are not in the steps. Usually this should only
+   * be the "unsolved goals" message, I believe.
+   */
+  diagnostics : InteractiveDiagnostic[];
+  completed : Boolean;
+  completedWithWarnings : Boolean;
 }

client/src/components/infoview/typewriter.tsx

@@ -5,7 +5,7 @@ import { faWandMagicSparkles } from '@fortawesome/free-solid-svg-icons'
 import * as monaco from 'monaco-editor/esm/vs/editor/editor.api.js'
 import { Registry } from 'monaco-textmate' // peer dependency
 import { wireTmGrammars } from 'monaco-editor-textmate'
-import { DiagnosticSeverity, PublishDiagnosticsParams } from 'vscode-languageserver-protocol';
+import { DiagnosticSeverity, PublishDiagnosticsParams, DocumentUri } from 'vscode-languageserver-protocol';
 import { useServerNotificationEffect } from '../../../../node_modules/lean4-infoview/src/infoview/util';
 import { AbbreviationRewriter } from 'lean4web/client/src/editor/abbreviation/rewriter/AbbreviationRewriter';
 import { AbbreviationProvider } from 'lean4web/client/src/editor/abbreviation/AbbreviationProvider';
@@ -13,13 +13,21 @@ import * as leanSyntax from 'lean4web/client/src/syntaxes/lean.json'
 import * as leanMarkdownSyntax from 'lean4web/client/src/syntaxes/lean-markdown.json'
 import * as codeblockSyntax from 'lean4web/client/src/syntaxes/codeblock.json'
 import languageConfig from 'lean4/language-configuration.json';
-import { InteractiveDiagnostic, getInteractiveDiagnostics } from '@leanprover/infoview-api';
+import { InteractiveDiagnostic, RpcSessionAtPos, getInteractiveDiagnostics } from '@leanprover/infoview-api';
 import { Diagnostic } from 'vscode-languageserver-types';
 import { DocumentPosition } from '../../../../node_modules/lean4-infoview/src/infoview/util';
 import { RpcContext } from '../../../../node_modules/lean4-infoview/src/infoview/rpcSessions';
-import { DeletedChatContext, InputModeContext, MonacoEditorContext, ProofContext, ProofStep } from './context'
+import { DeletedChatContext, InputModeContext, MonacoEditorContext, ProofContext } from './context'
-import { goalsToString } from './goals'
+import { goalsToString, lastStepHasErrors, loadGoals } from './goals'
-import { GameHint, InteractiveGoals } from './rpc_api'
+import { GameHint, ProofState } from './rpc_api'
+
+export interface GameDiagnosticsParams {
+  uri: DocumentUri;
+  diagnostics: Diagnostic[];
+}
+
+
+
 
 /* We register a new language `leancmd` that looks like lean4, but does not use the lsp server. */
 
@@ -64,7 +72,7 @@ config.autoClosingPairs = config.autoClosingPairs.map(
 monaco.languages.setLanguageConfiguration('lean4cmd', config);
 
 /** The input field */
-export function Typewriter({hidden, disabled}: {hidden?: boolean, disabled?: boolean}) {
+export function Typewriter({disabled}: {disabled?: boolean}) {
 
   /** Reference to the hidden multi-line editor */
   const editor = React.useContext(MonacoEditorContext)
@@ -79,7 +87,7 @@ export function Typewriter({hidden, disabled}: {hidden?: boolean, disabled?: boo
   const inputRef = useRef()
 
   // The context storing all information about the current proof
-  const {proof, setProof} = React.useContext(ProofContext)
+  const {proof, setProof, interimDiags, setInterimDiags, setCrashed} = React.useContext(ProofContext)
 
   // state to store the last batch of deleted messages
   const {setDeletedChat} = React.useContext(DeletedChatContext)
@@ -89,98 +97,98 @@ export function Typewriter({hidden, disabled}: {hidden?: boolean, disabled?: boo
   /** Load all goals an messages of the current proof (line-by-line) and save
    * the retrieved information into context (`ProofContext`)
    */
-  const loadAllGoals = React.useCallback(() => {
+  // const loadAllGoals = React.useCallback(() => {
 
-    let goalCalls = []
+  //   let goalCalls = []
-    let msgCalls = []
+  //   let msgCalls = []
 
-    // For each line of code ask the server for the goals and the messages on this line
+  //   // For each line of code ask the server for the goals and the messages on this line
-    for (let i = 0; i < model.getLineCount(); i++) {
+  //   for (let i = 0; i < model.getLineCount(); i++) {
-      goalCalls.push(
+  //     goalCalls.push(
-        rpcSess.call('Game.getInteractiveGoals', DocumentPosition.toTdpp({line: i, character: 0, uri: uri}))
+  //       rpcSess.call('Game.getInteractiveGoals', DocumentPosition.toTdpp({line: i, character: 0, uri: uri}))
-      )
+  //     )
-      msgCalls.push(
+  //     msgCalls.push(
-        getInteractiveDiagnostics(rpcSess, {start: i, end: i+1}).catch((error) => {console.debug("promise broken")})
+  //       getInteractiveDiagnostics(rpcSess, {start: i, end: i+1}).catch((error) => {console.debug("promise broken")})
-      )
+  //     )
-    }
+  //   }
 
-    // Wait for all these requests to be processed before saving the results
+  //   // Wait for all these requests to be processed before saving the results
-    Promise.all(goalCalls).then((steps : InteractiveGoals[]) => {
+  //   Promise.all(goalCalls).then((steps : InteractiveGoalsWithHints[]) => {
-      Promise.all(msgCalls).then((diagnostics : [InteractiveDiagnostic[]]) => {
+  //     Promise.all(msgCalls).then((diagnostics : [InteractiveDiagnostic[]]) => {
-        let tmpProof : ProofStep[] = []
+  //       let tmpProof : ProofStep[] = []
 
-        let goalCount = 0
+  //       let goalCount = 0
 
-        steps.map((goals, i) => {
+  //       steps.map((goals, i) => {
-          // The first step has an empty command and therefore also no error messages
+  //         // The first step has an empty command and therefore also no error messages
-          // Usually there is a newline at the end of the editors content, so we need to
+  //         // Usually there is a newline at the end of the editors content, so we need to
-          // display diagnostics from potentally two lines in the last step.
+  //         // display diagnostics from potentally two lines in the last step.
-          let messages = i ? (i == steps.length - 1 ? diagnostics.slice(i-1).flat() : diagnostics[i-1]) : []
+  //         let messages = i ? (i == steps.length - 1 ? diagnostics.slice(i-1).flat() : diagnostics[i-1]) : []
 
-          // Filter out the 'unsolved goals' message
+  //         // Filter out the 'unsolved goals' message
-          messages = messages.filter((msg) => {
+  //         messages = messages.filter((msg) => {
-            return !("append" in msg.message &&
+  //           return !("append" in msg.message &&
-              "text" in msg.message.append[0] &&
+  //             "text" in msg.message.append[0] &&
-              msg.message.append[0].text === "unsolved goals")
+  //             msg.message.append[0].text === "unsolved goals")
-          })
+  //         })
 
-          if (typeof goals == 'undefined') {
+  //         if (typeof goals == 'undefined') {
-            tmpProof.push({
+  //           tmpProof.push({
-              command: i ? model.getLineContent(i) : '',
+  //             command: i ? model.getLineContent(i) : '',
-              goals: [],
+  //             goals: [],
-              hints: [],
+  //             hints: [],
-              errors: messages
+  //             errors: messages
-            } as ProofStep)
+  //           } as ProofStep)
-            console.debug('goals is undefined')
+  //           console.debug('goals is undefined')
-            return
+  //           return
-          }
+  //         }
 
-          // If the number of goals reduce, show a message
+  //         // If the number of goals reduce, show a message
-          if (goals.goals.length && goalCount > goals.goals.length) {
+  //         if (goals.length && goalCount > goals.length) {
-            messages.unshift({
+  //           messages.unshift({
-              range: {
+  //             range: {
-                start: {
+  //               start: {
-                  line: i-1,
+  //                 line: i-1,
-                  character: 0,
+  //                 character: 0,
-                },
+  //               },
-                end: {
+  //               end: {
-                  line: i-1,
+  //                 line: i-1,
-                  character: 0,
+  //                 character: 0,
-                }},
+  //               }},
-              severity: DiagnosticSeverity.Information,
+  //             severity: DiagnosticSeverity.Information,
-              message: {
+  //             message: {
-              text: 'intermediate goal solved 🎉'
+  //             text: 'intermediate goal solved 🎉'
-              }
+  //             }
-            })
+  //           })
-          }
+  //         }
-          goalCount = goals.goals.length
+  //         goalCount = goals.length
 
-          // with no goals there will be no hints.
+  //         // with no goals there will be no hints.
-          let hints : GameHint[] = goals.goals.length ? goals.goals[0].hints : []
+  //         let hints : GameHint[] = goals.length ? goals[0].hints : []
 
-          console.debug(`Command (${i}): `, i ? model.getLineContent(i) : '')
+  //         console.debug(`Command (${i}): `, i ? model.getLineContent(i) : '')
-          console.debug(`Goals: (${i}): `, goalsToString(goals)) //
+  //         console.debug(`Goals: (${i}): `, goalsToString(goals)) //
-          console.debug(`Hints: (${i}): `, hints)
+  //         console.debug(`Hints: (${i}): `, hints)
-          console.debug(`Errors: (${i}): `, messages)
+  //         console.debug(`Errors: (${i}): `, messages)
 
-          tmpProof.push({
+  //         tmpProof.push({
-            // the command of the line above. Note that `getLineContent` starts counting
+  //           // the command of the line above. Note that `getLineContent` starts counting
-            // at `1` instead of `zero`. The first ProofStep will have an empty command.
+  //           // at `1` instead of `zero`. The first ProofStep will have an empty command.
-            command: i ? model.getLineContent(i) : '',
+  //           command: i ? model.getLineContent(i) : '',
-            // TODO: store correct data
+  //           // TODO: store correct data
-            goals: goals.goals,
+  //           goals: goals.map(g => g.goal),
-            // only need the hints of the active goals in chat
+  //           // only need the hints of the active goals in chat
-            hints: hints,
+  //           hints: hints,
-            // errors and messages from the server
+  //           // errors and messages from the server
-            errors: messages
+  //           errors: messages
-          } as ProofStep)
+  //         } as ProofStep)
 
-        })
+  //       })
-        // Save the proof to the context
+  //       // Save the proof to the context
-        setProof(tmpProof)
+  //       setProof(tmpProof)
-      }).catch((error) => {console.debug("promise broken")})
+  //     }).catch((error) => {console.debug("promise broken")})
-    }).catch((error) => {console.debug("promise broken")})
+  //   }).catch((error) => {console.debug("promise broken")})
-  }, [editor, rpcSess, uri, model])
+  // }, [editor, rpcSess, uri, model])
 
   // Run the command
   const runCommand = React.useCallback(() => {
@@ -201,6 +209,8 @@ export function Typewriter({hidden, disabled}: {hidden?: boolean, disabled?: boo
         forceMoveMarkers: false
       }])
       setTypewriterInput('')
+      // Load proof after executing edits
+      loadGoals(rpcSess, uri, setProof, setCrashed)
     }
 
     editor.setPosition(pos)
@@ -212,9 +222,15 @@ export function Typewriter({hidden, disabled}: {hidden?: boolean, disabled?: boo
     }
   }, [typewriterInput])
 
+  /* Load proof on start/switching to typewriter */
   useEffect(() => {
-    if (proof.length && hasInteractiveErrors(proof[proof.length - 1].errors)) {
+    loadGoals(rpcSess, uri, setProof, setCrashed)
-      setTypewriterInput(proof[proof.length - 1].command)
+  }, [])
+
+  /** If the last step has an error, add the command to the typewriter. */
+  useEffect(() => {
+    if (lastStepHasErrors(proof)) {
+      setTypewriterInput(proof?.steps[proof?.steps.length - 1].command)
     }
   }, [proof])
 
@@ -222,7 +238,14 @@ export function Typewriter({hidden, disabled}: {hidden?: boolean, disabled?: boo
   useServerNotificationEffect('textDocument/publishDiagnostics', (params: PublishDiagnosticsParams) => {
     if (params.uri == uri) {
       setProcessing(false)
-      loadAllGoals()
+
+      console.log('Received lean diagnostics')
+      console.log(params.diagnostics)
+      setInterimDiags(params.diagnostics)
+
+      //loadGoals(rpcSess, uri, setProof)
+
+      // TODO: loadAllGoals()
       if (!hasErrors(params.diagnostics)) {
         //setTypewriterInput("")
         editor.setPosition(editor.getModel().getFullModelRange().getEndPosition())
@@ -236,6 +259,15 @@ export function Typewriter({hidden, disabled}: {hidden?: boolean, disabled?: boo
     // loadAllGoals()
   }, [uri]);
 
+  // // React when answer from the server comes back
+  // useServerNotificationEffect('$/game/publishDiagnostics', (params: GameDiagnosticsParams) => {
+  //   console.log('Received game diagnostics')
+  //   console.log(`diag. uri : ${params.uri}`)
+  //   console.log(params.diagnostics)
+
+  // }, [uri]);
+
+
   useEffect(() => {
     const myEditor = monaco.editor.create(inputRef.current!, {
       value: typewriterInput,
@@ -306,7 +338,8 @@ export function Typewriter({hidden, disabled}: {hidden?: boolean, disabled?: boo
   useEffect(() => {
     console.debug(`time to update: ${uri} \n ${rpcSess}`)
     console.debug(rpcSess)
-    loadAllGoals()
+    // console.debug('LOAD ALL GOALS')
+    // TODO: loadAllGoals()
   }, [rpcSess])
 
   /** Process the entered command */
@@ -315,7 +348,8 @@ export function Typewriter({hidden, disabled}: {hidden?: boolean, disabled?: boo
     runCommand()
   }
 
-  return <div className={`typewriter${hidden ? ' hidden' : ''}${disabled ? ' disabled' : ''}`}>
+  // do not display if the proof is completed (with potential warnings still present)
+  return <div className={`typewriter${proof?.completedWithWarnings ? ' hidden' : ''}${disabled ? ' disabled' : ''}`}>
       <form onSubmit={handleSubmit}>
         <div className="typewriter-input-wrapper">
           <div ref={inputRef} className="typewriter-input" />
@@ -343,3 +377,14 @@ export function hasInteractiveErrors (diags: InteractiveDiagnostic[]) {
     (d) => (d.severity == DiagnosticSeverity.Error ) // || d.severity == DiagnosticSeverity.Warning
   )
 }
+
+export function getInteractiveDiagsAt (proof: ProofState, k : number) {
+  if (k == 0) {
+    return []
+  } else if (k >= proof?.steps.length-1) {
+    // TODO: Do we need that?
+    return proof?.diagnostics.filter(msg => msg.range.start.line >= proof?.steps.length-1)
+  } else {
+    return proof?.diagnostics.filter(msg => msg.range.start.line == k-1)
+  }
+}

client/src/components/landing_page.tsx

@@ -134,7 +134,8 @@ function LandingPage() {
     "leanprover-community/nng4",
     "hhu-adam/robo",
     "djvelleman/stg4",
-    "miguelmarco/STG4",
+    "miguelmarco/stg4",
+    "trequetrum/lean4game-logic",
   ]
   let allTiles = allGames.map((gameId) => (useGetGameInfoQuery({game: `g/${gameId}`}).data?.tile))
 

client/src/components/level.tsx

@@ -16,6 +16,7 @@ import { InfoviewApi } from '@leanprover/infoview'
 import { EditorContext } from '../../../node_modules/lean4-infoview/src/infoview/contexts'
 import { EditorConnection, EditorEvents } from '../../../node_modules/lean4-infoview/src/infoview/editorConnection'
 import { EventEmitter } from '../../../node_modules/lean4-infoview/src/infoview/event'
+import { Diagnostic } from 'vscode-languageserver-types'
 
 import { GameIdContext } from '../app'
 import { useAppDispatch, useAppSelector } from '../hooks'
@@ -27,11 +28,11 @@ import { Button } from './button'
 import Markdown from './markdown'
 import {InventoryPanel} from './inventory'
 import { hasInteractiveErrors } from './infoview/typewriter'
-import { DeletedChatContext, InputModeContext, MobileContext, MonacoEditorContext,
+import { DeletedChatContext, InputModeContext, PreferencesContext, MonacoEditorContext,
-  ProofContext, ProofStep, SelectionContext, WorldLevelIdContext } from './infoview/context'
+  ProofContext, SelectionContext, WorldLevelIdContext } from './infoview/context'
 import { DualEditor } from './infoview/main'
-import { GameHint } from './infoview/rpc_api'
+import { GameHint, InteractiveGoalsWithHints, ProofState } from './infoview/rpc_api'
-import { DeletedHints, Hint, Hints, filterHints } from './hints'
+import { DeletedHints, Hint, Hints, MoreHelpButton, filterHints } from './hints'
 import { PrivacyPolicyPopup } from './popup/privacy_policy'
 import path from 'path';
 
@@ -49,6 +50,7 @@ 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'
+import { isLastStepWithErrors, lastStepHasErrors } from './infoview/goals'
 
 
 monacoSetup()
@@ -72,9 +74,9 @@ function Level() {
   </WorldLevelIdContext.Provider>
 }
 
-function ChatPanel({lastLevel}) {
+function ChatPanel({lastLevel, visible = true}) {
   const chatRef = useRef<HTMLDivElement>(null)
-  const {mobile} = useContext(MobileContext)
+  const {mobile} = useContext(PreferencesContext)
   const gameId = useContext(GameIdContext)
   const {worldId, levelId} = useContext(WorldLevelIdContext)
   const level = useLoadLevelQuery({game: gameId, world: worldId, level: levelId})
@@ -83,9 +85,7 @@ function ChatPanel({lastLevel}) {
   const {selectedStep, setSelectedStep} = useContext(SelectionContext)
   const completed = useAppSelector(selectCompleted(gameId, worldId, levelId))
 
-  // If the last step has errors, we want to treat it as if it is part of the second-to-last step
+  let k = proof?.steps.length ? proof?.steps.length - (lastStepHasErrors(proof) ? 2 : 1) : 0
-  let k = proof.length - 1
-  let withErr = hasInteractiveErrors(proof[k]?.errors) ? 1 : 0
 
   function toggleSelection(line: number) {
     return (ev) => {
@@ -98,29 +98,6 @@ function ChatPanel({lastLevel}) {
     }
   }
 
-  function hasHiddenHints(i : number): boolean {
-    let step = proof[i]
-    // For example if the proof isn't loaded yet
-    if(!step) {return false}
-    return step.hints.some((hint) => hint.hidden)
-  }
-
-  const activateHiddenHints = (ev) => {
-    // If the last step (`k`) has errors, we want the hidden hints from the
-    // second-to-last step to be affected
-    if (!(proof.length)) {return}
-
-    // state must not be mutated, therefore we need to clone the set
-    let tmp = new Set(showHelp)
-    if (tmp.has(k - withErr)) {
-      tmp.delete(k - withErr)
-    } else {
-      tmp.add(k - withErr)
-    }
-    setShowHelp(tmp)
-    console.debug(`help: ${Array.from(tmp.values())}`)
-  }
-
   useEffect(() => {
     // TODO: For some reason this is always called twice
     console.debug('scroll chat')
@@ -146,29 +123,34 @@ function ChatPanel({lastLevel}) {
 
   let introText: Array<string> = level?.data?.introduction.split(/\n(\s*\n)+/)
 
