feat: Pickle constants in goal state

Reviewed-on: #134

.gitignore

@@ -1,6 +1,4 @@
 .*
 !.gitignore
-
-*.olean
-/build
-/lake-packages
+*.[io]lean
+/result

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
@@ -327,16 +326,17 @@ partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM
       -- Lean these are handled using a `#` prefix.
       pure s!"{deBruijnIndex}"
     | .fvar fvarId =>
-      let name := ofName fvarId.name
+      let name := fvarId.name
       pure s!"(:fv {name})"
     | .mvar mvarId => do
         let pref := if ← mvarId.isDelayedAssigned then "mvd" else "mv"
-        let name := ofName mvarId.name
+        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})"
@@ -346,20 +346,20 @@ partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM
       let args := " ".intercalate args
       pure s!"({fn'} {args})"
     | .lam binderName binderType body binderInfo => do
-      let binderName' := ofName binderName
+      let binderName' := binderName.eraseMacroScopes
       let binderType' ← self binderType
       let body' ← self body
       let binderInfo' := binderInfoSexp binderInfo
       pure s!"(:lambda {binderName'} {binderType'} {body'}{binderInfo'})"
     | .forallE binderName binderType body binderInfo => do
-      let binderName' := ofName binderName
+      let binderName' := binderName.eraseMacroScopes
       let binderType' ← self binderType
       let body' ← self body
       let binderInfo' := binderInfoSexp binderInfo
       pure s!"(:forall {binderName'} {binderType'} {body'}{binderInfo'})"
     | .letE name type value body _ => do
       -- Dependent boolean flag diacarded
-      let name' := serializeName name
+      let name' := name.eraseMacroScopes
       let type' ← self type
       let value' ← self value
       let body' ← self body
@@ -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
@@ -384,10 +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"
-  ofName (name: Name) := serializeName name sanitize
+    | .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
@@ -420,13 +419,13 @@ def serializeGoal (options: @&Protocol.Options) (goal: MVarId) (mvarDecl: Metava
       match localDecl with
       | .cdecl _ fvarId userName _ _ _ =>
         return {
-          name := ofName fvarId.name,
+          name := fvarId.name.toString,
           userName:= ofName userName.simpMacroScopes,
           isInaccessible := userName.isInaccessibleUserName
         }
       | .ldecl _ fvarId userName _ _ _ _ => do
         return {
-          name := ofName fvarId.name,
+          name := fvarId.name.toString,
           userName := toString userName.simpMacroScopes,
           isInaccessible := userName.isInaccessibleUserName
         }
@@ -436,7 +435,7 @@ def serializeGoal (options: @&Protocol.Options) (goal: MVarId) (mvarDecl: Metava
         let userName := userName.simpMacroScopes
         let type ← instantiate type
         return {
-          name := ofName fvarId.name,
+          name := fvarId.name.toString,
           userName:= ofName userName,
           isInaccessible := userName.isInaccessibleUserName
           type? := .some (← serializeExpression options type)
@@ -450,7 +449,7 @@ def serializeGoal (options: @&Protocol.Options) (goal: MVarId) (mvarDecl: Metava
         else
           pure $ .none
         return {
-          name := ofName fvarId.name,
+          name := fvarId.name.toString,
           userName:= ofName userName,
           isInaccessible := userName.isInaccessibleUserName
           type? := .some (← serializeExpression options type)
@@ -469,7 +468,7 @@ def serializeGoal (options: @&Protocol.Options) (goal: MVarId) (mvarDecl: Metava
           | false => ppVar localDecl
         return var::acc
     return {
-      name := ofName goal.name,
+      name := goal.name.toString,
       userName? := if mvarDecl.userName == .anonymous then .none else .some (ofName mvarDecl.userName),
       isConversion := isLHSGoal? mvarDecl.type |>.isSome,
       target := (← serializeExpression options (← instantiate mvarDecl.type)),
@@ -533,7 +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/Environment.lean

@@ -58,7 +58,7 @@ def inspect (args: Protocol.EnvInspect) (options: @&Protocol.Options): CoreM (Pr
     | none => return .error $ Protocol.errorIndex s!"Symbol not found {args.name}"
     | some info => pure info
   let module? := env.getModuleIdxFor? name >>=
-    (λ idx => env.allImportedModuleNames.get? idx.toNat) |>.map toString
+    (λ idx => env.allImportedModuleNames.get? idx.toNat)
   let value? := match args.value?, info with
     | .some true, _ => info.value?
     | .some false, _ => .none
@@ -80,7 +80,7 @@ def inspect (args: Protocol.EnvInspect) (options: @&Protocol.Options): CoreM (Pr
       then value?.map (λ e =>
         e.getUsedConstants.filter (!isNameInternal ·) |>.map (λ n => serializeName n) )
       else .none,
-    module? := module?
+    module? := module?.map (·.toString)
   }
   let result ← match info with
     | .inductInfo induct => pure { core with inductInfo? := .some {
@@ -113,6 +113,20 @@ def inspect (args: Protocol.EnvInspect) (options: @&Protocol.Options): CoreM (Pr
           k := r.k,
       } }
     | _ => pure core
+  let result ← if args.source?.getD false then
+      let srcSearchPath ← initSrcSearchPath
+      let sourceUri? ← module?.bindM (Server.documentUriFromModule srcSearchPath ·)
+      let declRange? ← findDeclarationRanges? name
+      let sourceStart? := declRange?.map (·.range.pos)
+      let sourceEnd? := declRange?.map (·.range.endPos)
+      .pure {
+        result with
+        sourceUri?,
+        sourceStart?,
+        sourceEnd?,
+      }
+    else
+      .pure result
   return .ok result
 def addDecl (args: Protocol.EnvAdd): CoreM (Protocol.CR Protocol.EnvAddResult) := do
   let env ← Lean.MonadEnv.getEnv

Pantograph/Frontend.lean

@@ -1,4 +1,4 @@
-/- Adapted from lean-training-data by semorrison -/
 import Pantograph.Frontend.Basic
 import Pantograph.Frontend.Elab
+import Pantograph.Frontend.InfoTree
 import Pantograph.Frontend.MetaTranslate

Pantograph/Frontend/Basic.lean

@@ -30,6 +30,13 @@ end Lean.PersistentArray
 
 namespace Pantograph.Frontend
 
+@[export pantograph_frontend_stx_byte_range]
+def stxByteRange (stx : Syntax) : String.Pos × String.Pos :=
+  let pos := stx.getPos?.getD 0
+  let endPos := stx.getTailPos?.getD 0
+  (pos, endPos)
+
+
 abbrev FrontendM := Elab.Frontend.FrontendM
 
 structure CompilationStep where
@@ -60,7 +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

@@ -1,87 +1,21 @@
-/- Adapted from https://github.com/semorrison/lean-training-data -/
 import Lean.Elab.Import
 import Lean.Elab.Command
 import Lean.Elab.InfoTree
+import Lean.DeclarationRange
 
 import Pantograph.Frontend.Basic
 import Pantograph.Frontend.MetaTranslate
 import Pantograph.Goal
 import Pantograph.Protocol
+import Pantograph.Frontend.InfoTree
 
 open Lean
 
-namespace Lean.Elab.Info
-/-- The `Syntax` for a `Lean.Elab.Info`, if there is one. -/
-protected def stx? : Info → Option Syntax
-  | .ofTacticInfo         info => info.stx
-  | .ofTermInfo           info => info.stx
-  | .ofCommandInfo        info => info.stx
-  | .ofMacroExpansionInfo info => info.stx
-  | .ofOptionInfo         info => info.stx
-  | .ofFieldInfo          info => info.stx
-  | .ofCompletionInfo     info => info.stx
-  | .ofUserWidgetInfo     info => info.stx
-  | .ofCustomInfo         info => info.stx
-  | .ofFVarAliasInfo      _    => none
-  | .ofFieldRedeclInfo    info => info.stx
-  | .ofOmissionInfo       info => info.stx
-/-- Is the `Syntax` for this `Lean.Elab.Info` original, or synthetic? -/
-protected def isOriginal (i : Info) : Bool :=
-  match i.stx? with
-  | none => true   -- Somewhat unclear what to do with `FVarAliasInfo`, so be conservative.
-  | some stx => match stx.getHeadInfo with
-    | .original .. => true
-    | _ => false
-end Lean.Elab.Info
-
-namespace Lean.Elab.TacticInfo
-
-/-- Find the name for the outermost `Syntax` in this `TacticInfo`. -/
-def name? (t : TacticInfo) : Option Name :=
-  match t.stx with
-  | Syntax.node _ n _ => some n
-  | _ => none
-/-- Decide whether a tactic is "substantive",
-or is merely a tactic combinator (e.g. `by`, `;`, multiline tactics, parenthesized tactics). -/
-def isSubstantive (t : TacticInfo) : Bool :=
-  match t.name? with
-  | none => false
-  | some `null => false
-  | some ``cdot => false
-  | some ``cdotTk => false
-  | some ``Lean.Parser.Term.byTactic => false
-  | some ``Lean.Parser.Tactic.tacticSeq => false
-  | some ``Lean.Parser.Tactic.tacticSeq1Indented => false
-  | some ``Lean.Parser.Tactic.«tactic_<;>_» => false
-  | some ``Lean.Parser.Tactic.paren => false
-  | _ => true
-
-end Lean.Elab.TacticInfo
-
-namespace Lean.Elab.InfoTree
-
-/--
-Keep `.node` nodes and `.hole` nodes satisfying predicates.
-
-Returns a `List InfoTree`, although in most situations this will be a singleton.
--/
-partial def filter (p : Info → Bool) (m : MVarId → Bool := fun _ => false) :
-    InfoTree → List InfoTree
-  | .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']
-    else
-      (children.toList.map (filter p m)).join
-  | .hole mvar => if m mvar then [.hole mvar] else []
-
-end Lean.Elab.InfoTree
-
-
 namespace Pantograph.Frontend
 
