lean4-htt/src/Lean/ReducibilityAttrs.lean
2020-06-25 11:21:17 -07:00

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/-
Copyright (c) 2019 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura
-/
import Lean.Attributes
namespace Lean
inductive ReducibilityStatus
| reducible | semireducible | irreducible
instance ReducibilityStatus.inhabited : Inhabited ReducibilityStatus := ⟨ReducibilityStatus.semireducible⟩
def mkReducibilityAttrs : IO (EnumAttributes ReducibilityStatus) :=
registerEnumAttributes `reducibility
[(`reducible, "reducible", ReducibilityStatus.reducible),
(`semireducible, "semireducible", ReducibilityStatus.semireducible),
(`irreducible, "irreducible", ReducibilityStatus.irreducible)]
@[init mkReducibilityAttrs]
constant reducibilityAttrs : EnumAttributes ReducibilityStatus := arbitrary _
@[export lean_get_reducibility_status]
def getReducibilityStatus (env : Environment) (n : Name) : ReducibilityStatus :=
match reducibilityAttrs.getValue env n with
| some s => s
| none => ReducibilityStatus.semireducible
@[export lean_set_reducibility_status]
def setReducibilityStatus (env : Environment) (n : Name) (s : ReducibilityStatus) : Environment :=
match reducibilityAttrs.setValue env n s with
| Except.ok env => env
| _ => env -- TODO(Leo): we should extend EnumAttributes.setValue in the future and ensure it never fails
def isReducible (env : Environment) (n : Name) : Bool :=
match getReducibilityStatus env n with
| ReducibilityStatus.reducible => true
| _ => false
end Lean