-  // experimental: Remove all hints that appeared identically in the previous step
+  return <div className={`chat-panel ${visible ? '' : 'hidden'}`}>
-  // This effectively prevent consequtive hints being shown.
-  let modifiedHints : GameHint[][] = filterHints(proof)
-
-  return <div className="chat-panel">
     <div ref={chatRef} className="chat">
       {introText?.filter(t => t.trim()).map(((t, i) =>
         // Show the level's intro text as hints, too
         <Hint key={`intro-p-${i}`}
-          hint={{text: t, hidden: false}} step={0} selected={selectedStep} toggleSelection={toggleSelection(0)} />
+          hint={{text: t, hidden: false, rawText: t, varNames: []}} step={0} selected={selectedStep} toggleSelection={toggleSelection(0)} />
       ))}
-      {modifiedHints.map((step, i) => {
+      {proof?.steps.map((step, i) => {
+        let filteredHints = filterHints(step.goals[0]?.hints, proof?.steps[i-1]?.goals[0]?.hints)
+        if (step.goals.length > 0 && !isLastStepWithErrors(proof, i)) {
+          return <Hints key={`hints-${i}`}
+          hints={filteredHints} showHidden={showHelp.has(i)} step={i}
+          selected={selectedStep} toggleSelection={toggleSelection(i)} lastLevel={i == proof?.steps.length - 1}/>
+        }
+      })}
+
+      {/* {modifiedHints.map((step, i) => {
         // It the last step has errors, it will have the same hints
         // as the second-to-last step. Therefore we should not display them.
-        if (!(i == proof.length - 1 && withErr)) {
+        if (!(i == proof?.steps.length - 1 && withErr)) {
           // TODO: Should not use index as key.
           return <Hints key={`hints-${i}`}
             hints={step} showHidden={showHelp.has(i)} step={i}
-            selected={selectedStep} toggleSelection={toggleSelection(i)} lastLevel={i == proof.length - 1}/>
+            selected={selectedStep} toggleSelection={toggleSelection(i)} lastLevel={i == proof?.steps.length - 1}/>
         }
-      })}
+      })} */}
       <DeletedHints hints={deletedChat}/>
-      {completed &&
+      {proof?.completed &&
         <>
           <div className={`message information recent step-${k}${selectedStep == k ? ' selected' : ''}`} onClick={toggleSelection(k)}>
             Level completed! 🎉
@@ -182,7 +164,7 @@ function ChatPanel({lastLevel}) {
       }
     </div>
     <div className="button-row">
-      {completed && (lastLevel ?
+      {proof?.completed && (lastLevel ?
         <Button to={`/${gameId}`}>
           <FontAwesomeIcon icon={faHome} />&nbsp;Leave World
         </Button> :
@@ -190,16 +172,13 @@ function ChatPanel({lastLevel}) {
           Next&nbsp;<FontAwesomeIcon icon={faArrowRight} />
         </Button>)
         }
-      {hasHiddenHints(proof.length - 1) && !showHelp.has(k - withErr) &&
+      <MoreHelpButton />
-        <Button to="" onClick={activateHiddenHints}>
-          Show more help!
-        </Button>
-      }
     </div>
   </div>
 }
 
-function ExercisePanel({codeviewRef, visible=true}) {
+
+function ExercisePanel({codeviewRef, visible=true}: {codeviewRef: React.MutableRefObject<HTMLDivElement>, visible?: boolean}) {
   const gameId = React.useContext(GameIdContext)
   const {worldId, levelId} = useContext(WorldLevelIdContext)
   const level = useLoadLevelQuery({game: gameId, world: worldId, level: levelId})
@@ -215,7 +194,7 @@ function PlayableLevel({impressum, setImpressum}) {
   const codeviewRef = useRef<HTMLDivElement>(null)
   const gameId = React.useContext(GameIdContext)
   const {worldId, levelId} = useContext(WorldLevelIdContext)
-  const {mobile} = React.useContext(MobileContext)
+  const {mobile} = React.useContext(PreferencesContext)
 
   const dispatch = useAppDispatch()
 
@@ -229,7 +208,11 @@ function PlayableLevel({impressum, setImpressum}) {
   const level = useLoadLevelQuery({game: gameId, world: worldId, level: levelId})
 
   // The state variables for the `ProofContext`
-  const [proof, setProof] = useState<Array<ProofStep>>([])
+  const [proof, setProof] = useState<ProofState>({steps: [], diagnostics: [], completed: false, completedWithWarnings: false})
+  const [interimDiags, setInterimDiags] = useState<Array<Diagnostic>>([])
+  const [isCrashed, setIsCrashed] = useState<Boolean>(false)
+
+
   // When deleting the proof, we want to keep to old messages around until
   // a new proof has been entered. e.g. to consult messages coming from dead ends
   const [deletedChat, setDeletedChat] = useState<Array<GameHint>>([])
@@ -356,15 +339,15 @@ function PlayableLevel({impressum, setImpressum}) {
 
   useEffect(() => {
     // Forget whether hidden hints are displayed for steps that don't exist yet
-    if (proof.length) {
+    if (proof?.steps.length) {
       console.debug(Array.from(showHelp))
-      setShowHelp(new Set(Array.from(showHelp).filter(i => (i < proof.length))))
+      setShowHelp(new Set(Array.from(showHelp).filter(i => (i < proof?.steps.length))))
     }
   }, [proof])
 
   // save showed help in store
   useEffect(() => {
-    if (proof.length) {
+    if (proof?.steps.length) {
       console.debug(`showHelp:\n ${showHelp}`)
       dispatch(helpEdited({game: gameId, world: worldId, level: levelId, help: Array.from(showHelp)}))
     }
@@ -402,7 +385,7 @@ function PlayableLevel({impressum, setImpressum}) {
     <DeletedChatContext.Provider value={{deletedChat, setDeletedChat, showHelp, setShowHelp}}>
       <SelectionContext.Provider value={{selectedStep, setSelectedStep}}>
         <InputModeContext.Provider value={{typewriterMode, setTypewriterMode, typewriterInput, setTypewriterInput, lockInputMode, setLockInputMode}}>
-          <ProofContext.Provider value={{proof, setProof}}>
+          <ProofContext.Provider value={{proof, setProof, interimDiags, setInterimDiags, crashed: isCrashed, setCrashed: setIsCrashed}}>
             <EditorContext.Provider value={editorConnection}>
               <MonacoEditorContext.Provider value={editor}>
                 <LevelAppBar
@@ -441,7 +424,7 @@ function PlayableLevel({impressum, setImpressum}) {
 function IntroductionPanel({gameInfo}) {
   const gameId = React.useContext(GameIdContext)
   const {worldId} = useContext(WorldLevelIdContext)
-  const {mobile} = React.useContext(MobileContext)
+  const {mobile} = React.useContext(PreferencesContext)
 
   let text: Array<string> = gameInfo.data?.worlds.nodes[worldId].introduction.split(/\n(\s*\n)+/)
 
@@ -449,7 +432,7 @@ function IntroductionPanel({gameInfo}) {
     <div className="chat">
       {text?.filter(t => t.trim()).map(((t, i) =>
         <Hint key={`intro-p-${i}`}
-          hint={{text: t, hidden: false}} step={0} selected={null} toggleSelection={undefined} />
+          hint={{text: t, hidden: false, rawText: t, varNames: []}} step={0} selected={null} toggleSelection={undefined} />
       ))}
     </div>
     <div className={`button-row${mobile ? ' mobile' : ''}`}>
@@ -468,7 +451,7 @@ export default Level
 /** The site with the introduction text of a world */
 function Introduction({impressum, setImpressum}) {
   const gameId = React.useContext(GameIdContext)
-  const {mobile} = useContext(MobileContext)
+  const {mobile} = useContext(PreferencesContext)
 
   const inventory = useLoadInventoryOverviewQuery({game: gameId})
 
@@ -622,7 +605,9 @@ function useLevelEditor(codeviewRef, initialCode, initialSelections, onDidChange
     }
     // loadRenderInfoview(imports, [infoProvider.getApi(), div], setInfoviewApi)
     setInfoProvider(infoProvider)
-    client.restart()
+
+    // TODO: it looks like we get errors "File Changed" here.
+    client.restart("Lean4Game")
 
     const editorApi = infoProvider.getApi()
 

client/src/components/popup/preferences.tsx

@@ -1,16 +1,42 @@
 import * as React from 'react'
 import { Input, Typography } from '@mui/material'
 import Markdown from '../markdown'
-import Switch from '@mui/material/Switch';
+import { Switch, Button, ButtonGroup } from '@mui/material';
+import Box from '@mui/material/Box';
+import Slider from '@mui/material/Slider';
+
 import FormControlLabel from '@mui/material/FormControlLabel';
 
-import { IMobileContext } from "../infoview/context"
+import { IPreferencesContext } from "../infoview/context"
 
-interface PreferencesPopupProps extends IMobileContext{
+interface PreferencesPopupProps extends Omit<IPreferencesContext, 'mobile'> {
     handleClose: () => void
-} 
+}
+
+export function PreferencesPopup({ layout, setLayout, isSavePreferences, setIsSavePreferences, handleClose }: PreferencesPopupProps) {
+
+    const marks = [
+        {
+            value: 0,
+            label: 'Mobile',
+            key: "mobile"
+        },
+        {
+            value: 1,
+            label: 'Auto',
+            key: "auto"
+        },
+        {
+            value: 2,
+            label: 'Desktop',
+            key: "desktop"
+        },
+    ];
+
+    const handlerChangeLayout = (_: Event, value: number) => {
+        setLayout(marks[value].key as IPreferencesContext["layout"])
+    }
 
-export function PreferencesPopup({ mobile, setMobile, lockMobile, setLockMobile, handleClose }: PreferencesPopupProps) {
     return <div className="modal-wrapper">
         <div className="modal-backdrop" onClick={handleClose} />
         <div className="modal">
@@ -18,34 +44,43 @@ export function PreferencesPopup({ mobile, setMobile, lockMobile, setLockMobile,
             <Typography variant="body1" component="div" className="settings">
                 <div className='preferences-category'>
                     <div className='category-title'>
-                        <h3>Mobile layout</h3>
+                        <h3>Layout</h3>
                     </div>
-                    <div className='preferences-item'>
+                    <div className='preferences-item first leave-left-gap'>
                         <FormControlLabel
                             control={
-                            <Switch
+                                <Box sx={{ width: 300 }}>
-                                checked={mobile}
+                                    <Slider
-                                onChange={() => setMobile(!mobile)}
+                                        aria-label="Always visible"
-                                name="checked"
+                                        value={marks.find(item => item.key === layout).value}
-                                color="primary"
+                                        step={1}
-                            />
+                                        marks={marks}
+                                        max={2}
+                                        sx={{
+                                            '& .MuiSlider-track': { display: 'none', },
+                                        }}
+                                        onChange={handlerChangeLayout}
+                                    />
+                                </Box>
                             }
-                            label="Enable"
+                            label=""
-                            labelPlacement="start"
                         />
                     </div>
+                </div>
+
+                <div className='preferences-category tail-category'>
                     <div className='preferences-item'>
                         <FormControlLabel
                             control={
-                            <Switch
+                                <Switch
-                                checked={!lockMobile}
+                                    checked={isSavePreferences}
-                                onChange={() => setLockMobile(!lockMobile)}
+                                    onChange={() => setIsSavePreferences(!isSavePreferences)}
-                                name="checked"
+                                    name="checked"
-                                color="primary"
+                                    color="primary"
-                            />
+                                />
                             }
-                            label="Auto"
+                            label="Save my settings (in the browser store)"
-                            labelPlacement="start"
+                            labelPlacement="end"
                         />
                     </div>
                 </div>

client/src/components/welcome.tsx

@@ -10,7 +10,7 @@ import { useAppDispatch, useAppSelector } from '../hooks'
 import { changedOpenedIntro, selectOpenedIntro } from '../state/progress'
 import { useGetGameInfoQuery, useLoadInventoryOverviewQuery } from '../state/api'
 import { Button } from './button'
-import { MobileContext } from './infoview/context'
+import { PreferencesContext } from './infoview/context'
 import { InventoryPanel } from './inventory'
 import { ErasePopup } from './popup/erase'
 import { InfoPopup } from './popup/game_info'
@@ -27,7 +27,7 @@ import { Hint } from './hints'
 
 /** the panel showing the game's introduction text */
 function IntroductionPanel({introduction, setPageNumber}: {introduction: string, setPageNumber}) {
-  const {mobile} = React.useContext(MobileContext)
+  const {mobile} = React.useContext(PreferencesContext)
   const gameId = React.useContext(GameIdContext)
   const dispatch = useAppDispatch()
 
@@ -64,7 +64,9 @@ function IntroductionPanel({introduction, setPageNumber}: {introduction: string,
 /** main page of the game showing among others the tree of worlds/levels */
 function Welcome() {
   const gameId = React.useContext(GameIdContext)
-  const {mobile, setMobile, lockMobile, setLockMobile} = React.useContext(MobileContext)
+  const {mobile} = React.useContext(PreferencesContext)
+  const {layout, isSavePreferences, setLayout, setIsSavePreferences} = React.useContext(PreferencesContext)
+
   const gameInfo = useGetGameInfoQuery({game: gameId})
   const inventory = useLoadInventoryOverviewQuery({game: gameId})
 
@@ -134,7 +136,7 @@ function Welcome() {
     {eraseMenu? <ErasePopup handleClose={closeEraseMenu}/> : null}
     {uploadMenu? <UploadPopup handleClose={closeUploadMenu}/> : null}
     {info ? <InfoPopup info={gameInfo.data?.info} handleClose={closeInfo}/> : null}
-    {preferencesPopup ? <PreferencesPopup mobile={mobile} setMobile={setMobile} lockMobile={lockMobile} setLockMobile={setLockMobile} handleClose={closePreferencesPopup}/> : null}
+    {preferencesPopup ? <PreferencesPopup layout={layout} isSavePreferences={isSavePreferences} setLayout={setLayout} setIsSavePreferences={setIsSavePreferences} handleClose={closePreferencesPopup}/> : null}
   </>
 }
 

client/src/components/world_tree.tsx

@@ -11,11 +11,12 @@ import { FontAwesomeIcon } from '@fortawesome/react-fontawesome'
 import { faXmark, faCircleQuestion } from '@fortawesome/free-solid-svg-icons'
 
 import { GameIdContext } from '../app'
-import { useAppDispatch, useMobile } from '../hooks'
+import { useAppDispatch } from '../hooks'
 import { selectDifficulty, changedDifficulty, selectCompleted } from '../state/progress'
 import { store } from '../state/store'
 
 import '../css/world_tree.css'
+import { PreferencesContext } from './infoview/context'
 
 // Settings for the world tree
 cytoscape.use( klay )
@@ -197,7 +198,7 @@ export function WorldSelectionMenu({rulesHelp, setRulesHelp}) {
   const gameId = React.useContext(GameIdContext)
   const difficulty = useSelector(selectDifficulty(gameId))
   const dispatch = useAppDispatch()
-  const { mobile } = useMobile()
+  const { mobile } = React.useContext(PreferencesContext)
 
 
   function label(x : number) {

client/src/css/infoview.css

@@ -41,6 +41,13 @@
 .level-completed {
   font-size: 1.8rem;
   font-weight: 500;
+  padding-left: .5em;
+  padding-right: .5em;
+  padding-top: .2em;
+  padding-bottom: .2em;
+  border-radius: .5em;
+  background-color: #eee;
+
 }
 
 .typewriter {
@@ -188,6 +195,18 @@
   flex-direction: row;
 }
 
+.exercise .failed-command {
+  background-color: #eee;
+  padding: .5em;
+  border-radius: .2em;
+  /* TODO: It seems my browsers merge the margings of the proof steps,
+  so that it only shows once 0.5rem instead of twice. Thus have 1.5 here now.
+  */
+  margin-bottom: 1.5rem;
+  display: flex;
+  flex-direction: row;
+}
+
 .exercise .command-text {
   flex: 1;
   background-color: #fff;
@@ -199,3 +218,10 @@
 .undo-button {
   color: #888;
 }
+
+.crashed_message {
+  color: #D8000C;
+  font-weight: bold;
+  padding-left: .5em;
+  padding-right: .5em;
+}

client/src/css/level.css

@@ -368,3 +368,8 @@ td code  {
   min-width: 40px;
   text-align: center;
 }
+
+/* DEBUG */
+/* .proof .step {
+  border: 2px solid rgb(0, 123, 255);
+} */

client/src/css/welcome.css

@@ -187,3 +187,15 @@ h5, h6 {
   margin-left: 0.3rem;
   margin-right: 0.3rem;
 }
+
+.preferences-category.tail-category{
+  margin-top: 2em;
+}
+
+.preferences-item.first{
+  margin-top: 1em;
+}
+
+.preferences-item.leave-left-gap{
+  margin-left: 3em;
+}

client/src/hooks.ts

@@ -1,30 +1,6 @@
 import { TypedUseSelectorHook, useDispatch, useSelector } from 'react-redux'
 import type { RootState, AppDispatch } from './state/store'
 
-import { setMobile as setMobileState, setLockMobile as setLockMobileState} from "./state/preferences"
-
 // Use throughout your app instead of plain `useDispatch` and `useSelector`
 export const useAppDispatch: () => AppDispatch = useDispatch
 export const useAppSelector: TypedUseSelectorHook<RootState> = useSelector
-
-export const useMobile = () => {
-  const dispatch = useAppDispatch();
-
-  const mobile = useAppSelector((state) => state.preferences.mobile);
-  const lockMobile = useAppSelector((state) => state.preferences.lockMobile);
-
-  const setMobile = (val: boolean) => {
-    dispatch(setMobileState(val));
-  };
-
-  const setLockMobile = (val: boolean) => {
-    dispatch(setLockMobileState(val));
-  };
-
-  return {
-    mobile,
-    setMobile,
-    lockMobile,
-    setLockMobile,
-  };
-};

client/src/state/hooks/use_preferences.ts

@@ -0,0 +1,41 @@
+import React, { useState } from "react";
+import { useAppDispatch, useAppSelector } from "../../hooks";
+import { 
+    PreferencesState, 
+    setLayout as setPreferencesLayout, 
+    setIsSavePreferences as setPreferencesIsSavePreferences,
+    getWindowDimensions,
+    AUTO_SWITCH_THRESHOLD
+} from "../preferences";
+
+
+const UsePreferences = () => {
+    const dispatch = useAppDispatch()
+    const [mobile, setMobile] = React.useState<boolean>()
+
+    const layout = useAppSelector((state) => state.preferences.layout);
+    const setLayout = (layout: PreferencesState["layout"]) => dispatch(setPreferencesLayout(layout))
+
+    const isSavePreferences = useAppSelector((state) => state.preferences.isSavePreferences);
+    const setIsSavePreferences = (isSave: boolean) => dispatch(setPreferencesIsSavePreferences(isSave))
+
+    const automaticallyAdjustLayout = () => {
+        const {width} = getWindowDimensions()
+        setMobile(width < AUTO_SWITCH_THRESHOLD)
+    }
+
+    React.useEffect(()=>{
+        if (layout === "auto"){
+          void automaticallyAdjustLayout()
+          window.addEventListener('resize', automaticallyAdjustLayout)
+    
+          return () => window.removeEventListener('resize', automaticallyAdjustLayout)
+        } else {
+          setMobile(layout === "mobile")
+        }
+    }, [layout])
+
+    return {mobile, layout, isSavePreferences, setLayout, setIsSavePreferences}
+} 
+
+export default UsePreferences;

client/src/state/local_storage.ts

@@ -57,3 +57,12 @@ export function savePreferences(state: any) {
     // Ignore
   }
 }
+
+export function removePreferences() {
+  try {
+    localStorage.removeItem(PREFERENCES_KEY);
+  } catch (e) {
+    // Ignore
+  }
+}
+

client/src/state/preferences.ts

@@ -1,10 +1,10 @@
 import { createSlice } from "@reduxjs/toolkit";
 
-import { loadPreferences } from "./local_storage";
+import { loadPreferences, removePreferences, savePreferences } from "./local_storage";
 
-interface PreferencesState {
+export interface PreferencesState {
-  mobile: boolean;
+  layout: "mobile" | "auto" | "desktop";
-  lockMobile: boolean;
+  isSavePreferences: boolean;
 }
 
 export function getWindowDimensions() {
@@ -12,26 +12,24 @@ export function getWindowDimensions() {
   return {width, height}
 }
 
-const { width } = getWindowDimensions()
-
 export const AUTO_SWITCH_THRESHOLD = 800
 
-const initialState: PreferencesState = loadPreferences() ?? {
+const initialState: PreferencesState = loadPreferences() ??{
-    mobile: width < AUTO_SWITCH_THRESHOLD,
+    layout: "auto",
-    lockMobile: false
+    isSavePreferences: false
 }
 
 export const preferencesSlice = createSlice({
   name: "preferences",
   initialState,
   reducers: {
-    setMobile: (state, action) => {
+    setLayout: (state, action) => {
-      state.mobile = action.payload;
+      state.layout = action.payload;
     },
-    setLockMobile: (state, action) => {
+    setIsSavePreferences: (state, action) => {
-      state.lockMobile = action.payload;
+      state.isSavePreferences = action.payload;
     },
   },
 });
 
-export const { setMobile, setLockMobile } = preferencesSlice.actions;
+export const { setLayout, setIsSavePreferences } = preferencesSlice.actions;

client/src/state/progress.ts

@@ -53,22 +53,22 @@ const initalLevelProgressState: LevelProgressState = {code: "", completed: false
 
 /** Add an empty skeleton with progress for the current game */
 function addGameProgress (state: ProgressState, action: PayloadAction<{game: string}>) {
-  if (!state.games[action.payload.game]) {
+  if (!state.games[action.payload.game.toLowerCase()]) {
-    state.games[action.payload.game] = {inventory: [], openedIntro: true, data: {}, difficulty: DEFAULT_DIFFICULTY}
+    state.games[action.payload.game.toLowerCase()] = {inventory: [], openedIntro: true, data: {}, difficulty: DEFAULT_DIFFICULTY}
   }
-  if (!state.games[action.payload.game].data) {
+  if (!state.games[action.payload.game.toLowerCase()].data) {
-    state.games[action.payload.game].data = {}
+    state.games[action.payload.game.toLowerCase()].data = {}
   }
 }
 
