f1707117f0
Specializes the congr lemma generated for the `arg` conv tactic to only rewrite the chosen argument. This makes it much more likely that the chosen argument is able to be accessed. Lets `arg` access the domain and codomain of pi types via `arg 1` and `arg 2` in more situations. Upstreams `pi_congr` for this from mathlib. Adds a negative indexing option, where `arg -2` accesses the second-to-last argument for example, making the behavior of `lhs` available to `arg`. This works for `enter` as well. Other improvement: when there is an error in the `enter [...]` tactic, individual locations get underlined with the error. The tactic info now also is like `rw`, so you can see the intermediate conv states. Closes #5871
61 lines
1.8 KiB
Text
61 lines
1.8 KiB
Text
import Lean
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open Lean Elab Meta Tactic
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opaque foo (p : Prop) [Decidable p] : Prop
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class PropClass (n : Nat) : Prop where
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opaque P1 (n : Nat) [PropClass n] : Prop
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class TypeClass (n : Nat) : Type where
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opaque P2 (n : Nat) [TypeClass n] : Prop
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/--
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info: thm for foo: ∀ (p p_1 : Prop), p = p_1 → ∀ {inst : Decidable p} {inst_1 : Decidable p_1}, foo p = foo p_1
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kinds: #[Lean.Meta.CongrArgKind.eq, Lean.Meta.CongrArgKind.subsingletonInst]
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---
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info: thm for P1: ∀ (n n_1 : Nat) (e_n : n = n_1) [inst : PropClass n], P1 n = P1 n_1
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kinds: #[Lean.Meta.CongrArgKind.eq, Lean.Meta.CongrArgKind.cast]
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---
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info: thm for P2: ∀ (n : Nat) [inst : TypeClass n], P2 n = P2 n
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kinds: #[Lean.Meta.CongrArgKind.fixed, Lean.Meta.CongrArgKind.fixed]
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-/
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#guard_msgs in
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run_meta
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#[``foo, ``P1, ``P2].forM fun n => do
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let e ← mkConstWithLevelParams n
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let some thm ← mkCongrSimp? e (subsingletonInstImplicitRhs := false) | throwError "no thm"
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let kinds ← getCongrSimpKinds e (← getFunInfo e)
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logInfo m!"thm for {e}: {thm.type}\nkinds: {repr kinds}"
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example [Decidable p] [Decidable (id p)] (h : foo p) : foo (id p) := by
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conv => arg 1; rw [id]
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exact h
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/--
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error: tactic 'fail' failed
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p : Prop
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inst✝ : Decidable p
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⊢ Decidable (id p)
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---
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error: unsolved goals
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p : Prop
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inst✝ : Decidable p
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⊢ foo (id p)
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-/
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#guard_msgs in
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example [Decidable p] : foo p := by
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conv =>
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arg 1
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· rw [← id.eq_def p]
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· tactic => fail
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example [PropClass n] [PropClass (id n)] (h : P1 n) : P1 (id n) := by
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conv => arg 1; rw [id]
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exact h
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example [PropClass n] (h : P1 n) : P1 n := by
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conv => arg 1; rw [← id.eq_def n]
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conv => arg 1; rw [id.eq_def n]
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exact h
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/-- error: 'arg' conv tactic failed, cannot select argument -/
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#guard_msgs in
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example [TypeClass n] [TypeClass (id n)] (h : P2 n) : P2 (id n) := by
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conv => arg 1
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