 -- Info tree filtering functions
 
+/- Adapted from lean-training-data -/
 structure TacticInvocation where
   info : Elab.TacticInfo
   ctx : Elab.ContextInfo
@@ -131,19 +65,10 @@ protected def usedConstants (t: TacticInvocation) : NameSet :=
 
 end TacticInvocation
 
-/-- Analogue of `Lean.Elab.InfoTree.findInfo?`, but that returns a list of all results. -/
-partial def findAllInfo (t : Elab.InfoTree) (context?: Option Elab.ContextInfo) (pred : Elab.Info → Bool) :
-    List (Elab.Info × Option Elab.ContextInfo × PersistentArray Elab.InfoTree) :=
-  match t with
-  | .context inner t => findAllInfo t (inner.mergeIntoOuter? context?) pred
-  | .node i children  =>
-      (if pred i then [(i, context?, children)] else []) ++ children.toList.bind (fun t => findAllInfo t context? pred)
-  | _ => []
-
 /-- Return all `TacticInfo` nodes in an `InfoTree` corresponding to tactics,
 each equipped with its relevant `ContextInfo`, and any children info trees. -/
 private def collectTacticNodes (t : Elab.InfoTree) : List TacticInvocation :=
-  let infos := findAllInfo t none fun i => match i with
+  let infos := t.findAllInfo none false fun i => match i with
     | .ofTacticInfo _ => true
     | _ => false
   infos.filterMap fun p => match p with
@@ -155,16 +80,18 @@ 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
-    let tactic ← invocation.ctx.runMetaM {} do
-      let t ← PrettyPrinter.ppTactic ⟨invocation.info.stx⟩
-      return t.pretty
+    let tactic ← invocation.ctx.runMetaM {} <| Meta.withMCtx invocation.info.mctxBefore do
+      return (← invocation.ctx.ppSyntax {} invocation.info.stx).pretty
+      -- FIXME: Why does this not work? There are problems with `term.pseudo.antiquot`
+      --PrettyPrinter.ppTactic ⟨invocation.info.stx⟩
+      --return t.pretty
     let usedConstants := invocation.usedConstants.toArray.map λ n => n.toString
     return {
       goalBefore,
@@ -177,47 +104,91 @@ structure InfoWithContext where
   info: Elab.Info
   context?: Option Elab.ContextInfo := .none
 
-private def collectSorrysInTree (t : Elab.InfoTree) : List InfoWithContext :=
-  let infos := findAllInfo t none fun i => match i with
-    | .ofTermInfo { expectedType?, expr, stx, .. } =>
-      expr.isSorry ∧ expectedType?.isSome ∧ stx.isOfKind `Lean.Parser.Term.sorry
+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, 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
+        Meta.isExprDefEqGuarded type expectedType
+      return match typeMatch, expr.hasSorry with
+      | false, true => (true, false) -- Types mismatch but has sorry -> collect, halt
+      | false, false => (true, false) -- Types mistmatch but no sorry -> collect, halt
+      | true, true => (false, true) -- Types match but has sorry -> continue
+      | true, false => (false, false) -- Types match but no sorries -> halt
     | .ofTacticInfo { stx, goalsBefore, .. } =>
       -- The `sorry` term is distinct from the `sorry` tactic
       let isSorry := stx.isOfKind `Lean.Parser.Tactic.tacticSorry
-      isSorry ∧ !goalsBefore.isEmpty
-    | _ => false
-  infos.map fun (info, context?, _) => { info, context? }
+      return (isSorry ∧ !goalsBefore.isEmpty, ¬ isSorry)
+    | _ => return (false, true)
+  return infos.map fun (info, context?, _) => { info, context? }
 
 -- NOTE: Plural deliberately not spelled "sorries"
 @[export pantograph_frontend_collect_sorrys_m]
-def collectSorrys (step: CompilationStep) : List InfoWithContext :=
-  step.trees.bind collectSorrysInTree
-
+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
+  srcBoundaries : List (String.Pos × String.Pos)
 
 /--
 Since we cannot directly merge `MetavarContext`s, we have to get creative. This
 function duplicates frozen mvars in term and tactic info nodes, and add them to
 the current `MetavarContext`.
 -/
-@[export pantograph_frontend_sorrys_to_goal_state]
-def sorrysToGoalState (sorrys : List InfoWithContext) : MetaM GoalState := do
+@[export pantograph_frontend_sorrys_to_goal_state_m]
+def sorrysToGoalState (sorrys : List InfoWithContext) : MetaM AnnotatedGoalState := do
   assert! !sorrys.isEmpty
   let goalsM := sorrys.mapM λ i => do
     match i.info with
     | .ofTermInfo termInfo  => do
       let mvarId ← MetaTranslate.translateMVarFromTermInfo termInfo i.context?
-      return [mvarId]
+      if (← mvarId.getType).hasSorry then
+        throwError s!"Coupling is not allowed in drafting"
+      return [(mvarId, stxByteRange termInfo.stx)]
     | .ofTacticInfo tacticInfo => do
-      MetaTranslate.translateMVarFromTacticInfoBefore tacticInfo i.context?
+      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 goals := 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
     | [] => panic! "No MVars generated"
     | [g] => g
     | _ => { name := .anonymous }
-  GoalState.createFromMVars goals root
+  let state ← GoalState.createFromMVars goals root
+  return { state, srcBoundaries }
 
 
+@[export pantograph_frontend_collect_new_defined_constants_m]
+def collectNewDefinedConstants (step : CompilationStep) : IO (List Name) := do
+  step.after.constants.map₂.foldlM (λ acc name _ => do
+    if step.before.contains name then
+      return acc
+    let coreM : CoreM Bool := Option.isSome <$> findDeclarationRanges? name
+    let hasRange ← coreM.run' { fileName := step.fileName, fileMap := step.fileMap } { env := step.after } |>.toBaseIO
+    match hasRange with
+    | .ok true => return name :: acc
+    | .ok false => return acc
+    | .error e => throw $ IO.userError (← e.toMessageData.toString)
+    ) []
 