 /** Add an empty skeleton with progress for the current level */
 function addLevelProgress(state: ProgressState, action: PayloadAction<{game: string, world: string, level: number}>) {
   addGameProgress(state, action)
-  if (!state.games[action.payload.game].data[action.payload.world]) {
+  if (!state.games[action.payload.game.toLowerCase()].data[action.payload.world]) {
-    state.games[action.payload.game].data[action.payload.world] = {}
+    state.games[action.payload.game.toLowerCase()].data[action.payload.world] = {}
   }
-  if (!state.games[action.payload.game].data[action.payload.world][action.payload.level]) {
+  if (!state.games[action.payload.game.toLowerCase()].data[action.payload.world][action.payload.level]) {
-    state.games[action.payload.game].data[action.payload.world][action.payload.level] = {...initalLevelProgressState}
+    state.games[action.payload.game.toLowerCase()].data[action.payload.world][action.payload.level] = {...initalLevelProgressState}
   }
 }
 
@@ -79,58 +79,58 @@ export const progressSlice = createSlice({
     /** put edited code in the state and set completed to false */
     codeEdited(state: ProgressState, action: PayloadAction<{game: string, world: string, level: number, code: string}>) {
       addLevelProgress(state, action)
-      state.games[action.payload.game].data[action.payload.world][action.payload.level].code = action.payload.code
+      state.games[action.payload.game.toLowerCase()].data[action.payload.world][action.payload.level].code = action.payload.code
-      state.games[action.payload.game].data[action.payload.world][action.payload.level].completed = false
+      state.games[action.payload.game.toLowerCase()].data[action.payload.world][action.payload.level].completed = false
     },
     /** TODO: docstring */
     changedSelection(state: ProgressState, action: PayloadAction<{game: string, world: string, level: number, selections: Selection[]}>) {
       addLevelProgress(state, action)
-      state.games[action.payload.game].data[action.payload.world][action.payload.level].selections = action.payload.selections
+      state.games[action.payload.game.toLowerCase()].data[action.payload.world][action.payload.level].selections = action.payload.selections
     },
     /** mark level as completed */
     levelCompleted(state: ProgressState, action: PayloadAction<{game: string, world: string, level: number}>) {
       addLevelProgress(state, action)
-      state.games[action.payload.game].data[action.payload.world][action.payload.level].completed = true
+      state.games[action.payload.game.toLowerCase()].data[action.payload.world][action.payload.level].completed = true
     },
     /** Set the list of rows where help is displayed */
     helpEdited(state: ProgressState, action: PayloadAction<{game: string, world: string, level: number, help: number[]}>) {
       addLevelProgress(state, action)
       console.debug(`!setting help to: ${action.payload.help}`)
-      state.games[action.payload.game].data[action.payload.world][action.payload.level].help = action.payload.help
+      state.games[action.payload.game.toLowerCase()].data[action.payload.world][action.payload.level].help = action.payload.help
     },
     /** delete all progress for this game */
     deleteProgress(state: ProgressState, action: PayloadAction<{game: string}>) {
-      state.games[action.payload.game] = {inventory: [], data: {}, openedIntro: true, difficulty: DEFAULT_DIFFICULTY}
+      state.games[action.payload.game.toLowerCase()] = {inventory: [], data: {}, openedIntro: true, difficulty: DEFAULT_DIFFICULTY}
     },
     /** delete progress for this level */
     deleteLevelProgress(state: ProgressState, action: PayloadAction<{game: string, world: string, level: number}>) {
       addLevelProgress(state, action)
-      state.games[action.payload.game].data[action.payload.world][action.payload.level] = initalLevelProgressState
+      state.games[action.payload.game.toLowerCase()].data[action.payload.world][action.payload.level] = initalLevelProgressState
     },
     /** load progress, e.g. from external import */
     loadProgress(state: ProgressState, action: PayloadAction<{game: string, data:GameProgressState}>) {
       console.debug(`setting data to:\n ${action.payload.data}`)
-      state.games[action.payload.game] = action.payload.data
+      state.games[action.payload.game.toLowerCase()] = action.payload.data
     },
     /** set the current inventory */
     changedInventory(state: ProgressState, action: PayloadAction<{game: string, inventory: string[]}>) {
       addGameProgress(state, action)
-      state.games[action.payload.game].inventory = action.payload.inventory
+      state.games[action.payload.game.toLowerCase()].inventory = action.payload.inventory
     },
     /** set the difficulty */
     changedDifficulty(state: ProgressState, action: PayloadAction<{game: string, difficulty: number}>) {
       addGameProgress(state, action)
-      state.games[action.payload.game].difficulty = action.payload.difficulty
+      state.games[action.payload.game.toLowerCase()].difficulty = action.payload.difficulty
     },
     /** set the difficulty */
     changedOpenedIntro(state: ProgressState, action: PayloadAction<{game: string, openedIntro: boolean}>) {
       addGameProgress(state, action)
-      state.games[action.payload.game].openedIntro = action.payload.openedIntro
+      state.games[action.payload.game.toLowerCase()].openedIntro = action.payload.openedIntro
     },
     /** set the typewriter mode */
     changeTypewriterMode(state: ProgressState, action: PayloadAction<{game: string, typewriterMode: boolean}>) {
       addGameProgress(state, action)
-      state.games[action.payload.game].typewriterMode = action.payload.typewriterMode
+      state.games[action.payload.game.toLowerCase()].typewriterMode = action.payload.typewriterMode
     }
   }
 })
@@ -138,74 +138,74 @@ export const progressSlice = createSlice({
 /** if the level does not exist, return default values */
 export function selectLevel(game: string, world: string, level: number) {
   return (state) =>{
-    if (!state.progress.games[game]) { return initalLevelProgressState }
+    if (!state.progress.games[game.toLowerCase()]) { return initalLevelProgressState }
-    if (!state.progress.games[game].data[world]) { return initalLevelProgressState }
+    if (!state.progress.games[game.toLowerCase()].data[world]) { return initalLevelProgressState }
-    if (!state.progress.games[game].data[world][level]) { return initalLevelProgressState }
+    if (!state.progress.games[game.toLowerCase()].data[world][level]) { return initalLevelProgressState }
-    return state.progress.games[game].data[world][level]
+    return state.progress.games[game.toLowerCase()].data[world][level]
   }
 }
 
 /** return the code of the current level */
 export function selectCode(game: string, world: string, level: number) {
   return (state) => {
-    return selectLevel(game, world, level)(state).code
+    return selectLevel(game.toLowerCase(), world, level)(state).code
   }
 }
 
 /** return the current inventory */
 export function selectInventory(game: string) {
   return (state) => {
-    if (!state.progress.games[game]) { return [] }
+    if (!state.progress.games[game.toLowerCase()]) { return [] }
-    return state.progress.games[game].inventory
+    return state.progress.games[game.toLowerCase()].inventory
   }
 }
 
 /** return the code of the current level */
 export function selectHelp(game: string, world: string, level: number) {
   return (state) => {
-    return selectLevel(game, world, level)(state).help
+    return selectLevel(game.toLowerCase(), world, level)(state).help
   }
 }
 
 /** return the selections made in the current level */
 export function selectSelections(game: string, world: string, level: number) {
   return (state) => {
-    return selectLevel(game, world, level)(state).selections
+    return selectLevel(game.toLowerCase(), world, level)(state).selections
   }
 }
 
 /** return whether the current level is clompleted */
 export function selectCompleted(game: string, world: string, level: number) {
   return (state) => {
-    return selectLevel(game, world, level)(state).completed
+    return selectLevel(game.toLowerCase(), world, level)(state).completed
   }
 }
 
 /** return progress for the current game if it exists */
 export function selectProgress(game: string) {
   return (state) => {
-    return state.progress.games[game] ?? null
+    return state.progress.games[game.toLowerCase()] ?? null
   }
 }
 
 /** return difficulty for the current game if it exists */
 export function selectDifficulty(game: string) {
   return (state) => {
-    return state.progress.games[game]?.difficulty ?? DEFAULT_DIFFICULTY
+    return state.progress.games[game.toLowerCase()]?.difficulty ?? DEFAULT_DIFFICULTY
   }
 }
 
 /** return whether the intro has been read */
 export function selectOpenedIntro(game: string) {
   return (state) => {
-    return state.progress.games[game]?.openedIntro
+    return state.progress.games[game.toLowerCase()]?.openedIntro
   }
 }
 
 /** return typewriter mode for the current game if it exists */
 export function selectTypewriterMode(game: string) {
   return (state) => {
-    return state.progress.games[game]?.typewriterMode ?? true
+    return state.progress.games[game.toLowerCase()]?.typewriterMode ?? true
   }
 }
 

client/src/state/store.ts

@@ -8,7 +8,7 @@ import { connection } from '../connection'
 import { apiSlice } from './api'
 import { progressSlice } from './progress'
 import { preferencesSlice } from "./preferences"
-import { saveState, savePreferences } from "./local_storage";
+import { saveState, savePreferences, removePreferences} from "./local_storage";
 
 
 export const store = configureStore({
@@ -29,7 +29,9 @@ export const store = configureStore({
 store.subscribe(
   debounce(() => {
     saveState(store.getState()[progressSlice.name]);
-    savePreferences(store.getState()[preferencesSlice.name]);
+
+    const preferencesState = store.getState()[preferencesSlice.name]
+    preferencesState.isSavePreferences ? savePreferences(preferencesState) : removePreferences()
   }, 800)
 );
 

doc/DOCUMENTATION.md

@@ -8,7 +8,7 @@ relays messages between the lean server and the client. `index.mjs` is the file
 be run, which is done for example using `pm2` or by calling `npm run start_server` or
 `npm run production`, see more later.
 
-The latter, "server", is the lean server which has two jobs. For one it produces the "gameserver"
+The latter, "server", is the lean server which has two jobs. For one, it produces the "gameserver"
 executable which is the lean server that handles the files the player plays on. The second job
 is to provide the lean commands which are used when creating a game. These are located in
 `Commands.lean`.
@@ -27,7 +27,7 @@ saved to lean env-extensions which the lean server has access to after loading t
 
 For games to be run successfully, it is important that the "gameserver" executable inside
 the game's `.lake` folder is actually built.
-Currently this happens through a lake-post-update-hook when calling `lake update -R` (in the game's folder), but if this fails, you can always build it manually by calling `lake build gameserver`.
+Currently, this happens through a lake-post-update-hook when calling `lake update -R` (in the game's folder), but if this fails, you can always build it manually by calling `lake build gameserver`.
 (both commands are to be executed in the game's directory!)
 
 ## Modifying the server
@@ -50,7 +50,7 @@ npm run start_client
 npm run production
 ```
 
-(in two separate terminals) to test the production modus of the server. This way it will only
+(in two separate terminals) to test the production mode of the server. This way it will only
 change once you build and restart the server.
 
 ### Modifying the lean server

doc/changelog.md

@@ -0,0 +1,9 @@
+# Changelog
+
+## v4.5.0
+
+### Breaking changes
+
+* Fix (#183): local store accepts case insensitive URL. The game progress has previously been saved under case sensitive URLs. You might need to recover old progress from your browser storage.
+
+## Other

doc/create_game.md

@@ -98,7 +98,7 @@ This introduction text is shown when one first enters a world.
 1. Use the template above and make sure you import all levels of this world.
 1. In `Game.lean` import the world with `import Game.Levels.MyWorld`
 
-Now you created a world with one level and added it🎉 The command `MakeGame` in `Game.lean` shows you any problems you might need to fix. Currently it shows
+Now you created a world with one level and added it🎉 The command `MakeGame` in `Game.lean` shows you any problems you might need to fix. Currently, it shows
 
 ```text
 No world introducing sorry, but required by MyWorld
@@ -125,26 +125,32 @@ The player has an inventory with tactics, theorems, and definitions that unlock
 
 ```lean
 NewTactic induction simp
-NewLemma Nat.zero_mul
+NewTheorem Nat.zero_mul
 NewDefinition Pow
 ```
 
 **Important:** All commands in this section 6a) expect the `Name` they take as input
-to be **fully qualified**. For example `NewLemma Nat.zero_mul` and not `NewLemma zero_mul`.
+to be **fully qualified**. For example `NewTheorem Nat.zero_mul` and not `NewTheorem zero_mul`.
 
 #### Doc entries
 
-You'll see a warning about a missing Lemma documentation. You can fix it by adding doc-entries like the following somewhere above it.
+You'll see a warning about a missing Theorem documentation. You can fix it by adding doc-entries like the following somewhere above it.
 
 ```lean
-LemmaDoc Nat.zero_mul as "zero_mul" in "Mul"
+/--
-"some description"
+some description
+-/
+TheoremDoc Nat.zero_mul as "zero_mul" in "Mul"
 
+/--
+some description
+-/
 TacticDoc simp
-"some description"
 
+/--
+some description
+-/
 DefinitionDoc Pow as "^"
-"some description"
 ```
 
 (e.g. you could also create a file `Game/Doc/MyTheorems.lean`, add there your documentation and import it)
@@ -156,7 +162,7 @@ If you do not provide any content for the inventory, the game will try to find a
 You have a few options to disable inventory items that have been unlocked in previous levels:
 
 ```lean
-DisableTactic, DisableLemma, OnlyTactic, OnlyLemma
+DisabledTactic, DisabledTheorem, OnlyTactic, OnlyTheorem
 ```
 
 have the same syntax as above. The former two disable items for this level, the latter two
@@ -164,7 +170,7 @@ disable all items except the ones specified.
 
 #### Theorem Tab
 
-Theorems are sorted into tabs. with `LemmaTab "Mul"` you specify which tab should be open by default in this level.
+Theorems are sorted into tabs. With `TheoremTab "Mul"` you specify which tab should be open by default in this level.
 
 #### HiddenTactic
 
@@ -179,12 +185,11 @@ and only `rw` would show up in the inventory.
 
 ### 6. b) Statement
 
-The statement is the exercise of the level. the basics work the same as they would in `example` or `theorem`. Note however, that you **must** do a tactic proof, i.e. the `:= by` is a hard-coded part of the syntax
+The statement is the exercise of the level. The basics work the same as they would in `example` or `theorem`. Note however, that you **must** do a tactic proof, i.e. the `:= by` is a hard-coded part of the syntax
 
 #### Name
 
-You can give your exercise a name: `Statement my_first_exercise (n : Nat) ...`. If you do so, it will be added to the inventory and be available in future levels.
+You can give your exercise a name: `Statement my_first_exercise (n : Nat) …`. If you do so, it will be added to the inventory and be available in future levels.
-
 You can but a `Statement` inside namespaces like you would with `theorem`.
 
 #### Doc String / Exercise statement
@@ -197,6 +202,28 @@ Statement ...
   sorry
 ```
 
+#### Local `let` definitions
+
+If you want to make a local definition/notation which only holds for this exercise (e.g.
+a function `f : ℤ → ℤ := fun x ↦ 2 * x`) the recommended way is to use a `let`-statement:
+
+```lean
+Statement (a : ℤ) (h : 0 < a) :
+    let f : ℤ → ℤ := fun x ↦ 2 * x
+    0 < f a := by
+  sorry
+```
+
+The game automatically `intros` such `let`-statements, such that you and the player will see
+the following initial proof state:
+
+```
+a: ℤ
+h: 0 < a
+f: ℤ → ℤ := fun x => 2 * x
+⊢ 0 < f a
+```
+
 #### Attributes
 
 You can add attributes as you would for a `theorem`. Most notably, you can make your named exercise a `simp` lemma:
@@ -210,12 +237,12 @@ Statement my_simp_lemma ...
 
 The proof must always be a tactic proof, i.e. `:= by` is a mandatory part of the syntax.
 
-There are a few extra tactics that help you structuring the proof:
+There are a few extra tactics that help you with structuring the proof:
 
 - `Hint`: You can use `Hint "text"` to display text if the goal state in-game matches
   the one where `Hint` is placed. For more options about hints, see below.
 - `Branch`: In the proof you can add a `Branch` that runs an alternative tactic sequence, which
-  helps setting `Hints` in different places. The `Branch` does not affect the main
+  helps to set `Hints` in different places. The `Branch` does not affect the main
   proof and does not need to finish any goals.
 - `Template`/`Hole`: Used to provide a sample proof template. Anything inside `Template`
   will be copied into the editor with all `Hole`s replaced with `sorry`. Note that
@@ -230,7 +257,7 @@ Most important for game development are probably the `Hints`.
 The hints will be displayed whenever the player's current goal matches the goal the hint is
 placed at inside the sample proof. You can use `Branch` to place hints in dead ends or alternative proof strands.
 
-Read [More about Hints](doc/hints.md) for how they work and what the options are.
+Read [More about Hints](hints.md) for how they work and what the options are.
 
 ### 6. e) Extra: Images
 You can add images on any layer of the game (i.e. game/world/level). These will be displayed in your game.
@@ -242,11 +269,11 @@ NOTE: At present, only the images for a world are displayed. They appear in the
 
 ## 7. Update your game
 
-In principle, it is as simple as modifying `lean-toolchain` to update your game to a new Lean version. However, you should read about the details in [Update An Existing Game](doc/update_game.md).
+In principle, it is as simple as modifying `lean-toolchain` to update your game to a new Lean version. However, you should read about the details in [Update An Existing Game](update_game.md).
 
 ## 8. Publish your game
 
-To publish your game on the official server, see [Publishing a game](doc/publish_game.md)
+To publish your game on the official server, see [Publishing a game](publish_game.md)
 
 There are a few more options you can add in `Game.lean` before the `MakeGame` command, which describe the tile that is visible on the server's landing page:
 
@@ -258,7 +285,7 @@ Prerequisites "NNG"
 CoverImage "images/cover.png"
 ```
 * `Languages`: Currently only a single language (capital English name). The tile will show a corresponding flag.
-* `CaptionShort`: One catch phrase. Appears above the image.
+* `CaptionShort`: One catchphrase. Appears above the image.
 * `CaptionLong`: 2-4 sentences to describe the game.
 * `Prerequisites` a list of other games you should play before this one, e.g. `Prerequisites "NNG" "STG"`. The game names are free-text.
 * `CoverImage`: You can create a folder `images/` and put images there for the game to use. The maximal ratio is ca. 500x200 (W x H) but it might be cropped horizontally on narrow screens.

doc/hints.md

@@ -10,7 +10,7 @@ Statement .... := by
   ...
 ```
 
-Note that hints are only **context-aware but not history-aware**. In particular they only look at the assumptions and the current goal. Player's might encounter hints in a different order - or not at all - if they decide to go for a unique proof idea. The `Branch` tactic helps placing hints outside the sample solution's proof.
+Note that hints are only **context-aware but not history-aware**. In particular, they only look at the assumptions and the current goal. Player's might encounter hints in a different order - or not at all - if they decide to go for a unique proof idea. The `Branch` tactic helps to place hints outside the sample solution's proof.
 
 ## 1. When do hints show?
 
@@ -19,7 +19,7 @@ sample solutions and the entire context from the sample solutions is present in
 player's context. The player's context may contain additional items.
 
 This means if you have multiple identical
-subgoals, you should only place a single hint in one of them and it will be displayed in
+subgoals, you should only place a single hint in one of them, and it will be displayed in
 all of them.
 
 However, identical (non-hidden) hints which where already present in the step
@@ -32,12 +32,12 @@ Hidden hints are not filtered.
 You can use `Branch` to place hints
 in dead ends or alternative proof strands.
 
-A proof inside a `Branch`-block is normally evaluated by lean but it's discarded at the end
+A proof inside a `Branch`-block is normally evaluated by lean, but it's discarded at the end
 so that no progress has been made on proofing the goal.
 
 ```
 Statement .... := by
-  Hint "Huse `rw` or `rewrite`."
+  Hint "use `rw` or `rewrite`."
   Branch
     rewrite [h]
     Hint "now you still need `rfl`"
@@ -86,4 +86,36 @@ create new assumptions.
 
 You can add use markdown to format your hints, for example you can use KaTex: `$\\iff$`
 
+**Escaping**: Generally, if you add text inside quotes `" "` (e.g. in `Hint`) you need to escape
+backslashes, but if you provide text inside a doc comment
+`/-- -/` (e.g. in the `Statement` description) you do not!
+
 TODO: Write a doc about latex/markdown options available.
+
+### Commutative diagrams
+
+Here is an example of how to write a commutative diagram in KaTeX:
+
+$$
+\begin{CD}
+      A  @>{f}>> B @<{g}<< C    \\
+  @V{h}VV    @V{i}VV   @V{j}VV \\
+      D  @<{k}<< E @>{l}>> F    \\
+  @A{m}AA    @A{n}AA   @V{p}VV \\
+      G  @<{q}<< H @>{r}>> I
+\end{CD}
+$$
+
+```
+$$
+\\begin{CD}
+      A  @>{f}>> B @<{g}<< C    \\\\
+  @V{h}VV    @V{i}VV   @V{j}VV \\\\
+      D  @<{k}<< E @>{l}>> F    \\\\
+  @A{m}AA    @A{n}AA   @V{p}VV \\\\
+      G  @<{q}<< H @>{r}>> I
+\\end{CD}
+$$
+```
+
+See https://www.jmilne.org/not/Mamscd.pdf

doc/publish_game.md

@@ -11,7 +11,7 @@ tab.
 
