fix replacement for 2+ variables

.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

client/src/components/hints.tsx

@@ -5,15 +5,33 @@ 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>
 }
 
@@ -31,7 +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>
 }
 

client/src/components/infoview/goals.tsx

@@ -268,7 +268,7 @@ interface GoalsProps {
 
 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.goal} filter={filter} />)}

client/src/components/infoview/main.tsx

@@ -232,7 +232,11 @@ 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">
-      {proof.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}

client/src/components/infoview/rpc_api.ts

@@ -49,6 +49,8 @@ export interface InteractiveTermGoal extends InteractiveGoalCore {
 export interface GameHint {
   text: string;
   hidden: boolean;
+  rawText: string;
+  varNames: string[][]; // in Lean: `Array (Name × Name)`
 }
 
 export interface InteractiveGoalWithHints {

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 {

client/src/css/level.css

@@ -370,6 +370,6 @@ td code  {
 }
 
 /* DEBUG */
-.proof .step {
+/* .proof .step {
   border: 2px solid rgb(0, 123, 255);
-}
+} */

doc/troubleshoot.md

@@ -2,6 +2,15 @@
 
 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
   running the `remote-containers.showReopenInContainerNotificationReset` command in vscode.

package-lock.json

@@ -8753,9 +8753,9 @@
       }
     },
     "node_modules/ip": {
-      "version": "1.1.8",
+      "version": "1.1.9",
-      "resolved": "https://registry.npmjs.org/ip/-/ip-1.1.8.tgz",
+      "resolved": "https://registry.npmjs.org/ip/-/ip-1.1.9.tgz",
-      "integrity": "sha512-PuExPYUiu6qMBQb4l06ecm6T6ujzhmh+MeJcW9wa89PoAz5pvd4zPgN5WJV104mb6S2T1AwNIAaB70JNrLQWhg=="
+      "integrity": "sha512-cyRxvOEpNHNtchU3Ln9KC/auJgup87llfQpQ+t5ghoC/UhL16SWzbueiCsdTnWmqAWl7LadfuwhlqmtOaqMHdQ=="
     },
     "node_modules/ip-anonymize": {
       "version": "0.1.0",
@@ -14341,6 +14341,14 @@
         "node": ">=6"
       }
     },
+    "node_modules/stacktrace-parser/node_modules/type-fest": {
+      "version": "0.7.1",
+      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-0.7.1.tgz",
+      "integrity": "sha512-Ne2YiiGN8bmrmJJEuTWTLJR32nh/JdL1+PSicowtNb0WFpn59GK8/lfD61bVtzguz7b3PBt74nxpv/Pw5po5Rg==",
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/statuses": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/statuses/-/statuses-2.0.1.tgz",
@@ -14902,9 +14910,12 @@
       }
     },
     "node_modules/type-fest": {
-      "version": "0.7.1",
+      "version": "4.10.3",
-      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-0.7.1.tgz",
+      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-4.10.3.tgz",
-      "integrity": "sha512-Ne2YiiGN8bmrmJJEuTWTLJR32nh/JdL1+PSicowtNb0WFpn59GK8/lfD61bVtzguz7b3PBt74nxpv/Pw5po5Rg==",
+      "integrity": "sha512-JLXyjizi072smKGGcZiAJDCNweT8J+AuRxmPZ1aG7TERg4ijx9REl8CNhbr36RV4qXqL1gO1FF9HL8OkVmmrsA==",
+      "dev": true,
+      "optional": true,
+      "peer": true,
       "engines": {
         "node": ">=8"
       }

server/GameServer/Commands.lean

@@ -2,6 +2,8 @@ import GameServer.Helpers
 import GameServer.Inventory
 import GameServer.Options
 import GameServer.SaveData
+import GameServer.Hints
+import I18n
 
 open Lean Meta Elab Command
 
@@ -32,16 +34,17 @@ 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 +52,7 @@ 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 +84,7 @@ 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 +97,13 @@ 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 +144,7 @@ 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 +169,7 @@ 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 +199,7 @@ 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 +346,9 @@ 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 := {} })
@@ -396,12 +405,41 @@ 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 +478,8 @@ 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

