Merge pull request 'feat: Draft tactic REPL interface' (#158) from tactic/draft into dev

Reviewed-on: #158

Pantograph/Delate.lean

@@ -264,25 +264,24 @@ def serializeName (name: Name) (sanitize: Bool := true): String :=
     if n.contains Lean.idBeginEscape then s!"{quote}{n}{quote}" else n
 
 /-- serialize a sort level. Expression is optimized to be compact e.g. `(+ u 2)` -/
-partial def serializeSortLevel (level: Level) (sanitize: Bool): String :=
+partial def serializeSortLevel (level: Level) : String :=
   let k := level.getOffset
   let u := level.getLevelOffset
   let u_str := match u with
     | .zero => "0"
     | .succ _ => panic! "getLevelOffset should not return .succ"
     | .max v w =>
-      let v := serializeSortLevel v sanitize
-      let w := serializeSortLevel w sanitize
+      let v := serializeSortLevel v
+      let w := serializeSortLevel w
       s!"(:max {v} {w})"
     | .imax v w =>
-      let v := serializeSortLevel v sanitize
-      let w := serializeSortLevel w sanitize
+      let v := serializeSortLevel v
+      let w := serializeSortLevel w
       s!"(:imax {v} {w})"
     | .param name =>
-      let name := serializeName name sanitize
       s!"{name}"
     | .mvar id =>
-      let name := serializeName id.name sanitize
+      let name := id.name
       s!"(:mv {name})"
   match k, u with
   | 0, _ => u_str
@@ -295,7 +294,7 @@ partial def serializeSortLevel (level: Level) (sanitize: Bool): String :=
 
 A `_` symbol in the AST indicates automatic deductions not present in the original expression.
 -/
-partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM String := do
+partial def serializeExpressionSexp (expr: Expr) : MetaM String := do
   self expr
   where
   delayedMVarToSexp (e: Expr): MetaM (Option String) := do
@@ -334,9 +333,10 @@ partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM
         let name := mvarId.name
         pure s!"(:{pref} {name})"
     | .sort level =>
-      let level := serializeSortLevel level sanitize
+      let level := serializeSortLevel level
       pure s!"(:sort {level})"
     | .const declName _ =>
+      let declName := serializeName declName (sanitize := false)
       -- The universe level of the const expression is elided since it should be
       -- inferrable from surrounding expression
       pure s!"(:c {declName})"
@@ -369,7 +369,7 @@ partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM
       -- is wrapped in a :lit sexp.
       let v' := match v with
         | .natVal val => toString val
-        | .strVal val => s!"\"{val}\""
+        | .strVal val => IR.EmitC.quoteString val
       pure s!"(:lit {v'})"
     | .mdata _ inner =>
       -- NOTE: Equivalent to expr itself, but mdata influences the prettyprinter
@@ -384,9 +384,9 @@ partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM
   -- Elides all unhygenic names
   binderInfoSexp : Lean.BinderInfo → String
     | .default => ""
-    | .implicit => " :implicit"
-    | .strictImplicit => " :strictImplicit"
-    | .instImplicit => " :instImplicit"
+    | .implicit => " :i"
+    | .strictImplicit => " :si"
+    | .instImplicit => " :ii"
 
 def serializeExpression (options: @&Protocol.Options) (e: Expr): MetaM Protocol.Expression := do
   let pp?: Option String ← match options.printExprPretty with
@@ -532,7 +532,7 @@ protected def GoalState.diag (goalState: GoalState) (parent?: Option GoalState :
         then instantiateAll decl.type
         else pure $ decl.type
       let type_sexp ← if options.printSexp then
-          let sexp ← serializeExpressionSexp type (sanitize := false)
+          let sexp ← serializeExpressionSexp type
           pure <| " " ++ sexp
         else
           pure ""

Pantograph/Frontend/Basic.lean

@@ -67,7 +67,7 @@ def processOneCommand: FrontendM (CompilationStep × Bool) := do
   let s := (← get).commandState
   let before := s.env
   let done ← Elab.Frontend.processCommand
-  let stx := (← get).commands.back
+  let stx := (← get).commands.back!
   let src := (← read).inputCtx.input.toSubstring.extract (← get).cmdPos (← get).parserState.pos
   let s' := (← get).commandState
   let after := s'.env

Pantograph/Frontend/Elab.lean

@@ -80,10 +80,10 @@ def collectTactics (t : Elab.InfoTree) : List TacticInvocation :=
 
 @[export pantograph_frontend_collect_tactics_from_compilation_step_m]
 def collectTacticsFromCompilationStep (step : CompilationStep) : IO (List Protocol.InvokedTactic) := do
-  let tacticInfoTrees := step.trees.bind λ tree => tree.filter λ
+  let tacticInfoTrees := step.trees.flatMap λ tree => tree.filter λ
     | info@(.ofTacticInfo _) => info.isOriginal
     | _ => false
-  let tactics := tacticInfoTrees.bind collectTactics
+  let tactics := tacticInfoTrees.flatMap collectTactics
   tactics.mapM λ invocation => do
     let goalBefore := (Format.joinSep (← invocation.goalState) "\n").pretty
     let goalAfter := (Format.joinSep (← invocation.goalStateAfter) "\n").pretty
@@ -104,14 +104,20 @@ structure InfoWithContext where
   info: Elab.Info
   context?: Option Elab.ContextInfo := .none
 
-private def collectSorrysInTree (t : Elab.InfoTree) : IO (List InfoWithContext) := do
+structure GoalCollectionOptions where
+  collectTypeErrors : Bool := false
+
+private def collectSorrysInTree (t : Elab.InfoTree) (options : GoalCollectionOptions := {})
+    : IO (List InfoWithContext) := do
   let infos ← t.findAllInfoM none fun i ctx? => match i with
-    | .ofTermInfo { expectedType?, expr, stx, lctx, .. } => do
+    | .ofTermInfo { expectedType?, expr, stx, lctx, isBinder := false, .. } => do
       let .some ctx := ctx? | return (false, true)
       if expr.isSorry ∧ stx.isOfKind `Lean.Parser.Term.sorry then
         if expectedType?.isNone then
           throw $ .userError "Sorry of indeterminant type is not allowed"
         return (true, false)
+      unless options.collectTypeErrors do
+        return (false, true)
       let .some expectedType := expectedType? | return (false, true)
       let typeMatch ← ctx.runMetaM lctx do
         let type ← Meta.inferType expr
@@ -130,8 +136,9 @@ private def collectSorrysInTree (t : Elab.InfoTree) : IO (List InfoWithContext)
 
 -- NOTE: Plural deliberately not spelled "sorries"
 @[export pantograph_frontend_collect_sorrys_m]
-def collectSorrys (step: CompilationStep) : IO (List InfoWithContext) := do
-  return (← step.trees.mapM collectSorrysInTree).join
+def collectSorrys (step: CompilationStep) (options : GoalCollectionOptions := {})
+    : IO (List InfoWithContext) := do
+  return (← step.trees.mapM $ λ tree => collectSorrysInTree tree options).flatten
 
 structure AnnotatedGoalState where
   state : GoalState
@@ -149,13 +156,18 @@ def sorrysToGoalState (sorrys : List InfoWithContext) : MetaM AnnotatedGoalState
     match i.info with
     | .ofTermInfo termInfo  => do
       let mvarId ← MetaTranslate.translateMVarFromTermInfo termInfo i.context?
+      if (← mvarId.getType).hasSorry then
+        throwError s!"Coupling is not allowed in drafting"
       return [(mvarId, stxByteRange termInfo.stx)]
     | .ofTacticInfo tacticInfo => do
       let mvarIds ← MetaTranslate.translateMVarFromTacticInfoBefore tacticInfo i.context?
+      for mvarId in mvarIds do
+        if (← mvarId.getType).hasSorry then
+          throwError s!"Coupling is not allowed in drafting"
       let range := stxByteRange tacticInfo.stx
       return mvarIds.map (·, range)
     | _ => panic! "Invalid info"
-  let annotatedGoals := List.join (← goalsM.run {} |>.run' {})
+  let annotatedGoals := List.flatten (← goalsM.run {} |>.run' {})
   let goals := annotatedGoals.map Prod.fst
   let srcBoundaries := annotatedGoals.map Prod.snd
   let root := match goals with