 end Pantograph.Frontend

Pantograph/Frontend/InfoTree.lean

@@ -0,0 +1,157 @@
+/- Adapted from lean-training-data -/
+import Lean.Elab.InfoTree
+import Lean.Parser.Term
+import Lean.PrettyPrinter
+
+open Lean
+
+namespace Lean.Elab
+
+private def elaboratorToString : Name → String
+  | .anonymous => ""
+  | n => s!"⟨{n}⟩ "
+private def indent (s : String) : String := "\n".intercalate $ s.splitOn "\n" |>.map ("\t" ++ .)
+
+/-- The `Syntax` for a `Lean.Elab.Info`, if there is one. -/
+protected def Info.stx? : Info → Option Syntax
+  | .ofTacticInfo         info => info.stx
+  | .ofTermInfo           info => info.stx
+  | .ofCommandInfo        info => info.stx
+  | .ofMacroExpansionInfo info => info.stx
+  | .ofOptionInfo         info => info.stx
+  | .ofFieldInfo          info => info.stx
+  | .ofCompletionInfo     info => info.stx
+  | .ofUserWidgetInfo     info => info.stx
+  | .ofCustomInfo         info => info.stx
+  | .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
+  | none => true   -- Somewhat unclear what to do with `FVarAliasInfo`, so be conservative.
+  | some stx => match stx.getHeadInfo with
+    | .original .. => true
+    | _ => false
+
+def ContextInfo.ppExpr (ctx : ContextInfo) (lctx : LocalContext) (e : Expr) : IO Format :=
+  ctx.runMetaM lctx (do Meta.ppExpr (← instantiateMVars e))
+
+def CommandInfo.toString (info : CommandInfo) (ctx : ContextInfo) : IO String := do
+  let stx := (← ctx.ppSyntax {} info.stx).pretty
+  return s!"{elaboratorToString info.elaborator}\n{stx}"
+
+def TermInfo.toString (info : TermInfo) (ctx : ContextInfo) : IO String := do
+  let stx := (← ctx.ppSyntax info.lctx info.stx).pretty
+  let expectedType := (← info.expectedType?.mapM fun ty => do
+    pure s!": {(← ctx.ppExpr info.lctx ty).pretty}").getD ""
+  let expr := (← ctx.ppExpr info.lctx info.expr).pretty
+  return s!"{elaboratorToString info.elaborator}{expr}{expectedType}\n{stx}"
+
+/-- Find the name for the outermost `Syntax` in this `TacticInfo`. -/
+def TacticInfo.name? (t : TacticInfo) : Option Name :=
+  match t.stx with
+  | Syntax.node _ n _ => some n
+  | _ => none
+/-- Decide whether a tactic is "substantive",
+or is merely a tactic combinator (e.g. `by`, `;`, multiline tactics, parenthesized tactics). -/
+def TacticInfo.isSubstantive (t : TacticInfo) : Bool :=
+  match t.name? with
+  | none => false
+  | some `null => false
+  | some ``cdot => false
+  | some ``cdotTk => false
+  | some ``Lean.Parser.Term.byTactic => false
+  | some ``Lean.Parser.Tactic.tacticSeq => false
+  | some ``Lean.Parser.Tactic.tacticSeq1Indented => false
+  | some ``Lean.Parser.Tactic.«tactic_<;>_» => false
+  | some ``Lean.Parser.Tactic.paren => false
+  | _ => true
+def TacticInfo.pp (info : TacticInfo) (ctx : ContextInfo) : IO Format :=
+  ctx.runMetaM {} try
+    Lean.PrettyPrinter.ppTactic ⟨info.stx⟩
+  catch _ =>
+    pure "<failed to pretty print>"
+def TacticInfo.toString (i : TacticInfo) (ctx : ContextInfo) : IO String := do
+  let name := i.name?
+  let stx := Format.pretty (← i.pp ctx)
+  return s!"{name}\n{stx}"
+
+/--
+Keep `.node` nodes and `.hole` nodes satisfying predicates.
+
+Returns a `List InfoTree`, although in most situations this will be a singleton.
+-/
+partial def InfoTree.filter (p : Info → Bool) (m : MVarId → Bool := fun _ => false) :
+    InfoTree → List InfoTree
+  | .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)).flatten.toPArray']
+    else
+      (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. -/
+partial def InfoTree.findAllInfo
+    (t : InfoTree)
+    (context?: Option Elab.ContextInfo)
+    (haltOnMatch : Bool := false)
+    (pred : Elab.Info → Bool)
+    : List (Elab.Info × Option Elab.ContextInfo × PersistentArray Elab.InfoTree) :=
+  match t with
+  | .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.flatMap (fun t => findAllInfo t context? haltOnMatch pred)
+    head ++ tail
+  | _ => []
+
+/-- Monadic analogue of `findAllInfo`, but predicate controls whether to recurse. -/
+partial def InfoTree.findAllInfoM [Monad m]
+    (t : InfoTree)
+    (context?: Option Elab.ContextInfo)
+    (pred : Elab.Info → Option Elab.ContextInfo → m (Bool × Bool))
+    : m (List (Elab.Info × Option Elab.ContextInfo × PersistentArray Elab.InfoTree)) := do
+  match t with
+  | .context inner t => t.findAllInfoM (inner.mergeIntoOuter? context?) pred
+  | .node i children  =>
+    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).flatten
+  | _ => return []
+
+@[export pantograph_infotree_to_string_m]
+partial def InfoTree.toString (t : InfoTree) (ctx?: Option Elab.ContextInfo := .none) : IO String := do
+  match t with
+  | .context ctx t => t.toString (ctx.mergeIntoOuter? ctx?)
+  | .node info children =>
+    if let some ctx := ctx? then
+      let node : String ← match info with
+      | .ofTermInfo    info => pure s!"[term] {(← info.toString ctx)}"
+      | .ofCommandInfo info => pure s!"[command] {(← info.toString ctx)}"
+      | .ofTacticInfo  info => pure s!"[tactic] {(← info.toString ctx)}"
+      | .ofMacroExpansionInfo _ => pure "[macro_exp]"
+      | .ofOptionInfo _ => pure "[option]"
+      | .ofFieldInfo _ => pure "[field]"
+      | .ofCompletionInfo _ => pure "[completion]"
+      | .ofUserWidgetInfo _ => pure "[user_widget]"
+      | .ofCustomInfo _ => pure "[custom]"
+      | .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."
+  | .hole mvarId =>
+    if let some ctx := ctx? then
+      let payload := (← ctx.runMetaM {} (do Meta.ppGoal mvarId)).pretty
+      return s!"[hole] {payload}"
+    else throw <| IO.userError "No `ContextInfo` available."
+
+end Lean.Elab

Pantograph/Goal.lean

@@ -10,8 +10,6 @@ import Lean
 namespace Pantograph
 open Lean
 
-def filename: String := "<pantograph>"
-
 /--
 Represents an interconnected set of metavariables, or a state in proof search
  -/
@@ -73,6 +71,8 @@ protected def GoalState.metaContextOfGoal (state: GoalState) (mvarId: MVarId): O
   return { lctx := mvarDecl.lctx, localInstances := mvarDecl.localInstances }
 protected def GoalState.metaState (state: GoalState): Meta.State :=
   state.savedState.term.meta.meta
+protected def GoalState.coreState (state: GoalState): Core.SavedState :=
+  state.savedState.term.meta.core
 
 protected def GoalState.withContext (state: GoalState) (mvarId: MVarId) (m: MetaM α): MetaM α := do
   mvarId.withContext m |>.run' (← read) state.metaState
@@ -177,16 +177,52 @@ protected def GoalState.getMVarEAssignment (goalState: GoalState) (mvarId: MVarI
 
 --- Tactic execution functions ---
 
-protected def GoalState.step (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM Unit)
+-- Mimics `Elab.Term.logUnassignedUsingErrorInfos`
+private def collectAllErroredMVars (src : MVarId) : Elab.TermElabM (List MVarId) := do
+  -- These descendants serve as "seed" mvars. If a MVarError's mvar is related
+  -- 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 (.mvar src)
+  --let _ ← Elab.Term.logUnassignedUsingErrorInfos descendants
+  let mut alreadyVisited : MVarIdSet := {}
+  let mut result : MVarIdSet := {}
+  for { mvarId, .. } in (← get).mvarErrorInfos do
+    unless alreadyVisited.contains mvarId do
+      alreadyVisited := alreadyVisited.insert mvarId
+      /- The metavariable `mvarErrorInfo.mvarId` may have been assigned or
+         delayed assigned to another metavariable that is unassigned. -/
+      let mvarDeps ← Meta.getMVars (.mvar mvarId)
+      if mvarDeps.any descendants.contains then do
+        result := mvarDeps.foldl (·.insert ·) result
+  return result.toList
+
+private def mergeMVarLists (li1 li2 : List MVarId) : List MVarId :=
+  let li2' := li2.filter (¬ li1.contains ·)
+  li1 ++ li2'
+
+/--
+Set `guardMVarErrors` to true to capture mvar errors. Lean will not
+automatically collect mvars from text tactics (vide
+`test_tactic_failure_synthesize_placeholder`)
+-/
+protected def GoalState.step (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM Unit) (guardMVarErrors : Bool := false)
   : Elab.TermElabM GoalState := do
   unless (← getMCtx).decls.contains goal do
     throwError s!"Goal is not in context: {goal.name}"
   goal.checkNotAssigned `GoalState.step
-  let (_, newGoals) ← tacticM { elaborator := .anonymous } |>.run { goals := [goal] }
+  let (_, { goals }) ← tacticM { elaborator := .anonymous } |>.run { goals := [goal] }
   let nextElabState ← MonadBacktrack.saveState
+  Elab.Term.synthesizeSyntheticMVarsNoPostponing
+
+  let goals ← if guardMVarErrors then
+      pure $ mergeMVarLists goals (← collectAllErroredMVars goal)
+    else
+      pure goals
   return {
     state with
-    savedState := { term := nextElabState, tactic := newGoals },
+    savedState := { term := nextElabState, tactic := { goals }, },
     parentMVar? := .some goal,
     calcPrevRhs? := .none,
   }
@@ -202,16 +238,37 @@ inductive TacticResult where
   -- The given action cannot be executed in the state
   | invalidAction (message: String)
 
