Add expression binding printing and import Lean

Main.lean

@@ -14,7 +14,7 @@ structure Context where
 /-- Stores state of the REPL -/
 structure State where
   --environments: Array Lean.Environment := #[]
-  proofTrees:   Array Meta.ProofTree := #[]
+  proofTrees:   Array ProofTree := #[]
 
 -- State monad
 abbrev Subroutine := ReaderT Context (StateT State Lean.Elab.TermElabM)
@@ -36,8 +36,6 @@ def parse_command (s: String): Except String Command := do
       return { cmd := s.take offset, payload := payload }
   | .none => throw "Command is empty"
 
-
-
 def execute (command: Command): Subroutine Lean.Json := do
   match command.cmd with
   | "catalog" =>
@@ -83,8 +81,12 @@ def execute (command: Command): Subroutine Lean.Json := do
       let format ← Lean.Meta.ppExpr info.toConstantVal.type
       let module? := env.getModuleIdxFor? name >>=
         (λ idx => env.allImportedModuleNames.get? idx.toNat) |>.map toString
+      let boundExpr? ← (match info.toConstantVal.type with
+        | .forallE _ _ _ _ => return .some (← type_expr_to_bound info.toConstantVal.type)
+        | _ => return Option.none)
       return Lean.toJson ({
         type := toString format,
+        boundExpr? := boundExpr?,
         module? := module?
       }: InspectResult)
   proof_start (args: ProofStart): Subroutine Lean.Json := do
@@ -92,10 +94,10 @@ def execute (command: Command): Subroutine Lean.Json := do
     let env ← Lean.MonadEnv.getEnv
     let expr?: Except Lean.Json Lean.Expr ← (match args.expr, args.copyFrom with
       | .some expr, .none =>
-        (match Serial.syntax_from_str env expr with
+        (match syntax_from_str env expr with
         | .error str => return .error <| Lean.toJson ({ error := "parsing", desc := str }: InteractionError)
         | .ok syn => do
-          (match (← Meta.syntax_to_expr syn) with
+          (match (← syntax_to_expr syn) with
           | .error str => return .error <| Lean.toJson ({ error := "elab", desc := str }: InteractionError)
           | .ok expr => return .ok expr))
       | .none, .some copyFrom =>
@@ -108,7 +110,7 @@ def execute (command: Command): Subroutine Lean.Json := do
     match expr? with
     | .error error => return error
     | .ok expr =>
-      let tree ← Meta.ProofTree.create (str_to_name <| args.name.getD "Untitled") expr
+      let tree ← ProofTree.create (str_to_name <| args.name.getD "Untitled") expr
       -- Put the new tree in the environment
       let nextTreeId := state.proofTrees.size
       set { state with proofTrees := state.proofTrees.push tree }
@@ -118,7 +120,7 @@ def execute (command: Command): Subroutine Lean.Json := do
     match state.proofTrees.get? args.treeId with
     | .none => return Lean.toJson <| errorIndex "Invalid tree index {args.treeId}"
     | .some tree =>
-      let (result, nextTree) ← Meta.ProofTree.execute
+      let (result, nextTree) ← ProofTree.execute
         (stateId := args.stateId)
         (goalId := args.goalId.getD 0)
         (tactic := args.tactic) |>.run tree
@@ -155,12 +157,42 @@ unsafe def loop : Subroutine Unit := do
     IO.println <| toString <| ret
   loop
 