@@ -122,7 +122,7 @@ partial def findForbiddenTactics (inputCtx : Parser.InputContext) (workerState :
     -- Atoms might be tactic names or other keywords.
     -- Note: We whitelisted known keywords because we cannot
     -- distinguish keywords from tactic names.
-    let allowed := ["with", "fun", "at", "only", "by", "to", "generalizing", "says"]
+    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
       -- Treat `simp?` and `simp!` like `simp`
@@ -169,15 +169,20 @@ partial def findForbiddenTactics (inputCtx : Parser.InputContext) (workerState :
       match theoremsAndDefs.find? (·.name == n) with
       | none =>
         -- Theorem will never be introduced in this game
-        addMessageByDifficulty info s!"You have not unlocked the theorem/definition '{n}' yet!"
+        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
-          -- Theorem is still locked.
+          match workerState.inventory.find? (· == n.toString) with
-          addMessageByDifficulty info s!"You have not unlocked the theorem/definition '{n}' yet!"
+          | 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 ()
 
 where addMessageByDifficulty (info : SourceInfo) (s : MessageData) :=
   -- See `GameServer.FileWorker.WorkerState.difficulty`. Send nothing/warnings/errors
@@ -299,7 +304,7 @@ 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 }
 
@@ -386,60 +391,60 @@ def publishProofState (m : DocumentMeta) (snap : Snapshot) (initParams : Lsp.Ini
 
   hOut.writeLspNotification { method := "$/game/publishProofState", param }
 
-  /-- Checks whether game level has been completed and sends a notification to the client -/
+/-- 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
+def publishGameCompleted (m : DocumentMeta) (hOut : FS.Stream) (snaps : Array Snapshot) : IO Unit := do
-    -- check if there is any error or warning
+  -- check if there is any error or warning
-    for snap in snaps do
+  for snap in snaps do
-      if snap.diagnostics.any fun d => d.severity? == some .error ∨ d.severity? == some .warning
+    if snap.diagnostics.any fun d => d.severity? == some .error ∨ d.severity? == some .warning
-      then return
+    then return
-    let param := { uri := m.uri : GameCompletedParams}
+  let param := { uri := m.uri : GameCompletedParams}
-    hOut.writeLspNotification { method := "$/game/completed", param }
+  hOut.writeLspNotification { method := "$/game/completed", param }
 
-  /-- copied from `Lean.Server.FileWorker.nextCmdSnap`. -/
+/-- copied from `Lean.Server.FileWorker.nextCmdSnap`. -/
-  -- @[inherit_doc Lean.Server.FileWorker.nextCmdSnap] -- cannot inherit from private
+-- @[inherit_doc Lean.Server.FileWorker.nextCmdSnap] -- cannot inherit from private
-  private def nextCmdSnap (ctx : WorkerContext) (m : DocumentMeta) (cancelTk : CancelToken)
+private def nextCmdSnap (ctx : WorkerContext) (m : DocumentMeta) (cancelTk : CancelToken)
-      (gameWorkerState : WorkerState) (initParams : Lsp.InitializeParams) :
+    (gameWorkerState : WorkerState) (initParams : Lsp.InitializeParams) :
-      AsyncElabM (Option Snapshot) := do
+    AsyncElabM (Option Snapshot) := do
-    cancelTk.check
+  cancelTk.check
-    let s ← get
+  let s ← get
-    let .some lastSnap := s.snaps.back? | panic! "empty snapshots"
+  let .some lastSnap := s.snaps.back? | panic! "empty snapshots"
-    if lastSnap.isAtEnd then
+  if lastSnap.isAtEnd then
-      publishDiagnostics m lastSnap.diagnostics.toArray ctx.hOut
+    publishDiagnostics m lastSnap.diagnostics.toArray ctx.hOut
-      publishProgressDone m ctx.hOut
+    publishProgressDone m ctx.hOut
-      publishIleanInfoFinal m ctx.hOut s.snaps
+    publishIleanInfoFinal m ctx.hOut s.snaps
-      return none
+    return none
-    publishProgressAtPos m lastSnap.endPos ctx.hOut
+  publishProgressAtPos m lastSnap.endPos ctx.hOut
 
