fix(frontends/lean/parser): add workaround for #461

src/frontends/lean/parser.cpp

@@ -1432,7 +1432,7 @@ expr parser::parse_tactic_led(expr left) {
         expr right = parse_tactic();
         return mk_app({save_pos(mk_constant(get_tactic_and_then_name()), p), left, right}, p);
     } else {
-        throw parser_error("invalid tactic expression", p);
+        return parse_led(left);
     }
 }
 

tests/lean/errors.lean.expected.out

@@ -1,6 +1,7 @@
 errors.lean:4:0: error: unknown identifier 'a'
 tst1 : nat → nat → nat
-errors.lean:12:12: error: invalid tactic expression
+errors.lean:12:2: error: function expected at
+  tactic.cases [tactic.expr add] tactic.expr_list.nil
 errors.lean:22:12: error: unknown identifier 'b'
 tst3 A : A → A → A
 foo.tst1 : ℕ → ℕ → ℕ

tests/lean/run/all_goals2.lean

@@ -0,0 +1,20 @@
+import data.nat
+open nat
+
+attribute nat.add [unfold-c 2]
+attribute nat.rec_on [unfold-c 2]
+
+namespace tactic
+  definition then_all (t1 t2 : tactic) : tactic :=
+  focus (t1 ; all_goals t2)
+  infixl `;;`:15 := tactic.then_all
+end tactic
+
+open tactic
+example (a b c : nat) : (a + 0 = 0 + a ∧ b + 0 = 0 + b) ∧ c = c :=
+
+begin
+  apply and.intro,
+  apply and.intro ;; (esimp{of_num}; state; rewrite zero_add),
+  apply rfl
+end