+namespace Lean
+-- This is better than the default version since it handles `.`
+def setOptionFromString' (opts : Options) (entry : String) : IO Options := do
+  let ps := (entry.splitOn "=").map String.trim
+  let [key, val] ← pure ps | throw $ IO.userError "invalid configuration option entry, it must be of the form '<key> = <value>'"
+  let key := str_to_name key
+  let defValue ← getOptionDefaultValue key
+  match defValue with
+  | DataValue.ofString _ => pure $ opts.setString key val
+  | DataValue.ofBool _   =>
+    match val with
+    | "true" => pure $ opts.setBool key true
+    | "false" => pure $ opts.setBool key false
+    | _ => throw $ IO.userError s!"invalid Bool option value '{val}'"
+  | DataValue.ofName _   => pure $ opts.setName key val.toName
+  | DataValue.ofNat _    =>
+    match val.toNat? with
+    | none   => throw (IO.userError s!"invalid Nat option value '{val}'")
+    | some v => pure $ opts.setNat key v
+  | DataValue.ofInt _    =>
+    match val.toInt? with
+    | none   => throw (IO.userError s!"invalid Int option value '{val}'")
+    | some v => pure $ opts.setInt key v
+  | DataValue.ofSyntax _ => throw (IO.userError s!"invalid Syntax option value")
+end Lean
+
 unsafe def main (args: List String): IO Unit := do
   Lean.enableInitializersExecution
   Lean.initSearchPath (← Lean.findSysroot)
 
+  -- Separate imports and options
+  let options := args.filterMap (λ s => if s.startsWith "--" then .some <| s.drop 2 else .none)
+  let imports:= args.filter (λ s => ¬ (s.startsWith "--"))
+
   let env ← Lean.importModules
-    (imports := args.map (λ str => { module := str_to_name str, runtimeOnly := false }))
+    (imports := imports.map (λ str => { module := str_to_name str, runtimeOnly := false }))
     (opts := {})
     (trustLevel := 1)
   let context: Context := {
@@ -169,7 +201,8 @@ unsafe def main (args: List String): IO Unit := do
     currNamespace := str_to_name "Aniva",
     openDecls := [],     -- No 'open' directives needed
     fileName := "<Pantograph>",
-    fileMap := { source := "", positions := #[0], lines := #[1] }
+    fileMap := { source := "", positions := #[0], lines := #[1] },
+    options := ← options.foldlM Lean.setOptionFromString' Lean.Options.empty
   }
   try
     let termElabM := loop.run context |>.run' {}

Pantograph/Commands.lean

@@ -1,6 +1,8 @@
 -- All the command input/output structures are stored here
 import Lean.Data.Json
 
+import Pantograph.Serial
+
 namespace Pantograph.Commands
 
 structure Command where
@@ -30,6 +32,8 @@ structure Inspect where
   deriving Lean.FromJson
 structure InspectResult where
   type: String
+  -- Decompose the bound expression when the type is forall.
+  boundExpr?: Option BoundExpression
   module?: Option String
   deriving Lean.ToJson
 

Pantograph/Meta.lean

@@ -7,38 +7,39 @@ import Pantograph.Symbols
 The proof state manipulation system
 
 A proof state is launched by providing
-1. Environment: `Lean.Environment`
-2. Expression: `Lean.Expr`
+1. Environment: `Environment`
+2. Expression: `Expr`
 The expression becomes the first meta variable in the saved tactic state
-`Lean.Elab.Tactic.SavedState`.
+`Elab.Tactic.SavedState`.
 From this point on, any proof which extends
-`Lean.Elab.Term.Context` and
+`Elab.Term.Context` and
 -/
 
-def Lean.MessageLog.getErrorMessages (log : Lean.MessageLog) : Lean.MessageLog :=
-{ msgs := log.msgs.filter fun m => match m.severity with | Lean.MessageSeverity.error => true | _ => false }
+def Lean.MessageLog.getErrorMessages (log : MessageLog) : MessageLog :=
+{ msgs := log.msgs.filter fun m => match m.severity with | MessageSeverity.error => true | _ => false }
 
 
-namespace Pantograph.Meta
+namespace Pantograph
+open Lean
 
 structure ProofState where
-  goals : List Lean.MVarId
-  savedState : Lean.Elab.Tactic.SavedState
+  goals : List MVarId
+  savedState : Elab.Tactic.SavedState
   parent : Option Nat := none
   parentGoalId : Nat  := 0
 structure ProofTree where
   -- All parameters needed to run a `TermElabM` monad
-  name: Lean.Name
+  name: Name
 
   -- Set of proof states
   states : Array ProofState := #[]
 