-    -- (modified part)
+  -- (modified part)
-    -- Make sure that there is at least one snap after the head snap, so that
+  -- 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
+  -- we can see the current goal even on an empty document
-    let couldBeEndSnap := s.snaps.size > 1
+  let couldBeEndSnap := s.snaps.size > 1
-    let snap ← compileProof m.mkInputContext lastSnap ctx.clientHasWidgets couldBeEndSnap
+  let snap ← compileProof m.mkInputContext lastSnap ctx.clientHasWidgets couldBeEndSnap
-      gameWorkerState initParams
+    gameWorkerState initParams
 
-    set { s with snaps := s.snaps.push snap }
+  set { s with snaps := s.snaps.push snap }
-    cancelTk.check
+  cancelTk.check
-    publishProofState m snap initParams ctx.hOut
+  publishProofState m snap initParams ctx.hOut
-    publishDiagnostics m snap.diagnostics.toArray ctx.hOut
+  publishDiagnostics m snap.diagnostics.toArray ctx.hOut
-    publishIleanInfoUpdate m ctx.hOut #[snap]
+  publishIleanInfoUpdate m ctx.hOut #[snap]
-    return some snap
+  return some snap
 
-  -- Copied from `Lean.Server.FileWorker.unfoldCmdSnaps` using our own `nextCmdSnap`.
+-- Copied from `Lean.Server.FileWorker.unfoldCmdSnaps` using our own `nextCmdSnap`.
-  @[inherit_doc Lean.Server.FileWorker.unfoldCmdSnaps]
+@[inherit_doc Lean.Server.FileWorker.unfoldCmdSnaps]
-  def unfoldCmdSnaps (m : DocumentMeta) (snaps : Array Snapshot) (cancelTk : CancelToken)
+def unfoldCmdSnaps (m : DocumentMeta) (snaps : Array Snapshot) (cancelTk : CancelToken)
-      (startAfterMs : UInt32) (gameWorkerState : WorkerState)
+    (startAfterMs : UInt32) (gameWorkerState : WorkerState)
-      : ReaderT WorkerContext IO (AsyncList ElabTaskError Snapshot) := do
+    : ReaderT WorkerContext IO (AsyncList ElabTaskError Snapshot) := do
-    let ctx ← read
+  let ctx ← read
-    let some headerSnap := snaps[0]? | panic! "empty snapshots"
+  let some headerSnap := snaps[0]? | panic! "empty snapshots"
-    if headerSnap.msgLog.hasErrors then
+  if headerSnap.msgLog.hasErrors then
-      publishProgressAtPos m headerSnap.beginPos ctx.hOut (kind := LeanFileProgressKind.fatalError)
+    publishProgressAtPos m headerSnap.beginPos ctx.hOut (kind := LeanFileProgressKind.fatalError)
-      publishIleanInfoFinal m ctx.hOut #[headerSnap]
+    publishIleanInfoFinal m ctx.hOut #[headerSnap]
-      return AsyncList.ofList [headerSnap]
+    return AsyncList.ofList [headerSnap]
-    else
+  else
-      publishIleanInfoUpdate m ctx.hOut snaps
+    publishIleanInfoUpdate m ctx.hOut snaps
-      return AsyncList.ofList snaps.toList ++ AsyncList.delayed (← EIO.asTask (ε := ElabTaskError) (prio := .dedicated) do
+    return AsyncList.ofList snaps.toList ++ AsyncList.delayed (← EIO.asTask (ε := ElabTaskError) (prio := .dedicated) do
-        IO.sleep startAfterMs
+      IO.sleep startAfterMs
-        AsyncList.unfoldAsync (nextCmdSnap ctx m cancelTk gameWorkerState ctx.initParams) { snaps })
+      AsyncList.unfoldAsync (nextCmdSnap ctx m cancelTk gameWorkerState ctx.initParams) { snaps })
 
 end Elab
 
@@ -503,6 +508,12 @@ def DocumentMeta.mkInputContext (doc : DocumentMeta) : Parser.InputContext where
   fileName := (System.Uri.fileUriToPath? doc.uri).getD doc.uri |>.toString
   fileMap  := default
 
