lean4-htt/src/Lean/KeyedDeclsAttribute.lean

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/-
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.Attributes
import Lean.Compiler.InitAttr
import Lean.ToExpr
import Lean.Meta.Message
/-!
A builder for attributes that are applied to declarations of a common type and
group them by the given attribute argument (an arbitrary `Name`, currently).
Also creates a second "builtin" attribute used for bootstrapping, which saves
the applied declarations in an `IO.Ref` instead of an environment extension.
Used to register elaborators, macros, tactics, and delaborators.
-/
namespace Lean
namespace KeyedDeclsAttribute
-- could be a parameter as well, but right now it's all names
abbrev Key := Name
/--
`KeyedDeclsAttribute` definition.
Important: `mkConst valueTypeName` and `γ` must be definitionally equal. -/
structure Def (γ : Type) :=
(builtinName : Name) -- Builtin attribute name (e.g., `builtinTermElab)
(name : Name) -- Attribute name (e.g., `termElab)
(descr : String) -- Attribute description
(valueTypeName : Name)
-- Convert `Syntax` into a `Key`, the default implementation expects an identifier.
(evalKey : Environment → Syntax → Except String Key :=
fun env arg => match attrParamSyntaxToIdentifier arg with
| some id => Except.ok id
| none => Except.error "invalid attribute argument, expected identifier")
structure OLeanEntry :=
(key : Key)
(decl : Name) -- Name of a declaration stored in the environment which has type `mkConst Def.valueTypeName`.
structure AttributeEntry (γ : Type) extends OLeanEntry :=
/- Recall that we cannot store `γ` into .olean files because it is a closure.
Given `OLeanEntry.decl`, we convert it into a `γ` by using the unsafe function `evalConstCheck`. -/
(value : γ)
abbrev Table (γ : Type) := SMap Key (List γ)
structure ExtensionState (γ : Type) :=
(newEntries : List OLeanEntry := [])
(table : Table γ := {})
abbrev Extension (γ : Type) := PersistentEnvExtension OLeanEntry (AttributeEntry γ) (ExtensionState γ)
end KeyedDeclsAttribute
structure KeyedDeclsAttribute (γ : Type) :=
-- imported/builtin instances
(tableRef : IO.Ref (KeyedDeclsAttribute.Table γ))
-- instances from current module
(ext : KeyedDeclsAttribute.Extension γ)
namespace KeyedDeclsAttribute
def Table.insert {γ : Type} (table : Table γ) (k : Key) (v : γ) : Table γ :=
match table.find? k with
| some vs => table.insert k (v::vs)
| none => table.insert k [v]
instance ExtensionState.inhabited {γ} : Inhabited (ExtensionState γ) :=
⟨{}⟩
instance KeyedDeclsAttribute.inhabited {γ} : Inhabited (KeyedDeclsAttribute γ) :=
⟨{ tableRef := arbitrary _, ext := arbitrary _ }⟩
private def mkInitial {γ} (tableRef : IO.Ref (Table γ)) : IO (ExtensionState γ) := do
table ← tableRef.get;
pure { table := table }
private unsafe def addImported {γ} (df : Def γ) (tableRef : IO.Ref (Table γ)) (env : Environment) (es : Array (Array OLeanEntry)) : IO (ExtensionState γ) := do
table ← tableRef.get;
table ← es.foldlM
(fun table entries =>
entries.foldlM
(fun (table : Table γ) entry =>
match env.evalConstCheck γ df.valueTypeName entry.decl with
| Except.ok f => pure $ table.insert entry.key f
| Except.error ex => throw (IO.userError ex))
table)
table;
pure { table := table }
private def addExtensionEntry {γ} (s : ExtensionState γ) (e : AttributeEntry γ) : ExtensionState γ :=
{ table := s.table.insert e.key e.value, newEntries := e.toOLeanEntry :: s.newEntries }
def addBuiltin {γ} (attr : KeyedDeclsAttribute γ) (key : Key) (val : γ) : IO Unit :=
attr.tableRef.modify $ fun m => m.insert key val
/--
def _regBuiltin$(declName) : IO Unit :=
@addBuiltin $(mkConst valueTypeName) $(mkConst attrDeclName) $(key) $(mkConst declName)
-/
def declareBuiltin {γ} (df : Def γ) (attrDeclName : Name) (env : Environment) (key : Key) (declName : Name) : IO Environment :=
let name := `_regBuiltin ++ declName;
let type := mkApp (mkConst `IO) (mkConst `Unit);
let val := mkAppN (mkConst `Lean.KeyedDeclsAttribute.addBuiltin) #[mkConst df.valueTypeName, mkConst attrDeclName, toExpr key, mkConst declName];
let decl := Declaration.defnDecl { name := name, lparams := [], type := type, value := val, hints := ReducibilityHints.opaque, isUnsafe := false };
match env.addAndCompile {} decl with
-- TODO: pretty print error
| Except.error e => throw (IO.userError ("failed to emit registration code for builtin '" ++ toString declName ++ "': " ++ toString (format $ e.toMessageData {})))
| Except.ok env => IO.ofExcept (setInitAttr env name)
/- TODO: add support for scoped attributes -/
protected unsafe def init {γ} (df : Def γ) (attrDeclName : Name) : IO (KeyedDeclsAttribute γ) := do
tableRef : IO.Ref (Table γ) ← IO.mkRef {};
ext : Extension γ ← registerPersistentEnvExtension {
name := df.name,
mkInitial := mkInitial tableRef,
addImportedFn := addImported df tableRef,
addEntryFn := addExtensionEntry,
exportEntriesFn := fun s => s.newEntries.reverse.toArray,
statsFn := fun s => format "number of local entries: " ++ format s.newEntries.length
};
registerBuiltinAttribute {
name := df.builtinName,
descr := "(builtin) " ++ df.descr,
add := fun env declName arg persistent => do {
unless persistent $ throw (IO.userError ("invalid attribute '" ++ toString df.builtinName ++ "', must be persistent"));
key ← IO.ofExcept $ df.evalKey env arg;
match env.find? declName with
| none => throw $ IO.userError "unknown declaration"
| some decl =>
match decl.type with
| Expr.const c _ _ =>
if c != df.valueTypeName then throw (IO.userError ("unexpected type at '" ++ toString declName ++ "', `" ++ toString df.valueTypeName ++ "` expected"))
else declareBuiltin df attrDeclName env key declName
| _ => throw (IO.userError ("unexpected type at '" ++ toString declName ++ "', `" ++ toString df.valueTypeName ++ "` expected"))
},
applicationTime := AttributeApplicationTime.afterCompilation
};
registerBuiltinAttribute {
name := df.name,
descr := df.descr,
add := fun env constName arg persistent => do
key ← IO.ofExcept $ df.evalKey env arg;
val ← IO.ofExcept $ env.evalConstCheck γ df.valueTypeName constName;
pure $ ext.addEntry env { key := key, decl := constName, value := val },
applicationTime := AttributeApplicationTime.afterCompilation
};
pure { tableRef := tableRef, ext := ext }
/-- Retrieve values tagged with `[attr key]` or `[builtinAttr key]`. -/
def getValues {γ} (attr : KeyedDeclsAttribute γ) (env : Environment) (key : Name) : List γ :=
(attr.ext.getState env).table.findD key []
end KeyedDeclsAttribute
end Lean