lean4-htt/src/Lean/Meta/GetUnfoldableConst.lean
Sebastian Ullrich d33aece210
feat: list definitions in defeq problems that could not be unfolded for lack of @[expose] (#10158)
This PR adds information about definitions blocked from unfolding via
the module system to type defeq errors.
2025-09-23 16:13:39 +00:00

64 lines
2 KiB
Text

/-
Copyright (c) 2019 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura
-/
module
prelude
public import Lean.Meta.GlobalInstances
public section
namespace Lean.Meta
private def canUnfoldDefault (cfg : Config) (info : ConstantInfo) : CoreM Bool := do
match cfg.transparency with
| .all => return true
| .default => return !(← isIrreducible info.name)
| m =>
if (← isReducible info.name) then
return true
else if m == .instances && isGlobalInstance (← getEnv) info.name then
return true
else
return false
def canUnfold (info : ConstantInfo) : MetaM Bool := do
let ctx ← read
let cfg ← getConfig
if let some f := ctx.canUnfold? then
f cfg info
else
canUnfoldDefault cfg info
/--
Look up a constant name, returning the `ConstantInfo`
if it is a def/theorem that should be unfolded at the current reducibility settings,
or `none` otherwise.
This is part of the implementation of `whnf`.
External users wanting to look up names should be using `Lean.getConstInfo`.
-/
def getUnfoldableConst? (constName : Name) : MetaM (Option ConstantInfo) := do
let some ainfo := (← getEnv).findAsync? constName | throwUnknownConstantAt (← getRef) constName
match ainfo.kind with
| .thm =>
if (← shouldReduceAll) then
return some ainfo.toConstantInfo
else
return none
| .defn => if (← canUnfold ainfo.toConstantInfo) then return ainfo.toConstantInfo else return none
| _ => return none
/--
As with `getUnfoldableConst?` but return `none` instead of failing if the constant is not found.
-/
def getUnfoldableConstNoEx? (constName : Name) : MetaM (Option ConstantInfo) := do
match (← getEnv).find? constName with
| some (info@(.thmInfo _)) => getTheoremInfo info
| some (info@(.defnInfo _)) => if (← canUnfold info) then return info else return none
| some (.axiomInfo _) => recordUnfoldAxiom constName; return none
| _ => return none
end Meta