Pantograph/Frontend/InfoTree.lean

@@ -26,6 +26,8 @@ protected def Info.stx? : Info → Option Syntax
   | .ofFVarAliasInfo      _    => none
   | .ofFieldRedeclInfo    info => info.stx
   | .ofOmissionInfo       info => info.stx
+  | .ofChoiceInfo         info => info.stx
+  | .ofPartialTermInfo    info => info.stx
 /-- Is the `Syntax` for this `Lean.Elab.Info` original, or synthetic? -/
 protected def Info.isOriginal (i : Info) : Bool :=
   match i.stx? with
@@ -87,9 +89,9 @@ partial def InfoTree.filter (p : Info → Bool) (m : MVarId → Bool := fun _ =>
   | .context ctx tree => tree.filter p m |>.map (.context ctx)
   | .node info children =>
     if p info then
-      [.node info (children.toList.map (filter p m)).join.toPArray']
+      [.node info (children.toList.map (filter p m)).flatten.toPArray']
     else
-      (children.toList.map (filter p m)).join
+      (children.toList.map (filter p m)).flatten
   | .hole mvar => if m mvar then [.hole mvar] else []
 
 /-- Analogue of `Lean.Elab.InfoTree.findInfo?`, but that returns a list of all results. -/
@@ -103,7 +105,7 @@ partial def InfoTree.findAllInfo
   | .context inner t => findAllInfo t (inner.mergeIntoOuter? context?) haltOnMatch pred
   | .node i children  =>
     let head := if pred i then [(i, context?, children)] else []
-    let tail := if haltOnMatch ∧ !head.isEmpty then [] else children.toList.bind (fun t => findAllInfo t context? haltOnMatch pred)
+    let tail := if haltOnMatch ∧ !head.isEmpty then [] else children.toList.flatMap (fun t => findAllInfo t context? haltOnMatch pred)
     head ++ tail
   | _ => []
 
@@ -119,7 +121,7 @@ partial def InfoTree.findAllInfoM [Monad m]
     let (flagCollect, flagRecurse) ← pred i context?
     let head := if flagCollect then [(i, context?, children)] else []
     let tail := if ¬ flagRecurse then pure [] else children.toList.mapM (fun t => t.findAllInfoM context? pred)
-    return head ++ (← tail).join
+    return head ++ (← tail).flatten
   | _ => return []
 
 @[export pantograph_infotree_to_string_m]
@@ -141,6 +143,8 @@ partial def InfoTree.toString (t : InfoTree) (ctx?: Option Elab.ContextInfo := .
       | .ofFVarAliasInfo _ => pure "[fvar]"
       | .ofFieldRedeclInfo _ => pure "[field_redecl]"
       | .ofOmissionInfo _ => pure "[omission]"
+      | .ofChoiceInfo _ => pure "[choice]"
+      | .ofPartialTermInfo  _ => pure "[partial_term]"
       let children := "\n".intercalate (← children.toList.mapM λ t' => do pure $ indent $ ← t'.toString ctx)
       return s!"{node}\n{children}"
     else throw <| IO.userError "No `ContextInfo` available."

Pantograph/Frontend/MetaTranslate.lean

@@ -68,7 +68,8 @@ private partial def translateExpr (srcExpr: Expr) : MetaTranslateM Expr := do
     match e with
     | .fvar fvarId =>
       let .some fvarId' := state.fvarMap[fvarId]? | panic! s!"FVar id not registered: {fvarId.name}"
-      assert! (← getLCtx).contains fvarId'
+      -- Delegating this to `Meta.check` later
+      --assert! (← getLCtx).contains fvarId'
       return .done $ .fvar fvarId'
     | .mvar mvarId => do
       -- Must not be assigned

Pantograph/Goal.lean

@@ -183,7 +183,8 @@ private def collectAllErroredMVars (src : MVarId) : Elab.TermElabM (List MVarId)
   -- to one of these seed mvars, it means an error has occurred when a tactic
   -- was executing on `src`. `evalTactic`, will not capture these mvars, so we
   -- need to manually find them and save them into the goal list.
-  let descendants ←  Meta.getMVars $ ← instantiateMVars (.mvar src)
+
+  let descendants ←  Meta.getMVars (.mvar src)
   --let _ ← Elab.Term.logUnassignedUsingErrorInfos descendants
   let mut alreadyVisited : MVarIdSet := {}
   let mut result : MVarIdSet := {}
@@ -237,25 +238,34 @@ inductive TacticResult where
   -- The given action cannot be executed in the state
   | invalidAction (message: String)
 
-/-- Executes a `TacticM` monad on this `GoalState`, collecting the errors as necessary -/
-protected def GoalState.tryTacticM (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM Unit) (guardMVarErrors : Bool := false):
-      Elab.TermElabM TacticResult := do
-  try
-    let nextState ← state.step goal tacticM guardMVarErrors
-
-    -- Check if error messages have been generated in the core.
-    let newMessages ← (← Core.getMessageLog).toList.drop state.coreState.messages.toList.length
+private def dumpMessageLog (prevMessageLength : Nat) : CoreM (Array String) := do
+  let newMessages ← (← Core.getMessageLog).toList.drop prevMessageLength
     |>.filterMapM λ m => do
       if m.severity == .error then
         return .some $ ← m.toString
       else
         return .none
   Core.resetMessageLog
+  return newMessages.toArray
+
+/-- Executes a `TacticM` monad on this `GoalState`, collecting the errors as necessary -/
+protected def GoalState.tryTacticM
+    (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM Unit)
+    (guardMVarErrors : Bool := false)
+    : Elab.TermElabM TacticResult := do
+  let prevMessageLength := state.coreState.messages.toList.length
+  try
+    let nextState ← state.step goal tacticM guardMVarErrors
+
+    -- Check if error messages have been generated in the core.
+    let newMessages ← dumpMessageLog prevMessageLength
     if ¬ newMessages.isEmpty then
-      return .failure newMessages.toArray
+      return .failure newMessages
     return .success nextState
   catch exception =>
-    return .failure #[← exception.toMessageData.toString]
+    match exception with
+    | .internal _ => return .failure $ ← dumpMessageLog prevMessageLength
+    | _ => return .failure #[← exception.toMessageData.toString]
 
 /-- Execute a string tactic on given state. Restores TermElabM -/
 @[export pantograph_goal_state_try_tactic_m]

Pantograph/Library.lean

@@ -207,6 +207,14 @@ protected def GoalState.tryNoConfuse (state: GoalState) (goal: MVarId) (eq: Stri
     | .ok syn => pure syn
     | .error error => return .parseError error
   state.tryTacticM goal (tacticM := Tactic.evalNoConfuse eq)
+@[export pantograph_goal_try_draft_m]
+protected def GoalState.tryDraft (state: GoalState) (goal: MVarId) (expr: String): CoreM TacticResult := do
+  let expr ← match (← parseTermM expr) with
+    | .ok syn => pure syn
+    | .error error => return .parseError error
+  runTermElabM do
+    state.restoreElabM
+    state.tryTacticM goal (Tactic.evalDraft expr)
 @[export pantograph_goal_let_m]
 def goalLet (state: GoalState) (goal: MVarId) (binderName: String) (type: String): CoreM TacticResult :=
   runTermElabM <| state.tryLet goal binderName type

Pantograph/Protocol.lean

@@ -237,6 +237,7 @@ structure GoalTactic where
   calc?: Option String := .none
   -- true to enter `conv`, `false` to exit. In case of exit the `goalId` is ignored.
   conv?: Option Bool := .none
+  draft?: Option String := .none
 
   -- In case of the `have` tactic, the new free variable name is provided here
   binderName?: Option String := .none
@@ -327,11 +328,13 @@ structure FrontendProcess where
   -- One of these two must be supplied: Either supply the file name or the content.
   fileName?: Option String := .none
   file?: Option String := .none
-  -- If set to true, collect tactic invocations
+  -- collect tactic invocations
   invocations: Bool := false
-  -- If set to true, collect `sorry`s
+  -- collect `sorry`s
   sorrys: Bool := false
-  -- If set to true, extract new constants
+  -- collect type errors
+  typeErrorsAsGoals: Bool := false
+  -- list new constants from each compilation step
   newConstants: Bool := false
   deriving Lean.FromJson
 structure InvokedTactic where

Pantograph/Tactic/Assign.lean

@@ -27,5 +27,38 @@ def evalAssign : Elab.Tactic.Tactic := fun stx => Elab.Tactic.withMainContext do
   goal.assign expr
   Elab.Tactic.replaceMainGoal nextGoals
 
+def sorryToHole (src : Expr) : StateRefT (List MVarId) MetaM Expr := do
+  Meta.transform src λ
+    | .app (.app (.const ``sorryAx ..) type) .. => do
+      let type ← instantiateMVars type
+      if type.hasSorry then
+        throwError s!"Coupling is not allowed in draft tactic: {← Meta.ppExpr type}"
+      let mvar ← Meta.mkFreshExprSyntheticOpaqueMVar type
+      modify (mvar.mvarId! :: .)
+      pure $ .done mvar
+    | _ => pure .continue
+
+-- Given a complete (no holes) expression, extract the sorry's from it and convert them into goals.
+def draft (goal : MVarId) (expr : Expr) : MetaM (List MVarId) := do
+  goal.checkNotAssigned `Pantograph.Tactic.draft
+  let exprType ← Meta.inferType expr
+  let goalType ← goal.getType
+  unless ← Meta.isDefEq goalType exprType do
+    throwError s!"{← Meta.ppExpr expr} : {← Meta.ppExpr exprType} ≠ {← Meta.ppExpr goalType}"
+
+  let (expr', holes) ← sorryToHole expr |>.run []
+  goal.assign expr'
+  return holes.reverse
+
+def evalDraft : Elab.Tactic.Tactic := fun stx ↦ Elab.Tactic.withMainContext do
+  let target ← Elab.Tactic.getMainTarget
+  let goal ← Elab.Tactic.getMainGoal
+  let (expr, holeGoals) ← Elab.Tactic.elabTermWithHoles stx
+    (expectedType? := .some target)
+    (tagSuffix := .anonymous)
+    (allowNaturalHoles := true)
+  let draftGoals ← draft goal expr
+  Elab.Tactic.replaceMainGoal $ holeGoals ++ draftGoals
+
 
 end Pantograph.Tactic

Pantograph/Tactic/Prograde.lean

@@ -40,7 +40,7 @@ def «have» (mvarId: MVarId) (binderName: Name) (type: Expr): MetaM BranchResul
   let fvarId ← mkFreshFVarId
   let lctxUpstream := lctx.mkLocalDecl fvarId binderName type
   let mvarUpstream ←
-    withTheReader Meta.Context (fun ctx => { ctx with lctx := lctxUpstream }) do
+    Meta.withLCtx lctxUpstream #[] do
       Meta.withNewLocalInstances #[.fvar fvarId] 0 do
         let mvarUpstream ← mkUpstreamMVar mvarId
         --let expr: Expr := .app (.lam binderName type mvarBranch .default) mvarUpstream

Pantograph/Version.lean

@@ -1,6 +1,6 @@
 namespace Pantograph
 
 @[export pantograph_version]
-def version := "0.2.23"
+def version := "0.2.25"
 
 end Pantograph

Repl.lean

@@ -145,24 +145,27 @@ def execute (command: Protocol.Command): MainM Lean.Json := do
     let .some goal := goalState.goals.get? args.goalId |
       return .error $ errorIndex s!"Invalid goal index {args.goalId}"
     let nextGoalState?: Except _ TacticResult ← runTermElabInMainM do
-      match args.tactic?, args.expr?, args.have?, args.let?, args.calc?, args.conv?  with
-      | .some tactic, .none, .none, .none, .none, .none => do
+      -- NOTE: Should probably use a macro to handle this...
+      match args.tactic?, args.expr?, args.have?, args.let?, args.calc?, args.conv?, args.draft?  with
+      | .some tactic, .none, .none, .none, .none, .none, .none => do
         pure <| Except.ok <| ← goalState.tryTactic goal tactic
-      | .none, .some expr, .none, .none, .none, .none => do
+      | .none, .some expr, .none, .none, .none, .none, .none => do
         pure <| Except.ok <| ← goalState.tryAssign goal expr
-      | .none, .none, .some type, .none, .none, .none => do
+      | .none, .none, .some type, .none, .none, .none, .none => do
         let binderName := args.binderName?.getD ""
         pure <| Except.ok <| ← goalState.tryHave goal binderName type
-      | .none, .none, .none, .some type, .none, .none => do
+      | .none, .none, .none, .some type, .none, .none, .none => do
         let binderName := args.binderName?.getD ""
         pure <| Except.ok <| ← goalState.tryLet goal binderName type
-      | .none, .none, .none, .none, .some pred, .none => do
+      | .none, .none, .none, .none, .some pred, .none, .none => do
         pure <| Except.ok <| ← goalState.tryCalc goal pred
-      | .none, .none, .none, .none, .none, .some true => do
+      | .none, .none, .none, .none, .none, .some true, .none => do
         pure <| Except.ok <| ← goalState.conv goal
-      | .none, .none, .none, .none, .none, .some false => do
+      | .none, .none, .none, .none, .none, .some false, .none => do
         pure <| Except.ok <| ← goalState.convExit
-      | _, _, _, _, _, _ =>
+      | .none, .none, .none, .none, .none, .none, .some draft => do
+        pure <| Except.ok <| ← goalState.tryDraft goal draft
+      | _, _, _, _, _, _, _ =>
         let error := errorI "arguments" "Exactly one of {tactic, expr, have, calc, conv} must be supplied"
         pure $ Except.error $ error
     match nextGoalState? with
@@ -265,7 +268,7 @@ def execute (command: Protocol.Command): MainM Lean.Json := do
           else
             pure .none
         let sorrys ← if args.sorrys then
-            Frontend.collectSorrys step
+            Frontend.collectSorrys step (options := { collectTypeErrors := args.typeErrorsAsGoals })
           else
             pure []
         let messages ← step.messageStrings

Test/Common.lean

@@ -48,6 +48,12 @@ namespace Condensed
 deriving instance BEq, Repr for LocalDecl
 deriving instance BEq, Repr for Goal
 
+-- Enable string interpolation
+instance : ToString FVarId where
+  toString id := id.name.toString
+instance : ToString MVarId where
+  toString id := id.name.toString
+
 protected def LocalDecl.devolatilize (decl: LocalDecl): LocalDecl :=
   {
     decl with fvarId := { name := .anonymous }

Test/Delate.lean

@@ -35,7 +35,7 @@ def test_sexp_of_symbol (env: Environment): IO LSpec.TestSeq := do
     ("Nat.add", "(:forall a (:c Nat) (:forall a (:c Nat) (:c Nat)))"),
     -- These ones are normal and easy
     ("Nat.add_one", "(:forall n (:c Nat) ((:c Eq) (:c Nat) ((:c HAdd.hAdd) (:c Nat) (:c Nat) (:c Nat) ((:c instHAdd) (:c Nat) (:c instAddNat)) 0 ((:c OfNat.ofNat) (:c Nat) (:lit 1) ((:c instOfNatNat) (:lit 1)))) ((:c Nat.succ) 0)))"),
-    ("Nat.le_of_succ_le", "(:forall n (:c Nat) (:forall m (:c Nat) (:forall h ((:c LE.le) (:c Nat) (:c instLENat) ((:c Nat.succ) 1) 0) ((:c LE.le) (:c Nat) (:c instLENat) 2 1)) :implicit) :implicit)"),
+    ("Nat.le_of_succ_le", "(:forall n (:c Nat) (:forall m (:c Nat) (:forall h ((:c LE.le) (:c Nat) (:c instLENat) ((:c Nat.succ) 1) 0) ((:c LE.le) (:c Nat) (:c instLENat) 2 1)) :i) :i)"),
     -- Handling of higher order types
     ("Or", "(:forall a (:sort 0) (:forall b (:sort 0) (:sort 0)))"),
     ("List", "(:forall α (:sort (+ u 1)) (:sort (+ u 1)))")
@@ -50,8 +50,8 @@ def test_sexp_of_elab (env: Environment): IO LSpec.TestSeq := do
   let entries: List (String × (List Name) × String) := [
     ("λ x: Nat × Bool => x.1", [], "(:lambda x ((:c Prod) (:c Nat) (:c Bool)) ((:c Prod.fst) (:c Nat) (:c Bool) 0))"),
     ("λ x: Array Nat => x.data", [], "(:lambda x ((:c Array) (:c Nat)) ((:c Array.data) (:c Nat) 0))"),
-    ("λ {α: Sort (u + 1)} => List α", [`u], "(:lambda α (:sort (+ u 1)) ((:c List) 0) :implicit)"),
-    ("λ {α} => List α", [], "(:lambda α (:sort (+ (:mv _uniq.4) 1)) ((:c List) 0) :implicit)"),
+    ("λ {α: Sort (u + 1)} => List α", [`u], "(:lambda α (:sort (+ u 1)) ((:c List) 0) :i)"),
+    ("λ {α} => List α", [], "(:lambda α (:sort (+ (:mv _uniq.4) 1)) ((:c List) 0) :i)"),
     ("(2: Nat) <= (5: Nat)", [], "((:c LE.le) (:mv _uniq.18) (:mv _uniq.19) ((:c OfNat.ofNat) (:mv _uniq.4) (:lit 2) (:mv _uniq.5)) ((:c OfNat.ofNat) (:mv _uniq.14) (:lit 5) (:mv _uniq.15)))"),
   ]
   entries.foldlM (λ suites (source, levels, target) =>
@@ -77,7 +77,7 @@ def test_sexp_of_expr (env: Environment): IO LSpec.TestSeq := do
             .default)
         .implicit)
       .implicit,
-      "(:lambda p (:sort 0) (:lambda q (:sort 0) (:lambda k ((:c And) 1 0) ((:c And.right) _ _ 0)) :implicit) :implicit)"
+      "(:lambda p (:sort 0) (:lambda q (:sort 0) (:lambda k ((:c And) 1 0) ((:c And.right) _ _ 0)) :i) :i)"
     ),
   ]
   let termElabM: Elab.TermElabM LSpec.TestSeq := entries.foldlM (λ suites (expr, target) => do

Test/Environment.lean

@@ -106,10 +106,10 @@ def test_symbol_location : TestT IO Unit := do
     let .ok result ← Environment.inspect { name := "Nat.le_of_succ_le", source? := .some true } (options := {}) | fail "Inspect failed"
     checkEq "module" result.module? <| .some "Init.Data.Nat.Basic"
 
-    -- Doesn't work for symbols in `Init` for some reason
-    --checkEq "file" result.sourceUri? <| .some "??"
-    checkEq "pos" result.sourceStart? <| .some { line := 344, column := 0 }
-    checkEq "pos" result.sourceEnd? <| .some { line := 344, column := 88 }
+    -- Extraction of source doesn't work for symbols in `Init` for some reason
+    checkTrue "file" result.sourceUri?.isNone
+    checkEq "pos" (result.sourceStart?.map (·.column)) <| .some 0
+    checkEq "pos" (result.sourceEnd?.map (·.column)) <| .some 88
 
 def suite: List (String × IO LSpec.TestSeq) :=
   [

Test/Frontend.lean

@@ -6,11 +6,12 @@ import Test.Common
 open Lean Pantograph
 namespace Pantograph.Test.Frontend
 
-def collectSorrysFromSource (source: String) : MetaM (List GoalState) := do
+def collectSorrysFromSource (source: String) (options : Frontend.GoalCollectionOptions := {})
+    : MetaM (List GoalState) := do
   let filename := "<anonymous>"
   let (context, state) ← do Frontend.createContextStateFromFile source filename (← getEnv) {}
   let m := Frontend.mapCompilationSteps λ step => do
-    return (step.before, ← Frontend.collectSorrys step)
+    return (step.before, ← Frontend.collectSorrys step options)
   let li ← m.run context |>.run' state
   let goalStates ← li.filterMapM λ (env, sorrys) => withEnv env do
     if sorrys.isEmpty then
@@ -181,9 +182,10 @@ def test_capture_type_mismatch : TestT MetaM Unit := do
   let input := "
 def mystery (k: Nat) : Nat := true
   "
-  let goalStates ← (collectSorrysFromSource input).run' {}
+  let options := { collectTypeErrors := true }
+  let goalStates ← (collectSorrysFromSource input options).run' {}
   let [goalState] := goalStates | panic! s!"Incorrect number of states: {goalStates.length}"
-  checkEq "goals" ((← goalState.serializeGoals (options := {})).map (·.devolatilize)) #[
+  checkEq "goals" ((← goalState.serializeGoals).map (·.devolatilize)) #[
     {
       target := { pp? := "Nat" },
       vars := #[{
@@ -193,6 +195,16 @@ def mystery (k: Nat) : Nat := true
     }
   ]
 
+def test_capture_type_mismatch_in_binder : TestT MetaM Unit := do
+  let input := "
+example (p: Prop) (h: (∀ (x: Prop), Nat) → p): p := h (λ (y: Nat) => 5)
+  "
+  let options := { collectTypeErrors := true }
+  let goalStates ← (collectSorrysFromSource input options).run' {}
+  let [goalState] := goalStates | panic! s!"Incorrect number of states: {goalStates.length}"
+  checkEq "goals" ((← goalState.serializeGoals (options := {})).map (·.devolatilize)) #[
+  ]
+
 def collectNewConstants (source: String) : MetaM (List (List Name)) := do
   let filename := "<anonymous>"
   let (context, state) ← do Frontend.createContextStateFromFile source filename (← getEnv) {}
@@ -227,6 +239,7 @@ def suite (env : Environment): List (String × IO LSpec.TestSeq) :=
     ("sorry_in_coupled", test_sorry_in_coupled),
     ("environment_capture", test_environment_capture),
     ("capture_type_mismatch", test_capture_type_mismatch),
+    --("capture_type_mismatch_in_binder", test_capture_type_mismatch_in_binder),
     ("collect_one_constant", test_collect_one_constant),
     ("collect_one_theorem", test_collect_one_theorem),
   ]

Test/Integration.lean

@@ -73,7 +73,7 @@ def test_tactic : Test :=
     step "goal.tactic" [("stateId", .num 0), ("goalId", .num 0), ("tactic", .str "intro x")]
      ({ nextStateId? := .some 1, goals? := #[goal1], }: Protocol.GoalTacticResult),
     step "goal.print" [("stateId", .num 1), ("parentExpr", .bool true), ("rootExpr", .bool true)]
-     ({ parent? := .some { pp? := .some "fun x => ?m.12 x" }, }: Protocol.GoalPrintResult),
+     ({ parent? := .some { pp? := .some "fun x => ?m.11" }, }: Protocol.GoalPrintResult),
     step "goal.tactic" [("stateId", .num 1), ("goalId", .num 0), ("tactic", .str "intro y")]
      ({ nextStateId? := .some 2, goals? := #[goal2], }: Protocol.GoalTacticResult),
   ]
@@ -90,27 +90,27 @@ def test_automatic_mode (automatic: Bool): Test :=
     ],
   }
   let goal2l: Protocol.Goal := {
-    name := "_uniq.59",
+    name := "_uniq.61",
     userName? := .some "inl",
     target := { pp? := .some "q ∨ p" },
     vars := varsPQ ++ #[
-      { name := "_uniq.47", userName := "h✝", type? := .some { pp? := .some "p" }, isInaccessible := true}
+      { name := "_uniq.49", userName := "h✝", type? := .some { pp? := .some "p" }, isInaccessible := true}
     ],
   }
   let goal2r: Protocol.Goal := {
-    name := "_uniq.72",
+    name := "_uniq.74",
     userName? := .some "inr",
     target := { pp? := .some "q ∨ p" },
     vars := varsPQ ++ #[
-      { name := "_uniq.60", userName := "h✝", type? := .some { pp? := .some "q" }, isInaccessible := true}
+      { name := "_uniq.62", userName := "h✝", type? := .some { pp? := .some "q" }, isInaccessible := true}
     ],
   }
   let goal3l: Protocol.Goal := {
-    name := "_uniq.78",
+    name := "_uniq.80",
     userName? := .some "inl.h",
     target := { pp? := .some "p" },
     vars := varsPQ ++ #[
-      { name := "_uniq.47", userName := "h✝", type? := .some { pp? := .some "p" }, isInaccessible := true}
+      { name := "_uniq.49", userName := "h✝", type? := .some { pp? := .some "p" }, isInaccessible := true}
     ],
   }
   [
@@ -174,6 +174,7 @@ def test_frontend_process : Test :=
         ("file",              .str file),
         ("invocations",       .bool true),
         ("sorrys",            .bool false),
+        ("typeErrorsAsGoals", .bool false),
         ("newConstants",      .bool false),
       ]
      ({
@@ -215,6 +216,7 @@ def test_frontend_process_sorry : Test :=
         ("file", .str file),
         ("invocations", .bool false),
         ("sorrys", .bool true),
+        ("typeErrorsAsGoals", .bool false),
         ("newConstants", .bool false),
       ]
      ({

Test/Main.lean

@@ -53,6 +53,7 @@ def main (args: List String) := do
     ("Proofs", Proofs.suite env_default),
     ("Delate", Delate.suite env_default),
     ("Serial", Serial.suite env_default),
+    ("Tactic/Assign", Tactic.Assign.suite env_default),
     ("Tactic/Congruence", Tactic.Congruence.suite env_default),
     ("Tactic/Motivated Apply", Tactic.MotivatedApply.suite env_default),
     ("Tactic/No Confuse", Tactic.NoConfuse.suite env_default),

Test/Metavar.lean

@@ -239,7 +239,7 @@ def test_partial_continuation: TestM Unit := do
       return ()
     | .ok state => pure state
   addTest $ LSpec.check "(continue)" ((← state1b.serializeGoals (options := ← read)).map (·.target.pp?) =
-    #[.some "2 ≤ ?m.succ", .some "?m.succ ≤ 5", .some "Nat"])
+    #[.some "2 ≤ Nat.succ ?m", .some "Nat.succ ?m ≤ 5", .some "Nat"])
   addTest $ LSpec.test "(2 root)" state1b.rootExpr?.isNone
 
   -- Roundtrip
@@ -253,7 +253,7 @@ def test_partial_continuation: TestM Unit := do
       return ()
     | .ok state => pure state
   addTest $ LSpec.check "(continue)" ((← state1b.serializeGoals (options := ← read)).map (·.target.pp?) =
-    #[.some "2 ≤ ?m.succ", .some "?m.succ ≤ 5", .some "Nat"])
+    #[.some "2 ≤ Nat.succ ?m", .some "Nat.succ ?m ≤ 5", .some "Nat"])
   addTest $ LSpec.test "(2 root)" state1b.rootExpr?.isNone
 
   -- Continuation should fail if the state does not exist:

Test/Proofs.lean

@@ -97,7 +97,7 @@ def test_identity: TestM Unit := do
   addTest $ LSpec.check tactic ((← state1.serializeGoals (options := ← read)).map (·.name) =
     #[inner])
   let state1parent ← state1.withParentContext do
-    serializeExpressionSexp (← instantiateAll state1.parentExpr?.get!) (sanitize := false)
+    serializeExpressionSexp (← instantiateAll state1.parentExpr?.get!)
   addTest $ LSpec.test "(1 parent)" (state1parent == s!"(:lambda p (:sort 0) (:lambda h 0 (:subst (:mv {inner}) 1 0)))")
 
 -- Individual test cases
@@ -241,13 +241,15 @@ def test_or_comm: TestM Unit := do
     | other => do
       addTest $ assertUnreachable $ other.toString
       return ()
-  let fvP := "_uniq.10"
-  let fvQ := "_uniq.13"
-  let fvH := "_uniq.16"
-  let state1g0 := "_uniq.17"
+  let [state1g0] := state1.goals | fail "Should have 1 goal"
+  let (fvP, fvQ, fvH) ← state1.withContext state1g0 do
+    let lctx ← getLCtx
+    let #[fvP, fvQ, fvH] := lctx.getFVarIds.map (toString ·.name) |
+      panic! "Incorrect number of decls"
+    pure (fvP, fvQ, fvH)
   addTest $ LSpec.check tactic ((← state1.serializeGoals (options := ← read)) =
     #[{
-      name := state1g0,
+      name := state1g0.name.toString,
       target := { pp? := .some "q ∨ p" },
       vars := #[
         { name := fvP, userName := "p", type? := .some { pp? := .some "Prop" } },
@@ -259,7 +261,7 @@ def test_or_comm: TestM Unit := do
   addTest $ LSpec.check "(1 root)" state1.rootExpr?.isNone
 
