feat(frontend): Dissect syntax tree

Pantograph/Delate.lean

@@ -454,6 +454,7 @@ def serializeExpression (options: @&Protocol.Options) (e: Expr): MetaM Protocol.
     dependentMVars?,
   }
 
+
 /-- Adapted from ppGoal -/
 def serializeGoal (options: @&Protocol.Options) (goal: MVarId) (mvarDecl: MetavarDecl) (parentDecl?: Option MetavarDecl := .none)
       : MetaM Protocol.Goal := do
@@ -519,6 +520,7 @@ def serializeGoal (options: @&Protocol.Options) (goal: MVarId) (mvarDecl: Metava
     return {
       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)),
       vars := vars.reverse.toArray
     }
@@ -528,20 +530,17 @@ def serializeGoal (options: @&Protocol.Options) (goal: MVarId) (mvarDecl: Metava
 
 protected def GoalState.serializeGoals
       (state: GoalState)
+      (parent: Option GoalState := .none)
       (options: @&Protocol.Options := {}):
     MetaM (Array Protocol.Goal):= do
   state.restoreMetaM
   let goals := state.goals.toArray
+  let parentDecl? := parent.bind (λ parentState => parentState.mctx.findDecl? state.parentMVar?.get!)
   goals.mapM fun goal => do
-    let fragment := match state.fragments[goal]? with
-      | .none => .tactic
-      | .some $ .calc .. => .calc
-      | .some $ .conv .. => .conv
-      | .some $ .convSentinel .. => .conv
     match state.mctx.findDecl? goal with
     | .some mvarDecl =>
-      let serializedGoal ← serializeGoal options goal mvarDecl (parentDecl? := .none)
+      let serializedGoal ← serializeGoal options goal mvarDecl (parentDecl? := parentDecl?)
-      pure { serializedGoal with fragment }
+      pure serializedGoal
     | .none => throwError s!"Metavariable does not exist in context {goal.name}"
 
 /-- Print the metavariables in a readable format -/
@@ -607,9 +606,7 @@ protected def GoalState.diag (goalState: GoalState) (parent?: Option GoalState :
     userNameToString : Name → String
       | .anonymous => ""
       | other => s!"[{other}]"
-    parentHasMVar (mvarId: MVarId): Bool := match parent? with
+    parentHasMVar (mvarId: MVarId): Bool := parent?.map (λ state => state.mctx.decls.contains mvarId) |>.getD true
-      | .some state => state.mctx.decls.contains mvarId
-      | .none => true
 
 initialize
   registerTraceClass `Pantograph.Delate

Pantograph/Frontend/InfoTree.lean

@@ -10,7 +10,7 @@ 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" ++ .)
+private def indent (s : String) : String := "\n".intercalate $ s.splitOn "\n" |>.map ("  " ++ .)
 
 /-- The `Syntax` for a `Lean.Elab.Info`, if there is one. -/
 protected def Info.stx? : Info → Option Syntax

Pantograph/Goal.lean

@@ -10,69 +10,22 @@ import Lean
 namespace Pantograph
 open Lean
 
-/-- The acting area of a tactic -/
-inductive Site where
-  -- Dormant all other goals
-  | focus (goal : MVarId)
-  -- Move the goal to the first in the list
-  | prefer (goal : MVarId)
-  -- Execute as-is, no goals go dormant
-  | unfocus
-  deriving BEq, Inhabited
-
-instance : Coe MVarId Site where
-  coe := .focus
-instance : ToString Site where
-  toString
-    | .focus { name } => s!"[{name}]"
-    | .prefer { name } => s!"[{name},...]"
-    | .unfocus => "[*]"
-
-/-- Executes a `TacticM` on a site and return affected goals -/
-protected def Site.runTacticM (site : Site)
-  { m } [Monad m] [MonadLiftT Elab.Tactic.TacticM m] [MonadControlT Elab.Tactic.TacticM m] [MonadMCtx m] [MonadError m]
-  (f : m α) : m (α × List MVarId) :=
-  match site with
-  | .focus goal => do
-    Elab.Tactic.setGoals [goal]
-    let a ← f
-    return (a, [goal])
-  | .prefer goal => do
-    let before ← Elab.Tactic.getUnsolvedGoals
-    let otherGoals := before.filter (· != goal)
-    Elab.Tactic.setGoals (goal :: otherGoals)
-    let a ← f
-    let after ← Elab.Tactic.getUnsolvedGoals
-    let parents := before.filter (¬ after.contains ·)
-    Elab.Tactic.pruneSolvedGoals
-    return (a, parents)
-  | .unfocus => do
-    let before ← Elab.Tactic.getUnsolvedGoals
-    let a ← f
-    let after ← Elab.Tactic.getUnsolvedGoals
-    let parents := before.filter (¬ after.contains ·)
-    Elab.Tactic.pruneSolvedGoals
-    return (a, parents)
-
 /--
-Kernel view of the state of a proof
+Represents an interconnected set of metavariables, or a state in proof search
  -/
 structure GoalState where
-  -- Captured `TacticM` state
   savedState : Elab.Tactic.SavedState
 
-  -- The root goal which is the search target
+  -- The root hole which is the search target
   root: MVarId
 
-  -- Parent goals assigned to produce this state
+  -- Parent state metavariable source
-  parentMVars : List MVarId := []
+  parentMVar?: Option MVarId := .none
 
   -- Any goal associated with a fragment has a partial tactic which has not
   -- finished executing.
   fragments : FragmentMap := .empty
 
-def throwNoGoals { m α } [Monad m] [MonadError m] : m α := throwError "no goals to be solved"
-
 @[export pantograph_goal_state_create_m]
 protected def GoalState.create (expr: Expr): Elab.TermElabM GoalState := do
   -- May be necessary to immediately synthesise all metavariables if we need to leave the elaboration context.
@@ -86,6 +39,7 @@ protected def GoalState.create (expr: Expr): Elab.TermElabM GoalState := do
   return {
     root := root.mvarId!,
     savedState,
+    parentMVar? := .none,
   }
 @[export pantograph_goal_state_create_from_mvars_m]
 protected def GoalState.createFromMVars (goals: List MVarId) (root: MVarId): MetaM GoalState := do
@@ -94,19 +48,10 @@ protected def GoalState.createFromMVars (goals: List MVarId) (root: MVarId): Met
   return {
     root,
     savedState,
+    parentMVar? := .none,
   }
-@[always_inline]
 protected def GoalState.goals (state: GoalState): List MVarId :=
   state.savedState.tactic.goals
-@[always_inline]
-protected def GoalState.mainGoal? (state : GoalState) : Option MVarId :=
-  state.goals.head?
-@[always_inline]
-protected def GoalState.actingGoal? (state : GoalState) (site : Site) : Option MVarId := do
-  match site with
-  | .focus goal | .prefer goal => return goal
-  | .unfocus => state.mainGoal?
-
 @[export pantograph_goal_state_goals]
 protected def GoalState.goalsArray (state: GoalState): Array MVarId := state.goals.toArray
 protected def GoalState.mctx (state: GoalState): MetavarContext :=
@@ -118,10 +63,8 @@ protected def GoalState.env (state: GoalState): Environment :=
 protected def GoalState.metaContextOfGoal (state: GoalState) (mvarId: MVarId): Option Meta.Context := do
   let mvarDecl ← state.mctx.findDecl? mvarId
   return { lctx := mvarDecl.lctx, localInstances := mvarDecl.localInstances }
-@[always_inline]
 protected def GoalState.metaState (state: GoalState): Meta.State :=
   state.savedState.term.meta.meta
-@[always_inline]
 protected def GoalState.coreState (state: GoalState): Core.SavedState :=
   state.savedState.term.meta.core
 
@@ -129,18 +72,18 @@ protected def GoalState.withContext' (state: GoalState) (mvarId: MVarId) (m: Met
   mvarId.withContext m |>.run' (← read) state.metaState
 protected def GoalState.withContext { m } [MonadControlT MetaM m] [Monad m] (state: GoalState) (mvarId: MVarId) : m α → m α :=
   Meta.mapMetaM <| state.withContext' mvarId
-/-- Uses context of the first parent -/
 protected def GoalState.withParentContext { n } [MonadControlT MetaM n] [Monad n] (state: GoalState): n α → n α :=
-  Meta.mapMetaM <| state.withContext' state.parentMVars[0]!
+  Meta.mapMetaM <| state.withContext' state.parentMVar?.get!
 protected def GoalState.withRootContext { n } [MonadControlT MetaM n] [Monad n] (state: GoalState): n α → n α :=
   Meta.mapMetaM <| state.withContext' state.root
 
-private def restoreCoreMExtra (state : Core.SavedState) : CoreM Unit :=
+private def GoalState.mvars (state: GoalState): SSet MVarId :=
-  modifyGetThe Core.State (fun st => ((),
+  state.mctx.decls.foldl (init := .empty) fun acc k _ => acc.insert k
-    { st with nextMacroScope := state.nextMacroScope, ngen := state.ngen }))
 -- Restore the name generator and macro scopes of the core state
-protected def GoalState.restoreCoreMExtra (state: GoalState): CoreM Unit :=
+protected def GoalState.restoreCoreMExtra (state: GoalState): CoreM Unit := do
-  restoreCoreMExtra state.coreState
+  let savedCore := state.coreState
+  modifyGetThe Core.State (fun st => ((),
+    { st with nextMacroScope := savedCore.nextMacroScope, ngen := savedCore.ngen }))
 protected def GoalState.restoreMetaM (state: GoalState): MetaM Unit := do
   state.restoreCoreMExtra
   state.savedState.term.meta.restore
@@ -151,13 +94,40 @@ private def GoalState.restoreTacticM (state: GoalState) (goal: MVarId): Elab.Tac
   state.restoreElabM
   Elab.Tactic.setGoals [goal]
 
+@[export pantograph_goal_state_focus]
+protected def GoalState.focus (state : GoalState) (goal : MVarId): Option GoalState := do
+  return {
+    state with
+    savedState := {
+      state.savedState with
+      tactic := { goals := [goal] },
+    },
+  }
+
+/-- Immediately bring all parent goals back into scope. Used in automatic mode -/
+@[export pantograph_goal_state_immediate_resume]
+protected def GoalState.immediateResume (state: GoalState) (parent: GoalState): GoalState :=
+  -- Prune parents solved goals
+  let mctx := state.mctx
+  let parentGoals := parent.goals.filter λ goal =>
+    let isDuplicate := state.goals.contains goal
+    let isSolved := mctx.eAssignment.contains goal || mctx.dAssignment.contains goal
+    (¬ isDuplicate) && (¬ isSolved)
+  {
+    state with
+    savedState := {
+      state.savedState with
+      tactic := { goals := state.goals ++ parentGoals },
+    },
+  }
+
 /--
 Brings into scope a list of goals. User must ensure `goals` are distinct.
 -/
 @[export pantograph_goal_state_resume]
 protected def GoalState.resume (state : GoalState) (goals : List MVarId) : Except String GoalState := do
-  if ¬ (goals.all (state.mctx.decls.contains ·)) then
+  if ¬ (goals.all (λ goal => state.mvars.contains goal)) then
-    let invalid_goals := goals.filter (λ goal => ¬ state.mctx.decls.contains goal) |>.map (·.name.toString)
+    let invalid_goals := goals.filter (λ goal => ¬ state.mvars.contains goal) |>.map (·.name.toString)
     .error s!"Goals {invalid_goals} are not in scope"
   -- Set goals to the goals that have not been assigned yet, similar to the `focus` tactic.
   let unassigned := goals.filter λ goal =>
@@ -195,21 +165,17 @@ protected def GoalState.isSolved (goalState : GoalState) : Bool :=
     | .some e => ¬ e.hasExprMVar
     | .none => true
   goalState.goals.isEmpty && solvedRoot
+@[export pantograph_goal_state_parent_expr]
+protected def GoalState.parentExpr? (goalState: GoalState): Option Expr := do
+  let parent ← goalState.parentMVar?
+  let expr := goalState.mctx.eAssignment.find! parent
+  let (expr, _) := instantiateMVarsCore (mctx := goalState.mctx) (e := expr)
+  return expr
 @[export pantograph_goal_state_get_mvar_e_assignment]
 protected def GoalState.getMVarEAssignment (goalState: GoalState) (mvarId: MVarId): Option Expr := do
   let expr ← goalState.mctx.eAssignment.find? mvarId
   let (expr, _) := instantiateMVarsCore (mctx := goalState.mctx) (e := expr)
   return expr
-@[export pantograph_goal_state_parent_exprs]
-protected def GoalState.parentExprs (state : GoalState) : List Expr :=
-  state.parentMVars.map λ goal => state.getMVarEAssignment goal |>.get!
-@[always_inline]
-protected def GoalState.hasUniqueParent (state : GoalState) : Bool :=
-  state.parentMVars.length == 1
-@[always_inline]
-protected def GoalState.parentExpr! (state : GoalState) : Expr :=
-  assert! state.parentMVars.length == 1
-  (state.getMVarEAssignment state.parentMVars[0]!).get!
 
 deriving instance BEq for DelayedMetavarAssignment
 
@@ -221,8 +187,7 @@ if conflicting assignments exist. We also assume the monotonicity property: In a
 chain of descending goal states, a mvar cannot be unassigned, and once assigned
 its assignment cannot change. -/
 @[export pantograph_goal_state_replay_m]
-protected def GoalState.replay (dst : GoalState) (src src' : GoalState) : CoreM GoalState :=
+protected def GoalState.replay (dst : GoalState) (src src' : GoalState) : CoreM GoalState := do
-  withTraceNode `Pantograph.GoalState.replay (fun _ => return m!"replay") do
   let srcNGen := src.coreState.ngen
   let srcNGen' := src'.coreState.ngen
   let dstNGen := dst.coreState.ngen
@@ -246,8 +211,6 @@ protected def GoalState.replay (dst : GoalState) (src src' : GoalState) : CoreM
       else
         id
     | id => id
-  let mapMVar : MVarId → MVarId
-    | { name } => ⟨mapId name⟩
   let rec mapLevel : Level → Level
     | .succ x => .succ (mapLevel x)
     | .max l1 l2 => .max (mapLevel l1) (mapLevel l2)
@@ -261,7 +224,7 @@ protected def GoalState.replay (dst : GoalState) (src src' : GoalState) : CoreM
   let mapDelayedAssignment (d : DelayedMetavarAssignment) : CoreM DelayedMetavarAssignment := do
     let { mvarIdPending, fvars } := d
     return {
-      mvarIdPending := mapMVar mvarIdPending,
+      mvarIdPending := ⟨mapId mvarIdPending.name⟩,
       fvars := ← fvars.mapM mapExpr,
     }
   let mapLocalDecl (ldecl : LocalDecl) : CoreM LocalDecl := do
@@ -342,7 +305,6 @@ protected def GoalState.replay (dst : GoalState) (src src' : GoalState) : CoreM
     }
   }
   let m : MetaM Meta.SavedState := Meta.withMCtx mctx do
-    restoreCoreMExtra savedMeta.core
     savedMeta.restore
 
     for (lmvarId, l') in src'.mctx.lAssignment do
@@ -374,7 +336,7 @@ protected def GoalState.replay (dst : GoalState) (src src' : GoalState) : CoreM
         throwError "Conflicting assignment of expr metavariable (d != d) {mvarId.name}"
 
     Meta.saveState
-  let goals := dst.savedState.tactic.goals ++
+  let goals :=dst.savedState.tactic.goals ++
     src'.savedState.tactic.goals.map (⟨mapId ·.name⟩)
   let fragments ← src'.fragments.foldM (init := dst.fragments) λ acc mvarId' fragment' => do
     let mvarId := ⟨mapId mvarId'.name⟩
@@ -393,21 +355,18 @@ protected def GoalState.replay (dst : GoalState) (src src' : GoalState) : CoreM
         meta := ← m.run',
       },
     },
-    parentMVars := dst.parentMVars ++ src.parentMVars.map mapMVar,
     fragments,
   }
 
 --- Tactic execution functions ---
 
-/--
+-- Mimics `Elab.Term.logUnassignedUsingErrorInfos`
-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. See the rationales document for the
-inspiration of this function.
--/
 private def collectAllErroredMVars (src : MVarId) : Elab.TermElabM (List MVarId) := do
-  -- Mimics `Elab.Term.logUnassignedUsingErrorInfos`
+  -- 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 := {}
@@ -422,7 +381,6 @@ private def collectAllErroredMVars (src : MVarId) : Elab.TermElabM (List MVarId)
         result := mvarDeps.foldl (·.insert ·) result
   return result.toList
 
-/-- Merger of two unique lists -/
 private def mergeMVarLists (li1 li2 : List MVarId) : List MVarId :=
   let li2' := li2.filter (¬ li1.contains ·)
   li1 ++ li2'
@@ -432,29 +390,28 @@ 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' { α } (state : GoalState) (site : Site) (tacticM : Elab.Tactic.TacticM α) (guardMVarErrors : Bool := false)
+protected def GoalState.step' { α } (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM α) (guardMVarErrors : Bool := false)
   : Elab.TermElabM (α × GoalState) := do
-  let ((a, parentMVars), { goals }) ← site.runTacticM tacticM
+  unless (← getMCtx).decls.contains goal do
-    |>.run { elaborator := .anonymous }
+    throwError s!"Goal is not in context: {goal.name}"
-    |>.run state.savedState.tactic
+  goal.checkNotAssigned `GoalState.step
+  let (a, { goals }) ← tacticM { elaborator := .anonymous } |>.run { goals := [goal] }
   let nextElabState ← MonadBacktrack.saveState
   --Elab.Term.synthesizeSyntheticMVarsNoPostponing
 
   let goals ← if guardMVarErrors then
-      parentMVars.foldlM (init := goals) λ goals parent => do
+      pure $ mergeMVarLists goals (← collectAllErroredMVars goal)
-        let errors ← collectAllErroredMVars parent
-        return mergeMVarLists goals errors
     else
       pure goals
   let state' := {
     state with
     savedState := { term := nextElabState, tactic := { goals }, },
-    parentMVars,
+    parentMVar? := .some goal,
   }
   return (a, state')
-protected def GoalState.step (state : GoalState) (site : Site) (tacticM : Elab.Tactic.TacticM Unit) (guardMVarErrors : Bool := false)
+protected def GoalState.step (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM Unit) (guardMVarErrors : Bool := false)
   : Elab.TermElabM GoalState :=
-  Prod.snd <$> GoalState.step' state site tacticM guardMVarErrors
+  Prod.snd <$> GoalState.step' state goal tacticM guardMVarErrors
 
 /-- Response for executing a tactic -/
 inductive TacticResult where
@@ -467,21 +424,21 @@ inductive TacticResult where
   -- The given action cannot be executed in the state
   | invalidAction (message : String)
 
-private def dumpMessageLog (prevMessageLength : Nat := 0) : CoreM (Bool × Array String) := do
+private def dumpMessageLog (prevMessageLength : Nat) : CoreM (Bool × Array String) := do
   let newMessages := (← Core.getMessageLog).toList.drop prevMessageLength
   let hasErrors := newMessages.any (·.severity == .error)
   let newMessages ← newMessages.mapM λ m => m.toString
   Core.resetMessageLog
   return (hasErrors, newMessages.toArray)
 
-/-- Execute a `TermElabM` producing a goal state, capturing the error and turn it into a `TacticResult` -/
 def withCapturingError (elabM : Elab.Term.TermElabM GoalState) : Elab.TermElabM TacticResult := do
-  assert! (← Core.getMessageLog).toList.isEmpty
+  -- FIXME: Maybe message log should be empty
+  let prevMessageLength := (← Core.getMessageLog).toList.length
   try
     let state ← elabM
 
     -- Check if error messages have been generated in the core.
-    let (hasError, newMessages) ← dumpMessageLog
+    let (hasError, newMessages) ← dumpMessageLog prevMessageLength
     if hasError then
       return .failure newMessages
     else
@@ -489,58 +446,62 @@ def withCapturingError (elabM : Elab.Term.TermElabM GoalState) : Elab.TermElabM
   catch exception =>
     match exception with
     | .internal _ =>
-      let (_, messages) ← dumpMessageLog
+      let (_, messages) ← dumpMessageLog prevMessageLength
       return .failure messages
     | _ => return .failure #[← exception.toMessageData.toString]
 
 /-- Executes a `TacticM` monad on this `GoalState`, collecting the errors as necessary -/
 protected def GoalState.tryTacticM
-    (state: GoalState) (site : Site)
+    (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM Unit)
-    (tacticM: Elab.Tactic.TacticM Unit)
     (guardMVarErrors : Bool := false)
-    : Elab.TermElabM TacticResult :=
+    : Elab.TermElabM TacticResult := do
   withCapturingError do
-    state.step site tacticM guardMVarErrors
+    state.step goal tacticM guardMVarErrors
 
 /-- Execute a string tactic on given state. Restores TermElabM -/
 @[export pantograph_goal_state_try_tactic_m]
-protected def GoalState.tryTactic (state: GoalState) (site : Site) (tactic: String):
+protected def GoalState.tryTactic (state: GoalState) (goal: MVarId) (tactic: String):
     Elab.TermElabM TacticResult := do
   state.restoreElabM
-  let .some goal := state.actingGoal? site | throwNoGoals
+  /-
   if let .some fragment := state.fragments[goal]? then
     return ← withCapturingError do
-      let (fragments, state') ← state.step' site do
+      let (moreFragments, state') ← state.step' goal (fragment.step goal tactic)
-        fragment.step goal tactic $ state.fragments.erase goal
+      let fragments := moreFragments.fold (init := state.fragments.erase goal) λ acc mvarId f =>
-      return { state' with fragments }
+        acc.insert mvarId f
+      return { state' with fragments } -/
+
+  let catName := match isLHSGoal? (← goal.getType) with
+    | .some _ => `conv
+    | .none => `tactic
   -- Normal tactic without fragment
   let tactic ← match Parser.runParserCategory
-    (env := ← getEnv)
+    (env := ← MonadEnv.getEnv)
-    (catName := `tactic)
+    (catName := catName)
     (input := tactic)
     (fileName := ← getFileName) with
     | .ok stx => pure $ stx
     | .error error => return .parseError error
   let tacticM := Elab.Tactic.evalTactic tactic
   withCapturingError do
-    state.step site tacticM (guardMVarErrors := true)
+    state.step goal tacticM (guardMVarErrors := true)
 
 -- Specialized Tactics
 
-protected def GoalState.tryAssign (state : GoalState) (site : Site) (expr : String)
+protected def GoalState.tryAssign (state: GoalState) (goal: MVarId) (expr: String):
-    : Elab.TermElabM TacticResult := do
+      Elab.TermElabM TacticResult := do
   state.restoreElabM
   let expr ← match Parser.runParserCategory
-    (env := ← getEnv)
+    (env := ← MonadEnv.getEnv)
     (catName := `term)
     (input := expr)
     (fileName := ← getFileName) with
     | .ok syn => pure syn
     | .error error => return .parseError error
-  state.tryTacticM site $ Tactic.evalAssign expr
+  state.tryTacticM goal $ Tactic.evalAssign expr
 
-protected def GoalState.tryLet (state : GoalState) (site : Site) (binderName : String) (type : String)
+protected def GoalState.tryLet (state: GoalState) (goal: MVarId) (binderName: String) (type: String):
-    : Elab.TermElabM TacticResult := do
+      Elab.TermElabM TacticResult := do
   state.restoreElabM
   let type ← match Parser.runParserCategory
     (env := ← MonadEnv.getEnv)
@@ -549,30 +510,28 @@ protected def GoalState.tryLet (state : GoalState) (site : Site) (binderName : S
     (fileName := ← getFileName) with
     | .ok syn => pure syn
     | .error error => return .parseError error
-  state.tryTacticM site $ Tactic.evalLet binderName.toName type
+  state.tryTacticM goal $ Tactic.evalLet binderName.toName type
 
 /-- Enter conv tactic mode -/
 @[export pantograph_goal_state_conv_enter_m]
-protected def GoalState.convEnter (state : GoalState) (site : Site) :
+protected def GoalState.conv (state : GoalState) (goal : MVarId) :
       Elab.TermElabM TacticResult := do
-  let .some goal := state.actingGoal? site | throwNoGoals
   if let .some (.conv ..) := state.fragments[goal]? then
     return .invalidAction "Already in conv state"
+  goal.checkNotAssigned `GoalState.conv
   withCapturingError do
-    let (fragments, state') ← state.step' site Fragment.enterConv
+    let (fragment, state') ← state.step' goal Fragment.enterConv
     return {
       state' with
-      fragments := fragments.fold (init := state'.fragments) λ acc goal fragment =>
+      fragments := state'.fragments.insert goal fragment
-        acc.insert goal fragment
     }
 
-/-- Exit from a tactic fragment. -/
+/-- Exit from `conv` mode. Resumes all goals before the mode starts and applys the conv -/
-@[export pantograph_goal_state_fragment_exit_m]
+@[export pantograph_goal_state_conv_exit_m]
-protected def GoalState.fragmentExit (state : GoalState) (site : Site):
+protected def GoalState.convExit (state : GoalState) (goal : MVarId):
       Elab.TermElabM TacticResult := do
-  let .some goal := state.actingGoal? site | throwNoGoals
+  let .some fragment@(.conv ..) := state.fragments[goal]? |
-  let .some fragment := state.fragments[goal]? |
+    return .invalidAction "Not in conv state"
-    return .invalidAction "Goal does not have a fragment"
   withCapturingError do
     let (fragments, state') ← state.step' goal (fragment.exit goal state.fragments)
     return {
@@ -584,17 +543,18 @@ protected def GoalState.calcPrevRhsOf? (state : GoalState) (goal : MVarId) : Opt
   let .some (.calc prevRhs?) := state.fragments[goal]? | .none
   prevRhs?
 
-@[export pantograph_goal_state_calc_enter_m]
+@[export pantograph_goal_state_try_calc_m]
-protected def GoalState.calcEnter (state : GoalState) (site : Site)
+protected def GoalState.tryCalc (state : GoalState) (goal : MVarId) (pred : String)
   : Elab.TermElabM TacticResult := do
-  let .some goal := state.actingGoal? site | throwNoGoals
+  let prevRhs? := state.calcPrevRhsOf? goal
-  if let .some _ := state.fragments[goal]? then
-    return .invalidAction "Goal already has a fragment"
   withCapturingError do
-    let fragment := Fragment.enterCalc
+    let (moreFragments, state') ← state.step' goal do
-    let fragments := state.fragments.insert goal fragment
+      let fragment := Fragment.calc prevRhs?
+      fragment.step goal pred
+    let fragments := moreFragments.fold (init := state.fragments.erase goal) λ acc mvarId f =>
+      acc.insert mvarId f
     return {
-      state with
+      state' with
       fragments,
     }
 

Pantograph/Library.lean

@@ -117,10 +117,10 @@ def goalStartExpr (expr: String) : Protocol.FallibleT Elab.TermElabM GoalState :
 
 @[export pantograph_goal_serialize_m]
 def goalSerialize (state: GoalState) (options: @&Protocol.Options): CoreM (Array Protocol.Goal) :=
-  runMetaM <| state.serializeGoals options
+  runMetaM <| state.serializeGoals (parent := .none) options
 
 @[export pantograph_goal_print_m]
-def goalPrint (state: GoalState) (rootExpr: Bool) (parentExprs: Bool) (goals: Bool) (extraMVars : Array String) (options: @&Protocol.Options)
+def goalPrint (state: GoalState) (rootExpr: Bool) (parentExpr: Bool) (goals: Bool) (extraMVars : Array String) (options: @&Protocol.Options)
   : CoreM Protocol.GoalPrintResult := runMetaM do
   state.restoreMetaM
 
@@ -130,10 +130,9 @@ def goalPrint (state: GoalState) (rootExpr: Bool) (parentExprs: Bool) (goals: Bo
         serializeExpression options (← instantiateAll expr)
     else
       pure .none
-  let parentExprs? ← if parentExprs then
+  let parent? ← if parentExpr then
-      .some <$> state.parentMVars.mapM λ parent => parent.withContext do
+      state.parentExpr?.mapM λ expr => state.withParentContext do
-        let val := state.getMVarEAssignment parent |>.get!
+        serializeExpression options (← instantiateAll expr)
-        serializeExpression options (← instantiateAll val)
     else
       pure .none
   let goals ← if goals then
@@ -149,7 +148,7 @@ def goalPrint (state: GoalState) (rootExpr: Bool) (parentExprs: Bool) (goals: Bo
   let env ← getEnv
   return {
     root?,
-    parentExprs?,
+    parent?,
     goals,
     extraMVars,
     rootHasSorry := rootExpr?.map (·.hasSorry) |>.getD false,
@@ -158,26 +157,26 @@ def goalPrint (state: GoalState) (rootExpr: Bool) (parentExprs: Bool) (goals: Bo
   }
 
 @[export pantograph_goal_have_m]
-protected def GoalState.tryHave (state: GoalState) (site : Site) (binderName: String) (type: String): Elab.TermElabM TacticResult := do
+protected def GoalState.tryHave (state: GoalState) (goal: MVarId) (binderName: String) (type: String): Elab.TermElabM TacticResult := do
   let type ← match (← parseTermM type) with
     | .ok syn => pure syn
     | .error error => return .parseError error
   state.restoreElabM
-  state.tryTacticM site $ Tactic.evalHave binderName.toName type
+  state.tryTacticM goal $ Tactic.evalHave binderName.toName type
 @[export pantograph_goal_try_define_m]
-protected def GoalState.tryDefine (state: GoalState) (site : Site) (binderName: String) (expr: String): Elab.TermElabM TacticResult := do
+protected def GoalState.tryDefine (state: GoalState) (goal: MVarId) (binderName: String) (expr: String): Elab.TermElabM TacticResult := do
   let expr ← match (← parseTermM expr) with
     | .ok syn => pure syn
     | .error error => return .parseError error
   state.restoreElabM
-  state.tryTacticM site $ Tactic.evalDefine binderName.toName expr
+  state.tryTacticM goal (Tactic.evalDefine binderName.toName expr)
 @[export pantograph_goal_try_draft_m]
-protected def GoalState.tryDraft (state: GoalState) (site : Site) (expr: String): Elab.TermElabM TacticResult := do
+protected def GoalState.tryDraft (state: GoalState) (goal: MVarId) (expr: String): Elab.TermElabM TacticResult := do
   let expr ← match (← parseTermM expr) with
     | .ok syn => pure syn
     | .error error => return .parseError error
   state.restoreElabM
-  state.tryTacticM site $ Tactic.evalDraft expr
+  state.tryTacticM goal (Tactic.evalDraft expr)
 
 -- Cancel the token after a timeout.
 @[export pantograph_run_cancel_token_with_timeout_m]

Pantograph/Protocol.lean

@@ -60,21 +60,16 @@ structure Variable where
   type?: Option Expression  := .none
   value?: Option Expression := .none
   deriving Lean.ToJson
-inductive Fragment where
-  | tactic
-  | conv
-  | calc
-  deriving BEq, DecidableEq, Repr, Lean.ToJson
 structure Goal where
+  name: String := ""
   /-- Name of the metavariable -/
-  name : String := ""
+  userName?: Option String  := .none
-  /-- User-facing name -/
+  /-- Is the goal in conversion mode -/
-  userName? : Option String  := .none
+  isConversion: Bool        := false
-  fragment : Fragment := .tactic
   /-- target expression type -/
-  target : Expression
+  target: Expression
   /-- Variables -/
-  vars : Array Variable      := #[]
+  vars: Array Variable      := #[]
   deriving Lean.ToJson
 
 
@@ -92,7 +87,6 @@ structure InteractionError where
   deriving Lean.ToJson
 
 def errorIndex (desc: String): InteractionError := { error := "index", desc }
-def errorOperation (desc: String): InteractionError := { error := "operation", desc }
 def errorExpr (desc: String): InteractionError := { error := "expr", desc }
 
 
@@ -254,17 +248,17 @@ structure GoalStartResult where
   root: String
   deriving Lean.ToJson
 structure GoalTactic where
+  -- Identifiers for tree, state, and goal
   stateId: Nat
-  -- If omitted, act on the first goal
+  goalId: Nat := 0
-  goalId?: Option Nat := .none
-  -- If set to true, goal will not go dormant. Defaults to `automaticMode`
-  autoResume?: Option Bool := .none
   -- One of the fields here must be filled
   tactic?: Option String := .none
-  mode?: Option String := .none -- Changes the current category to {"tactic", "calc", "conv"}
   expr?: Option String := .none
   have?: Option String := .none
   let?: Option String := .none
+  calc?: Option String := .none
+  -- true to enter `conv`, `false` to exit. In case of exit the `goalId` is ignored.
+  conv?: Option Bool := .none
   draft?: Option String := .none
 
   -- In case of the `have` tactic, the new free variable name is provided here
@@ -314,8 +308,8 @@ structure GoalPrint where
 
   -- Print root?
   rootExpr?: Option Bool := .some False
-  -- Print the parent expressions
+  -- Print the parent expr?
-  parentExprs?: Option Bool := .some False
+  parentExpr?: Option Bool := .some False
   -- Print goals?
   goals?: Option Bool := .some False
   -- Print values of extra mvars?
@@ -325,7 +319,7 @@ structure GoalPrintResult where
   -- The root expression
   root?: Option Expression := .none
   -- The filling expression of the parent goal
-  parentExprs?: Option (List Expression) := .none
+  parent?: Option Expression := .none
   goals: Array Goal := #[]
   extraMVars: Array Expression := #[]
 

Pantograph/Serial.lean

@@ -103,7 +103,7 @@ def goalStatePickle (goalState : GoalState) (path : System.FilePath) : IO Unit :
       tactic
     }
     root,
-    parentMVars,
+    parentMVar?,
     fragments,
   } := goalState
   Pantograph.pickle path (
@@ -115,7 +115,7 @@ def goalStatePickle (goalState : GoalState) (path : System.FilePath) : IO Unit :
     tactic,
 
     root,
-    parentMVars,
+    parentMVar?,
     fragments,
   )
 
@@ -131,7 +131,7 @@ def goalStateUnpickle (path : System.FilePath) (env : Environment)
     tactic,
 
     root,
-    parentMVars,
+    parentMVar?,
     fragments,
   ), region) ← Pantograph.unpickle (
     PHashMap Name ConstantInfo ×
@@ -142,7 +142,7 @@ def goalStateUnpickle (path : System.FilePath) (env : Environment)
     Elab.Tactic.State ×
 
     MVarId ×
-    List MVarId ×
+    Option MVarId ×
     FragmentMap
   ) path
   let env ← env.replay (Std.HashMap.ofList map₂.toList)
@@ -162,7 +162,7 @@ def goalStateUnpickle (path : System.FilePath) (env : Environment)
       tactic,
     },
     root,
-    parentMVars,
+    parentMVar?,
     fragments,
   }
   return (goalState, region)

Pantograph/Tactic/Fragment.lean

@@ -4,13 +4,6 @@ Here, a unified system handles all fragments.
 
 Inside a tactic fragment, the parser category may be different. An incomplete
 fragmented tactic may not be elaboratable..
-
-In line with continuation/resumption paradigms, the exit function of a fragment
-tactic is responsible for resuming incomplete goals with fragments. For example,
-when a conversion tactic finishes, the sentinels should resume the root of the
-conversion tactic goal. The user cannot be expected to execute this resumption,
-since the root is automatically dormanted at the entry of the conversion tactic
-mode.
 -/
 import Lean.Meta
 import Lean.Elab
@@ -21,79 +14,59 @@ namespace Pantograph
 
 inductive Fragment where
   | calc (prevRhs? : Option Expr)
-  | conv (rhs : MVarId)
+  | conv (rhs : MVarId) (dormant : List MVarId)
-  -- This goal is spawned from a `conv`
+  deriving BEq
-  | convSentinel (parent : MVarId)
-  deriving BEq, Inhabited
-
 abbrev FragmentMap := Std.HashMap MVarId Fragment
 def FragmentMap.empty : FragmentMap := Std.HashMap.emptyWithCapacity 2
-protected def FragmentMap.filter (map : FragmentMap) (pred : MVarId → Fragment → Bool) : FragmentMap :=
-  map.fold (init := FragmentMap.empty) λ acc mvarId fragment =>
-    if pred mvarId fragment then
-      acc.insert mvarId fragment
-    else
-      acc
 
 protected def Fragment.map (fragment : Fragment) (mapExpr : Expr → CoreM Expr) : CoreM Fragment :=
-  let mapMVar (mvarId : MVarId) : CoreM MVarId :=
+  let mapMVarId (mvarId : MVarId) : CoreM MVarId :=
     return (← mapExpr (.mvar mvarId)) |>.mvarId!
   match fragment with
   | .calc prevRhs? => return .calc (← prevRhs?.mapM mapExpr)
-  | .conv rhs => do
+  | .conv rhs dormant => do
-    let rhs' ← mapMVar rhs
+    let rhs' ← mapMVarId rhs
-    return .conv rhs'
+    let dormant' ← dormant.mapM mapMVarId
-  | .convSentinel parent => do
+    return .conv rhs' dormant'
-    return .convSentinel (← mapMVar parent)
 
-protected def Fragment.enterCalc : Fragment := .calc .none
+protected def Fragment.enterCalc : Elab.Tactic.TacticM Fragment := do
-protected def Fragment.enterConv : Elab.Tactic.TacticM FragmentMap := do
+  return .calc .none
+protected def Fragment.enterConv : Elab.Tactic.TacticM Fragment := do
   let goal ← Elab.Tactic.getMainGoal
-  goal.checkNotAssigned `GoalState.conv
+  let rhs ← goal.withContext do
-  let (rhs, newGoal) ← goal.withContext do
+    let (rhs, newGoal) ← Elab.Tactic.Conv.mkConvGoalFor (← Elab.Tactic.getMainTarget)
-    let target ← instantiateMVars (← goal.getType)
+    Elab.Tactic.replaceMainGoal [newGoal.mvarId!]
-    let (rhs, newGoal) ← Elab.Tactic.Conv.mkConvGoalFor target
+    pure rhs.mvarId!
-    pure (rhs.mvarId!, newGoal.mvarId!)
+  let otherGoals := (← Elab.Tactic.getGoals).filter (· != goal)
-  Elab.Tactic.replaceMainGoal [newGoal]
+  return conv rhs otherGoals
-  return FragmentMap.empty
-    |>.insert goal (.conv rhs)
-    |>.insert newGoal (.convSentinel goal)
 
-protected partial def Fragment.exit (fragment : Fragment) (goal : MVarId) (fragments : FragmentMap)
+protected def Fragment.exit (fragment : Fragment) (goal : MVarId) (fragments : FragmentMap)
   : Elab.Tactic.TacticM FragmentMap :=
   match fragment with
   | .calc .. => do
     Elab.Tactic.setGoals [goal]
     return fragments.erase goal
-  | .conv rhs => do
+  | .conv rhs otherGoals => do
-    let goals := (← Elab.Tactic.getGoals).filter λ descendant =>
+    -- FIXME: Only process the goals that are descendants of `goal`
-      match fragments[descendant]? with
+    let goals := (← Elab.Tactic.getGoals).filter λ goal => true
-      | .some s => (.convSentinel goal) == s
+      --match fragments[goal]? with
-      | _ => false -- Not a conv goal from this
+      --| .some f => fragment == f
+      --| .none => false -- Not a conv goal from this
     -- Close all existing goals with `refl`
     for mvarId in goals do
       liftM <| mvarId.refl <|> mvarId.inferInstance <|> pure ()
+    Elab.Tactic.pruneSolvedGoals
     unless (← goals.filterM (·.isAssignedOrDelayedAssigned)).isEmpty do
       throwError "convert tactic failed, there are unsolved goals\n{Elab.goalsToMessageData (goals)}"
 
-    -- Ensure the meta tactic runs on `goal` even if its dormant by forcing resumption
+    Elab.Tactic.setGoals $ [goal] ++ otherGoals
-    Elab.Tactic.setGoals $ goal :: (← Elab.Tactic.getGoals)
     let targetNew ← instantiateMVars (.mvar rhs)
     let proof ← instantiateMVars (.mvar goal)
 
     Elab.Tactic.liftMetaTactic1 (·.replaceTargetEq targetNew proof)
+    return fragments.erase goal
 
-    -- Try to solve maiinline by rfl
+protected def Fragment.step (fragment : Fragment) (goal : MVarId) (s : String)
-    let mvarId ← Elab.Tactic.getMainGoal
-    liftM <| mvarId.refl <|> mvarId.inferInstance <|> pure ()
-    Elab.Tactic.pruneSolvedGoals
-    return fragments.filter λ mvarId fragment =>
-      !(mvarId == goal || fragment == .convSentinel goal)
-  | .convSentinel parent =>
-    let parentFragment := fragments[parent]!
-    parentFragment.exit parent (fragments.erase goal)
-
-protected def Fragment.step (fragment : Fragment) (goal : MVarId) (s : String) (map : FragmentMap)
   : Elab.Tactic.TacticM FragmentMap := goal.withContext do
   assert! ¬ (← goal.isAssigned)
   match fragment with
@@ -148,41 +121,9 @@ protected def Fragment.step (fragment : Fragment) (goal : MVarId) (s : String) (
     let goals := [ mvarBranch ] ++ remainder?.toList
     Elab.Tactic.setGoals goals
     match remainder? with
-    | .some goal => return map.erase goal |>.insert goal $ .calc (.some rhs)
+    | .some goal => return FragmentMap.empty.insert goal $ .calc (.some rhs)
-    | .none => return map
+    | .none => return .empty
   | .conv .. => do
     throwError "Direct operation on conversion tactic parent goal is not allowed"
-  | fragment@(.convSentinel parent) => do
-    assert! isLHSGoal? (← goal.getType) |>.isSome
-    let tactic ← match Parser.runParserCategory
-      (env := ← MonadEnv.getEnv)
-      (catName := `conv)
-      (input := s)
-      (fileName := ← getFileName) with
-      | .ok stx => pure $ stx
-      | .error error => throwError error
-    let oldGoals ← Elab.Tactic.getGoals
-    -- Label newly generated goals as conv sentinels
-    Elab.Tactic.evalTactic tactic
-    let newConvGoals ← (← Elab.Tactic.getUnsolvedGoals).filterM λ g => do
-      -- conv tactic might generate non-conv goals
-      if oldGoals.contains g then
-        return false
-      return isLHSGoal? (← g.getType) |>.isSome
-    -- Conclude the conv by exiting the parent fragment if new goals is empty
-    if newConvGoals.isEmpty then
-      let hasSiblingFragment := map.fold (init := false) λ flag _ fragment =>
-        if flag then
-          true
-        else match fragment with
-          | .convSentinel parent' => parent == parent'
-          | _ => false
-      if ¬ hasSiblingFragment then
-        -- This fragment must exist since we have conv goals
-        let parentFragment := map[parent]!
-        -- All descendants exhausted. Exit from the parent conv.
-        return ← parentFragment.exit parent map
-    return newConvGoals.foldl (init := map) λ acc g =>
-      acc.insert g fragment
 
 end Pantograph

Repl.lean

@@ -97,77 +97,6 @@ def liftTermElabM { α } (termElabM : Elab.TermElabM α) (levelNames : List Name
   }
   runCoreM $ termElabM.run' context state |>.run'
 
-section Goal
-
-def goal_tactic (args: Protocol.GoalTactic): EMainM Protocol.GoalTacticResult := do
-  let state ← getMainState
-  let .some goalState := state.goalStates[args.stateId]? |
-    Protocol.throw $ Protocol.errorIndex s!"Invalid state index {args.stateId}"
-  let unshielded := args.autoResume?.getD state.options.automaticMode
-  let site ← match args.goalId?, unshielded with
-    | .some goalId, true => do
-      let .some goal := goalState.goals[goalId]? |
-        Protocol.throw $ Protocol.errorIndex s!"Invalid goal index {goalId}"
-      pure (.prefer goal)
-    | .some goalId, false => do
-      let .some goal := goalState.goals[goalId]? |
-        Protocol.throw $ Protocol.errorIndex s!"Invalid goal index {goalId}"
-      pure (.focus goal)
-    | .none, true => pure .unfocus
-    | .none, false => do
-      let .some goal := goalState.mainGoal? |
-        Protocol.throw $ Protocol.errorIndex s!"No goals to be solved"
-      pure (.focus goal)
-  let nextGoalState?: Except _ TacticResult ← liftTermElabM do
-    -- NOTE: Should probably use a macro to handle this...
-    match args.tactic?, args.mode?, args.expr?, args.have?, args.let?, args.draft?  with
-    | .some tactic, .none, .none, .none, .none, .none => do
-      pure $ Except.ok $ ← goalState.tryTactic site tactic
-    | .none, .some mode, .none, .none, .none, .none => match mode with
-      | "tactic" => do -- Exit from the current fragment
-        pure $ Except.ok $ ← goalState.fragmentExit site
-      | "conv" => do
-        pure $ Except.ok $ ← goalState.convEnter site
-      | "calc" => do
-        pure $ Except.ok $ ← goalState.calcEnter site
-      | _ => pure $ .error $ Protocol.errorOperation s!"Invalid mode {mode}"
-    | .none, .none, .some expr, .none, .none, .none => do
-      pure $ Except.ok $ ← goalState.tryAssign site expr
-    | .none, .none, .none, .some type, .none, .none => do
-      let binderName := args.binderName?.getD ""
-      pure $ Except.ok $ ← goalState.tryHave site binderName type
-    | .none, .none, .none, .none, .some type, .none => do
-      let binderName := args.binderName?.getD ""
-      pure $ Except.ok $ ← goalState.tryLet site binderName type
-    | .none, .none, .none, .none, .none, .some draft => do
-      pure $ Except.ok $ ← goalState.tryDraft site draft
-    | _, _, _, _, _, _ =>
-      pure $ .error $ Protocol.errorOperation
-        "Exactly one of {tactic, mode, expr, have, let, draft} must be supplied"
-  match nextGoalState? with
-  | .error error => Protocol.throw error
-  | .ok (.success nextGoalState messages) => do
-    let nextStateId ← newGoalState nextGoalState
-    let parentExprs := nextGoalState.parentExprs
-    let hasSorry := parentExprs.any (·.hasSorry)
-    let hasUnsafe := parentExprs.any ((← getEnv).hasUnsafe ·)
-    let goals ← runCoreM $ nextGoalState.serializeGoals (options := state.options) |>.run'
-    return {
-      nextStateId? := .some nextStateId,
-      goals? := .some goals,
-      messages? := .some messages,
-      hasSorry,
-      hasUnsafe,
-    }
-  | .ok (.parseError message) =>
-    return { messages? := .none, parseError? := .some message }
-  | .ok (.invalidAction message) =>
-    Protocol.throw $ errorI "invalid" message
-  | .ok (.failure messages) =>
-    return { messages? := .some messages }
-
-end Goal
-
 section Frontend
 
 structure CompilationUnit where
@@ -296,6 +225,7 @@ def execute (command: Protocol.Command): MainM Json := do
     return toJson error
   where
   errorCommand := errorI "command"
+  errorIndex := errorI "index"
   errorIO := errorI "io"
   -- Command Functions
   reset (_: Protocol.Reset): EMainM Protocol.StatResult := do
@@ -360,7 +290,7 @@ def execute (command: Protocol.Command): MainM Json := do
       | .some expr, .none => goalStartExpr expr |>.run
       | .none, .some copyFrom => do
         (match (← getEnv).find? <| copyFrom.toName with
-        | .none => return .error <| Protocol.errorIndex s!"Symbol not found: {copyFrom}"
+        | .none => return .error <| errorIndex s!"Symbol not found: {copyFrom}"
         | .some cInfo => return .ok (← GoalState.create cInfo.type))
       | _, _ =>
         return .error <| errorI "arguments" "Exactly one of {expr, copyFrom} must be supplied"
@@ -369,14 +299,70 @@ def execute (command: Protocol.Command): MainM Json := do
     | .ok goalState =>
       let stateId ← newGoalState goalState
       return { stateId, root := goalState.root.name.toString }
+  goal_tactic (args: Protocol.GoalTactic): EMainM Protocol.GoalTacticResult := do
+    let state ← getMainState
+    let .some goalState := state.goalStates[args.stateId]? |
+      Protocol.throw $ errorIndex s!"Invalid state index {args.stateId}"
+    -- FIXME: Allow proper conversion tactic exit even in automatic mode
+    let .some goal := goalState.goals[args.goalId]? |
+      Protocol.throw $ errorIndex s!"Invalid goal index {args.goalId}"
+    let nextGoalState?: Except _ TacticResult ← liftTermElabM do
+      -- NOTE: Should probably use a macro to handle this...
+      match args.tactic?, args.expr?, args.have?, args.let?, args.calc?, args.conv?, args.draft?  with
+      | .some tactic, .none, .none, .none, .none, .none, .none => do
+        pure <| Except.ok <| ← goalState.tryTactic goal tactic
+      | .none, .some expr, .none, .none, .none, .none, .none => do
+        pure <| Except.ok <| ← goalState.tryAssign goal expr
+      | .none, .none, .some type, .none, .none, .none, .none => do
+        let binderName := args.binderName?.getD ""
+        pure <| Except.ok <| ← goalState.tryHave goal binderName type
+      | .none, .none, .none, .some type, .none, .none, .none => do
+        let binderName := args.binderName?.getD ""
+        pure <| Except.ok <| ← goalState.tryLet goal binderName type
+      | .none, .none, .none, .none, .some pred, .none, .none => do
+        pure <| Except.ok <| ← goalState.tryCalc goal pred
+      | .none, .none, .none, .none, .none, .some true, .none => do
+        pure <| Except.ok <| ← goalState.conv goal
+      | .none, .none, .none, .none, .none, .some false, .none => do
+        pure <| Except.ok <| ← goalState.convExit goal
+      | .none, .none, .none, .none, .none, .none, .some draft => do
+        pure <| Except.ok <| ← goalState.tryDraft goal draft
+      | _, _, _, _, _, _, _ =>
+        let error := errorI "arguments" "Exactly one of {tactic, expr, have, let, calc, conv, draft} must be supplied"
+        pure $ .error error
+    match nextGoalState? with
+    | .error error => Protocol.throw error
+    | .ok (.success nextGoalState messages) => do
+      let nextGoalState ← match state.options.automaticMode, args.conv? with
+        | true, .none => do
+          pure $ nextGoalState.immediateResume goalState
+        | true, .some true => pure nextGoalState
+        | true, .some false => pure nextGoalState
+        | false, _ => pure nextGoalState
+      let nextStateId ← newGoalState nextGoalState
+      let parentExpr := nextGoalState.parentExpr?.get!
+      let goals ← runCoreM $ nextGoalState.serializeGoals (parent := .some goalState) (options := state.options) |>.run'
+      return {
+        nextStateId? := .some nextStateId,
+        goals? := .some goals,
+        messages? := .some messages,
+        hasSorry := parentExpr.hasSorry,
+        hasUnsafe := (← getEnv).hasUnsafe parentExpr,
+      }
+    | .ok (.parseError message) =>
+      return { messages? := .none, parseError? := .some message }
+    | .ok (.invalidAction message) =>
+      Protocol.throw $ errorI "invalid" message
+    | .ok (.failure messages) =>
+      return { messages? := .some messages }
   goal_continue (args: Protocol.GoalContinue): EMainM Protocol.GoalContinueResult := do
     let state ← getMainState
     let .some target := state.goalStates[args.target]? |
-      Protocol.throw $ Protocol.errorIndex s!"Invalid state index {args.target}"
+      Protocol.throw $ errorIndex s!"Invalid state index {args.target}"
     let nextGoalState? : GoalState  ← match args.branch?, args.goals? with
       | .some branchId, .none => do
         match state.goalStates[branchId]? with
-        | .none => Protocol.throw $ Protocol.errorIndex s!"Invalid state index {branchId}"
+        | .none => Protocol.throw $ errorIndex s!"Invalid state index {branchId}"
         | .some branch => pure $ target.continue branch
       | .none, .some goals =>
         let goals := goals.toList.map (λ n => { name := n.toName })
@@ -399,11 +385,11 @@ def execute (command: Protocol.Command): MainM Json := do
   goal_print (args: Protocol.GoalPrint): EMainM Protocol.GoalPrintResult := do
     let state ← getMainState
     let .some goalState := state.goalStates[args.stateId]? |
-      Protocol.throw $ Protocol.errorIndex s!"Invalid state index {args.stateId}"
+      Protocol.throw $ errorIndex s!"Invalid state index {args.stateId}"
     let result ← liftMetaM <| goalPrint
         goalState
         (rootExpr := args.rootExpr?.getD False)
-        (parentExprs := args.parentExprs?.getD False)
+        (parentExpr := args.parentExpr?.getD False)
         (goals := args.goals?.getD False)
         (extraMVars := args.extraMVars?.getD #[])
         (options := state.options)
@@ -411,7 +397,7 @@ def execute (command: Protocol.Command): MainM Json := do
   goal_save (args: Protocol.GoalSave): EMainM Protocol.GoalSaveResult := do
     let state ← getMainState
     let .some goalState := state.goalStates[args.id]? |
-      Protocol.throw $ Protocol.errorIndex s!"Invalid state index {args.id}"
+      Protocol.throw $ errorIndex s!"Invalid state index {args.id}"
     goalStatePickle goalState args.path
     return {}
   goal_load (args: Protocol.GoalLoad): EMainM Protocol.GoalLoadResult := do

Test/Integration.lean

@@ -88,10 +88,10 @@ def test_tactic : Test := do
    ({ stateId := 0, root := "_uniq.9" }: Protocol.GoalStartResult)
   step "goal.tactic" ({ stateId := 0, tactic? := .some "intro x" }: Protocol.GoalTactic)
    ({ nextStateId? := .some 1, goals? := #[goal1], }: Protocol.GoalTacticResult)
-  step "goal.print" ({ stateId := 1, parentExprs? := .some true, rootExpr? := .some true }: Protocol.GoalPrint)
+  step "goal.print" ({ stateId := 1, parentExpr? := .some true, rootExpr? := .some true }: Protocol.GoalPrint)
    ({
      root? := .some { pp? := "fun x => ?m.11"},
-     parentExprs? := .some [{ pp? := .some "fun x => ?m.11" }],
+     parent? := .some { pp? := .some "fun x => ?m.11" },
    }: Protocol.GoalPrintResult)
   step "goal.tactic" ({ stateId := 1, tactic? := .some "intro y" }: Protocol.GoalTactic)
    ({ nextStateId? := .some 2, goals? := #[goal2], }: Protocol.GoalTacticResult)