-abbrev M := Lean.Elab.TermElabM
+abbrev M := Elab.TermElabM
 
-def ProofTree.create (name: Lean.Name) (expr: Lean.Expr): M ProofTree := do
-  let expr ← Lean.instantiateMVars expr
-  let goal := (← Lean.Meta.mkFreshExprMVar expr (kind := Lean.MetavarKind.synthetic))
-  let savedStateMonad: Lean.Elab.Tactic.TacticM Lean.Elab.Tactic.SavedState := Lean.MonadBacktrack.saveState
+def ProofTree.create (name: Name) (expr: Expr): M ProofTree := do
+  let expr ← instantiateMVars expr
+  let goal := (← Meta.mkFreshExprMVar expr (kind := MetavarKind.synthetic))
+  let savedStateMonad: Elab.Tactic.TacticM Elab.Tactic.SavedState := MonadBacktrack.saveState
   let savedState ← savedStateMonad { elaborator := .anonymous } |>.run' { goals := [goal.mvarId!]}
   return {
     name := name,
@@ -54,42 +55,31 @@ def ProofTree.structure_array (tree: ProofTree): Array String :=
     | .none => ""
     | .some parent => s!"{parent}.{state.parentGoalId}"
 
--- Parsing syntax under the environment
-def syntax_to_expr (syn: Lean.Syntax): Lean.Elab.TermElabM (Except String Lean.Expr) := do
-  try
-    let expr ← Lean.Elab.Term.elabType syn
-    -- Immediately synthesise all metavariables if we need to leave the elaboration context.
-    -- See https://leanprover.zulipchat.com/#narrow/stream/270676-lean4/topic/Unknown.20universe.20metavariable/near/360130070
-    --Lean.Elab.Term.synthesizeSyntheticMVarsNoPostponing
-    let expr ← Lean.instantiateMVars expr
-    return .ok expr
-  catch ex => return .error (← ex.toMessageData.toString)
-
-def execute_tactic (state: Lean.Elab.Tactic.SavedState) (goal: Lean.MVarId) (tactic: String) :
-    M (Except (Array String) (Lean.Elab.Tactic.SavedState × List Lean.MVarId)):= do
-  let tacticM (stx: Lean.Syntax):  Lean.Elab.Tactic.TacticM (Except (Array String) (Lean.Elab.Tactic.SavedState × List Lean.MVarId)) := do
+def execute_tactic (state: Elab.Tactic.SavedState) (goal: MVarId) (tactic: String) :
+    M (Except (Array String) (Elab.Tactic.SavedState × List MVarId)):= do
+  let tacticM (stx: Syntax):  Elab.Tactic.TacticM (Except (Array String) (Elab.Tactic.SavedState × List MVarId)) := do
     state.restore
-    Lean.Elab.Tactic.setGoals [goal]
+    Elab.Tactic.setGoals [goal]
     try
-      Lean.Elab.Tactic.evalTactic stx
-      if (← getThe Lean.Core.State).messages.hasErrors then
-        let messages := (← getThe Lean.Core.State).messages.getErrorMessages |>.toList.toArray
-        let errors ← (messages.map Lean.Message.data).mapM fun md => md.toString
+      Elab.Tactic.evalTactic stx
+      if (← getThe Core.State).messages.hasErrors then
+        let messages := (← getThe Core.State).messages.getErrorMessages |>.toList.toArray
+        let errors ← (messages.map Message.data).mapM fun md => md.toString
         return .error errors
       else
-        return .ok (← Lean.MonadBacktrack.saveState, ← Lean.Elab.Tactic.getUnsolvedGoals)
+        return .ok (← MonadBacktrack.saveState, ← Elab.Tactic.getUnsolvedGoals)
     catch exception =>
       return .error #[← exception.toMessageData.toString]
-  match Lean.Parser.runParserCategory
-    (env := ← Lean.MonadEnv.getEnv)
+  match Parser.runParserCategory
+    (env := ← MonadEnv.getEnv)
     (catName := `tactic)
     (input := tactic)
     (fileName := "<stdin>") with
   | Except.error err => return .error #[err]
   | Except.ok stx    => tacticM stx { elaborator := .anonymous } |>.run' state.tactic
 