   let state1parent ← state1.withParentContext do
-    serializeExpressionSexp (← instantiateAll state1.parentExpr?.get!) (sanitize := false)
+    serializeExpressionSexp (← instantiateAll state1.parentExpr?.get!)
   addTest $ LSpec.test "(1 parent)" (state1parent == s!"(:lambda p (:sort 0) (:lambda q (:sort 0) (:lambda h ((:c Or) 1 0) (:subst (:mv {state1g0}) 2 1 0))))")
   let tactic := "cases h"
   let state2 ← match ← state1.tacticOn (goalId := 0) (tactic := tactic) with
@@ -269,14 +271,16 @@ def test_or_comm: TestM Unit := do
       return ()
   addTest $ LSpec.check tactic ((← state2.serializeGoals (options := ← read)).map (·.devolatilize) =
     #[branchGoal "inl" "p", branchGoal "inr" "q"])
-  let (caseL, caseR) := ("_uniq.64", "_uniq.77")
+  let [state2g0, state2g1] := state2.goals |
+    fail s!"Should have 2 goals, but it has {state2.goals.length}"
+  let (caseL, caseR) := (state2g0.name.toString, state2g1.name.toString)
   addTest $ LSpec.check tactic ((← state2.serializeGoals (options := ← read)).map (·.name) =
     #[caseL, caseR])
   addTest $ LSpec.check "(2 parent exists)" state2.parentExpr?.isSome
   addTest $ LSpec.check "(2 root)" state2.rootExpr?.isNone
 
   let state2parent ← state2.withParentContext do
-    serializeExpressionSexp (← instantiateAll state2.parentExpr?.get!) (sanitize := false)
+    serializeExpressionSexp (← instantiateAll state2.parentExpr?.get!)
   let orPQ := s!"((:c Or) (:fv {fvP}) (:fv {fvQ}))"
   let orQP := s!"((:c Or) (:fv {fvQ}) (:fv {fvP}))"
   let motive := s!"(:lambda t {orPQ} (:forall h ((:c Eq) ((:c Or) (:fv {fvP}) (:fv {fvQ})) (:fv {fvH}) 0) {orQP}))"
@@ -292,8 +296,9 @@ def test_or_comm: TestM Unit := do
       addTest $ assertUnreachable $ other.toString
       return ()
   let state3_1parent ← state3_1.withParentContext do
-    serializeExpressionSexp (← instantiateAll state3_1.parentExpr?.get!) (sanitize := false)
-  addTest $ LSpec.test "(3_1 parent)" (state3_1parent == s!"((:c Or.inr) (:fv {fvQ}) (:fv {fvP}) (:mv _uniq.91))")
+    serializeExpressionSexp (← instantiateAll state3_1.parentExpr?.get!)
+  let [state3_1goal0] := state3_1.goals | fail "Should have 1 goal"
+  addTest $ LSpec.test "(3_1 parent)" (state3_1parent == s!"((:c Or.inr) (:fv {fvQ}) (:fv {fvP}) (:mv {state3_1goal0}))")
   addTest $ LSpec.check "· apply Or.inr" (state3_1.goals.length = 1)
   let state4_1 ← match ← state3_1.tacticOn (goalId := 0) (tactic := "assumption") with
     | .success state => pure state
@@ -559,12 +564,15 @@ def test_nat_zero_add: TestM Unit := do
     | other => do
       addTest $ assertUnreachable $ other.toString
       return ()
+  let [mvarMotive, mvarMajor, mvarInduct, mvarConduit] := state2.goals |
+      fail "Incorrect number of goals"
+  let .num _ major := mvarMajor.name | fail "Incorrect form of mvar id"
   addTest $ LSpec.check s!"mapply {recursor}" ((← state2.serializeGoals (options := ← read)).map (·.devolatilizeVars) =
     #[
-      buildNamedGoal "_uniq.67" [("n", "Nat")] "Nat → Prop" (.some "motive"),
-      buildNamedGoal "_uniq.68" [("n", "Nat")] "Nat",
-      buildNamedGoal "_uniq.69" [("n", "Nat")] "∀ (t : Nat), Nat.below t → ?motive t",
-      buildNamedGoal "_uniq.70" [("n", "Nat")] "?motive ?m.68 = (n + 0 = n)" (.some "conduit")
+      buildNamedGoal mvarMotive.name.toString  [("n", "Nat")] "Nat → Prop" (.some "motive"),
+      buildNamedGoal mvarMajor.name.toString   [("n", "Nat")] "Nat",
+      buildNamedGoal mvarInduct.name.toString  [("n", "Nat")] "∀ (t : Nat), Nat.below t → ?motive t",
+      buildNamedGoal mvarConduit.name.toString [("n", "Nat")] s!"?motive ?m.{major} = (n + 0 = n)" (.some "conduit")
     ])
 
   let tactic := "exact n"
@@ -647,13 +655,15 @@ def test_nat_zero_add_alt: TestM Unit := do
     | other => do
       addTest $ assertUnreachable $ other.toString
       return ()
-  let major := "_uniq.68"
+  let [mvarMotive, mvarMajor, mvarInduct, mvarConduit] := state2.goals |
+      fail "Incorrect number of goals"
+  let .num _ major := mvarMajor.name | fail "Incorrect form of mvar id"
   addTest $ LSpec.check s!"mapply {recursor}" ((← state2.serializeGoals (options := ← read)).map (·.devolatilizeVars) =
     #[
-      buildNamedGoal "_uniq.67" [("n", "Nat")] "Nat → Prop" (.some "motive"),
-      buildNamedGoal major [("n", "Nat")] "Nat",
-      buildNamedGoal "_uniq.69" [("n", "Nat")] "∀ (t : Nat), Nat.below t → ?motive t",
-      buildNamedGoal "_uniq.70" [("n", "Nat")] "?motive ?m.68 = (n + 0 = n)" (.some "conduit")
+      buildNamedGoal mvarMotive.name.toString [("n", "Nat")] "Nat → Prop" (.some "motive"),
+      buildNamedGoal mvarMajor.name.toString [("n", "Nat")] "Nat",
+      buildNamedGoal mvarInduct.name.toString [("n", "Nat")] "∀ (t : Nat), Nat.below t → ?motive t",
+      buildNamedGoal mvarConduit.name.toString [("n", "Nat")] s!"?motive ?m.{major} = (n + 0 = n)" (.some "conduit")
     ])
 
   let tactic := "intro x"
@@ -670,8 +680,7 @@ def test_nat_zero_add_alt: TestM Unit := do
     | other => do
       addTest $ assertUnreachable $ other.toString
       return ()
-  let (eqL, eqR, eqT) := ("_uniq.88", "_uniq.89", "_uniq.87")
-  addTest $ LSpec.check tactic $ state3m2.goals.map (·.name.toString) = [eqL, eqR, eqT]
+  let [eqL, eqR, eqT] := state3m2.goals | fail "Incorrect number of goals"
   let [_motive, _major, _step, conduit] := state2.goals | panic! "Goals conflict"
   let state2b ← match state3m2.resume [conduit] with
     | .ok state => pure state
@@ -681,20 +690,26 @@ def test_nat_zero_add_alt: TestM Unit := do
 
   let cNatAdd := "(:c HAdd.hAdd) (:c Nat) (:c Nat) (:c Nat) ((:c instHAdd) (:c Nat) (:c instAddNat))"
   let cNat0 := "((:c OfNat.ofNat) (:c Nat) (:lit 0) ((:c instOfNatNat) (:lit 0)))"
-  let fvN := "_uniq.63"
+  let fvN ← state2b.withContext conduit do
+    let lctx ← getLCtx
+    pure $ lctx.getFVarIds.get! 0 |>.name
   let conduitRight := s!"((:c Eq) (:c Nat) ({cNatAdd} (:fv {fvN}) {cNat0}) (:fv {fvN}))"
-  let substOf (mv: String) := s!"(:subst (:mv {mv}) (:fv {fvN}) (:mv {major}))"
+  let substOf (mvarId: MVarId) := s!"(:subst (:mv {mvarId.name}) (:fv {fvN}) (:mv {mvarMajor}))"
+  let .num _ nL := eqL.name | fail "Incorrect form of mvar id"
+  let .num _ nR := eqR.name | fail "Incorrect form of mvar id"
+  let nL' := nL + 4
+  let nR' := nR + 5
   addTest $ LSpec.check "resume" ((← state2b.serializeGoals (options := { ← read with printExprAST := true })) =
     #[
       {
-        name := "_uniq.70",
+        name := mvarConduit.name.toString,
         userName? := .some "conduit",
         target := {
-          pp? := .some "(?m.92 ?m.68 = ?m.94 ?m.68) = (n + 0 = n)",
+          pp? := .some s!"(?m.{nL'} ?m.{major} = ?m.{nR'} ?m.{major}) = (n + 0 = n)",
           sexp? := .some s!"((:c Eq) (:sort 0) ((:c Eq) {substOf eqT} {substOf eqL} {substOf eqR}) {conduitRight})",
         },
         vars := #[{
-          name := fvN,
+          name := fvN.toString,
           userName := "n",
           type? := .some { pp? := .some "Nat", sexp? := .some "(:c Nat)" },
         }],
@@ -720,7 +735,6 @@ def test_tactic_failure_unresolved_goals : TestM Unit := do
   let .failure messages ← state1.tacticOn 0 tactic | addTest $ assertUnreachable s!"{tactic} should fail"
   checkEq s!"{tactic} fails" messages #[s!"{← getFileName}:0:12: error: unsolved goals\np : Nat → Prop\n⊢ p 0\n"]
 
-
 def test_tactic_failure_synthesize_placeholder : TestM Unit := do
   let state? ← startProof (.expr "∀ (p q r : Prop) (h : p → q), q ∧ r")
   let state0 ← match state? with
@@ -736,20 +750,25 @@ def test_tactic_failure_synthesize_placeholder : TestM Unit := do
       addTest $ assertUnreachable $ other.toString
       return ()
 
+  let iex : InternalExceptionId := { idx := 4 }
+  IO.println s!"{← iex.getName}"
   let tactic := "simpa [h] using And.imp_left h _"
-  let state2 ← match ← state1.tacticOn 0 tactic with
-    | .success state => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
+  --let state2 ← match ← state1.tacticOn 0 tactic with
+  --  | .success state => pure state
+  --  | other => do
+  --    addTest $ assertUnreachable $ other.toString
+  --    return ()
 
-  checkEq tactic ((← state2.serializeGoals).map (·.devolatilize))  #[
-    buildGoal [("p", "Prop"), ("q", "Prop"), ("r", "Prop"), ("h", "p → q")] "p ∧ r"
-  ]
+  -- Volatile behaviour. This easily changes across Lean versions
+
+  --checkEq tactic ((← state2.serializeGoals).map (·.devolatilize))  #[
+  --  buildGoal [("p", "Prop"), ("q", "Prop"), ("r", "Prop"), ("h", "p → q")] "p ∧ r"
+  --]
+
+  let .failure messages ← state1.tacticOn 0 tactic | addTest $ assertUnreachable s!"{tactic} should fail"
+  let message := s!"<Pantograph>:0:31: error: don't know how to synthesize placeholder\ncontext:\np q r : Prop\nh : p → q\n⊢ p ∧ r\n"
+  checkEq s!"{tactic} fails" messages #[message]
 
-  --let .failure messages ← state1.tacticOn 0 tactic | addTest $ assertUnreachable s!"{tactic} should fail"
-  --let message := s!"<Pantograph>:0:31: error: don't know how to synthesize placeholder\ncontext:\np q r : Prop\nh : p → q\n⊢ p ∧ r\n"
-  --checkEq s!"{tactic} fails" messages #[message]
 
 def suite (env: Environment): List (String × IO LSpec.TestSeq) :=
   let tests := [

Test/Tactic.lean

@@ -1,3 +1,4 @@
+import Test.Tactic.Assign
 import Test.Tactic.Congruence
 import Test.Tactic.MotivatedApply
 import Test.Tactic.NoConfuse

Test/Tactic/Assign.lean

@@ -0,0 +1,33 @@
+import Lean.Meta
+import Lean.Elab
+import LSpec
+import Test.Common
+
+open Lean
+
+namespace Pantograph.Test.Tactic.Assign
+
+def test_draft : TestT Elab.TermElabM Unit := do
+  let expr := "forall (p : Prop), (p ∨ p) ∨ p"
+  let skeleton := "by\nhave a : p ∨ p := sorry\nsorry"
+  let expr ← parseSentence expr
+  Meta.forallTelescope expr $ λ _ body => do
+    let skeleton' ← match Parser.runParserCategory
+      (env := ← MonadEnv.getEnv)
+      (catName := `term)
+      (input := skeleton)
+      (fileName := ← getFileName) with
+      | .ok syn => pure syn
+      | .error error => throwError "Failed to parse: {error}"
+    -- Apply the tactic
+    let target ← Meta.mkFreshExprSyntheticOpaqueMVar body
+    let tactic := Tactic.evalDraft skeleton'
+    let newGoals ← runTacticOnMVar tactic target.mvarId!
+    addTest $ LSpec.check "goals" ((← newGoals.mapM (λ g => do exprToStr (← g.getType))) = ["p ∨ p", "(p ∨ p) ∨ p"])
+
+def suite (env: Environment): List (String × IO LSpec.TestSeq) :=
+  [
+    ("draft", test_draft),
+  ] |>.map (λ (name, t) => (name, runTestTermElabM env t))
+
+end Pantograph.Test.Tactic.Assign

Test/Tactic/Congruence.lean

@@ -28,7 +28,7 @@ def test_congr_arg_list : TestT Elab.TermElabM Unit := do
     let results ← Meta.withAssignableSyntheticOpaque do f.apply (← parseSentence "List.reverse")
     addTest $ LSpec.check "apply" (results.length = 0)
     addTest $ LSpec.check "h" ((← exprToStr $ ← h.getType) = "?a₁ = ?a₂")
-    addTest $ LSpec.check "conduit" ((← exprToStr $ ← c.getType) = "(?a₁.reverse = ?a₂.reverse) = (l1.reverse = l2.reverse)")
+    addTest $ LSpec.check "conduit" ((← exprToStr $ ← c.getType) = "(List.reverse ?a₁ = List.reverse ?a₂) = (l1.reverse = l2.reverse)")
 def test_congr_arg : TestT Elab.TermElabM Unit := do
   let expr := "λ (n m: Nat) (h: n = m) => n * n = m * m"
   let expr ← parseSentence expr
@@ -37,7 +37,7 @@ def test_congr_arg : TestT Elab.TermElabM Unit := do
     let newGoals ← runTacticOnMVar Tactic.evalCongruenceArg target.mvarId!
     addTest $  LSpec.check "goals" ((← newGoals.mapM (λ x => mvarUserNameAndType x)) =
       [
-        (`α, "Sort ?u.70"),
+        (`α, "Sort ?u.73"),
         (`a₁, "?α"),
         (`a₂, "?α"),
         (`f, "?α → Nat"),
@@ -52,7 +52,7 @@ def test_congr_fun : TestT Elab.TermElabM Unit := do
     let newGoals ← runTacticOnMVar Tactic.evalCongruenceFun target.mvarId!
     addTest $ LSpec.check "goals" ((← newGoals.mapM (λ x => mvarUserNameAndType x)) =
       [
-        (`α, "Sort ?u.159"),
+        (`α, "Sort ?u.165"),
         (`f₁, "?α → Nat"),
         (`f₂, "?α → Nat"),
         (`h, "?f₁ = ?f₂"),