-/-- Executes a `TacticM` monads on this `GoalState`, collecting the errors as necessary -/
-protected def GoalState.tryTacticM (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM Unit):
-      Elab.TermElabM TacticResult := do
+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
+    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
     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]
 protected def GoalState.tryTactic (state: GoalState) (goal: MVarId) (tactic: String):
     Elab.TermElabM TacticResult := do
   state.restoreElabM
@@ -219,10 +276,10 @@ protected def GoalState.tryTactic (state: GoalState) (goal: MVarId) (tactic: Str
     (env := ← MonadEnv.getEnv)
     (catName := if state.isConv then `conv else `tactic)
     (input := tactic)
-    (fileName := filename) with
+    (fileName := ← getFileName) with
     | .ok stx => pure $ stx
     | .error error => return .parseError error
-  state.tryTacticM goal $ Elab.Tactic.evalTactic tactic
+  state.tryTacticM goal (Elab.Tactic.evalTactic tactic) true
 
 protected def GoalState.tryAssign (state: GoalState) (goal: MVarId) (expr: String):
       Elab.TermElabM TacticResult := do
@@ -231,7 +288,7 @@ protected def GoalState.tryAssign (state: GoalState) (goal: MVarId) (expr: Strin
     (env := ← MonadEnv.getEnv)
     (catName := `term)
     (input := expr)
-    (fileName := filename) with
+    (fileName := ← getFileName) with
     | .ok syn => pure syn
     | .error error => return .parseError error
   state.tryTacticM goal $ Tactic.evalAssign expr
@@ -245,7 +302,7 @@ protected def GoalState.tryLet (state: GoalState) (goal: MVarId) (binderName: St
     (env := ← MonadEnv.getEnv)
     (catName := `term)
     (input := type)
-    (fileName := filename) with
+    (fileName := ← getFileName) with
     | .ok syn => pure syn
     | .error error => return .parseError error
   state.tryTacticM goal $ Tactic.evalLet binderName.toName type
@@ -332,7 +389,7 @@ protected def GoalState.tryCalc (state: GoalState) (goal: MVarId) (pred: String)
     (env := state.env)
     (catName := `term)
     (input := pred)
-    (fileName := filename) with
+    (fileName := ← getFileName) with
     | .ok syn => pure syn
     | .error error => return .parseError error
   goal.checkNotAssigned `GoalState.tryCalc
@@ -353,7 +410,7 @@ protected def GoalState.tryCalc (state: GoalState) (goal: MVarId) (pred: String)
       throwErrorAt pred "invalid 'calc' step, relation expected{indentExpr step}"
     if let some prevRhs := calcPrevRhs? then
       unless ← Meta.isDefEqGuarded lhs prevRhs do
-        throwErrorAt pred "invalid 'calc' step, left-hand-side is{indentD m!"{lhs} : {← Meta.inferType lhs}"}\nprevious right-hand-side is{indentD m!"{prevRhs} : {← Meta.inferType prevRhs}"}" -- "
+        throwErrorAt pred "invalid 'calc' step, left-hand-side is{indentD m!"{lhs} : {← Meta.inferType lhs}"}\nprevious right-hand-side is{indentD m!"{prevRhs} : {← Meta.inferType prevRhs}"}"
 
     -- Creates a mvar to represent the proof that the calc tactic solves the
     -- current branch

Pantograph/Library.lean

@@ -138,17 +138,36 @@ def goalSerialize (state: GoalState) (options: @&Protocol.Options): CoreM (Array
   runMetaM <| state.serializeGoals (parent := .none) options
 
 @[export pantograph_goal_print_m]
-def goalPrint (state: GoalState) (options: @&Protocol.Options): CoreM Protocol.GoalPrintResult :=
-  runMetaM do
-    state.restoreMetaM
-    return {
-      root? := ← state.rootExpr?.mapM (λ expr =>
-        state.withRootContext do
-          serializeExpression options (← instantiateAll expr)),
-      parent? := ← state.parentExpr?.mapM (λ expr =>
-        state.withParentContext do
-          serializeExpression options (← instantiateAll expr)),
-    }
+def goalPrint (state: GoalState) (rootExpr: Bool) (parentExpr: Bool) (goals: Bool) (extraMVars : Array String) (options: @&Protocol.Options)
+  : CoreM Protocol.GoalPrintResult := runMetaM do
+  state.restoreMetaM
+
+  let root? ← if rootExpr then
+      state.rootExpr?.mapM λ expr => state.withRootContext do
+        serializeExpression options (← instantiateAll expr)
+    else
+      pure .none
+  let parent? ← if parentExpr then
+      state.parentExpr?.mapM λ expr => state.withParentContext do
+        serializeExpression options (← instantiateAll expr)
+    else
+      pure .none
+  let goals ← if goals then
+      goalSerialize state options
+    else
+      pure #[]
+  let extraMVars ← extraMVars.mapM λ mvarId => do
+    let mvarId: MVarId := { name := mvarId.toName }
+    let .some _ ← mvarId.findDecl? | return {}
+    state.withContext mvarId do
+      let .some expr ← getExprMVarAssignment? mvarId | return {}
+      serializeExpression options (← instantiateAll expr)
+  return {
+    root?,
+    parent?,
+    goals,
+    extraMVars,
+  }
 
 @[export pantograph_goal_tactic_m]
 def goalTactic (state: GoalState) (goal:  MVarId) (tactic: String): CoreM TacticResult :=

Pantograph/Protocol.lean

@@ -5,6 +5,7 @@ Note that no command other than `InteractionError` may have `error` as one of
 its field names to avoid confusion with error messages generated by the REPL.
 -/
 import Lean.Data.Json
+import Lean.Data.Position
 
 namespace Pantograph.Protocol
 
@@ -121,11 +122,13 @@ structure EnvCatalogResult where
 -- Print the type of a symbol
 structure EnvInspect where
   name: String
-  -- If true/false, show/hide the value expressions; By default definitions
-  -- values are shown and theorem values are hidden.
+  -- Show the value expressions; By default definitions values are shown and
+  -- theorem values are hidden.
   value?: Option Bool := .some false
-  -- If true, show the type and value dependencies
+  -- Show the type and value dependencies
   dependency?: Option Bool := .some false
+  -- Show source location
+  source?: Option Bool := .some false
   deriving Lean.FromJson
 -- See `InductiveVal`
 structure InductInfo where
@@ -172,6 +175,11 @@ structure EnvInspectResult where
   inductInfo?:      Option InductInfo      := .none
   constructorInfo?: Option ConstructorInfo := .none
   recursorInfo?:    Option RecursorInfo    := .none
+
+  -- Location in source
+  sourceUri?: Option String := .none
+  sourceStart?: Option Lean.Position := .none
+  sourceEnd?: Option Lean.Position := .none
   deriving Lean.ToJson
 
 structure EnvAdd where
@@ -271,12 +279,23 @@ structure GoalDeleteResult where
 
 structure GoalPrint where
   stateId: Nat
+
+  -- Print root?
+  rootExpr?: Option Bool := .some False
+  -- Print the parent expr?
+  parentExpr?: Option Bool := .some False
+  -- Print goals?
+  goals?: Option Bool := .some False
+  -- Print values of extra mvars?
+  extraMVars?: Option (Array String) := .none
   deriving Lean.FromJson
 structure GoalPrintResult where
   -- The root expression
   root?: Option Expression := .none
   -- The filling expression of the parent goal
-  parent?: Option Expression
+  parent?: Option Expression := .none
+  goals: Array Goal := #[]
+  extraMVars: Array Expression := #[]
   deriving Lean.ToJson
 
 -- Diagnostic Options, not available in REPL
@@ -308,10 +327,14 @@ 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
+  -- collect type errors
+  typeErrorsAsGoals: Bool := false
+  -- list new constants from each compilation step
+  newConstants: Bool := false
   deriving Lean.FromJson
 structure InvokedTactic where
   goalBefore: String
@@ -325,11 +348,16 @@ structure InvokedTactic where
 structure CompilationUnit where
   -- String boundaries of compilation units
   boundary: (Nat × Nat)
+  messages: Array String := #[]
   -- Tactic invocations
   invocations?: Option (List InvokedTactic) := .none
   goalStateId?: Option Nat := .none
-  goals: Array Goal := #[]
-  messages: Array String := #[]
+  goals?: Option (Array Goal) := .none
+  -- Code segments which generated the goals
+  goalSrcBoundaries?: Option (Array (Nat × Nat)) := .none
+
+  -- New constants defined in compilation unit
+  newConstants?: Option (Array String) := .none
   deriving Lean.ToJson
 structure FrontendProcessResult where
   units: List CompilationUnit

Pantograph/Serial.lean

@@ -59,6 +59,12 @@ and then add the new constants.
 def environmentPickle (env : Environment) (path : System.FilePath) : IO Unit :=
   Pantograph.pickle path (env.header.imports, env.constants.map₂)
 
+def resurrectEnvironment
+  (imports : Array Import)
+  (map₂ : PHashMap Name ConstantInfo)
+  : IO Environment := do
+  let env ← importModules imports {} 0
+  env.replay (Std.HashMap.ofList map₂.toList)
 /--
 Unpickle an `Environment` from disk.
 
