lean4-htt/library/init/lean/compiler/implementedbyattr.lean

34 lines
1.2 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
-/
prelude
import init.lean.attributes
namespace Lean
namespace Compiler
def mkImplementedByAttr : IO (ParametricAttribute Name) :=
registerParametricAttribute `implementedBy "name of the Lean (probably unsafe) function that implements opaque constant" $ λ env declName stx,
match env.find declName with
| none := Except.error "unknown declaration"
| some decl :=
match attrParamSyntaxToIdentifier stx with
| some fnName :=
match env.find fnName with
| none := Except.error ("unknown function '" ++ toString fnName ++ "'")
| some fnDecl :=
if decl.type == fnDecl.type then Except.ok fnName
else Except.error ("invalid function '" ++ toString fnName ++ "' type mismatch")
| _ := Except.error "expected identifier"
@[init mkImplementedByAttr]
constant implementedByAttr : ParametricAttribute Name := default _
@[export lean.get_implemented_by_core]
def getImplementedBy (env : Environment) (n : Name) : Option Name :=
implementedByAttr.getParam env n
end Compiler
end Lean