lean4-htt/tests/elab/test_proj_hints.lean
Garmelon 08eb78a5b2
chore: switch to new test/bench suite (#12590)
This PR sets up the new integrated test/bench suite. It then migrates
all benchmarks and some related tests to the new suite. There's also
some documentation and some linting.

For now, a lot of the old tests are left alone so this PR doesn't become
even larger than it already is. Eventually, all tests should be migrated
to the new suite though so there isn't a confusing mix of two systems.
2026-02-25 13:51:53 +00:00

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1.5 KiB
Text

import Lean
/-!
# Test: projection functions have `.abbrev` kernel hints
All projection functions receive `.abbrev` kernel hints at creation time.
Structure projections default to `.reducible` status, while class projections
default to `.semireducible` status. The `@[reducible]` attribute changes the
reducibility status but does **not** change the kernel hint.
These properties are relied upon by `isNonTrivialRegular` in `ExprDefEq.lean`.
That function uses the `.abbrev` branch to detect class projections and treat
them as nontrivial when `backward.whnf.reducibleClassField` is enabled, so that
`tryHeuristic` applies the argument-comparison heuristic (with the correct
transparency bump for instance-implicit parameters) instead of unfolding past
the `.proj` form. If the kernel hints or default reducibility status for
projections change, `isNonTrivialRegular` must be updated accordingly.
-/
structure Y where
x : Nat
class X where
x : Nat
open Lean
deriving instance Repr for ReducibilityHints
def showHintAndReduceAttr (declName : Name) : CoreM Unit := do
let info ← getConstInfo declName
IO.println (repr info.hints)
IO.println (repr (← getReducibilityStatus declName))
-- Structure projection: `.abbrev` hint, `.reducible` status
/--
info: Lean.ReducibilityHints.abbrev
Lean.ReducibilityStatus.reducible
-/
#guard_msgs in
#eval showHintAndReduceAttr ``Y.x
-- Class projection: `.abbrev` hint, `.semireducible` status
/--
info: Lean.ReducibilityHints.abbrev
Lean.ReducibilityStatus.semireducible
-/
#guard_msgs in
#eval showHintAndReduceAttr ``X.x