@@ -68,8 +74,7 @@ and then replace the new constants.
 @[export pantograph_env_unpickle_m]
 def environmentUnpickle (path : System.FilePath) : IO (Environment × CompactedRegion) := unsafe do
   let ((imports, map₂), region) ← Pantograph.unpickle (Array Import × PHashMap Name ConstantInfo) path
-  let env ← importModules imports {} 0
-  return (← env.replay (Std.HashMap.ofList map₂.toList), region)
+  return (← resurrectEnvironment imports map₂, region)
 
 
 open Lean.Core in
@@ -88,7 +93,9 @@ def goalStatePickle (goalState : GoalState) (path : System.FilePath) : IO Unit :
     savedState := {
       term := {
         meta := {
-          core,
+          core := {
+            env, nextMacroScope, ngen, ..
+          },
           meta,
         }
         «elab»,
@@ -100,9 +107,10 @@ def goalStatePickle (goalState : GoalState) (path : System.FilePath) : IO Unit :
     convMVar?,
     calcPrevRhs?,
   } := goalState
-  --let env := core.env
   Pantograph.pickle path (
-    ({ core with } : CompactCoreState),
+    env.constants.map₂,
+
+    ({ nextMacroScope, ngen } : CompactCoreState),
     meta,
     «elab»,
     tactic,
@@ -117,6 +125,8 @@ def goalStatePickle (goalState : GoalState) (path : System.FilePath) : IO Unit :
 def goalStateUnpickle (path : System.FilePath) (env : Environment)
     : IO (GoalState × CompactedRegion) := unsafe do
   let ((
+    map₂,
+
     compactCore,
     meta,
     «elab»,
@@ -127,6 +137,8 @@ def goalStateUnpickle (path : System.FilePath) (env : Environment)
     convMVar?,
     calcPrevRhs?,
   ), region) ← Pantograph.unpickle (
+    PHashMap Name ConstantInfo ×
+
     CompactCoreState ×
     Meta.State ×
     Elab.Term.State ×
@@ -137,6 +149,7 @@ def goalStateUnpickle (path : System.FilePath) (env : Environment)
     Option (MVarId × MVarId × List MVarId) ×
     Option (MVarId × Expr)
   ) path
+  let env ← env.replay (Std.HashMap.ofList map₂.toList)
   let goalState := {
     savedState := {
       term := {

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 := "0.2.19"
+def version := "0.2.25"
 
 end Pantograph

README.md

@@ -7,6 +7,8 @@ A Machine-to-Machine interaction system for Lean 4.
 Pantograph provides interfaces to execute proofs, construct expressions, and
 examine the symbol list of a Lean project for machine learning.
 
+See [documentations](doc/rationale.md) for design rationale and references.
+
 ## Installation
 
 For Nix users, run
@@ -15,7 +17,9 @@ nix build .#{sharedLib,executable}
 ```
 to build either the shared library or executable.
 
-Install `elan` and `lake`, and run
+Install `lake` and `lean` fixed to the version of the `lean-toolchain` file, and
+run
+
 ``` sh
 lake build
 ```
@@ -24,9 +28,12 @@ This builds the executable in `.lake/build/bin/pantograph-repl`.
 ## Executable Usage
 