 ## 2. Import the game
 
-You call the URL that's listed under "What's Next?" in the latest action run. Explicitely you call
+You call the URL that's listed under "What's Next?" in the latest action run. Explicitly you call
 the URL of the form
 
 > adam.math.hhu.de/import/trigger/{USER}/{REPOSITORY}

doc/running_locally.md

@@ -2,6 +2,8 @@
 
 The installation instructions are not yet tested on Mac/Windows. Comments very welcome!
 
+Please also consult the [Troubleshooting Collection](troubleshoot.md), where some known pitfalls are collected.
+
 There are several options to play a game locally:
 
 1. VSCode Dev Container: needs `docker` installed on your machine
@@ -31,24 +33,14 @@ The template game [GameSkeleton](https://github.com/hhu-adam/GameSkeleton) conta
 
     * The first start will take a while, ca. 2-15 minutes. After the first
       start this should be very quickly.
-    * Once built, you can open http://localhost:3000 in your browser. which should load the game.
+    * Once built, you can open http://localhost:3000 in your browser, which should load the game.
 
 3.  **Editing Files** *(everytime)*:<br/>
     After editing some Lean files in VSCode, open VSCode's terminal (View > Terminal) and run `lake build`. Now you can reload your browser to see the changes.
 
-### Errors
-
-* If you don't get the pop-up, you might have disabled them and you can reenable it by
-  running the `remote-containers.showReopenInContainerNotificationReset` command in vscode.
-* If the starting the container fails, in particular with a message `Error: network xyz not found`,
-  you might have deleted stuff from docker via your shell. Try deleting the container and image
-  explicitely in VSCode (left side, "Docker" icon). Then reopen vscode and let it rebuild the
-  container. (this will again take some time)
-* On a working dev container setup, http://localhost:3000 should directly redirect you to http://localhost:3000/#/g/local/game, try if the latter is accessible.
-
 ## Codespaces
 
-You can work on your game using Github codespaces (click "Code" and then "Codespaces" and then "create codespace on main"). It it should run the game locally in the background. You can open it for example under "Ports" and clicking on "Open in Browser".
+You can work on your game using Github codespaces (click "Code" and then "Codespaces" and then "create codespace on main"). It should run the game locally in the background. You can open it for example under "Ports" and clicking on "Open in Browser".
 
 Note: You have to wait until npm started properly, which might take a good while.
 
@@ -108,6 +100,29 @@ Run the game:
 npm start
 ```
 
+You should see a message like this:
+```bash
+[server] > lean4-game@0.1.0 start_server
+[server] > (cd server && lake build) && (cd relay && cross-env NODE_ENV=development nodemon -e mjs --exec "node ./index.mjs")
+[server]
+[client]
+[client] > lean4-game@0.1.0 start_client
+[client] > cross-env NODE_ENV=development vite --host
+[client]
+[server] [nodemon] 3.0.#
+[server] [nodemon] to restart at any time, enter `rs`
+[server] [nodemon] watching path(s): *.*
+[server] [nodemon] watching extensions: mjs
+[server] [nodemon] starting `node ./index.mjs`
+[client]
+[client]   VITE v4.5.1  ready in \#\#\# ms
+[client]
+[client]   ➜  Local:   http://localhost:3000/
+[client]   ➜  Network: http://###.###.###.##:3000/
+[client] [vite-plugin-static-copy] Collected 7 items.
+[server] (node:#####) [DEP0040] [server] Listening on 8080
+```
+
 This takes a little time. Eventually, the game is available on http://localhost:3000/#/g/local/GameSkeleton. Replace `GameSkeleton` with the folder name of your local game.
 
 ## Modifying the GameServer

doc/server.md

@@ -6,7 +6,7 @@ In order to set up the server to allow imports, one needs to create a
 repos will suffice.
 
 You need to set the environment variables `LEAN4GAME_GITHUB_USER` and `LEAN4GAME_GITHUB_TOKEN`
-with your user name and access token. For example, you can seet these in `ecosystem.config.cjs` if
+with your user name and access token. For example, you can set these in `ecosystem.config.cjs` if
 you're using `pm2`
 
 Then people can call:
@@ -22,7 +22,7 @@ where you replace:
 
 > https://{website}/#/g/{owner}/{repo}
 
-## data management
+## Data management
 Everything downloaded remains in the folder `lean4game/games`.
-the subfolder `tmp` contains downloaded artifacts and can be deleted without loss.
+The subfolder `tmp` contains downloaded artifacts and can be deleted without loss.
 The other folders should only contain the built lean-games, sorted by owner and repo.

doc/troubleshoot.md

@@ -2,12 +2,21 @@
 
 Here are some issues experienced by users.
 
+- You can reset the lake projects involved (i.e. the `server/` folder here as well as your [game's folder](https://github.com/hhu-adam/GameSkeleton)) with the following commands:
+  ```
+  cd [THE PROJECT]
+  rm -rf .lake/
+  lake update -R
+  lake build
+  ```
+  If you experience problems related to Lean or lake, you should first try to reset it this way.
+
 # VSCode Dev-Container
-* If you don't get the pop-up, you might have disabled them and you can reenable it by
+* If you don't get the pop-up, you might have disabled them, and you can reenable it by
   running the `remote-containers.showReopenInContainerNotificationReset` command in vscode.
 * If the starting the container fails, in particular with a message `Error: network xyz not found`,
   you might have deleted stuff from docker via your shell. Try deleting the container and image
-  explicitely in VSCode (left side, "Docker" icon). Then reopen vscode and let it rebuild the
+  explicitly in VSCode (left side, "Docker" icon). Then reopen vscode and let it rebuild the
   container. (this will again take some time)
 * On a working dev container setup, http://localhost:3000 should directly redirect you to http://localhost:3000/#/g/local/game, try if the latter is accessible.
 
@@ -21,3 +30,8 @@ Here are known issues/pitfalls with the local setup using `npm`.
   [server] npm run start_server exited with code 1
   ```
   As a fix you might need to delete your manually set `CDPATH` environment variable.
+
+# Publication
+Errors concerning uploads to the server.
+
+* Your game overview loads but the server crashes on loading a level: Check your game's github action is identical to the [GameSkeleton's](https://github.com/hhu-adam/GameSkeleton/blob/main/.github/workflows/build.yml), in particular that there is a step about building the "`gameserver`-executable".

package.json

@@ -28,8 +28,8 @@
     "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#b91645a7b88814675ba9f99817436d0a2ce3a0ec",
+    "lean4web": "github:hhu-adam/lean4web#414d9e62638a392fca278761b4c61a1d2e138bc7",
-    "octokit": "^2.0.14",
+    "octokit": "^3.1.2",
     "path-browserify": "^1.0.1",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",

relay/index.mjs

@@ -19,7 +19,8 @@ import { importTrigger, importStatus } from './import.mjs'
 const queueLength = {
   "g/hhu-adam/robo": 2,
   "g/hhu-adam/nng4": 5,
-  "g/djvelleman/stg4": 2,
+  "g/djvelleman/stg4": 0,
+  "g/trequetrum/lean4game-logic": 0,
 }
 
 const __filename = url.fileURLToPath(import.meta.url);

server/GameServer.lean

@@ -11,7 +11,7 @@ unsafe def main : List String → IO UInt32 := fun args => do
 
   -- TODO: remove this argument
   if args[0]? == some "--server" then
-    MyServer.FileWorker.workerMain {} args
+    GameServer.FileWorker.workerMain {} args
   else
     e.putStrLn s!"Expected `--server`"
     return 1

server/GameServer/Commands.lean

@@ -2,6 +2,9 @@ import GameServer.Helpers
 import GameServer.Inventory
 import GameServer.Options
 import GameServer.SaveData
+import GameServer.Hints
+import GameServer.Tactic.LetIntros
+import I18n
 
 open Lean Meta Elab Command
 
@@ -32,16 +35,17 @@ elab "Level" level:num : command => do
 
 /-- Define the title of the current game/world/level. -/
 elab "Title" t:str : command => do
+  let title ← t.getString.translate
   match ← getCurLayer with
-  | .Level => modifyCurLevel fun level => pure {level with title := t.getString}
+  | .Level => modifyCurLevel fun level => pure {level with title := title}
-  | .World => modifyCurWorld  fun world => pure {world with title := t.getString}
+  | .World => modifyCurWorld  fun world => pure {world with title := title}
   | .Game => modifyCurGame  fun game => pure {game with
       title := t.getString
-      tile := {game.tile with title := t.getString}}
+      tile := {game.tile with title := title}}
 
 /-- Define the introduction of the current game/world/level. -/
 elab "Introduction" t:str : command => do
-  let intro := t.getString
+  let intro ← t.getString.translate
   match ← getCurLayer with
   | .Level => modifyCurLevel fun level => pure {level with introduction := intro}
   | .World => modifyCurWorld  fun world => pure {world with introduction := intro}
@@ -49,7 +53,7 @@ elab "Introduction" t:str : command => do
 
 /-- Define the info of the current game. Used for e.g. credits -/
 elab "Info" t:str : command => do
-  let info:= t.getString
+  let info ← t.getString.translate
   match ← getCurLayer with
   | .Level =>
     logError "Can't use `Info` in a level!"
@@ -81,7 +85,7 @@ elab "Image" t:str : command => do
 /-- Define the conclusion of the current game or current level if some
 building a level. -/
 elab "Conclusion" t:str : command => do
-  let conclusion := t.getString
+  let conclusion ← t.getString.translate
   match ← getCurLayer with
   | .Level => modifyCurLevel fun level => pure {level with conclusion := conclusion}
   | .World => modifyCurWorld  fun world => pure {world with conclusion := conclusion}
@@ -94,13 +98,13 @@ elab "Prerequisites" t:str* : command => do
 
 /-- Short caption for the game (1 sentence) -/
 elab "CaptionShort" t:str : command => do
-  let caption := t.getString
+  let caption ← t.getString.translate
   modifyCurGame fun game => pure {game with
     tile := {game.tile with short := caption}}
 
 /-- More detailed description what the game is about (2-4 sentences). -/
 elab "CaptionLong" t:str : command => do
-  let caption := t.getString
+  let caption ← t.getString.translate
   modifyCurGame fun game => pure {game with
     tile := {game.tile with long := caption}}
 
@@ -141,6 +145,7 @@ TacticDoc rw "`rw` stands for rewrite, etc. "
  -/
 elab doc:docComment ? "TacticDoc" name:ident content:str ? : command => do
   let doc ← parseDocCommentLegacy doc content
+  let doc ← doc.translate
   modifyEnv (inventoryTemplateExt.addEntry · {
     type := .Tactic
     name := name.getId
@@ -165,6 +170,7 @@ The theorem/definition to have the same fully qualified name as in mathlib.
 elab doc:docComment ? "TheoremDoc" name:ident "as" displayName:str "in" category:str content:str ? :
     command => do
   let doc ← parseDocCommentLegacy doc content
+  let doc ← doc.translate
   modifyEnv (inventoryTemplateExt.addEntry · {
     type := .Lemma
     name := name.getId
@@ -194,6 +200,7 @@ The theorem/definition to have the same fully qualified name as in mathlib.
  -/
 elab doc:docComment ? "DefinitionDoc" name:ident "as" displayName:str template:str ? : command => do
   let doc ← parseDocCommentLegacy doc template
+  let doc ← doc.translate
   modifyEnv (inventoryTemplateExt.addEntry · {
     type := .Definition
     name := name.getId,
@@ -340,6 +347,9 @@ elab doc:docComment ? attrs:Parser.Term.attributes ?
   let lvlIdx ← getCurLevelIdx
 
   let docContent ← parseDocComment doc
+  let docContent ← match docContent with
+  | none => pure none
+  | some d => d.translate
 
   -- Save the messages before evaluation of the proof.
   let initMsgs ← modifyGet fun st => (st.messages, { st with messages := {} })
@@ -355,36 +365,38 @@ elab doc:docComment ? attrs:Parser.Term.attributes ?
     collectUsedInventory proof
   | _ => throwError "expected `:=`"
 
+  -- extract the `tacticSeq` from `val` in order to add `let_intros` in front.
+  -- TODO: don't understand meta-programming enough to avoid having `let_intros`
+  -- duplicated three times below…
+  let tacticStx : TSyntax `Lean.Parser.Tactic.tacticSeq := match val with
+  | `(Parser.Command.declVal| := by $proof) => proof
+  | _ => panic "expected `:= by`"
+
   -- Add theorem to context.
   match statementName with
   | some name =>
     let env ← getEnv
-
     let fullName := (← getCurrNamespace) ++ name.getId
-
     if env.contains fullName then
       let origType := (env.constants.map₁.find! fullName).type
       -- TODO: Check if `origType` agrees with `sig` and output `logInfo` instead of `logWarning`
       -- in that case.
       logWarningAt name (m!"Environment already contains {fullName}! Only the existing " ++
       m!"statement will be available in later levels:\n\n{origType}")
-      let thmStatement ← `(command| $[$doc]? $[$attrs:attributes]? theorem $defaultDeclName $sig $val)
+      let thmStatement ← `(command| $[$doc]? $[$attrs:attributes]? theorem $defaultDeclName $sig := by {let_intros; $(⟨tacticStx⟩)})
       elabCommand thmStatement
       -- Check that statement has a docs entry.
       checkInventoryDoc .Lemma name (name := fullName) (template := docContent)
-
     else
-      let thmStatement ← `(command| $[$doc]? $[$attrs:attributes]? theorem $name $sig $val)
+      let thmStatement ← `(command| $[$doc]? $[$attrs:attributes]? theorem $name $sig := by {let_intros; $(⟨tacticStx⟩)})
       elabCommand thmStatement
       -- Check that statement has a docs entry.
       checkInventoryDoc .Lemma name (name := fullName) (template := docContent)
-
   | none =>
-    let thmStatement ← `(command| $[$doc]? $[$attrs:attributes]? theorem $defaultDeclName $sig $val)
+    let thmStatement ← `(command| $[$doc]? $[$attrs:attributes]? theorem $defaultDeclName $sig := by {let_intros; $(⟨tacticStx⟩)})
     elabCommand thmStatement
 
   let msgs := (← get).messages
-
   let mut hints := #[]
   let mut nonHintMsgs := #[]
   for msg in msgs.msgs do
@@ -396,12 +408,41 @@ elab doc:docComment ? attrs:Parser.Term.attributes ?
         .nest hidden $
         .compose (.ofGoal text) (.ofGoal goal) := msg.data then
       let hint ← liftTermElabM $ withMCtx ctx.mctx $ withLCtx ctx.lctx #[] $ withEnv ctx.env do
+
+        let goalDecl ← goal.getDecl
+        let fvars := goalDecl.lctx.decls.toArray.filterMap id |> Array.map (·.fvarId)
+
+        -- NOTE: This code about `hintFVarsNames` is duplicated from `RpcHandlers`
+        -- where the variable bijection is constructed, and they
+        -- need to be matching.
+        -- NOTE: This is a bit a hack of somebody who does not know how meta-programming works.
+        -- All we want here is a list of `userNames` for the `FVarId`s in `hintFVars`...
+        -- and we wrap them in `«{}»` here since I don't know how to do it later.
+        let mut hintFVarsNames : Array Expr := #[]
+        for fvar in fvars do
+          let name₁ ← fvar.getUserName
+          hintFVarsNames := hintFVarsNames.push <| Expr.fvar ⟨s!"«\{{name₁}}»"⟩
+
+        let text ← instantiateMVars (mkMVar text)
+
+        -- Evaluate the text in the `Hint`'s context to get the old variable names.
+        let rawText := (← GameServer.evalHintMessage text) hintFVarsNames
+        let ctx₂ := {env := ← getEnv, mctx := ← getMCtx, lctx := ← getLCtx, opts := {}}
+        let rawText : String ← (MessageData.withContext ctx₂ rawText).toString
+
         return {
           goal := ← abstractCtx goal
-          text := ← instantiateMVars (mkMVar text)
+          text := text
+          rawText := rawText
           strict := strict == 1
           hidden := hidden == 1
         }
+
+      -- Note: The current setup for hints is a bit convoluted, but for now we need to
+      -- send the text once through i18n to register it in the env extension.
+      -- This could probably be rewritten once i18n works fully.
+      let _ ← hint.rawText.translate
+
       hints := hints.push hint
     else
       nonHintMsgs := nonHintMsgs.push msg
@@ -440,6 +481,8 @@ elab doc:docComment ? attrs:Parser.Term.attributes ?
 
 /-! # Hints -/
 
+open GameServer in
+
 /-- A tactic that can be used inside `Statement`s to indicate in which proof states players should
 see hints. The tactic does not affect the goal state.
 -/

server/GameServer/EnvExtensions.lean

@@ -1,7 +1,13 @@
 import GameServer.AbstractCtx
 import GameServer.Graph
+import GameServer.Hints
 
+open GameServer
 
+-- TODO: Is there a better place?
+/-- Keywords that the server should not consider as tactics. -/
+def GameServer.ALLOWED_KEYWORDS : List String :=
+  ["with", "fun", "at", "only", "by", "generalizing"]
 
 /-- The default game name if `Game "MyGame"` is not used. -/
 def defaultGameName: String := "MyGame"
@@ -18,22 +24,6 @@ defined in this file.
 
 open Lean
 
-/-! ## Hints -/
-
-/-- A hint to help the user with a specific goal state -/
-structure GoalHintEntry where
-  goal : AbstractCtxResult
-  /-- Text of the hint as an expression of type `Array Expr → MessageData` -/
-  text : Expr
-  /-- If true, then hint should be hidden and only be shown on player's request -/
-  hidden : Bool := false
-  /-- If true, then the goal must contain only the assumptions specified in `goal` and no others -/
-  strict : Bool := false
-
-instance : Repr GoalHintEntry := {
-  reprPrec := fun a n => reprPrec a.text n
-}
-
 /-! ## Inventory (documentation)
 
 The inventory contains documentation that the user can access.

server/GameServer/FileWorker.lean

@@ -3,8 +3,11 @@ import Lean.Server.FileWorker
 import GameServer.Game
 import GameServer.ImportModules
 import GameServer.SaveData
+import GameServer.EnvExtensions
+import GameServer.Tactic.LetIntros
 
 namespace MyModule
+
 open Lean
 open Elab
 open Parser
@@ -48,7 +51,8 @@ partial def parseTactic (inputCtx : InputContext) (pmctx : ParserModuleContext)
 
 end MyModule
 
-namespace MyServer.FileWorker
+namespace GameServer.FileWorker
+
 open Lean
 open Lean.Server
 open Lean.Server.FileWorker
@@ -57,103 +61,142 @@ open IO
 open Snapshots
 open JsonRpc
 
-structure GameWorkerState :=
+/--
+Game-specific state to be packed on top of the `Server.FileWorker.WorkerState`
+used by the Lean server.
+-/
+structure WorkerState :=
+  /--
+  Collection of items which are considered unlocked.
+  Tactics and theorems are mixed together.
+  -/
   inventory : Array String
   /--
-  Check for tactics/theorems that are not unlocked.
+  Difficulty determines whether tactics/theorems can be locked.
-  0: no check
+  * 0: do not check
-  1: give warnings
+  * 1: give warnings when locked items are used
-  2: give errors
+  * 2: give errors when locked items are used
   -/
   difficulty : Nat
+  /--
+  `levelInfo` contains all the (static) information about the level which is not influenced
+  by the user's progress.
+  -/
   levelInfo : LevelInfo
-  deriving ToJson, FromJson
+deriving ToJson, FromJson
 
-abbrev GameWorkerM := StateT GameWorkerState Server.FileWorker.WorkerM
+/--
+Pack the our custom `WorkerState` on top of the normal worker monad
+`Server.FileWorker.WorkerM`.
+-/
+abbrev WorkerM := StateT WorkerState Server.FileWorker.WorkerM
 
 section Elab
 
-def addErrorMessage (info : SourceInfo) (inputCtx : Parser.InputContext) (s : MessageData) :
+/-- Add a message. use `(severity := .warning)` to specify the severity-/
+def addMessage (info : SourceInfo) (inputCtx : Parser.InputContext)
+    (severity := MessageSeverity.warning) (s : MessageData) :
     Elab.Command.CommandElabM Unit := do
   modify fun st => { st with
-      messages := st.messages.add {
+    messages := st.messages.add {
-        fileName := inputCtx.fileName
+      fileName := inputCtx.fileName
-        severity := MessageSeverity.error
+      severity := severity
-        pos      := inputCtx.fileMap.toPosition (info.getPos?.getD 0)
+      pos      := inputCtx.fileMap.toPosition (info.getPos?.getD 0)
-        data     := s
+      data     := s }}
-      }
-    }
 
