lean4-htt/library/init/lean/localcontext.lean

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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.data.persistentarray.basic
import init.data.persistenthashmap.basic
import init.lean.expr
namespace Lean
inductive LocalDecl
| cdecl (index : Nat) (name : Name) (userName : Name) (type : Expr) (bi : BinderInfo)
| ldecl (index : Nat) (name : Name) (userName : Name) (type : Expr) (value : Expr)
namespace LocalDecl
instance : Inhabited LocalDecl := ⟨ldecl (default _) (default _) (default _) (default _) (default _)⟩
def isLet : LocalDecl → Bool
| cdecl _ _ _ _ _ => false
| ldecl _ _ _ _ _ => true
def index : LocalDecl → Nat
| cdecl idx _ _ _ _ => idx
| ldecl idx _ _ _ _ => idx
def name : LocalDecl → Name
| cdecl _ n _ _ _ => n
| ldecl _ n _ _ _ => n
def userName : LocalDecl → Name
| cdecl _ _ n _ _ => n
| ldecl _ _ n _ _ => n
def type : LocalDecl → Expr
| cdecl _ _ _ t _ => t
| ldecl _ _ _ t _ => t
def binderInfo : LocalDecl → BinderInfo
| cdecl _ _ _ _ bi => bi
| ldecl _ _ _ _ _ => BinderInfo.default
def valueOpt : LocalDecl → Option Expr
| cdecl _ _ _ _ _ => none
| ldecl _ _ _ _ v => some v
def value : LocalDecl → Expr
| cdecl _ _ _ _ _ => default _
| ldecl _ _ _ _ v => v
def updateUserName : LocalDecl → Name → LocalDecl
| cdecl index name _ type bi, userName => cdecl index name userName type bi
| ldecl index name _ type val, userName => ldecl index name userName type val
end LocalDecl
structure LocalContext :=
(nameToDecl : PersistentHashMap Name LocalDecl := {})
(decls : PersistentArray (Option LocalDecl) := {})
namespace LocalContext
instance : Inhabited LocalContext := ⟨{}⟩
@[export lean.mk_empty_local_ctx_core]
def mkEmpty : Unit → LocalContext :=
fun _ => {}
def empty : LocalContext :=
{}
@[export lean.local_ctx_is_empty_core]
def isEmpty (lctx : LocalContext) : Bool :=
lctx.nameToDecl.isEmpty
/- Low level API for creating local declarations. It is used to implement actions in the monads `Elab` and `Tactic`. It should not be used directly since the argument `(name : Name)` is assumed to be "unique". -/
@[export lean.local_ctx_mk_local_decl_core]
def mkLocalDecl (lctx : LocalContext) (name : Name) (userName : Name) (type : Expr) (bi : BinderInfo := BinderInfo.default) : LocalDecl × LocalContext :=
match lctx with
| { nameToDecl := map, decls := decls } =>
let idx := decls.size;
let decl := LocalDecl.cdecl idx name userName type bi;
(decl, { nameToDecl := map.insert name decl, decls := decls.push decl })
@[export lean.local_ctx_mk_let_decl_core]
def mkLetDecl (lctx : LocalContext) (name : Name) (userName : Name) (type : Expr) (value : Expr) : LocalDecl × LocalContext :=
match lctx with
| { nameToDecl := map, decls := decls } =>
let idx := decls.size;
let decl := LocalDecl.ldecl idx name userName type value;
(decl, { nameToDecl := map.insert name decl, decls := decls.push decl })
@[export lean.local_ctx_find_core]
def find (lctx : LocalContext) (name : Name) : Option LocalDecl :=
lctx.nameToDecl.find name
def findFVar (lctx : LocalContext) (e : Expr) : Option LocalDecl :=
match e with
| Expr.fvar n => lctx.find n
| _ => none
private partial def popTailNoneAux : PArray (Option LocalDecl) → PArray (Option LocalDecl)
| a =>
if a.size == 0 then a
else match a.get (a.size - 1) with
| none => popTailNoneAux a.pop
| some _ => a
@[export lean.local_ctx_erase_core]
def erase (lctx : LocalContext) (name : Name) : LocalContext :=
match lctx with
| { nameToDecl := map, decls := decls } =>
match map.find name with
| none => lctx
| some decl => { nameToDecl := map.erase name, decls := popTailNoneAux (decls.set decl.index none) }
@[export lean.local_ctx_pop_core]
def pop (lctx : LocalContext): LocalContext :=
match lctx with
| { nameToDecl := map, decls := decls } =>
if decls.size == 0 then lctx
else match decls.get (decls.size - 1) with
| none => lctx -- unreachable
| some decl => { nameToDecl := map.erase decl.name, decls := popTailNoneAux decls.pop }
@[export lean.local_ctx_find_from_user_name_core]
def findFromUserName (lctx : LocalContext) (userName : Name) : Option LocalDecl :=
lctx.decls.findRev (fun decl =>
match decl with
| none => none
| some decl => if decl.userName == userName then some decl else none)
@[export lean.local_ctx_uses_user_name_core]
def usesUserName (lctx : LocalContext) (userName : Name) : Bool :=
(lctx.findFromUserName userName).isSome
partial def getUnusedNameAux (lctx : LocalContext) (suggestion : Name) : Nat → