Pantograph/Library.lean

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

Pantograph/Protocol.lean

@@ -237,6 +237,7 @@ structure GoalTactic where
   calc?: Option String := .none
   -- true to enter `conv`, `false` to exit. In case of exit the `goalId` is ignored.
   conv?: Option Bool := .none
+  draft?: Option String := .none
 
   -- In case of the `have` tactic, the new free variable name is provided here
   binderName?: Option String := .none

Repl.lean

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

doc/repl.md

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