 -- TODO: use HashSet for allowed tactics?
-/-- Find all tactics in syntax object that are forbidden according to a
+/--
-set `allowed` of allowed tactics. -/
+Find all tactics in syntax object that are forbidden according to a
-partial def findForbiddenTactics (inputCtx : Parser.InputContext)
+set `allowed` of allowed tactics.
-    (gameWorkerState : GameWorkerState) (stx : Syntax) :
+-/
-    Elab.Command.CommandElabM Unit := do
+partial def findForbiddenTactics (inputCtx : Parser.InputContext) (workerState : WorkerState)
-  let levelInfo := gameWorkerState.levelInfo
+    (stx : Syntax) : Elab.Command.CommandElabM Unit := do
+  let levelInfo := workerState.levelInfo
+  -- Parse the syntax object and look for tactics and declarations.
   match stx with
   | .missing => return ()
   | .node _info _kind args =>
+    -- Go inside a node.
     for arg in args do
-      findForbiddenTactics inputCtx gameWorkerState arg
+      findForbiddenTactics inputCtx workerState arg
   | .atom info val =>
-    -- ignore syntax elements that do not start with a letter
+    -- Atoms might be tactic names or other keywords.
-    -- and ignore "with" keyword
+    -- Note: We whitelisted known keywords because we cannot
-    let allowed := ["with", "fun", "at", "only", "by", "to"]
+    -- distinguish keywords from tactic names.
+    let allowed := GameServer.ALLOWED_KEYWORDS
+    -- Ignore syntax elements that do not start with a letter or are listed above.
     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`
+      -- Treat `simp?` and `simp!` like `simp`
+      let val := val.dropRightWhile (fun c => c == '!' || c == '?')
       match levelInfo.tactics.find? (·.name.toString == val) with
       | none =>
-        -- Note: This case means that the tactic will never be introduced in the game.
+        -- Tactic will never be introduced in the game.
-        match gameWorkerState.inventory.find? (· == val) with
+        match workerState.inventory.find? (· == val) with
+        | some _ =>
+          -- Tactic is in the inventory, allow it.
+          -- Note: This case shouldn't be possible...
+          pure ()
         | none =>
-          addWarningMessage info s!"You have not unlocked the tactic '{val}' yet!"
+          -- Tactic is not in the inventory.
-        | some _ => pure () -- tactic is in the inventory, allow it.
+          addMessageByDifficulty info s!"The tactic '{val}' is not available in this game!"
       | some tac =>
-        if tac.locked then
+        -- Tactic is introduced at some point in the game.
-          match gameWorkerState.inventory.find? (· == val) with
+        if tac.disabled then
+          -- Tactic is disabled in this level.
+          addMessageByDifficulty info s!"The tactic '{val}' is disabled in this level!"
+        else if tac.locked then
+          match workerState.inventory.find? (· == val) with
           | none =>
-            addWarningMessage info s!"You have not unlocked the tactic '{val}' yet!"
+            -- Tactic is marked as locked and not in the inventory.
-          | some _ => pure () -- tactic is in the inventory, allow it.
+            addMessageByDifficulty info s!"You have not unlocked the tactic '{val}' yet!"
-        else if tac.disabled then
+          | some _ =>
-          addWarningMessage info s!"The tactic '{val}' is disabled in this level!"
+            -- Tactic is in the inventory, allow it.
+            pure ()
   | .ident info _rawVal val _preresolved =>
-      let ns ←
+    -- Try to resolve the name
-        try resolveGlobalConst (mkIdent val)
+    let ns ←
-        catch | _ => pure [] -- catch "unknown constant" error
+      try resolveGlobalConst (mkIdent val)
-      for n in ns do
+      -- Catch "unknown constant" error
-        let some (.thmInfo ..) := (← getEnv).find? n
+      catch | _ => pure []
-          | return () -- not a theorem -> ignore
+    for n in ns do
+      let some (.thmInfo ..) := (← getEnv).find? n
+        -- Not a theorem, no checks needed.
+        | return ()
+      if some n = levelInfo.statementName then
         -- Forbid the theorem we are proving currently
-        if some n = levelInfo.statementName then
+        addMessage info inputCtx (severity := .error)
-          addErrorMessage info inputCtx s!"Structural recursion: you can't use '{n}' to proof itself!"
+          s!"Structural recursion: you can't use '{n}' to proof itself!"
+      let theoremsAndDefs := levelInfo.lemmas ++ levelInfo.definitions
+      match theoremsAndDefs.find? (·.name == n) with
+      | none =>
+        -- Theorem will never be introduced in this game
+        addMessageByDifficulty info s!"The theorem/definition '{n}' is not available in this game!"
+      | some thm =>
+        -- Theorem is introduced at some point in the game.
+        if thm.disabled then
+          -- Theorem is disabled in this level.
+          addMessageByDifficulty info s!"The theorem/definition '{n}' is disabled in this level!"
+        else if thm.locked then
+          match workerState.inventory.find? (· == n.toString) with
+          | none =>
+            -- Theorem is still locked.
+            addMessageByDifficulty info s!"You have not unlocked the theorem/definition '{n}' yet!"
+          | some _ =>
+            -- Theorem is in the inventory, allow it.
+            pure ()
 
-        let lemmasAndDefs := levelInfo.lemmas ++ levelInfo.definitions
+where addMessageByDifficulty (info : SourceInfo) (s : MessageData) :=
-        match lemmasAndDefs.find? (fun l => l.name == n) with
+  -- See `GameServer.FileWorker.WorkerState.difficulty`. Send nothing/warnings/errors
-        | none => addWarningMessage info s!"You have not unlocked the lemma/definition '{n}' yet!"
+  -- deppending on difficulty.
-        | some lem =>
+  let difficulty := workerState.difficulty
-          if lem.locked then
-            addWarningMessage info s!"You have not unlocked the lemma/definition '{n}' yet!"
-          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 := gameWorkerState.difficulty
   if difficulty > 0 then
-    modify fun st => { st with
+    addMessage info inputCtx (if difficulty > 1 then .error else .warning) s
-      messages := st.messages.add {
-        fileName := inputCtx.fileName
-        severity := if difficulty > 1 then MessageSeverity.error else MessageSeverity.warning
-        pos      := inputCtx.fileMap.toPosition (info.getPos?.getD 0)
-        data     := s
-      }
-    }
   else pure ()
--- where addErrorMessage (info : SourceInfo) (s : MessageData) :=
---   pure ()
 
 open Elab Meta Expr in
+
 def compileProof (inputCtx : Parser.InputContext) (snap : Snapshot) (hasWidgets : Bool)
-    (couldBeEndSnap : Bool) (gameWorkerState : GameWorkerState)
+    (couldBeEndSnap : Bool) (gameWorkerState : WorkerState)
     (initParams : Lsp.InitializeParams) : IO Snapshot := do
   -- Recognize end snap
   if inputCtx.input.atEnd snap.mpState.pos ∧ couldBeEndSnap then
@@ -216,8 +259,11 @@ def compileProof (inputCtx : Parser.InputContext) (snap : Snapshot) (hasWidgets
           let tacticStx := (#[skip] ++ tacticStx.getArgs ++ #[done]).map (⟨.⟩)
           let tacticStx := ← `(Lean.Parser.Tactic.tacticSeq| $[$(tacticStx)]*)
 
+          -- Always call `let_intros` to get rid `let` statements in the goal.
+          -- This makes the experience for the user much nicer and allows for local
+          -- definitions in the exercise.
           let cmdStx ← `(command|
-            theorem the_theorem $(level.goal) := by {$(⟨tacticStx⟩)} )
+            theorem the_theorem $(level.goal) := by {let_intros; $(⟨tacticStx⟩)} )
           Elab.Command.elabCommandTopLevel cmdStx)
       cmdCtx cmdStateRef
   let postNew := (← tacticCacheNew.get).post
@@ -262,7 +308,7 @@ where
   private def publishIleanInfo (method : String) (m : DocumentMeta) (hOut : FS.Stream)
       (snaps : Array Snapshot) : IO Unit := do
     let trees := snaps.map fun snap => snap.infoTree
-    let references := findModuleRefs m.text trees (localVars := true)
+    let references ← findModuleRefs m.text trees (localVars := true) |>.toLspModuleRefs
     let param := { version := m.version, references : LeanIleanInfoParams }
     hOut.writeLspNotification { method, param }
 
@@ -276,303 +322,400 @@ where
     uri : String
   deriving ToJson, FromJson
 
-  /-- Checks whether game level has been completed and sends a notification to the client -/
+structure GameDiagnostics where
-  def publishGameCompleted (m : DocumentMeta) (hOut : FS.Stream) (snaps : Array Snapshot) : IO Unit := do
+  diagnostics : List Diagnostic
-    -- check if there is any error or warning
+deriving ToJson, FromJson
-    for snap in snaps do
-      if snap.diagnostics.any fun d => d.severity? == some .error ∨ d.severity? == some .warning
-      then return
-    let param := { uri := m.uri : GameCompletedParams}
-    hOut.writeLspNotification { method := "$/game/completed", param }
 
-  /-- Elaborates the next command after `parentSnap` and emits diagnostics into `hOut`. -/
+structure GameParams where
-  private def nextSnap (ctx : WorkerContext) (m : DocumentMeta) (cancelTk : CancelToken)
+  uri : String
-      (gameWorkerState : GameWorkerState) (initParams : Lsp.InitializeParams)
+  diagnostics : GameDiagnostics
-      : AsyncElabM (Option Snapshot) := do
+deriving ToJson, FromJson
-    cancelTk.check
-    let s ← get
-    let .some lastSnap := s.snaps.back? | panic! "empty snapshots"
-    if lastSnap.isAtEnd then
-      publishGameCompleted m ctx.hOut s.snaps
-      publishDiagnostics m lastSnap.diagnostics.toArray ctx.hOut
-      publishProgressDone m ctx.hOut
-      -- This will overwrite existing ilean info for the file, in case something
-      -- went wrong during the incremental updates.
-      publishIleanInfoFinal m ctx.hOut s.snaps
-      return none
-    publishProgressAtPos m lastSnap.endPos ctx.hOut
-    -- Make sure that there is at least one snap after the head snap, so that
-    -- 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
-      gameWorkerState initParams
-    set { s with snaps := s.snaps.push snap }
-    -- TODO(MH): check for interrupt with increased precision
-    cancelTk.check
-    /- NOTE(MH): This relies on the client discarding old diagnostics upon receiving new ones
-      while preferring newer versions over old ones. The former is necessary because we do
-      not explicitly clear older diagnostics, while the latter is necessary because we do
-      not guarantee that diagnostics are emitted in order. Specifically, it may happen that
-      we interrupted this elaboration task right at this point and a newer elaboration task
-      emits diagnostics, after which we emit old diagnostics because we did not yet detect
-      the interrupt. Explicitly clearing diagnostics is difficult for a similar reason,
-      because we cannot guarantee that no further diagnostics are emitted after clearing
-      them. -/
-    -- NOTE(WN): this is *not* redundant even if there are no new diagnostics in this snapshot
-    -- because empty diagnostics clear existing error/information squiggles. Therefore we always
-    -- want to publish in case there was previously a message at this position.
-    publishDiagnostics m snap.diagnostics.toArray ctx.hOut
-    publishIleanInfoUpdate m ctx.hOut #[snap]
-    return some snap
 
-  /-- Elaborates all commands after the last snap (at least the header snap is assumed to exist), emitting the diagnostics into `hOut`. -/
+/-- WIP: publish diagnostics, all intermediate goals and if the game is completed. -/
-  def unfoldSnaps (m : DocumentMeta) (snaps : Array Snapshot) (cancelTk : CancelToken)
+def publishProofState (m : DocumentMeta) (snap : Snapshot) (initParams : Lsp.InitializeParams) (hOut : FS.Stream) :
-      (startAfterMs : UInt32) (gameWorkerState : GameWorkerState)
+    IO Unit := do
-      : ReaderT WorkerContext IO (AsyncList ElabTaskError Snapshot) := do
+  -- let text := m.text
-    let ctx ← read
+
-    let some headerSnap := snaps[0]? | panic! "empty snapshots"
+  -- -- `snap` is the one snapshot containing the entire proof.
-    if headerSnap.msgLog.hasErrors then
+  -- let mut goals : Array <| InteractiveGoalsWithHints := #[]
-      -- Treat header processing errors as fatal so users aren't swamped with
+  -- for pos in text.positions do
-      -- followup errors
+  --   let source := text.getLineBefore pos
-      publishProgressAtPos m headerSnap.beginPos ctx.hOut (kind := LeanFileProgressKind.fatalError)
+  --   -- iterate over all newlines in the proof and get the goals and hints at each position
-      publishIleanInfoFinal m ctx.hOut #[headerSnap]
+  --   if let goalsAtResult@(_ :: _) := snap.infoTree.goalsAt? text pos then
-      return AsyncList.ofList [headerSnap]
+  --     pure ()
-    else
+  --     let goalAtPos : List <| List InteractiveGoalWithHints ← goalsAtResult.mapM
-      -- This will overwrite existing ilean info for the file since this has a
+  --       fun { ctxInfo := ci, tacticInfo := tacticInfo, useAfter := useAfter, .. } => do
-      -- higher version number.
+  --         -- TODO: What does this function body do?
-      publishIleanInfoUpdate m ctx.hOut snaps
+  --         -- let ciAfter := { ci with mctx := ti.mctxAfter }
-      return AsyncList.ofList snaps.toList ++ AsyncList.delayed (← EIO.asTask (ε := ElabTaskError) (prio := .dedicated) do
+  --         let ci := if useAfter then
-        IO.sleep startAfterMs
+  --             { ci with mctx := tacticInfo.mctxAfter }
-        AsyncList.unfoldAsync (nextSnap ctx m cancelTk gameWorkerState ctx.initParams) { snaps })
+  --           else
+  --             { ci with mctx := tacticInfo.mctxBefore }
+  --         -- compute the interactive goals
+  --         let goalMvars : List MVarId ← ci.runMetaM {} do
+  --           return if useAfter then tacticInfo.goalsAfter else tacticInfo.goalsBefore
+
+  --         let interactiveGoals : List InteractiveGoalWithHints ← ci.runMetaM {} do
+  --           goalMvars.mapM fun goal => do
+  --             let hints ← findHints goal m initParams
+  --             let interactiveGoal ← goalToInteractive goal
+  --             return ⟨interactiveGoal, hints⟩
+  --         -- TODO: This code is way old, can it be deleted?
+  --         -- compute the goal diff
+  --         -- let goals ← ciAfter.runMetaM {} (do
+  --         --     try
+  --         --       Widget.diffInteractiveGoals useAfter ti goals
+  --         --     catch _ =>
+  --         --       -- fail silently, since this is just a bonus feature
+  --         --       return goals
+  --         -- )
+  --         return interactiveGoals
+  --     let goalAtPos : Array InteractiveGoalWithHints := ⟨goalAtPos.foldl (· ++ ·) []⟩
+  --     goals := goals.push ⟨goalAtPos, source⟩
+  --   else
+  --     -- No goals present
+  --     goals := goals.push default
+
+  -- -- Question: Is there a difference between the diags of this snap and the last snap?
+  -- -- Should we get the diags from there?
+  -- let diag : Array Widget.InteractiveDiagnostic := snap.interactiveDiags.toArray
+
+  -- -- Level is completed if there are no errrors or warnings
+  -- let completed : Bool := ¬ diag.any (fun d =>
+  --   d.severity? == some .error ∨ d.severity? == some .warning)
+
+  -- let param : ProofState := {
+  --   steps := goals,
+  --   diagnostics := diag,
+  --   completed := completed }
+
+  -- TODO
+  let param := { uri := m.uri : GameCompletedParams}
+
+
+  hOut.writeLspNotification { method := "$/game/publishProofState", param }
+
+/-- Checks whether game level has been completed and sends a notification to the client -/
+def publishGameCompleted (m : DocumentMeta) (hOut : FS.Stream) (snaps : Array Snapshot) : IO Unit := do
+  -- check if there is any error or warning
+  for snap in snaps do
+    if snap.diagnostics.any fun d => d.severity? == some .error ∨ d.severity? == some .warning
+    then return
+  let param := { uri := m.uri : GameCompletedParams}
+  hOut.writeLspNotification { method := "$/game/completed", param }
+
+/-- copied from `Lean.Server.FileWorker.nextCmdSnap`. -/
+-- @[inherit_doc Lean.Server.FileWorker.nextCmdSnap] -- cannot inherit from private
+private def nextCmdSnap (ctx : WorkerContext) (m : DocumentMeta) (cancelTk : CancelToken)
+    (gameWorkerState : WorkerState) (initParams : Lsp.InitializeParams) :
+    AsyncElabM (Option Snapshot) := do
+  cancelTk.check
+  let s ← get
+  let .some lastSnap := s.snaps.back? | panic! "empty snapshots"
+  if lastSnap.isAtEnd then
+    publishDiagnostics m lastSnap.diagnostics.toArray ctx.hOut
+    publishProgressDone m ctx.hOut
+    publishIleanInfoFinal m ctx.hOut s.snaps
+    return none
+  publishProgressAtPos m lastSnap.endPos ctx.hOut
+
+  -- (modified part)
+  -- Make sure that there is at least one snap after the head snap, so that
+  -- 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
+    gameWorkerState initParams
+
+  set { s with snaps := s.snaps.push snap }
+  cancelTk.check
+  -- publishProofState m snap initParams ctx.hOut
+  publishDiagnostics m snap.diagnostics.toArray ctx.hOut
+  publishIleanInfoUpdate m ctx.hOut #[snap]
+  return some snap
+
+-- Copied from `Lean.Server.FileWorker.unfoldCmdSnaps` using our own `nextCmdSnap`.
+@[inherit_doc Lean.Server.FileWorker.unfoldCmdSnaps]
+def unfoldCmdSnaps (m : DocumentMeta) (snaps : Array Snapshot) (cancelTk : CancelToken)
+    (startAfterMs : UInt32) (gameWorkerState : WorkerState)
+    : ReaderT WorkerContext IO (AsyncList ElabTaskError Snapshot) := do
+  let ctx ← read
+  let some headerSnap := snaps[0]? | panic! "empty snapshots"
+  if headerSnap.msgLog.hasErrors then
+    publishProgressAtPos m headerSnap.beginPos ctx.hOut (kind := LeanFileProgressKind.fatalError)
+    publishIleanInfoFinal m ctx.hOut #[headerSnap]
+    return AsyncList.ofList [headerSnap]
+  else
+    publishIleanInfoUpdate m ctx.hOut snaps
+    return AsyncList.ofList snaps.toList ++ AsyncList.delayed (← EIO.asTask (ε := ElabTaskError) (prio := .dedicated) do
+      IO.sleep startAfterMs
+      AsyncList.unfoldAsync (nextCmdSnap ctx m cancelTk gameWorkerState ctx.initParams) { snaps })
 
