lean4-htt/src/Lean/Meta/GetUnfoldableConst.lean
Leonardo de Moura b1e52f1475
chore: mark Meta.Context.config as private (#6051)
Motivation: we want to modify the internal representation and improve
`isDefEq` caching.
This PR is preparing the stage for future modifications.
2024-11-13 13:30:06 +11:00

56 lines
1.9 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
-/
prelude
import Lean.Meta.GlobalInstances
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 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
match (← getEnv).find? constName with
| some (info@(.thmInfo _)) => getTheoremInfo info
| some (info@(.defnInfo _)) => if (← canUnfold info) then return info else return none
| some info => return some info
| none => throwUnknownConstant constName
/--
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 info => return some info
| none => return none
end Meta