5d54b0b13f
This PR fixes a bug introduced in #7830 where if the cursor is at the indicated position ```lean example (as bs : List Nat) : (as.append bs).length = as.length + bs.length := by induction as with | nil => -- cursor | cons b bs ih => ``` then the Infoview would show "no goals" rather than the `nil` goal. The PR also fixes a separate bug where placing the cursor on the next line after the `induction`/`cases` tactics like in ```lean induction as with | nil => sorry | cons b bs ih => sorry I -- < cursor ``` would report the original goal in the goal list. Furthermore, there are numerous improvements to error recovery (including `allGoals`-type logic for pre-tactics) and the visible tactic states when there are errors. Adds `Tactic.throwOrLogErrorAt`/`Tactic.throwOrLogError` for throwing or logging errors depending on the recovery state.
75 lines
2 KiB
Text
75 lines
2 KiB
Text
universe u
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axiom elimEx (motive : Nat → Nat → Sort u) (x y : Nat)
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(diag : (a : Nat) → motive a a)
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(upper : (delta a : Nat) → motive a (a + delta.succ))
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(lower : (delta a : Nat) → motive (a + delta.succ) a)
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: motive y x
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/--
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error: Invalid alternative name 'lower2': Expected 'lower'
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---
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error: unsolved goals
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case upper.h
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q d : Nat
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⊢ q + d.succ > q
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---
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error: Alternative 'lower' has not been provided
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-/
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#guard_msgs in
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theorem invalidAlt (p: Nat) : p ≤ q ∨ p > q := by
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cases p, q using elimEx with
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| lower2 /- error -/ d => apply Or.inl; admit
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| upper d => apply Or.inr
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| diag => apply Or.inl; apply Nat.le_refl
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/--
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error: Invalid alternative name 'lower2': Expected 'lower'
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---
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error: Alternative 'lower' has not been provided
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-/
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#guard_msgs in
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theorem oneMissingAlt (p: Nat) : p ≤ q ∨ p > q := by
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cases p, q using elimEx with
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| upper d => apply Or.inl; admit
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| diag => apply Or.inl; apply Nat.le_refl
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| lower2 /- error -/ => apply Or.inr
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/--
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error: Duplicate alternative name 'upper'
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---
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error: Alternative 'lower' has not been provided
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-/
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#guard_msgs in
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theorem doubleAlt (p: Nat) : p ≤ q ∨ p > q := by
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cases p, q using elimEx with
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| upper d => apply Or.inl; admit
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| upper d /- error -/ => apply Or.inr
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| diag => apply Or.inl; apply Nat.le_refl
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/--
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error: Invalid occurrence of the wildcard alternative `| _ => ...`: It must be the last alternative
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-/
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#guard_msgs in
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theorem invalidWildCard (p: Nat) : p ≤ q ∨ p > q := by
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cases p, q using elimEx with
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| upper d => apply Or.inl; admit
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| _ /- error -/ => apply Or.inr
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| diag => apply Or.inl; apply Nat.le_refl
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/--
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error: Invalid alternative name 'lower2': There are no unhandled alternatives
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---
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error: unsolved goals
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case lower.h
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p delta✝ : Nat
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⊢ p > p + delta✝.succ
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-/
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#guard_msgs in
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theorem noAlt (p: Nat) : p ≤ q ∨ p > q := by
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cases p, q using elimEx with
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| upper d => apply Or.inl; admit
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| lower => apply Or.inr
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| diag => apply Or.inl; apply Nat.le_refl
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| lower2 /- error -/ => apply Or.inr
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