lean4-htt/tests/lean/run/exposeDiff.lean
jrr6 34bd6e8bfd
feat: improve split error messages (#9424)
This PR improves the error messages produced by the `split` tactic,
including suggesting syntax fixes and related tactics with which it
might be confused.

Note that, to avoid clashing with the new error message styling
conventions used in these messages, this PR also updates the formatting
of the message produced by `throwTacticEx`.

Closes #6224
2025-07-18 22:36:10 +00:00

52 lines
1.1 KiB
Text

/--
error: Tactic `apply` failed: could not unify the type of `x`
PUnit.{1}
with the goal
PUnit.{0}
x : PUnit
⊢ PUnit
-/
#guard_msgs in
example (x : PUnit.{1}) : PUnit.{0} := by
apply x
/--
error: type mismatch
x
has type
PUnit.{1}
of sort `Type` but is expected to have type
PUnit.{0}
of sort `Prop`
-/
#guard_msgs in
example (x : PUnit.{1}) : PUnit.{0} :=
x
/--
error: Tactic `rfl` failed: the left-hand side
∀ (x : PUnit.{1}), True
is not definitionally equal to the right-hand side
∀ (x : PUnit.{2}), True
⊢ (∀ (x : PUnit), True) ↔ ∀ (x : PUnit), True
-/
#guard_msgs in
example : (∀ _ : PUnit.{1}, True) ↔ ∀ _ : PUnit.{2}, True := by
rfl
inductive Test where
| mk (x : Prop)
/--
error: Tactic `rfl` failed: the left-hand side
(Test.mk (∀ (x : PUnit.{1}), True)).1
is not definitionally equal to the right-hand side
(Test.mk (∀ (x : PUnit.{2}), True)).1
⊢ (Test.mk (∀ (x : PUnit), True)).1 = (Test.mk (∀ (x : PUnit), True)).1
-/
#guard_msgs in
example : (Test.mk (∀ _ : PUnit.{1}, True)).1 = (Test.mk (∀ _ : PUnit.{2}, True)).1 := by
rfl