-def goals_to_string (goals: List Lean.MVarId): M (Array String) := do
-  let goals ← goals.mapM fun g => do pure $ toString (← Lean.Meta.ppGoal g)
+def goals_to_string (goals: List MVarId): M (Array String) := do
+  let goals ← goals.mapM fun g => do pure $ toString (← Meta.ppGoal g)
   pure goals.toArray
 
 
@@ -128,4 +118,4 @@ def ProofTree.execute (stateId: Nat) (goalId: Nat) (tactic: String): StateRefT P
           modify fun s => { s with states := s.states.push proofState }
         return .success (.some nextId) (← goals_to_string nextGoals)
 
-end Pantograph.Meta
+end Pantograph

Pantograph/Serial.lean

@@ -1,23 +1,44 @@
+/-
+All serialisation functions
+-/
 import Lean
 
-/-
-Expression IO
--/
-
-
-namespace Pantograph.Serial
+namespace Pantograph
+open Lean
 
 
 /-- Read a theorem from the environment -/
-def expr_from_const (env: Lean.Environment) (name: Lean.Name): Except String Lean.Expr :=
+def expr_from_const (env: Environment) (name: Name): Except String Lean.Expr :=
   match env.find? name with
   | none       => throw s!"Symbol not found: {name}"
   | some cInfo => return cInfo.type
-def syntax_from_str (env: Lean.Environment) (s: String): Except String Lean.Syntax :=
-  Lean.Parser.runParserCategory
+def syntax_from_str (env: Environment) (s: String): Except String Syntax :=
+  Parser.runParserCategory
     (env := env)
     (catName := `term)
     (input := s)
     (fileName := "<stdin>")
 
-end Pantograph.Serial
+
+def syntax_to_expr (syn: Syntax): Elab.TermElabM (Except String Expr) := do
+  try
+    let expr ← Elab.Term.elabType syn
+    -- Immediately synthesise all metavariables if we need to leave the elaboration context.
+    -- See https://leanprover.zulipchat.com/#narrow/stream/270676-lean4/topic/Unknown.20universe.20metavariable/near/360130070
+    --Elab.Term.synthesizeSyntheticMVarsNoPostponing
+    let expr ← instantiateMVars expr
+    return .ok expr
+  catch ex => return .error (← ex.toMessageData.toString)
+
+structure BoundExpression where
+  binders: Array (String × String)
+  target: String
+  deriving ToJson
+def type_expr_to_bound (expr: Expr): MetaM BoundExpression := do
+  Meta.forallTelescope expr fun arr body => do
+    let binders ← arr.mapM fun fvar => do
+      return (toString (← fvar.fvarId!.getUserName), toString (← Meta.ppExpr (← fvar.fvarId!.getType)))
+    return { binders, target := toString (← Meta.ppExpr body) }
+
+
+end Pantograph

Test/Proofs.lean

@@ -4,15 +4,15 @@ import Pantograph.Serial
 
 namespace Pantograph.Test
 open Pantograph
+open Lean
 
 inductive Start where
   | copy (name: String) -- Start from some name in the environment
   | expr (expr: String) -- Start from some expression
 
-abbrev M := Meta.M
-abbrev TestM := StateRefT Meta.ProofTree M
+abbrev TestM := StateRefT ProofTree M
 
