lean4-htt/src/Lean/Elab/Attributes.lean
2021-04-24 11:25:08 +02:00

74 lines
3 KiB
Text

/-
Copyright (c) 2020 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura, Sebastian Ullrich
-/
import Lean.Parser.Attr
import Lean.Attributes
import Lean.MonadEnv
import Lean.Elab.Util
namespace Lean.Elab
structure Attribute where
kind : AttributeKind := AttributeKind.global
name : Name
stx : Syntax := Syntax.missing
instance : ToFormat Attribute where
format attr :=
let kindStr := match attr.kind with
| AttributeKind.global => ""
| AttributeKind.local => "local "
| AttributeKind.scoped => "scoped "
Format.bracket "@[" f!"{kindStr}{attr.name}{toString attr.stx}" "]"
instance : Inhabited Attribute where
default := { name := arbitrary }
/-
```
attrKind := leading_parser optional («scoped» <|> «local»)
```
-/
def toAttributeKind (attrKindStx : Syntax) : MacroM AttributeKind := do
if attrKindStx[0].isNone then
return AttributeKind.global
else if attrKindStx[0][0].getKind == ``Lean.Parser.Term.scoped then
if (← Macro.getCurrNamespace).isAnonymous then
throw <| Macro.Exception.error (← getRef) "scoped attributes must be used inside namespaces"
return AttributeKind.scoped
else
return AttributeKind.local
def mkAttrKindGlobal : Syntax :=
Syntax.node ``Lean.Parser.Term.attrKind #[mkNullNode]
def elabAttr {m} [Monad m] [MonadEnv m] [MonadResolveName m] [MonadError m] [MonadMacroAdapter m] [MonadRecDepth m] [MonadTrace m] [MonadOptions m] [AddMessageContext m] (attrInstance : Syntax) : m Attribute := do
/- attrInstance := ppGroup $ leading_parser attrKind >> attrParser -/
let attrKind ← liftMacroM <| toAttributeKind attrInstance[0]
let attr := attrInstance[1]
let attr ← liftMacroM <| expandMacros attr
let attrName ←
if attr.getKind == ``Parser.Attr.simple then
pure attr[0].getId.eraseMacroScopes
else
match attr.getKind with
| Name.str _ s _ => pure <| Name.mkSimple s
| _ => throwErrorAt attr "unknown attribute"
unless isAttribute (← getEnv) attrName do
throwError "unknown attribute [{attrName}]"
/- The `AttrM` does not have sufficient information for expanding macros in `args`.
So, we expand them before here before we invoke the attributer handlers implemented using `AttrM`. -/
pure { kind := attrKind, name := attrName, stx := attr }
def elabAttrs {m} [Monad m] [MonadEnv m] [MonadResolveName m] [MonadError m] [MonadMacroAdapter m] [MonadRecDepth m] [MonadTrace m] [MonadOptions m] [AddMessageContext m] (attrInstances : Array Syntax) : m (Array Attribute) := do
let mut attrs := #[]
for attr in attrInstances do
attrs := attrs.push (← elabAttr attr)
return attrs
-- leading_parser "@[" >> sepBy1 attrInstance ", " >> "]"
def elabDeclAttrs {m} [Monad m] [MonadEnv m] [MonadResolveName m] [MonadError m] [MonadMacroAdapter m] [MonadRecDepth m] [MonadTrace m] [MonadOptions m] [AddMessageContext m] (stx : Syntax) : m (Array Attribute) :=
elabAttrs stx[1].getSepArgs
end Lean.Elab