 ``` sh
-pantograph MODULES|LEAN_OPTIONS
+pantograph-repl MODULES|LEAN_OPTIONS
 ```
 
+The `pantograph-repl` executable must be run with a list of modules to import.
+It can also accept lean options of the form `--key=value` e.g. `--pp.raw=true`.
+
 The REPL loop accepts commands as single-line JSON inputs and outputs either an
 `Error:` (indicating malformed command) or a JSON return value indicating the
 result of a command execution.  The command can be passed in one of two formats
@@ -37,8 +44,6 @@ command { ... }
 The list of available commands can be found in `Pantograph/Protocol.lean` and below. An
 empty command aborts the REPL.
 
-The `pantograph` executable must be run with a list of modules to import. It can
-also accept lean options of the form `--key=value` e.g. `--pp.raw=true`.
 
 Example: (~5k symbols)
 ```
@@ -75,7 +80,7 @@ the environment might be setup like this:
 
 ``` sh
 LIB="../lib"
-LIB_MATHLIB="$LIB/mathlib4/lake-packages"
+LIB_MATHLIB="$LIB/mathlib4/.lake"
 export LEAN_PATH="$LIB/mathlib4/build/lib:$LIB_MATHLIB/aesop/build/lib:$LIB_MATHLIB/Qq/build/lib:$LIB_MATHLIB/std/build/lib"
 
 LEAN_PATH=$LEAN_PATH build/bin/pantograph $@

Repl.lean

@@ -79,6 +79,7 @@ def execute (command: Protocol.Command): MainM Lean.Json := do
     let state ← get
     let nGoals := state.goalStates.size
     set { state with nextId := 0, goalStates := .empty }
+    Lean.Core.resetMessageLog
     return .ok { nGoals }
   stat (_: Protocol.Stat): MainM (CR Protocol.StatResult) := do
     let state ← get
@@ -222,7 +223,13 @@ def execute (command: Protocol.Command): MainM Lean.Json := do
     let state ← get
     let .some goalState := state.goalStates[args.stateId]? |
       return .error $ errorIndex s!"Invalid state index {args.stateId}"
-    let result ← runMetaInMainM <| goalPrint goalState state.options
+    let result ← runMetaInMainM <| goalPrint
+        goalState
+        (rootExpr := args.rootExpr?.getD False)
+        (parentExpr := args.parentExpr?.getD False)
+        (goals := args.goals?.getD False)
+        (extraMVars := args.extraMVars?.getD #[])
+        (options := state.options)
     return .ok result
   goal_save (args: Protocol.GoalSave): MainM (CR Protocol.GoalSaveResult) := do
     let state ← get
@@ -257,27 +264,38 @@ def execute (command: Protocol.Command): MainM Lean.Json := do
             pure $ .some invocations
           else
             pure .none
-        let sorrys := if args.sorrys then
-            Frontend.collectSorrys step
+        let sorrys ← if args.sorrys then
+            Frontend.collectSorrys step (options := { collectTypeErrors := args.typeErrorsAsGoals })
           else
-            []
+            pure []
         let messages ← step.messageStrings
-        return (step.before, boundary, invocations?, sorrys, messages)
+        let newConstants ← if args.newConstants then
+            Frontend.collectNewDefinedConstants step
+          else
+            pure []
+        return (step.before, boundary, invocations?, sorrys, messages, newConstants)
       let li ← frontendM.run context |>.run' state
-      let units ← li.mapM λ (env, boundary, invocations?, sorrys, messages) => Lean.withEnv env do
-        let (goalStateId?, goals) ← if sorrys.isEmpty then do
-            pure (.none, #[])
+      let units ← li.mapM λ (env, boundary, invocations?, sorrys, messages, newConstants) => Lean.withEnv env do
+        let newConstants? := if args.newConstants then
+            .some $ newConstants.toArray.map λ name => name.toString
+          else
+            .none
+        let (goalStateId?, goals?, goalSrcBoundaries?) ← if sorrys.isEmpty then do
+            pure (.none, .none, .none)
           else do
-            let goalState ← runMetaInMainM $ Frontend.sorrysToGoalState sorrys
-            let stateId ← newGoalState goalState
-            let goals ← goalSerialize goalState options
-            pure (.some stateId, goals)
+            let { state, srcBoundaries } ← runMetaInMainM $ Frontend.sorrysToGoalState sorrys
+            let stateId ← newGoalState state
+            let goals ← goalSerialize state options
+            let srcBoundaries := srcBoundaries.toArray.map (λ (b, e) => (b.byteIdx, e.byteIdx))
+            pure (.some stateId, .some goals, .some srcBoundaries)
         return {
           boundary,
+          messages,
           invocations?,
           goalStateId?,
-          goals,
-          messages,
+          goals?,
+          goalSrcBoundaries?,
+          newConstants?,
         }
       return .ok { units }
     catch e =>

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 }
@@ -95,19 +101,19 @@ def runTermElabMSeq (env: Environment) (termElabM: Elab.TermElabM LSpec.TestSeq)
 
 def exprToStr (e: Expr): Lean.MetaM String := toString <$> Meta.ppExpr e
 
-def strToTermSyntax [Monad m] [MonadEnv m] (s: String): m Syntax := do
+def strToTermSyntax (s: String): CoreM Syntax := do
   let .ok stx := Parser.runParserCategory
     (env := ← MonadEnv.getEnv)
     (catName := `term)
     (input := s)
-    (fileName := filename) | panic! s!"Failed to parse {s}"
+    (fileName := ← getFileName) | panic! s!"Failed to parse {s}"
   return stx
 def parseSentence (s: String): Elab.TermElabM Expr := do
   let stx ← match Parser.runParserCategory
     (env := ← MonadEnv.getEnv)
     (catName := `term)
     (input := s)
-    (fileName := filename) with
+    (fileName := ← getFileName) with
     | .ok syn => pure syn
     | .error error => throwError "Failed to parse: {error}"
   Elab.Term.elabTerm (stx := stx) .none
@@ -123,22 +129,30 @@ def mvarUserNameAndType (mvarId: MVarId): MetaM (Name × String) := do
 
 -- Monadic testing
 
-abbrev TestT := StateT LSpec.TestSeq
+abbrev TestT := StateRefT' IO.RealWorld LSpec.TestSeq
 
-def addTest [Monad m] (test: LSpec.TestSeq) : TestT m Unit := do
+section Monadic
+
+variable [Monad m] [MonadLiftT (ST IO.RealWorld) m]
+
+def addTest (test: LSpec.TestSeq) : TestT m Unit := do
   set $ (← get) ++ test
 
-def checkEq [Monad m] [DecidableEq α] (desc : String) (lhs rhs : α) : TestT m Unit := do
-  addTest $ LSpec.check desc (lhs == rhs)
-def checkTrue [Monad m] (desc : String) (flag : Bool) : TestT m Unit := do
+def checkEq [DecidableEq α] [Repr α] (desc : String) (lhs rhs : α) : TestT m Unit := do
+  addTest $ LSpec.check desc (lhs = rhs)
+def checkTrue (desc : String) (flag : Bool) : TestT m Unit := do
   addTest $ LSpec.check desc flag
-def fail [Monad m] (desc : String) : TestT m Unit := do
+def fail (desc : String) : TestT m Unit := do
   addTest $ LSpec.check desc false
 
-def runTest [Monad m] (t: TestT m Unit): m LSpec.TestSeq :=
+def runTest (t: TestT m Unit): m LSpec.TestSeq :=
   Prod.snd <$> t.run LSpec.TestSeq.done
-def runTestWithResult { α } [Monad m] (t: TestT m α): m (α × LSpec.TestSeq) :=
+def runTestWithResult { α } (t: TestT m α): m (α × LSpec.TestSeq) :=
   t.run LSpec.TestSeq.done
+def runTestCoreM (env: Environment) (coreM: TestT CoreM Unit) (options: Array String := #[]): IO LSpec.TestSeq := do
+  runCoreMSeq env (runTest coreM) options
+
+end Monadic
 
 def runTestTermElabM (env: Environment) (t: TestT Elab.TermElabM Unit):
   IO LSpec.TestSeq :=

Test/Delate.lean

@@ -32,10 +32,10 @@ def test_expr_to_binder (env: Environment): IO LSpec.TestSeq := do
 def test_sexp_of_symbol (env: Environment): IO LSpec.TestSeq := do
   let entries: List (String × String) := [
     -- This one contains unhygienic variable names which must be suppressed
-    ("Nat.add", "(:forall _ (:c Nat) (:forall _ (:c Nat) (:c Nat)))"),
+    ("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

@@ -97,11 +97,26 @@ def test_inspect: IO LSpec.TestSeq := do
     ) LSpec.TestSeq.done
   runCoreMSeq env inner
 
+def test_symbol_location : TestT IO Unit := do
+  let env: Environment ← importModules
+    (imports := #[`Init])
+    (opts := {})
+    (trustLevel := 1)
+  addTest $ ← runTestCoreM env 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"
+
+    -- 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) :=
   [
     ("Catalog", test_catalog),
     ("Symbol Visibility", test_symbol_visibility),
     ("Inspect", test_inspect),
+    ("Symbol Location", runTest test_symbol_location),
   ]
 
 end Pantograph.Test.Environment

Test/Frontend.lean

@@ -6,17 +6,18 @@ 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
       return .none
-    let goalState ← Frontend.sorrysToGoalState sorrys
-    return .some goalState
+    let { state, .. } ← Frontend.sorrysToGoalState sorrys
+    return .some state
   return goalStates
 
 def test_multiple_sorrys_in_proof : TestT MetaM Unit := do
@@ -177,6 +178,58 @@ example (n: Nat) : mystery n + 1 = n + 2 := sorry
     }
   ])
 
+def test_capture_type_mismatch : TestT MetaM Unit := do
+  let input := "
+def mystery (k: Nat) : Nat := true
+  "
+  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).map (·.devolatilize)) #[
+    {
+      target := { pp? := "Nat" },
+      vars := #[{
+         userName := "k",
+         type? := .some { pp? := "Nat" },
+      }],
+    }
+  ]
+
+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) {}
+  let m := Frontend.mapCompilationSteps λ step => do
+    Frontend.collectNewDefinedConstants step
+  m.run context |>.run' state
+
+def test_collect_one_constant : TestT MetaM Unit := do
+  let input := "
+def mystery : Nat := 123
+  "
+  let names ← collectNewConstants input
+  checkEq "constants" names [[`mystery]]
+def test_collect_one_theorem : TestT MetaM Unit := do
+  let input := "
+theorem mystery [SizeOf α] (as : List α) (i : Fin as.length) : sizeOf (as.get i) < sizeOf as := by
+  match as, i with
+  | a::as, ⟨0, _⟩  => simp_arith [get]
+  | a::as, ⟨i+1, h⟩ =>
+    have ih := sizeOf_get as ⟨i, Nat.le_of_succ_le_succ h⟩
+    apply Nat.lt_trans ih
+    simp_arith
+  "
+  let names ← collectNewConstants input
+  checkEq "constants" names [[`mystery]]
 
 def suite (env : Environment): List (String × IO LSpec.TestSeq) :=
   let tests := [
@@ -185,6 +238,10 @@ def suite (env : Environment): List (String × IO LSpec.TestSeq) :=
