lean4-htt/src/Lean/AuxRecursor.lean
2025-07-25 12:02:51 +00:00

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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
-/
module
prelude
public import Lean.EnvExtension
public section
namespace Lean
def casesOnSuffix := "casesOn"
def recOnSuffix := "recOn"
def brecOnSuffix := "brecOn"
def belowSuffix := "below"
def mkCasesOnName (indDeclName : Name) : Name := Name.mkStr indDeclName casesOnSuffix
def mkRecOnName (indDeclName : Name) : Name := Name.mkStr indDeclName recOnSuffix
def mkBRecOnName (indDeclName : Name) : Name := Name.mkStr indDeclName brecOnSuffix
def mkBelowName (indDeclName : Name) : Name := Name.mkStr indDeclName belowSuffix
builtin_initialize auxRecExt : TagDeclarationExtension ← mkTagDeclarationExtension
def markAuxRecursor (env : Environment) (declName : Name) : Environment :=
auxRecExt.tag env declName
@[export lean_is_aux_recursor]
def isAuxRecursor (env : Environment) (declName : Name) : Bool :=
auxRecExt.isTagged env declName
-- TODO: use `markAuxRecursor` when they are defined
-- An attribute is not a good solution since we don't want users to control what is tagged as an auxiliary recursor.
|| declName == ``Eq.ndrec
|| declName == ``Eq.ndrecOn
def isAuxRecursorWithSuffix (env : Environment) (declName : Name) (suffix : String) : Bool :=
match declName with
| .str _ s => (s == suffix || s.startsWith s!"{suffix}_") && isAuxRecursor env declName
| _ => false
def isCasesOnRecursor (env : Environment) (declName : Name) : Bool :=
isAuxRecursorWithSuffix env declName casesOnSuffix
def isRecOnRecursor (env : Environment) (declName : Name) : Bool :=
isAuxRecursorWithSuffix env declName recOnSuffix
def isBRecOnRecursor (env : Environment) (declName : Name) : Bool :=
isAuxRecursorWithSuffix env declName brecOnSuffix
builtin_initialize noConfusionExt : TagDeclarationExtension ← mkTagDeclarationExtension
def markNoConfusion (env : Environment) (n : Name) : Environment :=
noConfusionExt.tag env n
@[export lean_is_no_confusion]
def isNoConfusion (env : Environment) (n : Name) : Bool :=
noConfusionExt.isTagged env n
end Lean