 end Elab
 
 section Updates
 
 /-- Given the new document, updates editable doc state. -/
-  def updateDocument (newMeta : DocumentMeta) : GameWorkerM Unit := do
+def updateDocument (newMeta : DocumentMeta) : WorkerM Unit := do
-    let s ← get
+  let s ← get
-    let ctx ← read
+  let ctx ← read
-    let oldDoc := (← StateT.lift get).doc
+  let oldDoc := (← StateT.lift get).doc
-    oldDoc.cancelTk.set
+  oldDoc.cancelTk.set
-    let initHeaderStx := (← StateT.lift get).initHeaderStx
+  let initHeaderStx := (← StateT.lift get).initHeaderStx
-    let (newHeaderStx, newMpState, _) ← Parser.parseHeader newMeta.mkInputContext
+  let (newHeaderStx, newMpState, _) ← Parser.parseHeader newMeta.mkInputContext
-    let cancelTk ← CancelToken.new
+  let cancelTk ← CancelToken.new
-    let headSnapTask := oldDoc.cmdSnaps.waitHead?
+  let headSnapTask := oldDoc.cmdSnaps.waitHead?
-    let newSnaps ← if initHeaderStx != newHeaderStx then
+  let newSnaps ← if initHeaderStx != newHeaderStx then
-      EIO.asTask (ε := ElabTaskError) (prio := .dedicated) do
+    EIO.asTask (ε := ElabTaskError) (prio := .dedicated) do
-        IO.sleep ctx.initParams.editDelay.toUInt32
+      IO.sleep ctx.initParams.editDelay.toUInt32
-        cancelTk.check
+      cancelTk.check
-        IO.Process.exit 2
+      IO.Process.exit 2
-    else EIO.mapTask (ε := ElabTaskError) (t := headSnapTask) (prio := .dedicated) fun headSnap?? => do
+  else EIO.mapTask (ε := ElabTaskError) (t := headSnapTask) (prio := .dedicated) fun headSnap?? => do
-      -- There is always at least one snapshot absent exceptions
+    -- There is always at least one snapshot absent exceptions
-      let some headSnap ← MonadExcept.ofExcept headSnap?? | panic! "empty snapshots"
+    let some headSnap ← MonadExcept.ofExcept headSnap?? | panic! "empty snapshots"
-      let newHeaderSnap := { headSnap with stx := newHeaderStx, mpState := newMpState }
+    let newHeaderSnap := { headSnap with stx := newHeaderStx, mpState := newMpState }
-      let changePos := oldDoc.meta.text.source.firstDiffPos newMeta.text.source
+    let changePos := oldDoc.meta.text.source.firstDiffPos newMeta.text.source
-      -- Ignore exceptions, we are only interested in the successful snapshots
+    -- Ignore exceptions, we are only interested in the successful snapshots
-      let (cmdSnaps, _) ← oldDoc.cmdSnaps.getFinishedPrefix
+    let (cmdSnaps, _) ← oldDoc.cmdSnaps.getFinishedPrefix
-      -- NOTE(WN): we invalidate eagerly as `endPos` consumes input greedily. To re-elaborate only
+    -- NOTE(WN): we invalidate eagerly as `endPos` consumes input greedily. To re-elaborate only
-      -- when really necessary, we could do a whitespace-aware `Syntax` comparison instead.
+    -- when really necessary, we could do a whitespace-aware `Syntax` comparison instead.
-      let mut validSnaps ← pure (cmdSnaps.takeWhile (fun s => s.endPos < changePos))
+    let mut validSnaps ← pure (cmdSnaps.takeWhile (fun s => s.endPos < changePos))
-      if h : validSnaps.length ≤ 1 then
+    if h : validSnaps.length ≤ 1 then
-        validSnaps := [newHeaderSnap]
+      validSnaps := [newHeaderSnap]
-      else
+    else
-        /- When at least one valid non-header snap exists, it may happen that a change does not fall
+      /- When at least one valid non-header snap exists, it may happen that a change does not fall
-           within the syntactic range of that last snap but still modifies it by appending tokens.
+          within the syntactic range of that last snap but still modifies it by appending tokens.
-           We check for this here. We do not currently handle crazy grammars in which an appended
+          We check for this here. We do not currently handle crazy grammars in which an appended
-           token can merge two or more previous commands into one. To do so would require reparsing
+          token can merge two or more previous commands into one. To do so would require reparsing
-           the entire file. -/
+          the entire file. -/
-        have : validSnaps.length ≥ 2 := Nat.gt_of_not_le h
+      have : validSnaps.length ≥ 2 := Nat.gt_of_not_le h
-        let mut lastSnap := validSnaps.getLast (by subst ·; simp at h)
+      let mut lastSnap := validSnaps.getLast (by subst ·; simp at h)
-        let preLastSnap :=
+      let preLastSnap :=
-          have : 0 < validSnaps.length := Nat.lt_of_lt_of_le (by decide) this
+        have : 0 < validSnaps.length := Nat.lt_of_lt_of_le (by decide) this
-          have : validSnaps.length - 2 < validSnaps.length := Nat.sub_lt this (by decide)
+        have : validSnaps.length - 2 < validSnaps.length := Nat.sub_lt this (by decide)
-          validSnaps[validSnaps.length - 2]
+        validSnaps[validSnaps.length - 2]
-        let newLastStx ← parseNextCmd newMeta.mkInputContext preLastSnap
+      let newLastStx ← parseNextCmd newMeta.mkInputContext preLastSnap
-        if newLastStx != lastSnap.stx then
+      if newLastStx != lastSnap.stx then
-          validSnaps := validSnaps.dropLast
+        validSnaps := validSnaps.dropLast
-      -- wait for a bit, giving the initial `cancelTk.check` in `nextCmdSnap` time to trigger
+    -- 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)
+    -- before kicking off any expensive elaboration (TODO: make expensive elaboration cancelable)
-      unfoldSnaps newMeta validSnaps.toArray cancelTk s ctx
+    unfoldCmdSnaps newMeta validSnaps.toArray cancelTk s ctx
-        (startAfterMs := ctx.initParams.editDelay.toUInt32)
+      (startAfterMs := ctx.initParams.editDelay.toUInt32)
-    StateT.lift <| modify fun st => { st with
+  StateT.lift <| modify fun st => { st with
-      doc := { meta := newMeta, cmdSnaps := AsyncList.delayed newSnaps, cancelTk }}
+    doc := { meta := newMeta, cmdSnaps := AsyncList.delayed newSnaps, cancelTk }}
 
 end Updates
 
 section Initialization
 
-  def DocumentMeta.mkInputContext (doc : DocumentMeta) : Parser.InputContext where
+def DocumentMeta.mkInputContext (doc : DocumentMeta) : Parser.InputContext where
-    input    := "" -- No header!
+  input    := "" -- No header!
-    fileName := (System.Uri.fileUriToPath? doc.uri).getD doc.uri |>.toString
+  fileName := (System.Uri.fileUriToPath? doc.uri).getD doc.uri |>.toString
-    fileMap  := default
+  fileMap  := default
 
-  def compileHeader (m : DocumentMeta) (hOut : FS.Stream) (opts : Options) (hasWidgets : Bool)
+/-- `gameDir` and `module` were added.
-      (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 := 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
+TODO: In general this resembles little similarity with the
-    let paths : List System.FilePath := System.SearchPath.parse out.stdout.trim
+original code, and I don't know why...
-    let currentDir ← IO.currentDir
+-/
-    let paths := paths.map fun p => currentDir / (gameDir : System.FilePath) / p
+-- @[inherit_doc Lean.Server.FileWorker.compileHeader]
+def compileHeader (m : DocumentMeta) (hOut : FS.Stream) (opts : Options) (hasWidgets : Bool)
+    (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 := gameDir, cmd := "lake", args := #["env","printenv","LEAN_PATH"] }
+  if out.exitCode != 0 then
+    throwServerError s!"Error while running Lake: {out.stderr}"
 
-    -- Set the search path
+  -- Make the paths relative to the current directory
-    Lean.searchPathRef.set paths
+  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
 
-    let env ← importModules' #[{ module := `Init : Import }, { module := module : Import }]
+  -- Set the search path
+  Lean.searchPathRef.set paths
 
-    -- use empty header
+  let env ← importModules' #[{ module := `Init : Import }, { module := module : Import }]
-    let (headerStx, headerParserState, msgLog) ← Parser.parseHeader
-      {m.mkInputContext with
-        input := ""
-        fileMap := FileMap.ofString ""}
-    (headerStx, ·) <$> EIO.asTask do
-      let mut srcSearchPath : SearchPath := paths --← initSrcSearchPath (← getBuildDir)
-      let headerEnv := env
-      let mut headerEnv := headerEnv
-      try
-        if let some path := System.Uri.fileUriToPath? m.uri then
-          headerEnv := headerEnv.setMainModule (← moduleNameOfFileName path none)
-      catch _ => pure ()
-      let cmdState := Elab.Command.mkState headerEnv {} opts
-      let cmdState := { cmdState with infoState := {
-        enabled := true
-        trees := #[Elab.InfoTree.context ({
-          env     := headerEnv
-          fileMap := m.text
-          ngen    := { namePrefix := `_worker }
-        }) (Elab.InfoTree.node
-            (Elab.Info.ofCommandInfo { elaborator := `header, stx := headerStx })
-            (headerStx[1].getArgs.toList.map (fun importStx =>
-              Elab.InfoTree.node (Elab.Info.ofCommandInfo {
-                elaborator := `import
-                stx := importStx
-              }) #[].toPArray'
-            )).toPArray'
-        )].toPArray'
-      }}
-      let headerSnap := {
-        beginPos := 0
-        stx := headerStx
-        mpState := {}
-        cmdState := cmdState
-        interactiveDiags := ← cmdState.messages.msgs.mapM (Widget.msgToInteractiveDiagnostic m.text · hasWidgets)
-        tacticCache := (← IO.mkRef {})
-      }
-      publishDiagnostics m headerSnap.diagnostics.toArray hOut
-      return (headerSnap, srcSearchPath)
 
-  def initializeWorker (meta : DocumentMeta) (i o e : FS.Stream) (initParams : InitializeParams) (opts : Options)
+  -- use empty header
-      (gameDir : String) (gameWorkerState : GameWorkerState) : IO (WorkerContext × WorkerState) := do
+  let (headerStx, headerParserState, msgLog) ← Parser.parseHeader
-    let clientHasWidgets := initParams.initializationOptions?.bind (·.hasWidgets?) |>.getD false
+    {m.mkInputContext with
+      input := ""
+      fileMap := FileMap.ofString ""}
+  (headerStx, ·) <$> EIO.asTask do
+    let mut srcSearchPath : SearchPath := paths --← initSrcSearchPath (← getBuildDir)
+    let headerEnv := env
+    let mut headerEnv := headerEnv
+    try
+      if let some path := System.Uri.fileUriToPath? m.uri then
+        headerEnv := headerEnv.setMainModule (← moduleNameOfFileName path none)
+    catch _ => pure ()
+    let cmdState := Elab.Command.mkState headerEnv {} opts
+    let cmdState := { cmdState with infoState := {
+      enabled := true
+      trees := #[Elab.InfoTree.context (.commandCtx {
+        env     := headerEnv
+        fileMap := m.text
+        ngen    := { namePrefix := `_worker }
+      }) (Elab.InfoTree.node
+          (Elab.Info.ofCommandInfo { elaborator := `header, stx := headerStx })
+          (headerStx[1].getArgs.toList.map (fun importStx =>
+            Elab.InfoTree.node (Elab.Info.ofCommandInfo {
+              elaborator := `import
+              stx := importStx
+            }) #[].toPArray'
+          )).toPArray'
+      )].toPArray'
+    }}
+    let headerSnap := {
+      beginPos := 0
+      stx := headerStx
+      mpState := {} -- was `headerParserState`
+      cmdState := cmdState
+      interactiveDiags := ← cmdState.messages.msgs.mapM (Widget.msgToInteractiveDiagnostic m.text · hasWidgets)
+      tacticCache := (← IO.mkRef {})
+    }
+    publishDiagnostics m headerSnap.diagnostics.toArray hOut
+    return (headerSnap, srcSearchPath)
 
-    let (headerStx, headerTask) ← compileHeader meta o opts (hasWidgets := clientHasWidgets)
+/-- Copied from `Lean.Server.FileWorker.initializeWorker`. Added `gameDir` and
-      gameDir gameWorkerState.levelInfo.module
+`gameWorkerState` arguments and use custom `unfoldCmdSnaps`. -/
-    let cancelTk ← CancelToken.new
+-- @[inherit_doc Lean.Server.FileWorker.initializeWorker]
-    let ctx :=
+def initializeWorker (meta : DocumentMeta) (i o e : FS.Stream) (initParams : InitializeParams) (opts : Options)
-      { hIn  := i
+    (gameDir : String) (gameWorkerState : WorkerState) : IO (WorkerContext × Server.FileWorker.WorkerState) := do
-        hOut := o
+  let clientHasWidgets := initParams.initializationOptions?.bind (·.hasWidgets?) |>.getD false
-        hLog := e
+  let (headerStx, headerTask) ← compileHeader meta o opts (hasWidgets := clientHasWidgets)
-        headerTask
+    (gameDir := gameDir) (module := gameWorkerState.levelInfo.module)
-        initParams
+  let cancelTk ← CancelToken.new
-        clientHasWidgets
+  let ctx := {
-      }
+    hIn  := i
-    let cmdSnaps ← EIO.mapTask (t := headerTask) (match · with
+    hOut := o
-      | Except.ok (s, _) => unfoldSnaps meta #[s] cancelTk gameWorkerState ctx (startAfterMs := 0)
+    hLog := e
-      | Except.error e   => throw (e : ElabTaskError))
+    headerTask
-    let doc : EditableDocument := { meta, cmdSnaps := AsyncList.delayed cmdSnaps, cancelTk }
+    initParams
-    return (ctx,
+    clientHasWidgets
-    { doc             := doc
+  }
-      initHeaderStx   := headerStx
+  let cmdSnaps ← EIO.mapTask (t := headerTask) (match · with
-      currHeaderStx      := headerStx
+    | Except.ok (s, _) => unfoldCmdSnaps meta #[s] cancelTk gameWorkerState ctx (startAfterMs := 0)
-      importCachingTask? := none
+    | Except.error e   => throw (e : ElabTaskError))
-      pendingRequests := RBMap.empty
+  let doc : EditableDocument := { meta, cmdSnaps := AsyncList.delayed cmdSnaps, cancelTk }
-      rpcSessions     := RBMap.empty
+  return (ctx, {
-    })
+    doc                := doc
+    initHeaderStx      := headerStx
+    currHeaderStx      := headerStx
+    importCachingTask? := none
+    pendingRequests    := RBMap.empty
+    rpcSessions        := RBMap.empty
+  })
 
 end Initialization
 
 section NotificationHandling
 
-  def handleDidChange (p : DidChangeTextDocumentParams) : GameWorkerM Unit := do
+/-- Copied from `Lean.Server.FileWorker.handleDidChange` but with our custom `WorkerM` and
-    let docId := p.textDocument
+`updateDocument` -/
-    let changes := p.contentChanges
+-- @[inherit_doc Lean.Server.FileWorker.handleDidChange]
-    let oldDoc := (← StateT.lift get).doc
+def handleDidChange (p : DidChangeTextDocumentParams) : WorkerM Unit := do
-    let some newVersion ← pure docId.version?
+  let docId := p.textDocument
-      | throwServerError "Expected version number"
+  let changes := p.contentChanges
-    if newVersion ≤ oldDoc.meta.version then
+  let oldDoc := (← StateT.lift get).doc -- needed a lift to our custom `WorkerM`
-      -- TODO(WN): This happens on restart sometimes.
+  let newVersion := docId.version?.getD 0
-      IO.eprintln s!"Got outdated version number: {newVersion} ≤ {oldDoc.meta.version}"
+  if ¬ changes.isEmpty then
-    else if ¬ changes.isEmpty then
+    let newDocText := foldDocumentChanges changes oldDoc.meta.text
-      let newDocText := foldDocumentChanges changes oldDoc.meta.text
+    -- modification: set the `DependencyBuildMode` from
-      updateDocument ⟨docId.uri, newVersion, newDocText, .always⟩
+    -- `oldDoc.meta.dependencyBuildMode` to `.always`
+    updateDocument ⟨docId.uri, newVersion, newDocText, .always⟩
 
 end NotificationHandling
 
 section MessageHandling
 
-  def handleNotification (method : String) (params : Json) : GameWorkerM Unit := do
+
-    let handle := fun paramType [FromJson paramType] (handler : paramType → GameWorkerM Unit) =>
+/--
-      (StateT.lift <| parseParams paramType params) >>= handler
+Modified notification handler.
-    match method with
+
-    | "textDocument/didChange" => handle DidChangeTextDocumentParams (handleDidChange)
+Compare to `Lean.Server.FileWorker.handleNotification`.
-    | "$/cancelRequest"        => handle CancelParams (handleCancelRequest ·)
+We use the modified `WorkerM` and use our custom `handleDidChange`.
-    | "$/setTrace"        => pure ()
+
-    | "$/lean/rpc/release"     => handle RpcReleaseParams (handleRpcRelease ·)
+-/
-    | "$/lean/rpc/keepAlive"   => handle RpcKeepAliveParams (handleRpcKeepAlive ·)
+def handleNotification (method : String) (params : Json) : WorkerM Unit := do
-    | _                        => throwServerError s!"Got unsupported notification method: {method}"
+  let handle := fun paramType [FromJson paramType] (handler : paramType → WorkerM Unit) =>
+    (StateT.lift <| parseParams paramType params) >>= handler
+  match method with
+  -- Modified `textDocument/didChange`, using a custom `handleDidChange`
+  | "textDocument/didChange" => handle DidChangeTextDocumentParams (handleDidChange)
+  -- unmodified
+  | "$/cancelRequest"        => handle CancelParams (handleCancelRequest ·)
+  -- unmodified
+  | "$/lean/rpc/release"     => handle RpcReleaseParams (handleRpcRelease ·)
+  -- unmodified
+  | "$/lean/rpc/keepAlive"   => handle RpcKeepAliveParams (handleRpcKeepAlive ·)
+  -- New. TODO: What is this for?
+  | "$/setTrace"        => pure ()
+  | _                        => throwServerError s!"Got unsupported notification method: {method}"
 
 end MessageHandling
 
 section MainLoop
-  partial def mainLoop : GameWorkerM Unit := do
-    let ctx ← read
-    let mut st ← StateT.lift get
-    let msg ← ctx.hIn.readLspMessage
-    let filterFinishedTasks (acc : PendingRequestMap) (id : RequestID) (task : Task (Except IO.Error Unit))
-        : IO PendingRequestMap := do
-      if (← hasFinished task) then
-        /- Handler tasks are constructed so that the only possible errors here
-        are failures of writing a response into the stream. -/
-        if let Except.error e := task.get then
-          throwServerError s!"Failed responding to request {id}: {e}"
-        pure <| acc.erase id
-      else pure acc
-    let pendingRequests ← st.pendingRequests.foldM (fun acc id task => filterFinishedTasks acc id task) st.pendingRequests
-    st := { st with pendingRequests }
 
-    -- Opportunistically (i.e. when we wake up on messages) check if any RPC session has expired.
+/--
-    for (id, seshRef) in st.rpcSessions do
+The main-loop. Copied from `Lean.Server.FileWorker.mainLoop`. Use custom `WorkerM` as well
-      let sesh ← seshRef.get
+as custom `handleNotification`.
-      if (← sesh.hasExpired) then
+-/
-        st := { st with rpcSessions := st.rpcSessions.erase id }
+--@[inherit_doc Lean.Server.FileWorker.mainLoop]
+partial def mainLoop : WorkerM Unit := do
+  let ctx ← read
+  let mut st ← StateT.lift get
+  let msg ← ctx.hIn.readLspMessage
+  -- Erase finished tasks if there are no errors.
+  let filterFinishedTasks (acc : PendingRequestMap) (id : RequestID) (task : Task (Except IO.Error Unit))
+      : IO PendingRequestMap := do
+    if (← hasFinished task) then
+      if let Except.error e := task.get then
+        throwServerError s!"Failed responding to request {id}: {e}"
+      pure <| acc.erase id
+    else pure acc
+  let pendingRequests ← st.pendingRequests.foldM (fun acc id task => filterFinishedTasks acc id task) st.pendingRequests
+  st := { st with pendingRequests }
+  for (id, seshRef) in st.rpcSessions do
+    let sesh ← seshRef.get
+    if (← sesh.hasExpired) then
+      st := { st with rpcSessions := st.rpcSessions.erase id }
+
+  set st
+  -- Process the RPC-message and restart main-loop.
+  match msg with
+  | Message.request id "shutdown" none =>
+    --added. TODO: why do we need that? Or has it just removed in Lean since when we started?
+    ctx.hOut.writeLspResponse ⟨id, Json.null⟩
+    mainLoop
+  | Message.request id method (some params) =>
+    -- Requests are handled by the unmodified lean server.
+    handleRequest id method (toJson params)
+    mainLoop
+  | Message.notification "exit" none =>
+    let doc := st.doc
+    doc.cancelTk.set
+    doc.cmdSnaps.cancel
+    return ()
+  | Message.notification method (some params) =>
+    -- Custom notification handler
+    handleNotification method (toJson params)
+    mainLoop
+  | _ =>
+    throwServerError s!"Got invalid JSON-RPC message: {toJson msg}"
 
-    set st
-    match msg with
-    | Message.request id method (some params) =>
-      handleRequest id method (toJson params)
-      mainLoop
-    | Message.notification "exit" none =>
-      let doc := st.doc
-      doc.cancelTk.set
-      return ()
-    | Message.request id "shutdown" none =>
-      ctx.hOut.writeLspResponse ⟨id, Json.null⟩
-      mainLoop
-    | Message.notification method (some params) =>
-      handleNotification method (toJson params)
-      mainLoop
-    | _ => throwServerError s!"Got invalid JSON-RPC message: {toJson msg}"
 end MainLoop
 