     ("sorry_in_induction", test_sorry_in_induction),
     ("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),
   ]
   tests.map (fun (name, test) => (name, runMetaMSeq env $ runTest test))
 

Test/Integration.lean

@@ -72,8 +72,8 @@ def test_tactic : Test :=
      ({ stateId := 0, root := "_uniq.9" }: Protocol.GoalStartResult),
     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)]
-     ({ parent? := .some { pp? := .some "fun x => ?m.12 x" }, }: Protocol.GoalPrintResult),
+    step "goal.print" [("stateId", .num 1), ("parentExpr", .bool true), ("rootExpr", .bool true)]
+     ({ 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}
     ],
   }
   [
@@ -171,9 +171,11 @@ def test_frontend_process : Test :=
     let goal1 := "p q : Prop\nh : p\n⊢ p ∨ q"
     step "frontend.process"
       [
-        ("file", .str file),
-        ("invocations", .bool true),
-        ("sorrys", .bool false),
+        ("file",              .str file),
+        ("invocations",       .bool true),
+        ("sorrys",            .bool false),
+        ("typeErrorsAsGoals", .bool false),
+        ("newConstants",      .bool false),
       ]
      ({
        units := [{
@@ -214,6 +216,8 @@ def test_frontend_process_sorry : Test :=
         ("file", .str file),
         ("invocations", .bool false),
         ("sorrys", .bool true),
+        ("typeErrorsAsGoals", .bool false),
+        ("newConstants", .bool false),
       ]
      ({
        units := [{
@@ -221,7 +225,8 @@ def test_frontend_process_sorry : Test :=
        }, {
          boundary := (solved.utf8ByteSize, solved.utf8ByteSize + withSorry.utf8ByteSize),
          goalStateId? := .some 0,
-         goals := #[goal1],
+         goals? := .some #[goal1],
+         goalSrcBoundaries? := .some #[(57, 62)],
          messages := #["<anonymous>:2:0: warning: declaration uses 'sorry'\n"],
        }],
     }: Protocol.FrontendProcessResult),

Test/Library.lean

@@ -24,7 +24,7 @@ def test_expr_echo (env: Environment): IO LSpec.TestSeq := do
       },
       expr := {
         pp? := "⟨∀ (x : Prop), x → x, fun x h => h⟩",
-        sexp? := "((:c PSigma.mk) (:sort 0) (:lambda p (:sort 0) 0) (:forall x (:sort 0) (:forall _ 0 1)) (:lambda x (:sort 0) (:lambda h 0 0)))",
+        sexp? := "((:c PSigma.mk) (:sort 0) (:lambda p (:sort 0) 0) (:forall x (:sort 0) (:forall a 0 1)) (:lambda x (:sort 0) (:lambda h 0 0)))",
       }
     }))
     return tests

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

@@ -8,10 +8,7 @@ namespace Pantograph.Test.Metavar
 open Pantograph
 open Lean
 
-abbrev TestM := StateRefT LSpec.TestSeq (ReaderT Protocol.Options Elab.TermElabM)
-
-def addTest (test: LSpec.TestSeq): TestM Unit := do
-  set $ (← get) ++ test
+abbrev TestM := TestT $ ReaderT Protocol.Options Elab.TermElabM
 
 -- Tests that all delay assigned mvars are instantiated
 def test_instantiate_mvar: TestM Unit := do
@@ -32,8 +29,6 @@ def test_instantiate_mvar: TestM Unit := do
     "((:c LE.le) (:c Nat) (:c instLENat) ((:c OfNat.ofNat) (:mv _uniq.2) (:lit 2) (:mv _uniq.3)) ((:c OfNat.ofNat) (:mv _uniq.14) (:lit 5) (:mv _uniq.15)))")
   return ()
 
-
-
 def startProof (expr: String): TestM (Option GoalState) := do
   let env ← Lean.MonadEnv.getEnv
   let syn? := parseTerm env expr
@@ -244,7 +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
@@ -258,7 +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

@@ -14,10 +14,7 @@ inductive Start where
   | copy (name: String) -- Start from some name in the environment
   | expr (expr: String) -- Start from some expression
 
-abbrev TestM := StateRefT LSpec.TestSeq (ReaderT Protocol.Options Elab.TermElabM)
-
-def addTest (test: LSpec.TestSeq): TestM Unit := do
-  set $ (← get) ++ test
+abbrev TestM := TestT $ ReaderT Protocol.Options $ Elab.TermElabM
 
 def startProof (start: Start): TestM (Option GoalState) := do
   let env ← Lean.MonadEnv.getEnv
@@ -100,7 +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
@@ -244,13 +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" } },
@@ -262,7 +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
@@ -272,19 +271,21 @@ 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._@._hyg.26 {orPQ} (:forall h ((:c Eq) ((:c Or) (:fv {fvP}) (:fv {fvQ})) (:fv {fvH}) 0) {orQP}))"
-  let caseL := s!"(:lambda h._@._hyg.27 (:fv {fvP}) (:lambda h._@._hyg.28 ((:c Eq) {orPQ} (:fv {fvH}) ((:c Or.inl) (:fv {fvP}) (:fv {fvQ}) 0)) (:subst (:mv {caseL}) (:fv {fvP}) (:fv {fvQ}) 1)))"
-  let caseR := s!"(:lambda h._@._hyg.29 (:fv {fvQ}) (:lambda h._@._hyg.30 ((:c Eq) {orPQ} (:fv {fvH}) ((:c Or.inr) (:fv {fvP}) (:fv {fvQ}) 0)) (:subst (:mv {caseR}) (:fv {fvP}) (:fv {fvQ}) 1)))"
+  let motive := s!"(:lambda t {orPQ} (:forall h ((:c Eq) ((:c Or) (:fv {fvP}) (:fv {fvQ})) (:fv {fvH}) 0) {orQP}))"
+  let caseL := s!"(:lambda h (:fv {fvP}) (:lambda h ((:c Eq) {orPQ} (:fv {fvH}) ((:c Or.inl) (:fv {fvP}) (:fv {fvQ}) 0)) (:subst (:mv {caseL}) (:fv {fvP}) (:fv {fvQ}) 1)))"
+  let caseR := s!"(:lambda h (:fv {fvQ}) (:lambda h ((:c Eq) {orPQ} (:fv {fvH}) ((:c Or.inr) (:fv {fvP}) (:fv {fvQ}) 0)) (:subst (:mv {caseR}) (:fv {fvP}) (:fv {fvQ}) 1)))"
   let conduit := s!"((:c Eq.refl) {orPQ} (:fv {fvH}))"
   addTest $ LSpec.test "(2 parent)" (state2parent ==
     s!"((:c Or.casesOn) (:fv {fvP}) (:fv {fvQ}) {motive} (:fv {fvH}) {caseL} {caseR} {conduit})")
@@ -295,8 +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
@@ -562,12 +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"
@@ -650,13 +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"
@@ -673,8 +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
@@ -684,26 +690,86 @@ 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)" },
         }],
       }
     ])
 
+def test_tactic_failure_unresolved_goals : TestM Unit := do
+  let state? ← startProof (.expr "∀ (p : Nat → Prop), ∃ (x : Nat), p (0 + x + 0)")
+  let state0 ← match state? with
+    | .some state => pure state
+    | .none => do
+      addTest $ assertUnreachable "Goal could not parse"
+      return ()
+
+  let tactic := "intro p"
+  let state1 ← match ← state0.tacticOn 0 tactic with
+    | .success state => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+
+  let tactic := "exact ⟨0, by simp⟩"
+  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
+    | .some state => pure state
+    | .none => do
+      addTest $ assertUnreachable "Goal could not parse"
+      return ()
+
+  let tactic := "intro p q r h"
+  let state1 ← match ← state0.tacticOn 0 tactic with
+    | .success state => pure state
+    | other => 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 ()
+
+  -- 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]
+
+
 def suite (env: Environment): List (String × IO LSpec.TestSeq) :=
   let tests := [
     ("identity", test_identity),
@@ -716,6 +782,8 @@ def suite (env: Environment): List (String × IO LSpec.TestSeq) :=
     ("calc", test_calc),
     ("Nat.zero_add", test_nat_zero_add),
     ("Nat.zero_add alt", test_nat_zero_add_alt),
+    ("tactic failure with unresolved goals", test_tactic_failure_unresolved_goals),
+    ("tactic failure with synthesize placeholder", test_tactic_failure_synthesize_placeholder),
   ]
   tests.map (fun (name, test) => (name, proofRunner env test))
 

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

@@ -28,7 +28,7 @@ def test_nat_brec_on : TestT Elab.TermElabM Unit := do
       (env := ← MonadEnv.getEnv)
       (catName := `term)
       (input := "@Nat.brecOn")
-      (fileName := filename) with
+      (fileName := ← getFileName) with
       | .ok syn => pure syn
       | .error error => throwError "Failed to parse: {error}"
     -- Apply the tactic
@@ -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
 
@@ -52,7 +52,7 @@ def test_list_brec_on : TestT Elab.TermElabM Unit := do
       (env := ← MonadEnv.getEnv)
       (catName := `term)
       (input := "@List.brecOn")
-      (fileName := filename) with
+      (fileName := ← getFileName) with
       | .ok syn => pure syn
       | .error error => throwError "Failed to parse: {error}"
     -- Apply the tactic
@@ -74,7 +74,7 @@ def test_partial_motive_instantiation : TestT Elab.TermElabM Unit := do
     (env := ← MonadEnv.getEnv)
     (catName := `term)
     (input := "@Nat.brecOn")
-    (fileName := filename) with
+    (fileName := ← getFileName) with
     | .ok syn => pure syn
     | .error error => throwError "Failed to parse: {error}"
   let expr ← parseSentence expr
@@ -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) :=
   [

Test/Tactic/NoConfuse.lean

@@ -15,7 +15,7 @@ def test_nat : TestT Elab.TermElabM Unit := do
       (env := ← MonadEnv.getEnv)
       (catName := `term)
       (input := "h")
-      (fileName := filename) with
+      (fileName := ← getFileName) with
       | .ok syn => pure syn
       | .error error => throwError "Failed to parse: {error}"
     -- Apply the tactic
@@ -32,7 +32,7 @@ def test_nat_fail : TestT Elab.TermElabM Unit := do
       (env := ← MonadEnv.getEnv)
       (catName := `term)
       (input := "h")
-      (fileName := filename) with
+      (fileName := ← getFileName) with
       | .ok syn => pure syn
       | .error error => throwError "Failed to parse: {error}"
     -- Apply the tactic
@@ -52,7 +52,7 @@ def test_list : TestT Elab.TermElabM Unit := do
       (env := ← MonadEnv.getEnv)
       (catName := `term)
       (input := "h")
-      (fileName := filename) with
+      (fileName := ← getFileName) with
       | .ok syn => pure syn
       | .error error => throwError "Failed to parse: {error}"
     -- Apply the tactic

Test/Tactic/Prograde.lean

@@ -15,7 +15,7 @@ def test_define : TestT Elab.TermElabM Unit := do
       (env := ← MonadEnv.getEnv)
       (catName := `term)
       (input := "Or.inl h")
-      (fileName := filename) with
+      (fileName := ← getFileName) with
       | .ok syn => pure syn
       | .error error => throwError "Failed to parse: {error}"
     -- Apply the tactic

doc/icon.svg

@@ -4,17 +4,17 @@
 <svg
    width="256"
    height="256"
-   viewBox="0 0 55.900957 55.900957"
+   viewBox="0 0 67.733332 67.733333"
    version="1.1"
-   id="svg21534"
