lean4-htt/library/Init/Lean/Compiler/ExportAttr.lean
Leonardo de Moura c3e9ac73e2 refactor: default ==> arbitrary
Make sure it is opaque, and avoid `irreducible`
2019-11-05 14:42:42 -08:00

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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
-/
prelude
import Init.Lean.Attributes
namespace Lean
private def isValidCppId (id : String) : Bool :=
let first := id.get 0;
first.isAlpha && (id.toSubstring.drop 1).all (fun c => c.isAlpha || c.isDigit || c == '_')
private def isValidCppName : Name → Bool
| Name.mkString Name.anonymous s => isValidCppId s
| Name.mkString p s => isValidCppId s && isValidCppName p
| _ => false
def mkExportAttr : IO (ParametricAttribute Name) :=
registerParametricAttribute `export "name to be used by code generators" $ fun _ _ stx =>
match attrParamSyntaxToIdentifier stx with
| some exportName =>
if isValidCppName exportName then Except.ok exportName
else Except.error "invalid 'export' function name, is not a valid C++ identifier"
| _ => Except.error "unexpected kind of argument"
@[init mkExportAttr]
constant exportAttr : ParametricAttribute Name := arbitrary _
@[export lean_get_export_name_for]
def getExportNameFor (env : Environment) (n : Name) : Option Name :=
exportAttr.getParam env n
def isExport (env : Environment) (n : Name) : Bool :=
(getExportNameFor env n).isSome
end Lean