+/-- Modified from `Lean.Server.FileWorker.initAndRunWorker`.
+Added `gameDir` argument, -/
+-- @[inherit_doc Lean.Server.FileWorker.initAndRunWorker]
 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
+
+
+  -- BIG MODIFICATION
   let initRequest ← i.readLspRequestAs "initialize" Game.InitializeParams
   o.writeLspResponse {
     id     := initRequest.id
@@ -588,16 +731,16 @@ def initAndRunWorker (i o e : FS.Stream) (opts : Options) (gameDir : String) : I
   discard $ i.readLspNotificationAs "initialized" InitializedParams
   let ⟨_, param⟩ ← i.readLspNotificationAs "textDocument/didOpen" DidOpenTextDocumentParams
 
+
   let doc := param.textDocument
-  /- NOTE(WN): `toFileMap` marks line beginnings as immediately following
+  -- modification: using `.always`
-    "\n", which should be enough to handle both LF and CRLF correctly.
-    This is because LSP always refers to characters by (line, column),
-    so if we get the line number correct it shouldn't matter that there
-    is a CR there. -/
   let meta : DocumentMeta := ⟨doc.uri, doc.version, doc.text.toFileMap, .always⟩
   let e := e.withPrefix s!"[{param.textDocument.uri}] "
   let _ ← IO.setStderr e
   try
+
+
+    -- BIG MODIFICATION
     let game ← loadGameData gameDir
     -- TODO: We misuse the `rootUri` field to the gameName
     let rootUri? : Option String := some (toString game.name)
@@ -608,14 +751,17 @@ def initAndRunWorker (i o e : FS.Stream) (opts : Options) (gameDir : String) : I
     let levelInfo ← loadLevelData gameDir levelId.world levelId.level
     let some initializationOptions := initRequest.param.initializationOptions?
       | throwServerError "no initialization options found"
-    let gameWorkerState : GameWorkerState:= {
+    let gameWorkerState : WorkerState := {
       inventory := initializationOptions.inventory
       difficulty := initializationOptions.difficulty
       levelInfo
     }
     let (ctx, st) ← initializeWorker meta i o e initParams opts gameDir gameWorkerState
+    -- Run the main loop
     let _ ← StateRefT'.run (s := st) <| ReaderT.run (r := ctx) <|
       StateT.run (s := gameWorkerState) <| (mainLoop)
+
+
     return (0 : UInt32)
   catch e =>
     IO.eprintln e
@@ -625,6 +771,15 @@ def initAndRunWorker (i o e : FS.Stream) (opts : Options) (gameDir : String) : I
       message := e.toString }] o
     return (1 : UInt32)
 
+/--
+The main function. Simply wrapping `initAndRunWorker`.
+
+Copied from `Lean.Server.FileWorker.workerMain`. We add `args` as an argument to pass on
+the `gameDir`.
+
+TODO: The first arg `args[0]` is always expected to be `--server`. We could drop this completely.
+-/
+-- @[inherit_doc Lean.Server.FileWorker.workerMain]
 def workerMain (opts : Options) (args : List String): IO UInt32 := do
   let i ← IO.getStdin
   let o ← IO.getStdout
@@ -632,8 +787,6 @@ def workerMain (opts : Options) (args : List String): IO UInt32 := do
   try
     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
     e.flush
     IO.Process.exit exitCode.toUInt8
@@ -641,4 +794,4 @@ def workerMain (opts : Options) (args : List String): IO UInt32 := do
     e.putStrLn s!"worker initialization error: {err}"
     return (1 : UInt32)
 
-end MyServer.FileWorker
+end GameServer.FileWorker

server/GameServer/Helpers.lean

@@ -4,8 +4,6 @@ import Lean
 
 open Lean Meta Elab Command
 
-syntax hintArg := atomic(" (" (&"strict" <|> &"hidden") " := " withoutPosition(term) ")")
-
 /-! ## Doc Comment Parsing -/
 
 /-- Read a doc comment and get its content. Return `""` if no doc comment available. -/
@@ -85,23 +83,6 @@ def getStatementString (name : Name) : CommandElabM String := do
 syntax statementAttr := "(" &"attr" ":=" Parser.Term.attrInstance,* ")"
 -- TODO
 
-
-/-- Remove any spaces at the beginning of a new line -/
-partial def removeIndentation (s : String) : String :=
-  let rec loop (i : String.Pos) (acc : String) (removeSpaces := false) : String :=
-    let c := s.get i
-    let i := s.next i
-    if s.atEnd i then
-      acc.push c
-    else if removeSpaces && c == ' ' then
-      loop i acc (removeSpaces := true)
-    else if c == '\n' then
-      loop i (acc.push c) (removeSpaces := true)
-    else
-      loop i (acc.push c)
-  loop ⟨0⟩ ""
-
-
 /-! ## Loops in Graph-like construct
 
 TODO: Why are we not using graphs here but our own construct `HashMap Name (HashSet Name)`?

server/GameServer/Hints.lean

@@ -0,0 +1,54 @@
+import GameServer.AbstractCtx
+
+/-!
+This file contains anything related to the `Hint` tactic used to add hints to a game level.
+-/
+
+open Lean Meta Elab
+
+namespace GameServer
+
+syntax hintArg := atomic(" (" (&"strict" <|> &"hidden") " := " withoutPosition(term) ")")
+
+/-- A hint to help the user with a specific goal state -/
+structure GoalHintEntry where
+  goal : AbstractCtxResult
+  /-- Text of the hint as an expression of type `Array Expr → MessageData` -/
+  text : Expr
+  rawText : String
+  /-- If true, then hint should be hidden and only be shown on player's request -/
+  hidden : Bool := false
+  /-- If true, then the goal must contain only the assumptions specified in `goal` and no others -/
+  strict : Bool := false
+
+instance : Repr GoalHintEntry := {
+  reprPrec := fun a n => reprPrec a.text n
+}
+
+/-- For a hint `(hint : GoalHintEntry)` one uses `(← evalHintMessage hint.text) x`
+ where `(x : Array Expr)` contains the names of all the variables that should be inserted
+ in the text.
+
+ TODO: explain better. -/
+unsafe def evalHintMessageUnsafe : Expr → MetaM (Array Expr → MessageData) :=
+  evalExpr (Array Expr → MessageData)
+    (.forallE default (mkApp (mkConst ``Array [levelZero]) (mkConst ``Expr))
+      (mkConst ``MessageData) .default)
+
+@[implemented_by evalHintMessageUnsafe]
+def evalHintMessage : Expr → MetaM (Array Expr → MessageData) := fun _ => pure (fun _ => "")
+
+/-- Remove any spaces at the beginning of a new line -/
+partial def removeIndentation (s : String) : String :=
+  let rec loop (i : String.Pos) (acc : String) (removeSpaces := false) : String :=
+    let c := s.get i
+    let i := s.next i
+    if s.atEnd i then
+      acc.push c
+    else if removeSpaces && c == ' ' then
+      loop i acc (removeSpaces := true)
+    else if c == '\n' then
+      loop i (acc.push c) (removeSpaces := true)
+    else
+      loop i (acc.push c)
+  loop ⟨0⟩ ""

server/GameServer/InteractiveGoal.lean

@@ -1,74 +1,19 @@
-/- This file is mostly copied from `Lean/Widget/InteractiveGoal.lean`. -/
+import GameServer.Structures
 
-import Lean.Widget.InteractiveGoal
+/-!
+This file is a modified copy of `Lean.Widget.InteractiveGoal`.
 
-/-! Functionality related to tactic-mode and term-mode goals with embedded `CodeWithInfos`. -/
+Note that the structures have been moved to `Structures.lean`, but most of the
+functions here must be duplicated from `Lean.Widget.InteractiveGoal` in order
+to use the duplicated structures.
+-/
 
 namespace GameServer
+
 open Lean Lean.Widget Lean.Server
 
-structure GameHint where
+-- duplicated with custom `InteractiveGoalCore`
-  text : String
+-- @[inherit_doc Lean.Widget.InteractiveGoalCore.pretty]
-  hidden : Bool
-deriving FromJson, ToJson
-
-/-- In the infoview, if multiple hypotheses `h₁`, `h₂` have the same type `α`, they are rendered
-as `h₁ h₂ : α`. We call this a 'hypothesis bundle'. We use `none` instead of `some false` for
-booleans to save space in the json encoding. -/
-structure InteractiveHypothesisBundle where
-  /-- The user-friendly name for each hypothesis. -/
-  names : Array Name
-  /-- The ids for each variable. Should have the same length as `names`. -/
-  fvarIds : Array FVarId
-  type : CodeWithInfos
-  /-- The value, in the case the hypothesis is a `let`-binder. -/
-  val? : Option CodeWithInfos := none
-  /-- The hypothesis is a typeclass instance. -/
-  isInstance? : Option Bool := none
-  /-- The hypothesis is a type. -/
-  isType? : Option Bool := none
-  /-- The hypothesis's type is of type `Prop` -/
-  isAssumption? : Option Bool := none
-  /-- If true, the hypothesis was not present on the previous tactic state.
-  Only present in tactic-mode goals. -/
-  isInserted? : Option Bool := none
-  /-- If true, the hypothesis will be removed in the next tactic state.
-  Only present in tactic-mode goals. -/
-  isRemoved? : Option Bool := none
-  deriving Inhabited, RpcEncodable
-
-/-- The shared parts of interactive term-mode and tactic-mode goals. -/
-structure InteractiveGoalCore where
-  hyps : Array InteractiveHypothesisBundle
-  /-- The target type. -/
-  type : CodeWithInfos
-  /-- Metavariable context that the goal is well-typed in. -/
-  ctx : WithRpcRef Elab.ContextInfo
-
-/-- An interactive tactic-mode goal. -/
-structure InteractiveGoal extends InteractiveGoalCore where
-  /-- The name `foo` in `case foo`, if any. -/
-  userName? : Option String
-  /-- The symbol to display before the target type. Usually `⊢ ` but `conv` goals use `∣ `
-  and it could be extended. -/
-  goalPrefix : String
-  /-- Identifies the goal (ie with the unique name of the MVar that it is a goal for.) -/
-  mvarId : MVarId
-  /-- If true, the goal was not present on the previous tactic state. -/
-  isInserted? : Option Bool := none
-  /-- If true, the goal will be removed on the next tactic state. -/
-  isRemoved? : Option Bool := none
-  hints : Array GameHint := #[]
-  deriving RpcEncodable
-
-/-- An interactive term-mode goal. -/
-structure InteractiveTermGoal extends InteractiveGoalCore where
-  /-- Syntactic range of the term. -/
-  range : Lsp.Range
-  /-- Information about the term whose type is the term-mode goal. -/
-  term : WithRpcRef Elab.TermInfo
-  deriving RpcEncodable
-
 def InteractiveGoalCore.pretty (g : InteractiveGoalCore) (userName? : Option String)
     (goalPrefix : String) : Format := Id.run do
   let indent := 2 -- Use option
@@ -79,8 +24,7 @@ def InteractiveGoalCore.pretty (g : InteractiveGoalCore) (userName? : Option Str
     ret := addLine ret
     let names := hyp.names
         |>.toList
-        |>.filter (not ∘ Name.isAnonymous)
+        |>.filter (· != toString Name.anonymous)
-        |>.map toString
         |> " ".intercalate
     match names with
     | "" =>
@@ -97,16 +41,24 @@ where
   addLine (fmt : Format) : Format :=
     if fmt.isNil then fmt else fmt ++ Format.line
 
+-- duplicated with custom `InteractiveGoal`
+-- @[inherit_doc Lean.Widget.InteractiveGoal.pretty]
 def InteractiveGoal.pretty (g : InteractiveGoal) : Format :=
   g.toInteractiveGoalCore.pretty g.userName? g.goalPrefix
 
+-- duplicated with custom `InteractiveTermGoal`
+-- @[inherit_doc Lean.Widget.InteractiveTermGoal.pretty]
 def InteractiveTermGoal.pretty (g : InteractiveTermGoal) : Format :=
   g.toInteractiveGoalCore.pretty none "⊢ "
 
+-- duplicated with custom `InteractiveGoal`
+-- @[inherit_doc Lean.Widget.InteractiveGoals]
 structure InteractiveGoals where
   goals : Array InteractiveGoal
   deriving RpcEncodable
 
+-- duplicated with custom `InteractiveGoals`
+-- @[inherit_doc Lean.Widget.InteractiveGoals.append]
 def InteractiveGoals.append (l r : InteractiveGoals) : InteractiveGoals where
   goals := l.goals ++ r.goals
 
@@ -114,9 +66,10 @@ instance : Append InteractiveGoals := ⟨InteractiveGoals.append⟩
 instance : EmptyCollection InteractiveGoals := ⟨{goals := #[]}⟩
 
 open Meta in
-/-- Extend an array of hypothesis bundles with another bundle. -/
+-- duplicated with custom `InteractiveHypothesisBundle` and therefore added `isAssumption?`
+@[inherit_doc Lean.Widget.addInteractiveHypothesisBundle]
 def addInteractiveHypothesisBundle (hyps : Array InteractiveHypothesisBundle)
-    (ids : Array (Name × FVarId)) (type : Expr) (value? : Option Expr := none) :
+    (ids : Array (String × FVarId)) (type : Expr) (value? : Option Expr := none) :
     MetaM (Array InteractiveHypothesisBundle) := do
   if ids.size == 0 then
     throwError "Can only add a nonzero number of ids as an InteractiveHypothesisBundle."
@@ -125,11 +78,12 @@ def addInteractiveHypothesisBundle (hyps : Array InteractiveHypothesisBundle)
   return hyps.push {
     names
     fvarIds
-    type           := (← ppExprTagged type)
+    type        := (← ppExprTagged type)
-    val?           := (← value?.mapM ppExprTagged)
+    val?        := (← value?.mapM ppExprTagged)
-    isInstance?    := if (← isClass? type).isSome then true else none
+    isInstance? := if (← isClass? type).isSome then true else none
-    isType?        := if (← instantiateMVars type).isSort then true else none
+    isType?     := if (← instantiateMVars type).isSort then true else none
-    isAssumption?  := if (← inferType type).isProp then true else none
+    -- Added:
+    isAssumption? := if (← inferType type).isProp then true else none
   }
 
 open Meta in
@@ -142,13 +96,15 @@ def withGoalCtx (goal : MVarId) (action : LocalContext → MetavarDecl → n α)
   withLCtx lctx mvarDecl.localInstances (action lctx mvarDecl)
 
 open Meta in
-/-- A variant of `Meta.ppGoal` which preserves subexpression information for interactivity. -/
+
-def goalToInteractive (mvarId : MVarId) (hints : Array GameHint): MetaM InteractiveGoal := do
+-- Duplicated from `Lean.Widget.goalToInteractive` with custom structures
+@[inherit_doc Lean.Widget.goalToInteractive]
+def goalToInteractive (mvarId : MVarId) : MetaM InteractiveGoal := do
   let ppAuxDecls := pp.auxDecls.get (← getOptions)
   let ppImplDetailHyps := pp.implementationDetailHyps.get (← getOptions)
   let showLetValues := pp.showLetValues.get (← getOptions)
   withGoalCtx mvarId fun lctx mvarDecl => do
-    let pushPending (ids : Array (Name × FVarId)) (type? : Option Expr) (hyps : Array InteractiveHypothesisBundle)
+    let pushPending (ids : Array (String × FVarId)) (type? : Option Expr) (hyps : Array InteractiveHypothesisBundle)
         : MetaM (Array InteractiveHypothesisBundle) :=
       if ids.isEmpty then
         pure hyps
@@ -156,7 +112,7 @@ def goalToInteractive (mvarId : MVarId) (hints : Array GameHint): MetaM Interact
         match type? with
         | none      => pure hyps
         | some type => addInteractiveHypothesisBundle hyps ids type
-    let mut varNames : Array (Name × FVarId) := #[]
+    let mut varNames : Array (String × FVarId) := #[]
     let mut prevType? : Option Expr := none
     let mut hyps : Array InteractiveHypothesisBundle := #[]
     for localDecl in lctx do
@@ -165,7 +121,7 @@ def goalToInteractive (mvarId : MVarId) (hints : Array GameHint): MetaM Interact
       else
         match localDecl with
         | LocalDecl.cdecl _index fvarId varName type _ _ =>
-          let varName := varName.simpMacroScopes
+          let varName := toString varName
           let type ← instantiateMVars type
           if prevType? == none || prevType? == some type then
             varNames := varNames.push (varName, fvarId)
@@ -174,7 +130,7 @@ def goalToInteractive (mvarId : MVarId) (hints : Array GameHint): MetaM Interact
             varNames := #[(varName, fvarId)]
           prevType? := some type
         | LocalDecl.ldecl _index fvarId varName type val _ _ => do
-          let varName := varName.simpMacroScopes
+          let varName := toString varName
           hyps ← pushPending varNames prevType? hyps
           let type ← instantiateMVars type
           let val? ← if showLetValues then pure (some (← instantiateMVars val)) else pure none
@@ -190,11 +146,10 @@ def goalToInteractive (mvarId : MVarId) (hints : Array GameHint): MetaM Interact
     return {
       hyps
       type := goalFmt
-      ctx := ⟨← Elab.ContextInfo.save⟩
+      ctx := ⟨{← Elab.CommandContextInfo.save with }⟩
       userName?
       goalPrefix := getGoalPrefix mvarDecl
       mvarId
-      hints
     }
 
 end GameServer

server/GameServer/Inventory.lean

@@ -121,7 +121,7 @@ partial def collectUsedInventory (stx : Syntax) (acc : UsedInventory := {}) : Co
   | .atom _info val =>
     -- ignore syntax elements that do not start with a letter
     -- and ignore some standard keywords
-    let allowed := ["with", "fun", "at", "only", "by"]
+    let allowed := GameServer.ALLOWED_KEYWORDS
     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`
       return {acc with tactics := acc.tactics.insert val}

server/GameServer/RpcHandlers.lean

@@ -1,5 +1,7 @@
 import GameServer.EnvExtensions
 import GameServer.InteractiveGoal
+import Std.Data.Array.Init.Basic
+import GameServer.Hints
 
 open Lean
 open Server
@@ -7,7 +9,6 @@ open Widget
 open RequestM
 open Meta
 
-
 /-! ## GameGoal -/
 
 namespace GameServer
@@ -103,49 +104,236 @@ def matchDecls (patterns : Array Expr) (fvars : Array Expr) (strict := true) (in
   then return some bij
   else return none
 
-unsafe def evalHintMessageUnsafe : Expr → MetaM (Array Expr → MessageData) :=
-  evalExpr (Array Expr → MessageData)
-    (.forallE default (mkApp (mkConst ``Array [levelZero]) (mkConst ``Expr))
-      (mkConst ``MessageData) .default)
-
-@[implemented_by evalHintMessageUnsafe]
-def evalHintMessage : Expr → MetaM (Array Expr → MessageData) := fun _ => pure (fun _ => "")
-
 open Meta in
 /-- Find all hints whose trigger matches the current goal -/
-def findHints (goal : MVarId) (doc : FileWorker.EditableDocument) (initParams : Lsp.InitializeParams) : MetaM (Array GameHint) := do
+def findHints (goal : MVarId) (m : DocumentMeta) (initParams : Lsp.InitializeParams) : MetaM (Array GameHint) := do
   goal.withContext do
-    let some level ← getLevelByFileName? initParams doc.meta.mkInputContext.fileName
+    let some level ← getLevelByFileName? initParams m.mkInputContext.fileName
-      | throwError "Level not found: {doc.meta.mkInputContext.fileName}"
+      | throwError "Level not found: {m.mkInputContext.fileName}"
     let hints ← level.hints.filterMapM fun hint => do
       openAbstractCtxResult hint.goal fun hintFVars hintGoal => do
         if let some fvarBij := matchExpr (← instantiateMVars $ hintGoal) (← instantiateMVars $ ← inferType $ mkMVar goal)
         then
-          let lctx := (← goal.getDecl).lctx
+
-          if let some bij ← matchDecls hintFVars lctx.getFVars (strict := hint.strict) (initBij := fvarBij)
+          -- NOTE: This code for `hintFVarsNames` is also duplicated in the
+          -- "Statement" command, where `hint.rawText` is created. They need to be matching.
+          -- NOTE: This is a bit a hack of somebody who does not know how meta-programming works.
+          -- All we want here is a list of `userNames` for the `FVarId`s in `hintFVars`...
+          -- and we wrap them in `«{}»` here since I don't know how to do it later.
+          let mut hintFVarsNames : Array Expr := #[]
+          for fvar in hintFVars do
+            let name₁ ← fvar.fvarId!.getUserName
+            hintFVarsNames := hintFVarsNames.push <| Expr.fvar ⟨s!"«\{{name₁}}»"⟩
+
+          let lctx := (← goal.getDecl).lctx -- the player's local context
+          if let some bij ← matchDecls hintFVars lctx.getFVars
+            (strict := hint.strict) (initBij := fvarBij)
           then
             let userFVars := hintFVars.map fun v => bij.forward.findD v.fvarId! v.fvarId!
+            -- Evaluate the text in the player's context to get the new variable names.
             let text := (← evalHintMessage hint.text) (userFVars.map Expr.fvar)
             let ctx := {env := ← getEnv, mctx := ← getMCtx, lctx := lctx, opts := {}}
             let text ← (MessageData.withContext ctx text).toString
-            return some { text := text, hidden := hint.hidden }
+
+            -- Here we map the goal's variable names to the player's variable names.
+            let mut varNames : Array <| Name × Name := #[]
+            for (fvar₁, fvar₂) in bij.forward.toArray do
+              -- get the `userName` of the fvar in the opened local context of the hint.
+              let name₁ ← fvar₁.getUserName
+              -- get the `userName` in the player's local context.
+              let name₂ := (lctx.get! fvar₂).userName
+              varNames := varNames.push (name₁, name₂)
+
+            return some {
+              text := text,
+              hidden := hint.hidden,
+              rawText := hint.rawText,
+              varNames := varNames }
+
           else return none
         else
           return none
     return hints
 