-   xml:space="preserve"
-   inkscape:version="1.2.2 (b0a8486541, 2022-12-01)"
+   id="svg1"
    sodipodi:docname="icon.svg"
+   inkscape:version="1.3.2 (091e20ef0f, 2023-11-25, custom)"
    xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
    xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
    xmlns="http://www.w3.org/2000/svg"
-   xmlns:svg="http://www.w3.org/2000/svg"><sodipodi:namedview
-     id="namedview21536"
+   xmlns:svg="http://www.w3.org/2000/svg">
+  <sodipodi:namedview
+     id="namedview1"
      pagecolor="#ffffff"
      bordercolor="#111111"
      borderopacity="1"
@@ -23,51 +23,135 @@
      inkscape:pagecheckerboard="1"
      inkscape:deskcolor="#d1d1d1"
      inkscape:document-units="px"
-     showgrid="true"
-     inkscape:zoom="5.1754899"
-     inkscape:cx="158.82554"
-     inkscape:cy="91.682142"
-     inkscape:window-width="3777"
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+     showguides="true"
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+     id="layer4"
+     inkscape:label="bg" />
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+     inkscape:groupmode="layer"
+     id="layer1"
+     inkscape:label="Circle">
+    <path
+       id="path1"
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doc/rationale.md

@@ -0,0 +1,59 @@
+# Design Rationale
+
+A great problem in machine learning is to use ML agents to automatically prove
+mathematical theorems. This sort of proof necessarily involves *search*.
+Compatibility for search is the main reason for creating Pantograph.  The Lean 4
+LSP interface is not conducive to search. Pantograph is designed with this in
+mind. It emphasizes the difference between 3 views of a proof:
+
+- **Presentation View**: The view of a written, polished proof. e.g. Mathlib and
+  math papers are almost always written in this form.
+- **Search View**: The view of a proof exploration trajectory. This is not
+  explicitly supported by Lean LSP.
+- **Kernel View**: The proof viewed as a set of metavariables.
+
+Pantograph enables proof agents to operate on the search view.
+
+## Name
+
+The name Pantograph is a pun. It means two things
+- A pantograph is an instrument for copying down writing. As an agent explores
+  the vast proof search space, Pantograph records the current state to ensure
+  the proof is sound.
+- A pantograph is also an equipment for an electric train. It supplies power to
+  a locomotive. In comparison the (relatively) simple Pantograph software powers
+  theorem proving projects.
+
+## Caveats and Limitations
+
+Pantograph does not exactly mimic Lean LSP's behaviour. That would not grant the
+flexibility it offers.  To support tree search means Pantograph has to act
+differently from Lean in some times, but never at the sacrifice of soundness.
+
+- When Lean LSP says "don't know how to synthesize placeholder", this indicates
+  the human operator needs to manually move the cursor to the placeholder and
+  type in the correct expression. This error therefore should not halt the proof
+  process, and the placeholder should be turned into a goal.
+- When Lean LSP says "unresolved goals", that means a proof cannot finish where
+  it is supposed to finish at the end of a `by` block. Pantograph will raise the
+  error in this case, since it indicates the termination of a proof search branch.
+- `pick_goal` or `swap` will not work since they run contrary to tree search
+  paradigms. However, if there are tactics which perform non-trivial operations
+  to multiple goals at the same time, this constrain could potentially be
+  relaxed at a cost of great bookkeeping overhead to the user.
+
+Pantograph cannot perform things that are inherently constrained by Lean. These
+include:
+
+- If a tactic loses track of metavariables, it will not be caught until the end
+  of the proof search. This is a bug in the tactic itself.
+- Timeouts for executing tactics is not available. Maybe this will change in the
+  future.
+- Interceptions of parsing errors generally cannot be turned into goals (e.g.
+  `def mystery : Nat := :=`) due to Lean's parsing system.
+
+
+## References
+
+* [Pantograph Paper](https://arxiv.org/abs/2410.16429)
+

doc/repl.md

@@ -11,8 +11,8 @@ See `Pantograph/Protocol.lean` for a description of the parameters and return va
 * `env.inspect {"name": <name>, "value": <bool>}`: Show the type and package of a
   given symbol; If value flag is set, the value is printed or hidden. By default
   only the values of definitions are printed.
-* `env.save { path }`, `env.load { path }`: Save/Load the current environment
-  to/from a file
+* `env.save { "path": <fileName> }`, `env.load { "path": <fileName> }`: Save/Load the
+  current environment to/from a file
 * `options.set { key: value, ... }`: Set one or more options (not Lean options; those
   have to be set via command line arguments.), for options, see `Pantograph/Protocol.lean`
 
@@ -39,13 +39,16 @@ See `Pantograph/Protocol.lean` for a description of the parameters and return va
   - `{ "goals": <names> }`: Resume the given goals
 * `goal.remove {"stateIds": [<id>]}"`: Drop the goal states specified in the list
 * `goal.print {"stateId": <id>}"`: Print a goal state
-* `goal.save{ id, path }`, `goal.load { path }`: Save/Load a goal state to/from a
-  file. The environment is not carried with the 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> }`: Executes the Lean frontend on a file, collecting
-  either the tactic invocations (`"invocations": true`) or the sorrys into goal
-  states (`"sorrys": true`)
+* `goal.save { "id": <id>, "path": <fileName> }`, `goal.load { "path": <fileName> }`:
+  Save/Load a goal state to/from a file. The environment is not carried with the
+  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`.
 
 ## 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

@@ -18,80 +18,89 @@
     lean4-nix,
     lspec,
     ...
-  } : flake-parts.lib.mkFlake { inherit inputs; } {
-    flake = {
-    };
-    systems = [
-      "x86_64-linux"
-      "x86_64-darwin"
-    ];
-    perSystem = { system, pkgs, ... }: let
-      pkgs = import nixpkgs {
-        inherit system;
-        overlays = [ (lean4-nix.readToolchainFile ./lean-toolchain) ];
+  }:
+    flake-parts.lib.mkFlake {inherit inputs;} {
+      flake = {
       };
-      lspecLib = pkgs.lean.buildLeanPackage {
-        name = "LSpec";
-        roots = [ "Main" "LSpec" ];
-        src = "${lspec}";
-      };
-      project = pkgs.lean.buildLeanPackage {
-        name = "Pantograph";
-        roots = [ "Pantograph" ];
-        src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
-          src = ./.;
-          filter = path: type:
-            !(pkgs.lib.hasInfix "/Test/" path) &&
-            !(pkgs.lib.hasSuffix ".md" path) &&
-            !(pkgs.lib.hasSuffix "Repl.lean" path);
-        });
-      };
-      repl = pkgs.lean.buildLeanPackage {
-        name = "Repl";
-        roots = [ "Main" "Repl" ];
-        deps = [ project ];
-        src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
-          src = ./.;
-          filter = path: type:
-            !(pkgs.lib.hasInfix "/Test/" path) &&
-            !(pkgs.lib.hasSuffix ".md" path);
-        });
-      };
-      test = pkgs.lean.buildLeanPackage {
-        name = "Test";
-        # NOTE: The src directory must be ./. since that is where the import
-        # root begins (e.g. `import Test.Environment` and not `import
-        # Environment`) and thats where `lakefile.lean` resides.
-        roots = [ "Test.Main" ];
-        deps = [ lspecLib repl ];
-        src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
-          src = ./.;
-          filter = path: type:
-            !(pkgs.lib.hasInfix "Pantograph" path);
-        });
-      };
-    in rec {
-      packages = {
-        inherit (pkgs.lean) lean lean-all;
-        inherit (project) sharedLib iTree;
-        inherit (repl) executable;
-        default = repl.executable;
-      };
-      legacyPackages = {
-        inherit project;
-        leanPkgs = pkgs.lean;
-      };
-      checks = {
-        test = pkgs.runCommand "test" {
-          buildInputs = [ test.executable pkgs.lean.lean-all ];
-        } ''
-          #export LEAN_SRC_PATH="${./.}"
-          ${test.executable}/bin/test > $out
-        '';
-      };
-      devShells.default = pkgs.mkShell {
-        buildInputs = [ pkgs.lean.lean-all pkgs.lean.lean ];
+      systems = [
+        "aarch64-linux"
+        "aarch64-darwin"
+        "x86_64-linux"
+        "x86_64-darwin"
+      ];
+      perSystem = {
+        system,
+        pkgs,
+        ...
+      }: let
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [(lean4-nix.readToolchainFile ./lean-toolchain)];
+        };
+        lspecLib = pkgs.lean.buildLeanPackage {
+          name = "LSpec";
+          roots = ["Main" "LSpec"];
+          src = "${lspec}";
+        };
+        project = pkgs.lean.buildLeanPackage {
+          name = "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);
+          });
+        };
+        repl = pkgs.lean.buildLeanPackage {
+          name = "Repl";
+          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);
+          });
+        };
+        test = pkgs.lean.buildLeanPackage {
+          name = "Test";
+          # 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];
+          src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
+            src = ./.;
+            filter = path: type:
+              !(pkgs.lib.hasInfix "Pantograph" path);
+          });
+        };
+      in rec {
+        packages = {
+          inherit (pkgs.lean) lean lean-all;
+          inherit (project) sharedLib iTree;
+          inherit (repl) executable;
+          default = repl.executable;
+        };
+        legacyPackages = {
+          inherit project;
+          leanPkgs = pkgs.lean;
+        };
+        checks = {
+          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];
+        };
       };
     };
-  };
 }

lean-toolchain

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