Test/Main.lean

@@ -55,7 +55,6 @@ def main (args: List String) := do
     ("Delate", Delate.suite),
     ("Serial", Serial.suite),
     ("Tactic/Assign", Tactic.Assign.suite),
-    ("Tactic/Fragment", Tactic.Fragment.suite),
     ("Tactic/Prograde", Tactic.Prograde.suite),
     ("Tactic/Special", Tactic.Special.suite),
   ]

Test/Proofs.lean

@@ -32,7 +32,7 @@ def startProof (start: Start): TestM (Option GoalState) := do
     let expr ← parseSentence expr
     return .some $ ← GoalState.create (expr := expr)
 
-private def buildNamedGoal (name: String) (nameType: List (String × String)) (target: String)
+def buildNamedGoal (name: String) (nameType: List (String × String)) (target: String)
     (userName?: Option String := .none): Protocol.Goal :=
   {
     name,
@@ -43,7 +43,7 @@ private def buildNamedGoal (name: String) (nameType: List (String × String)) (t
       type? := .some { pp? := .some x.snd },
     })).toArray
   }
-private def buildGoal (nameType: List (String × String)) (target: String) (userName?: Option String := .none):
+def buildGoal (nameType: List (String × String)) (target: String) (userName?: Option String := .none):
     Protocol.Goal :=
   {
     userName?,
@@ -53,7 +53,7 @@ private def buildGoal (nameType: List (String × String)) (target: String) (user
       type? := .some { pp? := .some x.snd },
     })).toArray
   }
-private def proofRunner (env: Lean.Environment) (tests: TestM Unit): IO LSpec.TestSeq := do
+def proofRunner (env: Lean.Environment) (tests: TestM Unit): IO LSpec.TestSeq := do
   let termElabM := tests.run LSpec.TestSeq.done |>.run {} -- with default options
 
   let coreContext: Lean.Core.Context ← createCoreContext #[]
@@ -77,7 +77,7 @@ def test_identity: TestM Unit := do
   addTest $ LSpec.check "intro" ((← state1.serializeGoals (options := ← read)).map (·.name) =
     #[inner])
   let state1parent ← state1.withParentContext do
-    serializeExpressionSexp (← instantiateAll state1.parentExpr!)
+    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
@@ -117,6 +117,41 @@ def test_nat_add_comm (manual: Bool): TestM Unit := do
   addTest $ LSpec.test "rw [Nat.add_comm]" state2.goals.isEmpty
 
   return ()
+def test_delta_variable: TestM Unit := do
+  let options: Protocol.Options := { noRepeat := true }
+  let state? ← startProof <| .expr "∀ (a b: Nat), a + b = b + a"
+  addTest $ LSpec.check "Start goal" state?.isSome
+  let state0 ← match state? with
+    | .some state => pure state
+    | .none => do
+      addTest $ assertUnreachable "Goal could not parse"
+      return ()
+
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := "intro n") with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check "intro n" ((← state1.serializeGoals (parent := state0) options).map (·.devolatilize) =
+    #[buildGoalSelective [("n", .some "Nat")] "∀ (b : Nat), n + b = b + n"])
+  let state2 ← match ← state1.tacticOn (goalId := 0) (tactic := "intro m") with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check "intro m" ((← state2.serializeGoals (parent := state1) options).map (·.devolatilize) =
+    #[buildGoalSelective [("n", .none), ("m", .some "Nat")] "n + m = m + n"])
+  return ()
+  where
+-- Like `buildGoal` but allow certain variables to be elided.
+  buildGoalSelective (nameType: List (String × Option String)) (target: String): Protocol.Goal :=
+    {
+      target := { pp? := .some target},
+      vars := (nameType.map fun x => ({
+        userName := x.fst,
+        type? := x.snd.map (λ type => { pp? := type }),
+      })).toArray
+    }
 
 example (w x y z : Nat) (p : Nat → Prop)
         (h : p (x * y + z * w * x)) : p (x * w * z + y * x) := by
@@ -177,8 +212,8 @@ def test_or_comm: TestM Unit := do
     | .none => do
       addTest $ assertUnreachable "Goal could not parse"
       return ()
-  checkTrue "(0 parent)" state0.parentMVars.isEmpty
+  addTest $ LSpec.check "(0 parent)" state0.parentExpr?.isNone
-  checkTrue "(0 root)" state0.rootExpr?.isNone
+  addTest $ LSpec.check "(0 root)" state0.rootExpr?.isNone
 
   let tactic := "intro p q h"
   let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
@@ -202,11 +237,11 @@ def test_or_comm: TestM Unit := do
         { name := fvH, userName := "h", type? := .some { pp? := .some "p ∨ q" } }
       ]
     }])
-  checkTrue "(1 parent)" state1.hasUniqueParent
+  checkTrue "(1 parent)" state1.parentExpr?.isSome
   checkTrue "(1 root)" $ ¬ state1.isSolved
 
   let state1parent ← state1.withParentContext do
-    serializeExpressionSexp (← instantiateAll state1.parentExpr!)
+    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
@@ -221,11 +256,11 @@ def test_or_comm: TestM Unit := do
   let (caseL, caseR) := (state2g0.name.toString, state2g1.name.toString)
   addTest $ LSpec.check tactic ((← state2.serializeGoals (options := ← read)).map (·.name) =
     #[caseL, caseR])
-  checkTrue "(2 parent exists)" state2.hasUniqueParent
+  checkTrue "(2 parent exists)" state2.parentExpr?.isSome
   checkTrue "(2 root)" $ ¬ state2.isSolved
 
   let state2parent ← state2.withParentContext do
-    serializeExpressionSexp (← instantiateAll state2.parentExpr!)
+    serializeExpressionSexp (← instantiateAll state2.parentExpr?.get!)
   let orPQ := s!"((:c Or) (:fv {fvP}) (:fv {fvQ}))"
   let orQP := s!"((:c Or) (:fv {fvQ}) (:fv {fvP}))"
   let motive := s!"(:lambda t {orPQ} (:forall h ((:c Eq) ((:c Or) (:fv {fvP}) (:fv {fvQ})) (:fv {fvH}) 0) {orQP}))"
@@ -241,7 +276,7 @@ def test_or_comm: TestM Unit := do
       addTest $ assertUnreachable $ other.toString
       return ()
   let state3_1parent ← state3_1.withParentContext do
-    serializeExpressionSexp (← instantiateAll state3_1.parentExpr!)
+    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)
@@ -251,7 +286,7 @@ def test_or_comm: TestM Unit := do
       addTest $ assertUnreachable $ other.toString
       return ()
   addTest $ LSpec.check "  assumption" state4_1.goals.isEmpty
-  let state4_1parent ← instantiateAll state4_1.parentExpr!
+  let state4_1parent ← instantiateAll state4_1.parentExpr?.get!
   addTest $ LSpec.test "(4_1 parent)" state4_1parent.isFVar
   checkTrue "(4_1 root)" $ ¬ state4_1.isSolved
   let state3_2 ← match ← state2.tacticOn (goalId := 1) (tactic := "apply Or.inl") with
@@ -301,6 +336,194 @@ def test_or_comm: TestM Unit := do
       ]
     }
 