-def start_proof (start: Start): M (LSpec.TestSeq × Option Meta.ProofTree) := do
+def start_proof (start: Start): M (LSpec.TestSeq × Option ProofTree) := do
   let env ← Lean.MonadEnv.getEnv
   let mut testSeq := LSpec.TestSeq.done
   match start with
@@ -21,37 +21,37 @@ def start_proof (start: Start): M (LSpec.TestSeq × Option Meta.ProofTree) := do
     testSeq := testSeq ++ LSpec.check s!"Symbol exists {name}" cInfo?.isSome
     match cInfo? with
     | .some cInfo =>
-      let state ← Meta.ProofTree.create
+      let state ← ProofTree.create
         (name := str_to_name "TestExample")
         (expr := cInfo.type)
       return (testSeq, Option.some state)
     | .none =>
       return (testSeq, Option.none)
   | .expr expr =>
-    let syn? := Serial.syntax_from_str env expr
+    let syn? := syntax_from_str env expr
     testSeq := testSeq ++ LSpec.check s!"Parsing {expr}" (syn?.isOk)
     match syn? with
     | .error error =>
       IO.println error
       return (testSeq, Option.none)
     | .ok syn =>
-      let expr? ← Meta.syntax_to_expr syn
+      let expr? ← syntax_to_expr syn
       testSeq := testSeq ++ LSpec.check s!"Elaborating" expr?.isOk
       match expr? with
       | .error error =>
         IO.println error
         return (testSeq, Option.none)
       | .ok expr =>
-        let state ← Meta.ProofTree.create
+        let state ← ProofTree.create
           (name := str_to_name "TestExample")
           (expr := expr)
         return (testSeq, Option.some state)
 
-deriving instance DecidableEq, Repr for Meta.TacticResult
+deriving instance DecidableEq, Repr for TacticResult
 
 def proof_step (stateId: Nat) (goalId: Nat) (tactic: String)
-    (expected: Meta.TacticResult) : TestM LSpec.TestSeq := do
-  let result: Meta.TacticResult ← Meta.ProofTree.execute stateId goalId tactic
+    (expected: TacticResult) : TestM LSpec.TestSeq := do
+  let result: TacticResult ← ProofTree.execute stateId goalId tactic
   match expected, result with
   | .success (.some i) #[], .success (.some _) goals =>
     -- If the goals are omitted but the next state is specified, we imply that

Test/Serial.lean

@@ -1,10 +1,43 @@
 import LSpec
+import Pantograph.Serial
 import Pantograph.Symbols
 
 namespace Pantograph.Test
 
+open Pantograph
+open Lean
+
+deriving instance Repr, DecidableEq for BoundExpression
+
+def test_expr_to_binder (env: Environment): IO LSpec.TestSeq := do
+  let cases: List (String × BoundExpression) := [
+    ("Nat.add_comm", { binders := #[("n", "Nat"), ("m", "Nat")], target := "n + m = m + n" }),
+    ("Nat.le_of_succ_le", { binders := #[("n", "Nat"), ("m", "Nat"), ("h", "Nat.succ n ≤ m")], target := "n ≤ m" })
+  ]
+  let coreM := cases.foldlM (λ suites (symbol, target) => do
+    let env ← MonadEnv.getEnv
+    let expr := str_to_name symbol |> env.find? |>.get! |>.type
+    let test := LSpec.check symbol ((← type_expr_to_bound expr) = target)
+    return LSpec.TestSeq.append suites test) LSpec.TestSeq.done |>.run'
+  let coreContext: Core.Context := {
+    currNamespace := str_to_name "Aniva",
+    openDecls := [],     -- No 'open' directives needed
+    fileName := "<Pantograph>",
+    fileMap := { source := "", positions := #[0], lines := #[1] }
+  }
+  match ← (coreM.run' coreContext { env := env }).toBaseIO with
+  | .error exception =>
+    return LSpec.test "Exception" (s!"internal exception #{← exception.toMessageData.toString}" = "")
+  | .ok a            => return a
+
 def test_serial: IO LSpec.TestSeq := do
+  let env: Environment ← importModules
+    (imports := ["Init"].map (λ str => { module := str_to_name str, runtimeOnly := false }))
+    (opts := {})
+    (trustLevel := 1)
+
   return LSpec.group "Serialisation" $
-    LSpec.test "Symbol parsing" (Lean.Name.str (.str (.str .anonymous "Lean") "Meta") "run" = Pantograph.str_to_name "Lean.Meta.run")
+    (LSpec.group "Expression binder" (← test_expr_to_binder env)) ++
+    LSpec.test "Symbol parsing" (Name.str (.str (.str .anonymous "Lean") "Meta") "run" = Pantograph.str_to_name "Lean.Meta.run")
 
 end Pantograph.Test