f7031c7aa9
This PR adds a `Unit` assumption to alternatives of the splitter that would otherwise not have arguments. This fixes #11211. In practice these argument-less alternatives did not cause wrong behavior, as the motive when used with `split` is always a function type. But it is better to be safe here (maybe someone uses splitters in other ways), it may increase the effectiveness of #10184 and simplifies #11220. The perf impact is insignificant in the grand scheme of things on stdlib, but the change is effective: ``` ~/lean4 $ build/release/stage1/bin/lean tests/lean/run/matchSplitStats.lean 969 splitters found 455 splitters are const defs ~/lean4 $ build/release/stage2/bin/lean tests/lean/run/matchSplitStats.lean 969 splitters found 829 splitters are const defs ```
84 lines
3.2 KiB
Text
84 lines
3.2 KiB
Text
import Lean
|
|
open Lean Expr Level -- just for shorter outpt
|
|
|
|
-- set_option trace.Meta.Match.match true
|
|
-- set_option trace.Meta.Match.debug true
|
|
-- set_option trace.Meta.Tactic.induction true
|
|
|
|
def simple : Lean.Expr → Bool
|
|
| .sort _ => true
|
|
| _ => false
|
|
|
|
def expensive : Lean.Expr → Lean.Expr → Bool
|
|
| .app (.app (.sort 1) (.sort 1)) (.sort 1), .app (.app (.sort 1) (.sort 1)) (.sort 1) => false
|
|
| _, _ => true
|
|
|
|
/-- info: false -/
|
|
#guard_msgs in
|
|
#eval expensive (.app (.app (.sort 1) (.sort 1)) (.sort 1)) (.app (.app (.sort 1) (.sort 1)) (.sort 1))
|
|
|
|
/-- info: true -/
|
|
#guard_msgs in
|
|
#eval expensive (.app (.app (.sort 2) (.sort 1)) (.sort 1)) (.app (.app (.sort 1) (.sort 1)) (.sort 1))
|
|
|
|
example : expensive (.app (.app (.sort 1) (.sort 1)) (.sort 1)) (.app (.app (.sort 1) (.sort 1)) (.sort 1)) = false := rfl
|
|
example : expensive (.app (.app (.sort 2) (.sort 1)) (.sort 1)) (.app (.app (.sort 1) (.sort 1)) (.sort 1)) = true := rfl
|
|
|
|
/--
|
|
info: expensive.match_1.{u_1} (motive : Expr → Expr → Sort u_1) (x✝ x✝¹ : Expr)
|
|
(h_1 :
|
|
Unit →
|
|
motive (((sort zero.succ).app (sort zero.succ)).app (sort zero.succ))
|
|
(((sort zero.succ).app (sort zero.succ)).app (sort zero.succ)))
|
|
(h_2 : (x x_1 : Expr) → motive x x_1) : motive x✝ x✝¹
|
|
-/
|
|
#guard_msgs in
|
|
#check expensive.match_1
|
|
/--
|
|
info: expensive.match_1.splitter.{u_1} (motive : Expr → Expr → Sort u_1) (x✝ x✝¹ : Expr)
|
|
(h_1 :
|
|
Unit →
|
|
motive (((sort zero.succ).app (sort zero.succ)).app (sort zero.succ))
|
|
(((sort zero.succ).app (sort zero.succ)).app (sort zero.succ)))
|
|
(h_2 :
|
|
(x x_1 : Expr) →
|
|
(x = ((sort zero.succ).app (sort zero.succ)).app (sort zero.succ) →
|
|
x_1 = ((sort zero.succ).app (sort zero.succ)).app (sort zero.succ) → False) →
|
|
motive x x_1) :
|
|
motive x✝ x✝¹
|
|
-/
|
|
#guard_msgs in
|
|
#check expensive.match_1.splitter
|
|
/--
|
|
info: expensive.match_1.eq_1.{u_1} (motive : Expr → Expr → Sort u_1)
|
|
(h_1 :
|
|
Unit →
|
|
motive (((sort zero.succ).app (sort zero.succ)).app (sort zero.succ))
|
|
(((sort zero.succ).app (sort zero.succ)).app (sort zero.succ)))
|
|
(h_2 : (x x_1 : Expr) → motive x x_1) :
|
|
(match ((sort zero.succ).app (sort zero.succ)).app (sort zero.succ),
|
|
((sort zero.succ).app (sort zero.succ)).app (sort zero.succ) with
|
|
| ((sort zero.succ).app (sort zero.succ)).app (sort zero.succ),
|
|
((sort zero.succ).app (sort zero.succ)).app (sort zero.succ) => h_1 ()
|
|
| x, x_1 => h_2 x x_1) =
|
|
h_1 ()
|
|
-/
|
|
#guard_msgs in
|
|
#check expensive.match_1.eq_1
|
|
/--
|
|
info: expensive.match_1.eq_2.{u_1} (motive : Expr → Expr → Sort u_1) (x✝ x✝¹ : Expr)
|
|
(h_1 :
|
|
Unit →
|
|
motive (((sort zero.succ).app (sort zero.succ)).app (sort zero.succ))
|
|
(((sort zero.succ).app (sort zero.succ)).app (sort zero.succ)))
|
|
(h_2 : (x x_1 : Expr) → motive x x_1) :
|
|
(x✝ = ((sort zero.succ).app (sort zero.succ)).app (sort zero.succ) →
|
|
x✝¹ = ((sort zero.succ).app (sort zero.succ)).app (sort zero.succ) → False) →
|
|
(match x✝, x✝¹ with
|
|
| ((sort zero.succ).app (sort zero.succ)).app (sort zero.succ),
|
|
((sort zero.succ).app (sort zero.succ)).app (sort zero.succ) => h_1 ()
|
|
| x, x_1 => h_2 x x_1) =
|
|
h_2 x✝ x✝¹
|
|
-/
|
|
#guard_msgs in
|
|
#check expensive.match_1.eq_2
|