lean4-htt/library/init/lean/compiler/util.lean
2019-08-09 09:13:49 -07:00

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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.environment
namespace Lean
namespace Compiler
def neutralExpr : Expr := Expr.const `_neutral []
def unreachableExpr : Expr := Expr.const `_unreachable []
def objectType : Expr := Expr.const `_obj []
def voidType : Expr := Expr.const `_void []
def mkLcProof (pred : Expr) := Expr.app (Expr.const `lcProof []) pred
namespace atMostOnce
structure AtMostOnceData :=
(found result : Bool)
def Visitor := AtMostOnceData → AtMostOnceData
@[inline] def seq (f g : Visitor) : Visitor :=
fun d => match f d with
| ⟨found, false⟩ => ⟨found, false⟩
| other => g other
instance : HasAndthen Visitor :=
⟨seq⟩
@[inline] def skip : Visitor := id
@[inline] def visitFVar (x y : Name) : Visitor
| d@{result := false, ..} => d
| {found := false, result := true} => {found := x == y, result := true}
| {found := true, result := true} => {found := true, result := x != y}
def visit (x : Name) : Expr → Visitor
| Expr.fvar y => visitFVar y x
| Expr.app f a => visit a >> visit f
| Expr.lam _ _ d b => visit d >> visit b
| Expr.pi _ _ d b => visit d >> visit b
| Expr.elet _ t v b => visit t >> visit v >> visit b
| Expr.mdata _ e => visit e
| Expr.proj _ _ e => visit e
| _ => skip
end atMostOnce
/-- Return true iff the free variable with id `x` occurs at most once in `e` -/
@[export lean.at_most_once_core]
def atMostOnce (e : Expr) (x : Name) : Bool :=
let {result := result, ..} := atMostOnce.visit x e {found := false, result := true};
result
/- Helper functions for creating auxiliary names used in compiler passes. -/
@[export lean.mk_eager_lambda_lifting_name_core]
def mkEagerLambdaLiftingName (n : Name) (idx : Nat) : Name :=
Name.mkString n ("_elambda_" ++ toString idx)
@[export lean.is_eager_lambda_lifting_name_core]
def isEagerLambdaLiftingName : Name → Bool
| Name.mkString p s => "_elambda".isPrefixOf s || isEagerLambdaLiftingName p
| Name.mkNumeral p _ => isEagerLambdaLiftingName p
| _ => false
/-- Return the name of new definitions in the a given declaration.
Here we consider only declarations we generate code for.
We use this definition to implement `add_and_compile`. -/
@[export lean.get_decl_names_for_code_gen_core]
private def getDeclNamesForCodeGen : Declaration → List Name
| Declaration.defnDecl { name := n, .. } => [n]
| Declaration.mutualDefnDecl defs => defs.map $ fun d => d.name
| _ => []
def checkIsDefinition (env : Environment) (n : Name) : Except String Unit :=
match env.find n with
| (some (ConstantInfo.defnInfo _)) => Except.ok ()
| none => Except.error "unknow declaration"
| _ => Except.error "declaration is not a definition"
end Compiler
end Lean