Test/Tactic/MotivatedApply.lean

@@ -40,7 +40,7 @@ def test_nat_brec_on : TestT Elab.TermElabM Unit := do
         "Nat → Prop",
         "Nat",
         "∀ (t : Nat), Nat.below t → ?motive t",
-        "?motive ?m.67 = (n + 0 = n)",
+        "?motive ?m.74 = (n + 0 = n)",
       ])
     addTest test
 
@@ -83,7 +83,7 @@ def test_partial_motive_instantiation : TestT Elab.TermElabM Unit := do
     let target ← Meta.mkFreshExprSyntheticOpaqueMVar body
     let tactic := Tactic.evalMotivatedApply recursor
     let newGoals ← runTacticOnMVar tactic target.mvarId!
-    let majorId := 67
+    let majorId := 74
     addTest $ (LSpec.check "goals" ((← newGoals.mapM (λ g => do exprToStr (← g.getType))) =
       [
         "Nat → Prop",
@@ -100,7 +100,7 @@ def test_partial_motive_instantiation : TestT Elab.TermElabM Unit := do
 
     addTest $ ← conduit.withContext do
       let t := toString (← Meta.ppExpr $ ← conduit.getType)
-      return LSpec.check "conduit" (t = s!"(?m.{majorId}.add + 0 = ?m.138 ?m.{majorId}) = (n + 0 = n)")
+      return LSpec.check "conduit" (t = s!"(Nat.add ?m.{majorId} + 0 = ?m.149 ?m.{majorId}) = (n + 0 = n)")
 
 def suite (env: Environment): List (String × IO LSpec.TestSeq) :=
   [

doc/repl.md

@@ -33,6 +33,7 @@ See `Pantograph/Protocol.lean` for a description of the parameters and return va
     to the previous `rhs`.
   - `{ "conv": <bool> }`: Enter or exit conversion tactic mode. In the case of
     exit, the goal id is ignored.
+  - `{ "draft": <expr> }`: Draft an expression with `sorry`s, turning them into goals. Coupling is not allowed.
 * `goal.continue {"stateId": <id>, ["branch": <id>], ["goals": <names>]}`:
   Execute continuation/resumption
   - `{ "branch": <id> }`: Continue on branch state. The current state must have no goals.
@@ -44,11 +45,12 @@ See `Pantograph/Protocol.lean` for a description of the parameters and return va
   state. The user is responsible to ensure the sender/receiver instances share
   the same environment.
 * `frontend.process { ["fileName": <fileName>,] ["file": <str>], invocations:
-  <bool>, sorrys: <bool>, newConstants: <bool> }`: Executes the Lean frontend on
-  a file, collecting the tactic invocations (`"invocations": true`), the
-  sorrys and type errors into goal states (`"sorrys": true`), and new constants
-  (`"newConstants": true`). In the case of `sorrys`, this command additionally
-  outputs the position of each captured `sorry`.
+  <bool>, sorrys: <bool>, typeErrorsAsGoals: <bool>, newConstants: <bool> }`:
+  Executes the Lean frontend on a file, collecting the tactic invocations
+  (`"invocations": true`), the sorrys and type errors into goal states
+  (`"sorrys": true`), and new constants (`"newConstants": true`). In the case of
+  `sorrys`, this command additionally outputs the position of each captured
+  `sorry`.
 
 ## Errors
 

flake.lock

@@ -42,11 +42,11 @@
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1731711316,
-        "narHash": "sha256-s5u+A2/Ea9gPveB5wwVM5dWW0NST6kamDsTeovGuLEs=",
+        "lastModified": 1736388194,
+        "narHash": "sha256-ymSrd/A8Pw+9FzbxUbR7CkFHLJK1b4SnFFWg/1e0JeE=",
         "owner": "lenianiva",
         "repo": "lean4-nix",
-        "rev": "136fc6057c48de970579e960b62421e9c295b67d",
+        "rev": "90f496bc0694fb97bdfa6adedfc2dc2c841a4cf2",
         "type": "github"
       },
       "original": {

flake.nix

@@ -18,7 +18,8 @@
     lean4-nix,
     lspec,
     ...
-  } : flake-parts.lib.mkFlake { inherit inputs; } {
+  }:
+    flake-parts.lib.mkFlake {inherit inputs;} {
       flake = {
       };
       systems = [
@@ -27,36 +28,40 @@
         "x86_64-linux"
         "x86_64-darwin"
       ];
-    perSystem = { system, pkgs, ... }: let
+      perSystem = {
+        system,
+        pkgs,
+        ...
+      }: let
         pkgs = import nixpkgs {
           inherit system;
-        overlays = [ (lean4-nix.readToolchainFile ./lean-toolchain) ];
+          overlays = [(lean4-nix.readToolchainFile ./lean-toolchain)];
         };
         lspecLib = pkgs.lean.buildLeanPackage {
           name = "LSpec";
-        roots = [ "Main" "LSpec" ];
+          roots = ["Main" "LSpec"];
           src = "${lspec}";
         };
         project = pkgs.lean.buildLeanPackage {
           name = "Pantograph";
-        roots = [ "Pantograph" ];
+          roots = ["Pantograph"];
           src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
             src = ./.;
             filter = path: type:
-            !(pkgs.lib.hasInfix "/Test/" path) &&
-            !(pkgs.lib.hasSuffix ".md" path) &&
-            !(pkgs.lib.hasSuffix "Repl.lean" path);
+              !(pkgs.lib.hasInfix "/Test/" path)
+              && !(pkgs.lib.hasSuffix ".md" path)
+              && !(pkgs.lib.hasSuffix "Repl.lean" path);
           });
         };
         repl = pkgs.lean.buildLeanPackage {
           name = "Repl";
-        roots = [ "Main" "Repl" ];
-        deps = [ project ];
+          roots = ["Main" "Repl"];
+          deps = [project];
           src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
             src = ./.;
             filter = path: type:
-            !(pkgs.lib.hasInfix "/Test/" path) &&
-            !(pkgs.lib.hasSuffix ".md" path);
+              !(pkgs.lib.hasInfix "/Test/" path)
+              && !(pkgs.lib.hasSuffix ".md" path);
           });
         };
         test = pkgs.lean.buildLeanPackage {
@@ -64,8 +69,8 @@
           # NOTE: The src directory must be ./. since that is where the import
           # root begins (e.g. `import Test.Environment` and not `import
           # Environment`) and thats where `lakefile.lean` resides.
-        roots = [ "Test.Main" ];
-        deps = [ lspecLib repl ];
+          roots = ["Test.Main"];
+          deps = [lspecLib repl];
           src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
             src = ./.;
             filter = path: type:
@@ -84,15 +89,17 @@
           leanPkgs = pkgs.lean;
         };
         checks = {
-        test = pkgs.runCommand "test" {
-          buildInputs = [ test.executable pkgs.lean.lean-all ];
+          test =
+            pkgs.runCommand "test" {
+              buildInputs = [test.executable pkgs.lean.lean-all];
             } ''
               #export LEAN_SRC_PATH="${./.}"
               ${test.executable}/bin/test > $out
             '';
         };
+        formatter = pkgs.alejandra;
         devShells.default = pkgs.mkShell {
-        buildInputs = [ pkgs.lean.lean-all pkgs.lean.lean ];
+          buildInputs = [pkgs.lean.lean-all pkgs.lean.lean];
         };
       };
     };

lean-toolchain

@@ -1 +1 @@
-leanprover/lean4:v4.12.0
+leanprover/lean4:v4.15.0