+/-- `gameDir` and `module` were added.
+
+TODO: In general this resembles little similarity with the
+original code, and I don't know why...
+-/
+-- @[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
@@ -538,7 +549,7 @@ def compileHeader (m : DocumentMeta) (hOut : FS.Stream) (opts : Options) (hasWid
     let cmdState := Elab.Command.mkState headerEnv {} opts
     let cmdState := { cmdState with infoState := {
       enabled := true
-      trees := #[Elab.InfoTree.context ({
+      trees := #[Elab.InfoTree.context (.commandCtx {
         env     := headerEnv
         fileMap := m.text
         ngen    := { namePrefix := `_worker }
@@ -555,7 +566,7 @@ def compileHeader (m : DocumentMeta) (hOut : FS.Stream) (opts : Options) (hasWid
     let headerSnap := {
       beginPos := 0
       stx := headerStx
-      mpState := {}
+      mpState := {} -- was `headerParserState`
       cmdState := cmdState
       interactiveDiags := ← cmdState.messages.msgs.mapM (Widget.msgToInteractiveDiagnostic m.text · hasWidgets)
       tacticCache := (← IO.mkRef {})

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

@@ -146,7 +146,7 @@ def goalToInteractive (mvarId : MVarId) : MetaM InteractiveGoal := do
     return {
       hyps
       type := goalFmt
-      ctx := ⟨← Elab.ContextInfo.save⟩
+      ctx := ⟨{← Elab.CommandContextInfo.save with }⟩
       userName?
       goalPrefix := getGoalPrefix mvarDecl
       mvarId

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

@@ -1,6 +1,7 @@
 import GameServer.EnvExtensions
 import GameServer.InteractiveGoal
 import Std.Data.Array.Init.Basic
+import GameServer.Hints
 
 open Lean
 open Server
@@ -103,14 +104,6 @@ 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) (m : DocumentMeta) (initParams : Lsp.InitializeParams) : MetaM (Array GameHint) := do
@@ -121,14 +114,42 @@ def findHints (goal : MVarId) (m : DocumentMeta) (initParams : Lsp.InitializePar
       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

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

@@ -54,8 +54,17 @@ 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. -/

server/lake-manifest.json

@@ -4,10 +4,19 @@
  [{"url": "https://github.com/leanprover/std4.git",
    "type": "git",
    "subDir": null,
-   "rev": "08ec2584b1892869e3a5f4122b029989bcb4ca79",
+   "rev": "a7543d1a6934d52086971f510e482d743fe30cf3",
    "name": "std",
    "manifestFile": "lake-manifest.json",
-   "inputRev": "v4.5.0",
+   "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

@@ -7,8 +7,7 @@ package GameServer
 def leanVersion : String := s!"v{Lean.versionString}"
 
 require std from git "https://github.com/leanprover/std4.git" @ leanVersion
-
+require i18n from git "https://github.com/hhu-adam/lean-i18n.git" @ leanVersion
--- require importGraph from git "https://github.com/leanprover-community/import-graph" @ leanVersion
 
 lean_lib GameServer
 

server/lean-toolchain

@@ -1 +1 @@
-leanprover/lean4:v4.5.0
+leanprover/lean4:v4.6.0

tsconfig.json

@@ -11,6 +11,9 @@
     "downlevelIteration": true,
     "experimentalDecorators": true,
     "allowSyntheticDefaultImports": true,
+    "lib": [
+      "ES2021.String"
+    ]
   },
   "exclude": ["server", "relay"]
 }