+example : ∀ (a b c1 c2: Nat), (b + a) + c1 = (b + a) + c2 → (a + b) + c1 = (b + a) + c2 := by
+  intro a b c1 c2 h
+  conv =>
+    lhs
+    congr
+    . rw [Nat.add_comm]
+    . rfl
+  exact h
+
+def test_conv: TestM Unit := do
+  let state? ← startProof (.expr "∀ (a b c1 c2: Nat), (b + a) + c1 = (b + a) + c2 → (a + b) + c1 = (b + a) + c2")
+  let state0 ← match state? with
+    | .some state => pure state
+    | .none => do
+      addTest $ assertUnreachable "Goal could not parse"
+      return ()
+
+  let tactic := "intro a b c1 c2 h"
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check tactic ((← state1.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[interiorGoal [] "a + b + c1 = b + a + c2"])
+
+  let goalConv := state1.goals[0]!
+  let state2 ← match ← state1.conv (state1.get! 0) with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check "conv => ..." ((← state2.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[{ interiorGoal [] "a + b + c1 = b + a + c2" with isConversion := true }])
+
+  let convTactic := "rhs"
+  let state3R ← match ← state2.tacticOn (goalId := 0) convTactic with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check s!"  {convTactic} (discard)" ((← state3R.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[{ interiorGoal [] "b + a + c2" with isConversion := true }])
+
+  let convTactic := "lhs"
+  let state3L ← match ← state2.tacticOn (goalId := 0) convTactic with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check s!"  {convTactic}" ((← state3L.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[{ interiorGoal [] "a + b + c1" with isConversion := true }])
+
+  let convTactic := "congr"
+  let state4 ← match ← state3L.tacticOn (goalId := 0) convTactic with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check s!"  {convTactic}" ((← state4.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[
+      { interiorGoal [] "a + b" with isConversion := true, userName? := .some "a" },
+      { interiorGoal [] "c1" with isConversion := true, userName? := .some "a" }
+    ])
+
+  let convTactic := "rw [Nat.add_comm]"
+  let state5_1 ← match ← state4.tacticOn (goalId := 0) convTactic with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check s!"  · {convTactic}" ((← state5_1.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[{ interiorGoal [] "b + a" with isConversion := true, userName? := .some "a" }])
+
+  let convTactic := "rfl"
+  let state6_1 ← match ← state5_1.tacticOn (goalId := 0) convTactic with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check s!"    {convTactic}" ((← state6_1.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[])
+
+  let state4_1 ← match state6_1.continue state4 with
+    | .ok state => pure state
+    | .error e => do
+      addTest $ expectationFailure "continue" e
+      return ()
+
+  let convTactic := "rfl"
+  let state6 ← match ← state4_1.tacticOn (goalId := 0) convTactic with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check s!"  · {convTactic}" ((← state6.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[])
+
+  let state1_1 ← match ← state6.convExit goalConv with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+
+  let tactic := "exact h"
+  let stateF ← match ← state1_1.tacticOn (goalId := 0) (tactic := tactic) with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check tactic ((← stateF.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[])
+
+  where
+    h := "b + a + c1 = b + a + c2"
+    interiorGoal (free: List (String × String)) (target: String) :=
+      let free := [("a", "Nat"), ("b", "Nat"), ("c1", "Nat"), ("c2", "Nat"), ("h", h)] ++ free
+      buildGoal free target
+
+example : ∀ (a b c d: Nat), a + b = b + c → b + c = c + d → a + b = c + d := by
+  intro a b c d h1 h2
+  calc a + b = b + c := by apply h1
+    _ = c + d := by apply h2
+
+def test_calc: TestM Unit := do
+  let state? ← startProof (.expr "∀ (a b c d: Nat), a + b = b + c → b + c = c + d → a + b = c + d")
+  let state0 ← match state? with
+    | .some state => pure state
+    | .none => do
+      addTest $ assertUnreachable "Goal could not parse"
+      return ()
+  let tactic := "intro a b c d h1 h2"
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check tactic ((← state1.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[interiorGoal [] "a + b = c + d"])
+  let pred := "a + b = b + c"
+  let state2 ← match ← state1.tryCalc (state1.get! 0) (pred := pred) with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check s!"calc {pred} := _" ((← state2.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[
+      interiorGoal [] "a + b = b + c" (.some "calc"),
+      interiorGoal [] "b + c = c + d"
+    ])
+  addTest $ LSpec.test "(2.0 prev rhs)" (state2.calcPrevRhsOf? (state2.get! 0) |>.isNone)
+  addTest $ LSpec.test "(2.1 prev rhs)" (state2.calcPrevRhsOf? (state2.get! 1) |>.isSome)
+
+  let tactic := "apply h1"
+  let state2m ← match ← state2.tacticOn (goalId := 0) (tactic := tactic) with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  let state3 ← match state2m.continue state2 with
+    | .ok state => pure state
+    | .error e => do
+      addTest $ expectationFailure "continue" e
+      return ()
+  let pred := "_ = c + d"
+  let state4 ← match ← state3.tryCalc (state3.get! 0) (pred := pred) with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.check s!"calc {pred} := _" ((← state4.serializeGoals (options := ← read)).map (·.devolatilize) =
+    #[
+      interiorGoal [] "b + c = c + d" (.some "calc")
+    ])
+  addTest $ LSpec.test "(4.0 prev rhs)" (state4.calcPrevRhsOf? (state4.get! 0) |>.isNone)
+  let tactic := "apply h2"
+  let state4m ← match ← state4.tacticOn (goalId := 0) (tactic := tactic) with
+    | .success state _ => pure state
+    | other => do
+      addTest $ assertUnreachable $ other.toString
+      return ()
+  addTest $ LSpec.test "(4m root)" state4m.rootExpr?.isSome
+  where
+    interiorGoal (free: List (String × String)) (target: String) (userName?: Option String := .none) :=
+      let free := [("a", "Nat"), ("b", "Nat"), ("c", "Nat"), ("d", "Nat"),
+        ("h1", "a + b = b + c"), ("h2", "b + c = c + d")] ++ free
+      buildGoal free target userName?
+
 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
@@ -377,8 +600,11 @@ def suite (env: Environment): List (String × IO LSpec.TestSeq) :=
     ("identity", test_identity),
     ("Nat.add_comm", test_nat_add_comm false),
     ("Nat.add_comm manual", test_nat_add_comm true),
+    ("Nat.add_comm delta", test_delta_variable),
     ("arithmetic", test_arith),
     ("Or.comm", test_or_comm),
+    ("conv", test_conv),
+    ("calc", test_calc),
     ("tactic failure with unresolved goals", test_tactic_failure_unresolved_goals),
     ("tactic failure with synthesize placeholder", test_tactic_failure_synthesize_placeholder),
     ("deconstruct", test_deconstruct),

Test/Serial.lean

@@ -87,12 +87,12 @@ def test_pickling_env_extensions : TestM Unit := do
       let .ok value ← elabTerm (← `(term|sorry)) (.some type) | unreachable!
       pure (type, value)
     let .success state1 _ ← state.tryTacticM goal (Tactic.assignWithAuxLemma type value) | unreachable!
-    let parentExpr := state1.parentExpr!
+    let parentExpr := state1.parentExpr?.get!
     checkTrue "src has aux lemma" $ parentExpr.getUsedConstants.any λ name => name.isAuxLemma
     goalStatePickle state1 statePath
   let ((), _) ← runCoreM coreDst $ transformTestT runTermElabMInCore do
     let (state1, _) ← goalStateUnpickle statePath (← getEnv)
-    let parentExpr := state1.parentExpr!
+    let parentExpr := state1.parentExpr?.get!
     checkTrue "dst has aux lemma" $ parentExpr.getUsedConstants.any λ name => name.isAuxLemma
 
   return ()

Test/Tactic.lean

@@ -1,4 +1,3 @@
 import Test.Tactic.Assign
-import Test.Tactic.Fragment
 import Test.Tactic.Prograde
 import Test.Tactic.Special

