d1ec806834
This PR improves the error messages produced by invalid pattern-match alternatives and improves parity in error placement between pattern-matching tactics and elaborators. Closes #7170
51 lines
1.7 KiB
Text
51 lines
1.7 KiB
Text
universe u
|
||
|
||
axiom elimEx (motive : Nat → Nat → Sort u) (x y : Nat)
|
||
(diag : (a : Nat) → motive a a)
|
||
(upper : (delta a : Nat) → motive a (a + delta.succ))
|
||
(lower : (delta a : Nat) → motive (a + delta.succ) a)
|
||
: motive y x
|
||
|
||
/-- error: Invalid alternative name 'lower2': Expected 'diag', 'upper', or 'lower' -/
|
||
#guard_msgs in
|
||
theorem invalidAlt (p: Nat) : p ≤ q ∨ p > q := by
|
||
cases p, q using elimEx with
|
||
| lower2 /- error -/ d => apply Or.inl; admit
|
||
| upper d => apply Or.inr
|
||
| diag => apply Or.inl; apply Nat.le_refl
|
||
|
||
/-- error: Invalid alternative name 'lower2': Expected 'lower' -/
|
||
#guard_msgs in
|
||
theorem oneMissingAlt (p: Nat) : p ≤ q ∨ p > q := by
|
||
cases p, q using elimEx with
|
||
| upper d => apply Or.inl; admit
|
||
| diag => apply Or.inl; apply Nat.le_refl
|
||
| lower2 /- error -/ => apply Or.inr
|
||
|
||
/-- error: Duplicate alternative name 'upper' -/
|
||
#guard_msgs in
|
||
theorem doubleAlt (p: Nat) : p ≤ q ∨ p > q := by
|
||
cases p, q using elimEx with
|
||
| upper d => apply Or.inl; admit
|
||
| upper d /- error -/ => apply Or.inr
|
||
| diag => apply Or.inl; apply Nat.le_refl
|
||
|
||
/--
|
||
error: Invalid occurrence of the wildcard alternative `| _ => ...`: It must be the last alternative
|
||
-/
|
||
#guard_msgs in
|
||
theorem invalidWildCard (p: Nat) : p ≤ q ∨ p > q := by
|
||
cases p, q using elimEx with
|
||
| upper d => apply Or.inl; admit
|
||
| _ /- error -/ => apply Or.inr
|
||
| diag => apply Or.inl; apply Nat.le_refl
|
||
|
||
|
||
/-- error: Invalid alternative name 'lower2': There are no unhandled alternatives -/
|
||
#guard_msgs in
|
||
theorem noAlt (p: Nat) : p ≤ q ∨ p > q := by
|
||
cases p, q using elimEx with
|
||
| upper d => apply Or.inl; admit
|
||
| lower => apply Or.inr
|
||
| diag => apply Or.inl; apply Nat.le_refl
|
||
| lower2 /- error -/ => apply Or.inr
|