-open RequestM in
+def filterUnsolvedGoal (a : Array InteractiveDiagnostic) :
-def getInteractiveGoals (p : Lsp.PlainGoalParams) : RequestM (RequestTask (Option InteractiveGoals)) := do
+    Array InteractiveDiagnostic :=
+  a.filter (fun d => match d.message with
+  | .append ⟨(.text x) :: _⟩ => x != "unsolved goals"
+  | _ => true)
+
+-- TODO: no need to have `RequestM`, just anything where `mut` works
+/-- Add custom diagnostics about whether the level is completed. -/
+def completionDiagnostics (goalCount : Nat) (prevGoalCount : Nat) (completed : Bool)
+    (completedWithWarnings : Bool) (pos : Lsp.Position)
+    (startDiags : Array InteractiveDiagnostic := #[]) :
+    RequestM <| Array InteractiveDiagnostic := do
+  let mut out : Array InteractiveDiagnostic := startDiags
+  if goalCount == 0 then
+    if completed then
+      out := out.push {
+        message := .text "level completed! 🎉"
+        range := {
+          start := pos
+          «end» := pos
+          }
+        severity? := Lsp.DiagnosticSeverity.information }
+    else if completedWithWarnings then
+      out := out.push {
+        message := .text "level completed with warnings… 🎭"
+        range := {
+          start := pos
+          «end» := pos
+          }
+        severity? := Lsp.DiagnosticSeverity.information }
+    else
+      pure ()
+  else if goalCount < prevGoalCount then
+    -- If there is any errors, goals might vanish without being 'solved'
+    -- so showing the message "intermediate goal solved" would be confusing.
+    if (¬ (filterUnsolvedGoal startDiags).any (·.severity? == some .error)) then
+      out := out.push {
+        message := .text "intermediate goal solved! 🎉"
+        range := {
+          start := pos
+          «end» := pos
+          }
+        severity? := Lsp.DiagnosticSeverity.information
+      }
+
+  return out
+
+
+/-- Request that returns the goals at the end of each line of the tactic proof
+plus the diagnostics (i.e. warnings/errors) for the proof.
+ -/
+def getProofState (_ : Lsp.PlainGoalParams) : RequestM (RequestTask (Option ProofState)) := do
   let doc ← readDoc
   let rc ← readThe RequestContext
   let text := doc.meta.text
+
+  withWaitFindSnap
+    doc
+    -- TODO (Alex): I couldn't find a good condition to find the correct snap. So we are looking
+    -- for the first snap with goals here.
+    -- NOTE (Jon): The entire proof is in one snap, so hoped that Position `0` is good enough.
+    (fun snap => ¬ (snap.infoTree.goalsAt? doc.meta.text 0).isEmpty)
+    (notFoundX := return none)
+    fun snap => do
+      -- `snap` is the one snapshot containing the entire proof.
+      let mut steps : Array <| InteractiveGoalsWithHints := #[]
+
+      -- Question: Is there a difference between the diags of this snap and the last snap?
+      -- Should we get the diags from there?
+      -- Answer: The last snap only copied the diags from the end of this snap
+      let mut diag : Array InteractiveDiagnostic := snap.interactiveDiags.toArray
+
+      -- Level is completed if there are no errrors or warnings
+      let completedWithWarnings : Bool := ¬ diag.any (·.severity? == some .error)
+      let completed : Bool := completedWithWarnings ∧ ¬ diag.any (·.severity? == some .warning)
+
+      let mut intermediateGoalCount := 0
+
+      -- only the positions that have non-whitespace characters since the last position
+      -- should add a new proof step.
+      let positionsWithSource : Array (String.Pos × String) :=
+        text.positions.zipWithIndex.filterMap (
+          fun (pos, i) => match i with
+          | 0 => some (pos, "")
+          | i' + 1 =>
+            let source : String := Substring.toString ⟨text.source, text.positions.get! i', pos⟩
+            if source.trim.length == 0 then
+              none
+            else
+              some (pos, source))
+
+      -- Drop the last position as we ensured that there is always a newline at the end
+      for ((pos, source), i) in positionsWithSource.zipWithIndex do
+        -- iterate over all steps in the proof and get the goals and hints at each position
+
+        -- diags are labeled in Lsp-positions, which differ from the lean-internal
+        -- positions by `1`.
+        let lspPosAt := text.utf8PosToLspPos pos
+
+        let mut diagsAtPos : Array InteractiveDiagnostic := filterUnsolvedGoal <|
+          -- `+1` for getting the errors after the line.
+          match i with
+          | 0 =>
+            -- `lspPosAt` is `(0, 0)`
+            diag.filter (fun d => d.range.start == lspPosAt )
+          | i' + 1 =>
+            diag.filter (fun d =>
+              ((text.utf8PosToLspPos <| (positionsWithSource.get! i').1) ≤ d.range.start) ∧
+              d.range.start < lspPosAt )
+
+        if let goalsAtResult@(_ :: _) := snap.infoTree.goalsAt? doc.meta.text pos then
+          let goalsAtPos' : List <| List InteractiveGoalWithHints ← goalsAtResult.mapM
+            fun { ctxInfo := ci, tacticInfo := tacticInfo, useAfter := useAfter, .. } => do
+              -- TODO: What does this function body do?
+              -- let ciAfter := { ci with mctx := ti.mctxAfter }
+              let ci := if useAfter then
+                  { ci with mctx := tacticInfo.mctxAfter }
+                else
+                  { ci with mctx := tacticInfo.mctxBefore }
+              -- compute the interactive goals
+              let goalMvars : List MVarId ← ci.runMetaM {} do
+                return if useAfter then tacticInfo.goalsAfter else tacticInfo.goalsBefore
+
+              let interactiveGoals : List InteractiveGoalWithHints ← ci.runMetaM {} do
+                goalMvars.mapM fun goal => do
+                  let hints ← findHints goal doc.meta rc.initParams
+                  let interactiveGoal ← goalToInteractive goal
+                  return ⟨interactiveGoal, hints⟩
+              -- TODO: This code is way old, can it be deleted?
+              -- compute the goal diff
+              -- let goals ← ciAfter.runMetaM {} (do
+              --     try
+              --       Widget.diffInteractiveGoals useAfter ti goals
+              --     catch _ =>
+              --       -- fail silently, since this is just a bonus feature
+              --       return goals
+              -- )
+              return interactiveGoals
+          let goalsAtPos : Array InteractiveGoalWithHints := ⟨goalsAtPos'.foldl (· ++ ·) []⟩
+
+          diagsAtPos ← completionDiagnostics goalsAtPos.size intermediateGoalCount
+            completed completedWithWarnings lspPosAt diagsAtPos
+
+          intermediateGoalCount := goalsAtPos.size
+
+          steps := steps.push ⟨goalsAtPos, source, diagsAtPos, lspPosAt.line, lspPosAt.character⟩
+        else
+          -- No goals present
+          steps := steps.push ⟨#[], source, diagsAtPos, lspPosAt.line, none⟩
+
+      -- Filter out the "unsolved goals" message
+      diag := filterUnsolvedGoal diag
+
+      let lastPos := text.utf8PosToLspPos positionsWithSource.back.1
+      let remainingDiags : Array InteractiveDiagnostic :=
+        diag.filter (fun d => lastPos ≤ d.range.start)
+
+      return some {
+        steps := steps,
+        diagnostics := remainingDiags,
+        completed := completed,
+        completedWithWarnings := completedWithWarnings,
+        lastPos := lastPos.line
+        }
+
+open RequestM in
+
+-- The editor apparently uses this
+def getInteractiveGoals (p : Lsp.PlainGoalParams) : RequestM (RequestTask (Option <| InteractiveGoals)) := do
+  let doc ← readDoc
+  -- let rc ← readThe RequestContext
+  let text := doc.meta.text
   let hoverPos := text.lspPosToUtf8Pos p.position
   -- TODO: I couldn't find a good condition to find the correct snap. So we are looking
   -- for the first snap with goals here:
   withWaitFindSnap doc (fun s => ¬ (s.infoTree.goalsAt? doc.meta.text hoverPos).isEmpty)
     (notFoundX := return none) fun snap => do
       if let rs@(_ :: _) := snap.infoTree.goalsAt? doc.meta.text hoverPos then
-        let goals : List InteractiveGoals ← rs.mapM fun { ctxInfo := ci, tacticInfo := ti, useAfter := useAfter, .. } => do
+        let goals : List <| Array InteractiveGoal ← rs.mapM fun { ctxInfo := ci, tacticInfo := ti, useAfter := useAfter, .. } => do
           let ciAfter := { ci with mctx := ti.mctxAfter }
           let ci := if useAfter then ciAfter else { ci with mctx := ti.mctxBefore }
           -- compute the interactive goals
@@ -153,8 +341,8 @@ def getInteractiveGoals (p : Lsp.PlainGoalParams) : RequestM (RequestTask (Optio
             return List.toArray <| if useAfter then ti.goalsAfter else ti.goalsBefore
           let goals ← ci.runMetaM {} do
              goals.mapM fun goal => do
-              let hints ← findHints goal doc rc.initParams
+              -- let hints ← findHints goal doc.meta rc.initParams
-              return ← goalToInteractive goal hints
+              return ← goalToInteractive goal
           -- compute the goal diff
           -- let goals ← ciAfter.runMetaM {} (do
           --     try
@@ -163,8 +351,8 @@ def getInteractiveGoals (p : Lsp.PlainGoalParams) : RequestM (RequestTask (Optio
           --       -- fail silently, since this is just a bonus feature
           --       return goals
           -- )
-          return {goals}
+          return goals
-        return some <| goals.foldl (· ++ ·) ⟨#[]⟩
+        return some <| ⟨goals.foldl (· ++ ·) #[]⟩
       else
         return none
 
@@ -172,7 +360,16 @@ builtin_initialize
   registerBuiltinRpcProcedure
     `Game.getInteractiveGoals
     Lsp.PlainGoalParams
-    (Option InteractiveGoals)
+    (Option <| InteractiveGoals
+    )
     getInteractiveGoals
 
+builtin_initialize
+  registerBuiltinRpcProcedure
+    `Game.getProofState
+    Lsp.PlainGoalParams
+    (Option ProofState)
+    getProofState
+
+
 end GameServer

server/GameServer/SaveData.lean

@@ -1,8 +1,8 @@
 import GameServer.EnvExtensions
+import I18n
 
 open Lean Meta Elab Command
 
-
 /-! ## Copy images -/
 
 open IO.FS System FilePath in
@@ -59,6 +59,9 @@ def saveGameData (allItemsByType : HashMap InventoryType (HashSet Name))
 
   IO.FS.writeFile (path / inventoryFileName) (toString (toJson inventory))
 
+  -- write PO file for translation
+  I18n.createPOTemplate
+
 open GameData
 
 def loadData (f : System.FilePath) (α : Type) [FromJson α] : IO α := do

server/GameServer/Structures.lean

@@ -0,0 +1,102 @@
+import Lean.Widget.InteractiveGoal
+import Lean.Widget.InteractiveDiagnostic
+import Lean.Data.Lsp.Diagnostics
+
+/-!
+This file contains the custom data structures use by the server.
+
+Some of them overwrite built-in structures from Lean.
+
+In particular, the structures from `Lean.Widget.InteractiveGoal` are duplicated with
+the following extension:
+
+* `isAssumption?` in `InteractiveHypothesisBundle`: stores if a hypothesis is of type `Prop`.
+
+NOTE: Changes here need to be reflected in  the corresponding `interface` in `rcp_api.ts`
+on the client-side.
+-/
+
+open Lean Server Widget
+
+namespace GameServer
+
+/-- Extend the interactive hypothesis bundle with an option to distinguish
+"assumptions" from "objects". "Assumptions" are hypotheses of type `Prop`. -/
+-- @[inherit_doc Lean.Widget.InteractiveHypothesisBundle]
+structure InteractiveHypothesisBundle extends Lean.Widget.InteractiveHypothesisBundle where
+  /-- The hypothesis's type is of type `Prop` -/
+  isAssumption? : Option Bool := none
+deriving RpcEncodable
+
+-- duplicated but with custom `InteractiveHypothesisBundle`
+@[inherit_doc Lean.Widget.InteractiveGoalCore]
+structure InteractiveGoalCore where
+  hyps : Array InteractiveHypothesisBundle
+  type : CodeWithInfos
+  ctx : WithRpcRef Elab.ContextInfo
+
+-- duplicated but with custom `InteractiveGoalCore`
+@[inherit_doc Lean.Widget.InteractiveGoal]
+structure InteractiveGoal extends InteractiveGoalCore where
+  userName? : Option String
+  goalPrefix : String
+  mvarId : MVarId
+  isInserted? : Option Bool := none
+  isRemoved? : Option Bool := none
+deriving RpcEncodable
+
+-- duplicated with custom `InteractiveGoalCore`
+@[inherit_doc Lean.Widget.InteractiveTermGoal]
+structure InteractiveTermGoal extends InteractiveGoalCore where
+  range : Lsp.Range
+  term : WithRpcRef Elab.TermInfo
+deriving RpcEncodable
+
+/-- A hint in the game at the corresponding goal. -/
+structure GameHint where
+  /-- The text with the variable names already inserted.
+
+  Note: This is in theory superfluous and will be completely replaced by `rawText`. We just left
+  it in for debugging for now. -/
+  text : String
+  /-- Flag whether the hint should be hidden initially. -/
+  hidden : Bool
+  /-- The text with the variables not inserted yet. -/
+  rawText : String
+  /-- The assignment of variable names in the `rawText` to the ones the player used. -/
+  varNames : Array <| Name × Name
+deriving FromJson, ToJson
+
+/-- Bundled `InteractiveGoal` together with an array of hints that apply at this stage. -/
+structure InteractiveGoalWithHints where
+  goal : InteractiveGoal
+  /-- Extended the `InteractiveGoal` by an array of hints at that goal. -/
+  hints : Array GameHint
+deriving RpcEncodable
+
+structure InteractiveGoalsWithHints where
+  goals : Array InteractiveGoalWithHints
+  /-- The content of the line evaluated. -/
+  command : String
+  diags : Array InteractiveDiagnostic := default
+  line : Option Nat -- only for debugging
+  column : Option Nat -- only for debugging
+
+deriving RpcEncodable
+
+instance : Inhabited InteractiveGoalsWithHints := ⟨default, default, default, none, none⟩
+
+/-- Collected goals throughout the proof. Used for communication with the game client. -/
+structure ProofState where
+  /-- goals after each line. includes the hints. -/
+  steps : Array <| InteractiveGoalsWithHints
+  /-- diagnostics contains all errors and warnings.
+
+  TODO: I think they contain information about which line they belong to. Verify this.
+  -/
+  diagnostics : Array InteractiveDiagnostic := default
+  /-- Whether the level is considered solved. -/
+  completed : Bool
+  completedWithWarnings : Bool
+  lastPos : Nat -- only for debugging
+deriving RpcEncodable

server/GameServer/Tactic/LetIntros.lean

@@ -0,0 +1,65 @@
+import Lean.Elab.Binders
+import Lean.Elab.Tactic.Basic
+import Lean.Meta.Tactic.Intro
+
+/-!
+# `let_intros` Tactic
+
+`let_intros` is a weaker form of `intros` aimed to only introduce `let` statements,
+but not for example `∀`-binders.
+-/
+
+namespace GameServer
+
+open Lean Meta Elab Parser Tactic
+
+/--
+Copied from `Lean.Meta.getIntrosSize`.
+-/
+private partial def getLetIntrosSize : Expr → Nat
+  -- | .forallE _ _ b _ => getLetIntrosSize b + 1
+  | .letE _ _ _ b _  => getLetIntrosSize b + 1
+  | .mdata _ b       => getLetIntrosSize b
+  | e                =>
+    if let some (_, _, _, b) := e.letFun? then
+      getLetIntrosSize b + 1
+    else
+      0
+
+/--
+Copied and from `Lean.MVarId.intros`.
+-/
+def _root_.Lean.MVarId.letIntros (mvarId : MVarId) : MetaM (Array FVarId × MVarId) := do
+  let type ← mvarId.getType
+  let type ← instantiateMVars type
+  let n := getLetIntrosSize type
+  if n == 0 then
+    return (#[], mvarId)
+  else
+    -- `introNP` preserves the binder names
+    mvarId.introNP n
+
+/--
+`let_intros` introduces all `let` statements that are preceeding the proof. Concretely
+it does a subset of what `intros` does.
+
+If names are provided, it will introduce as many `let` statements as there are names.
+-/
+syntax (name := letIntros) "let_intros" : tactic
+-- (ppSpace colGt (ident <|> hole))*
+
+#check letIntros
+
+@[tactic letIntros] def evalLetIntros : Tactic := fun stx => do
+  match stx with
+  | `(tactic| let_intros) => liftMetaTactic fun mvarId => do
+    let (_, mvarId) ← mvarId.letIntros
+    return [mvarId]
+  -- | `(tactic| let_intros $ids*) => do
+  --   let fvars ← liftMetaTacticAux fun mvarId => do
+  --     let (fvars, mvarId) ← mvarId.introN ids.size (ids.map getNameOfIdent').toList
+  --     return (fvars, [mvarId])
+  --   withMainContext do
+  --     for stx in ids, fvar in fvars do
+  --       Term.addLocalVarInfo stx (mkFVar fvar)
+  | _ => throwUnsupportedSyntax

server/lake-manifest.json

@@ -4,10 +4,19 @@
  [{"url": "https://github.com/leanprover/std4.git",
    "type": "git",
    "subDir": null,
-   "rev": "af7f36db6e7e9e395710a70635f915e8e3a0e69b",
+   "rev": "a7543d1a6934d52086971f510e482d743fe30cf3",
    "name": "std",
    "manifestFile": "lake-manifest.json",
-   "inputRev": "v4.4.0",
+   "inputRev": "v4.6.0",
+   "inherited": false,
+   "configFile": "lakefile.lean"},
+  {"url": "https://github.com/hhu-adam/lean-i18n.git",
+   "type": "git",
+   "subDir": null,
+   "rev": "c5b84feffb28dbd5b1ac74b3bf63271296fabfa5",
+   "name": "i18n",
+   "manifestFile": "lake-manifest.json",
+   "inputRev": "v4.6.0",
    "inherited": false,
    "configFile": "lakefile.lean"}],
  "name": "GameServer",

server/lakefile.lean

@@ -4,9 +4,11 @@ open Lake DSL
 package GameServer
 
 -- Using this assumes that each dependency has a tag of the form `v4.X.0`.
-def leanVersion : String := s!"v{Lean.versionString}"
+-- def leanVersion : String := s!"v{Lean.versionString}"
+def leanVersion := "v4.6.0" -- TODO
 
 require std from git "https://github.com/leanprover/std4.git" @ leanVersion
+require i18n from git "https://github.com/hhu-adam/lean-i18n.git" @ leanVersion
 
 lean_lib GameServer
 

server/lean-toolchain

@@ -1 +1 @@
-leanprover/lean4:v4.4.0
+leanprover/lean4:v4.6.1

server/test/let_intros.lean

@@ -0,0 +1,17 @@
+import GameServer.Tactic.LetIntros
+
+set_option linter.unusedVariables false in
+
+example (f : Nat) :
+    let f := fun x ↦ x + 1
+    let g : Nat → Nat := fun y ↦ y
+    ∀ x : Nat, x ≤ f x := by
+  let_intros
+  /-
+  f✝ : Nat
+  f : Nat → Nat := fun x => x + 1
+  g : Nat → Nat := fun y => y
+  ⊢ ∀ (x : Nat), x ≤ f x
+  -/
+  intro x
+  exact Nat.le_succ x

tsconfig.json

@@ -11,6 +11,10 @@
     "downlevelIteration": true,
     "experimentalDecorators": true,
     "allowSyntheticDefaultImports": true,
+    "lib": [
+      "ES2021.String",
+      "DOM"
+    ]
   },
   "exclude": ["server", "relay"]
 }