Test/Tactic/Fragment.lean

@@ -1,312 +0,0 @@
-import Pantograph.Goal
-import Test.Common
-
-open Lean
-
-namespace Pantograph.Test.Tactic.Fragment
-
-private def buildGoal (nameType: List (String × String)) (target: String):
-    Protocol.Goal :=
-  {
-    target := { pp? := .some target},
-    vars := (nameType.map fun x => ({
-      userName := x.fst,
-      type? := .some { pp? := .some x.snd },
-    })).toArray
-  }
-
-abbrev TestM := TestT $ Elab.TermElabM
-
-example : ∀ (a b c1 c2: Nat), (b + a) + c1 = (b + a) + c2 → (a + b) + c1 = (b + a) + c2 := by
-  intro a b c1 c2 h
-  conv =>
-    lhs
-    congr
-    . rw [Nat.add_comm]
-    . rfl
-  exact h
-
-def test_conv_simple: TestM Unit := do
-  let rootTarget ← parseSentence "∀ (a b c1 c2: Nat), (b + a) + c1 = (b + a) + c2 → (a + b) + c1 = (b + a) + c2"
-  let state0 ← GoalState.create rootTarget
-
-  let tactic := "intro a b c1 c2 h"
-  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check tactic ((← state1.serializeGoals).map (·.devolatilize) =
-    #[interiorGoal [] "a + b + c1 = b + a + c2"])
-
-  let goalConv := state1.goals[0]!
-  let state2 ← match ← state1.convEnter (state1.get! 0) with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check "conv => ..." ((← state2.serializeGoals).map (·.devolatilize) =
-    #[{ interiorGoal [] "a + b + c1 = b + a + c2" with fragment := .conv }])
-
-  let convTactic := "rhs"
-  let state3R ← match ← state2.tacticOn (goalId := 0) convTactic with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check s!"  {convTactic} (discard)" ((← state3R.serializeGoals).map (·.devolatilize) =
-    #[{ interiorGoal [] "b + a + c2" with fragment := .conv }])
-
-  let convTactic := "lhs"
-  let state3L ← match ← state2.tacticOn (goalId := 0) convTactic with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check s!"  {convTactic}" ((← state3L.serializeGoals).map (·.devolatilize) =
-    #[{ interiorGoal [] "a + b + c1" with fragment := .conv }])
-
-  let convTactic := "congr"
-  let state4 ← match ← state3L.tacticOn (goalId := 0) convTactic with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check s!"  {convTactic}" ((← state4.serializeGoals).map (·.devolatilize) =
-    #[
-      { interiorGoal [] "a + b" with fragment := .conv, userName? := .some "a" },
-      { interiorGoal [] "c1" with fragment := .conv, userName? := .some "a" }
-    ])
-
-  let convTactic := "rw [Nat.add_comm]"
-  let state5_1 ← match ← state4.tacticOn (goalId := 0) convTactic with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check s!"  · {convTactic}" ((← state5_1.serializeGoals).map (·.devolatilize) =
-    #[{ interiorGoal [] "b + a" with fragment := .conv, userName? := .some "a" }])
-
-  let convTactic := "rfl"
-  let state6_1 ← match ← state5_1.tacticOn (goalId := 0) convTactic with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check s!"    {convTactic}" ((← state6_1.serializeGoals).map (·.devolatilize) =
-    #[])
-
-  let state4_1 ← match state6_1.continue state4 with
-    | .ok state => pure state
-    | .error e => do
-      addTest $ expectationFailure "continue" e
-      return ()
-
-  let convTactic := "rfl"
-  let state1_1 ← match ← state4_1.tacticOn (goalId := 0) convTactic with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check s!"  · {convTactic}" ((← state1_1.serializeGoals).map (·.devolatilize) =
-    #[interiorGoal [] "b + a + c1 = b + a + c2"])
-  checkEq "(fragments)" state1_1.fragments.size 0
-
-  /-
-  let state1_1 ← match ← state6.fragmentExit goalConv with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  -/
-
-  let tactic := "exact h"
-  let stateF ← match ← state1_1.tacticOn (goalId := 0) (tactic := tactic) with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check tactic ((← stateF.serializeGoals).map (·.devolatilize) =
-    #[])
-
-  where
-    h := "b + a + c1 = b + a + c2"
-    interiorGoal (free: List (String × String)) (target: String) :=
-      let free := [("a", "Nat"), ("b", "Nat"), ("c1", "Nat"), ("c2", "Nat"), ("h", h)] ++ free
-      buildGoal free target
-
-example (p : Prop) (x y z : Nat) : p → (p → x = y) → x + z = y + z ∧ p := by
-  intro hp hi
-  apply And.intro
-  conv =>
-    rhs
-    arg 1
-    rw [←hi]
-    rfl
-    tactic => exact hp
-  exact hp
-
-def test_conv_unshielded : TestM Unit := do
-  let rootTarget ← parseSentence "∀ (p : Prop) (x y z : Nat), p → (p → x = y) → x + z = y + z ∧ p"
-  let state ← GoalState.create rootTarget
-  let tactic := "intro p x y z hp hi"
-  let .success state _ ← state.tacticOn 0 tactic | fail "intro failed"
-  let tactic := "apply And.intro"
-  let .success state _ ← state.tacticOn 0 tactic | fail "apply failed"
-  let .success state _ ← state.convEnter (.prefer state.goals[0]!) | fail "Cannot enter conversion tactic mode"
-  let .success state _ ← state.tryTactic .unfocus "rhs" | fail "rhs failed"
-  let tactic := "arg 1"
-  let .success state _ ← state.tryTactic .unfocus tactic | fail s!"{tactic} failed"
-  checkEq s!"  {tactic}" ((← state.serializeGoals).map (·.devolatilize))
-    #[
-      { interiorGoal [] "y" with fragment := .conv },
-      { interiorGoal [] "p" with userName? := "right", },
-    ]
-  let tactic := "rw [←hi]"
-  let .success state _ ← state.tryTactic .unfocus tactic | fail s!"{tactic} failed"
-  checkEq s!"  {tactic}" state.goals.length 3
-  let tactic := "rfl"
-  let .success state _ ← state.tryTactic .unfocus tactic | fail s!"{tactic} failed"
-  checkEq s!"  {tactic}" ((← state.serializeGoals).map (·.devolatilize))
-    #[
-      interiorGoal [] "p",
-      { interiorGoal [] "p" with userName? := "right", },
-    ]
-  checkEq "(n goals)" state.goals.length 2
-  checkEq "(fragments)" state.fragments.size 0
-  let tactic := "exact hp"
-  let .success state _ ← state.tryTactic .unfocus tactic | fail s!"{tactic} failed"
-  let tactic := "exact hp"
-  let .success state _ ← state.tryTactic .unfocus tactic | fail s!"{tactic} failed"
-  let root? := state.rootExpr?
-  checkTrue "root" root?.isSome
-  where
-  interiorGoal (free: List (String × String)) (target: String) :=
-    let free := [("p", "Prop"), ("x", "Nat"), ("y", "Nat"), ("z", "Nat"), ("hp", "p"), ("hi", "p → x = y")] ++ free
-    buildGoal free target
-
-example : ∀ (x y z w : Nat), y = z → x + z = w → x + y = w := by
-  intro x y z w hyz hxzw
-  conv =>
-    lhs
-    arg 2
-    rw [hyz]
-    rfl
-  exact hxzw
-
-def test_conv_unfinished : TestM Unit := do
-  let rootTarget ← parseSentence "∀ (x y z w : Nat), y = z → x + z = w → x + y = w"
-  let state ← GoalState.create rootTarget
-  let tactic := "intro x y z w hyz hxzw"
-  let .success state _ ← state.tacticOn 0 tactic | fail "intro failed"
-  let convParent := state.goals[0]!
-  let .success state _ ← state.convEnter (.prefer convParent) | fail "Cannot enter conversion tactic mode"
-  let .success state _ ← state.tryTactic .unfocus "lhs" | fail "rhs failed"
-  let tactic := "arg 2"
-  let .success state _ ← state.tryTactic .unfocus tactic | fail s!"{tactic} failed"
-  checkEq s!"  {tactic}" ((← state.serializeGoals).map (·.devolatilize))
-    #[
-      { interiorGoal [] "y" with fragment := .conv },
-    ]
-  let tactic := "rw [hyz]"
-  let .success state _ ← state.tryTactic .unfocus tactic | fail s!"{tactic} failed"
-  checkEq s!"  {tactic}" ((← state.serializeGoals).map (·.devolatilize))
-    #[
-      { interiorGoal [] "z" with fragment := .conv },
-    ]
-  checkTrue "  (fragment)" $ state.fragments.contains state.mainGoal?.get!
-  checkTrue "  (fragment parent)" $ state.fragments.contains convParent
-  checkTrue "  (main goal)" state.mainGoal?.isSome
-  let tactic := "rfl"
-  let .success state _ ← state.tryTactic .unfocus tactic | fail s!"{tactic} failed"
-  checkEq s!"  {tactic}" ((← state.serializeGoals).map (·.devolatilize))
-    #[
-      interiorGoal [] "x + z = w",
-    ]
-  checkEq "(fragments)" state.fragments.size 0
-  checkEq s!"  {tactic}" state.goals.length 1
-  let tactic := "exact hxzw"
-  let .success state _ ← state.tryTactic .unfocus tactic | fail s!"{tactic} failed"
-  let root? := state.rootExpr?
-  checkTrue "root" root?.isSome
-  where
-  interiorGoal (free: List (String × String)) (target: String) :=
-    let free := [("x", "Nat"), ("y", "Nat"), ("z", "Nat"), ("w", "Nat"), ("hyz", "y = z"), ("hxzw", "x + z = w")] ++ free
-    buildGoal free target
-
-example : ∀ (a b c d: Nat), a + b = b + c → b + c = c + d → a + b = c + d := by
-  intro a b c d h1 h2
-  calc a + b = b + c := by apply h1
-    _ = c + d := by apply h2
-
-def test_calc: TestM Unit := do
-  let rootTarget ← parseSentence "∀ (a b c d: Nat), a + b = b + c → b + c = c + d → a + b = c + d"
-  let state0 ← GoalState.create rootTarget
-  let tactic := "intro a b c d h1 h2"
-  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check tactic ((← state1.serializeGoals).map (·.devolatilize) =
-    #[interiorGoal [] "a + b = c + d"])
-  let pred := "a + b = b + c"
-  let .success state1 _ ← state1.calcEnter state1.mainGoal?.get! | fail "Could not enter calc"
-  let state2 ← match ← state1.tacticOn 0 pred with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check s!"calc {pred} := _" ((← state2.serializeGoals).map (·.devolatilize) =
-    #[
-      { interiorGoal [] "a + b = b + c" with userName? := .some "calc" },
-      { interiorGoal [] "b + c = c + d" with fragment := .calc },
-    ])
-  addTest $ LSpec.test "(2.0 prev rhs)" (state2.calcPrevRhsOf? (state2.get! 0) |>.isNone)
-  addTest $ LSpec.test "(2.1 prev rhs)" (state2.calcPrevRhsOf? (state2.get! 1) |>.isSome)
-
-  let tactic := "apply h1"
-  let state2m ← match ← state2.tacticOn (goalId := 0) (tactic := tactic) with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  let state3 ← match state2m.continue state2 with
-    | .ok state => pure state
-    | .error e => do
-      addTest $ expectationFailure "continue" e
-      return ()
-  let pred := "_ = c + d"
-  let state4 ← match ← state3.tacticOn 0 pred with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  addTest $ LSpec.check s!"calc {pred} := _" ((← state4.serializeGoals).map (·.devolatilize) =
-    #[
-      { interiorGoal [] "b + c = c + d" with userName? := .some "calc" },
-    ])
-  addTest $ LSpec.test "(4.0 prev rhs)" (state4.calcPrevRhsOf? (state4.get! 0) |>.isNone)
-  let tactic := "apply h2"
-  let state4m ← match ← state4.tacticOn (goalId := 0) (tactic := tactic) with
-    | .success state _ => pure state
-    | other => do
-      addTest $ assertUnreachable $ other.toString
-      return ()
-  checkEq "(fragments)" state4m.fragments.size 0
-  addTest $ LSpec.test "(4m root)" state4m.rootExpr?.isSome
-  where
-    interiorGoal (free: List (String × String)) (target: String) :=
-      let free := [("a", "Nat"), ("b", "Nat"), ("c", "Nat"), ("d", "Nat"),
-        ("h1", "a + b = b + c"), ("h2", "b + c = c + d")] ++ free
-      buildGoal free target
-
-def suite (env: Environment): List (String × IO LSpec.TestSeq) :=
-  [
-    ("conv simple", test_conv_simple),
-    ("conv unshielded", test_conv_unshielded),
-    ("conv unfinished", test_conv_unfinished),
-    ("calc", test_calc),
-  ] |>.map (λ (name, t) => (name, runTestTermElabM env t))
-
-end Pantograph.Test.Tactic.Fragment

Tomograph.lean

@@ -0,0 +1,29 @@
+import Pantograph.Frontend
+
+open Lean
+
+namespace Pantograph
+
+def fail (s : String) : IO Unit := do
+  IO.eprintln s
+
+def dissect (args: List String): IO Unit := do
+  let fileName :: _args := args | fail s!"Must supply a file name"
+  let file ← IO.FS.readFile fileName
+  let (context, state) ← do Frontend.createContextStateFromFile file fileName (env? := .none) {}
+  let frontendM: Elab.Frontend.FrontendM _ :=
+    Frontend.mapCompilationSteps λ step => do
+      for tree in step.trees do
+        IO.println s!"{← tree.toString}"
+  let (_, _) ← frontendM.run context |>.run state
+  return ()
+
+end Pantograph
+
+open Pantograph
+
+def main (args : List String) : IO Unit := do
+  let command :: args := args | IO.eprintln "Must supply a command"
+  match command with
+  | "dissect" => dissect args
+  | _ => IO.eprintln s!"Unknown command {command}"

doc/repl.md

@@ -13,7 +13,7 @@ See `Pantograph/Protocol.lean` for a description of the parameters and return va
   only the values of definitions are printed.
 * `env.save { "path": <fileName> }`, `env.load { "path": <fileName> }`: Save/Load the
   current environment to/from a file
-* `env.module_read { "module": <name> }`: Reads a list of symbols from a module
+* `env.module_read { "module": <name }`: Reads a list of symbols from a module
 * `env.describe {}`: Describes the imports and modules in the current environment
 * `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`
@@ -28,19 +28,16 @@ See `Pantograph/Protocol.lean` for a description of the parameters and return va
 * `options.print`: Display the current set of options
 * `goal.start {["name": <name>], ["expr": <expr>], ["levels": [<levels>]], ["copyFrom": <symbol>]}`:
   Start a new proof from a given expression or symbol
-* `goal.tactic {"stateId": <id>, ["goalId": <id>], ["autoResume": <bool>], ...}`:
+* `goal.tactic {"stateId": <id>, "goalId": <id>, ...}`: Execute a tactic string on a
-  Execute a tactic string on a given goal site. The tactic is supplied as additional
+  given goal. The tactic is supplied as additional key-value pairs in one of the following formats:
-  key-value pairs in one of the following formats:
+  - `{ "tactic": <tactic> }`: Execute an ordinary tactic
-  - `{ "tactic": <tactic> }`: Executes a tactic in the current mode
-  - `{ "mode": <mode> }`: Enter a different tactic mode. The permitted values
-    are `tactic` (default), `conv`, `calc`. In case of `calc`, each step must
-    be of the form `lhs op rhs`. An `lhs` of `_` indicates that it should be set
-    to the previous `rhs`.
   - `{ "expr": <expr> }`: Assign the given proof term to the current goal
   - `{ "have": <expr>, "binderName": <name> }`: Execute `have` and creates a branch goal
-  - `{ "let": <expr>, "binderName": <name> }`: Execute `let` and creates a branch goal
+  - `{ "calc": <expr> }`: Execute one step of a `calc` tactic. Each step must
-  - `{ "draft": <expr> }`: Draft an expression with `sorry`s, turning them into
+    be of the form `lhs op rhs`. An `lhs` of `_` indicates that it should be set
-    goals. Coupling is not allowed.
+    to the previous `rhs`.
+  - `{ "conv": <bool> }`: Enter or exit conversion tactic mode.
+  - `{ "draft": <expr> }`: Draft an expression with `sorry`s, turning them into goals. Coupling is not allowed.
   If the `goals` field does not exist, the tactic execution has failed. Read
   `messages` to find the reason.
 * `goal.continue {"stateId": <id>, ["branch": <id>], ["goals": <names>]}`:

lakefile.lean

@@ -10,6 +10,7 @@ lean_lib Pantograph {
 
 lean_lib Repl {
 }
+
 @[default_target]
 lean_exe repl {
   root := `Main
@@ -17,6 +18,13 @@ lean_exe repl {
   supportInterpreter := true
 }
 
+@[default_target]
+lean_exe tomograph {
+  root := `Tomograph
+  -- Solves the native symbol not found problem
+  supportInterpreter := true
+}
+
 require LSpec from git
   "https://github.com/argumentcomputer/LSpec.git" @ "a6652a48b5c67b0d8dd3930fad6390a97d127e8d"
 lean_lib Test {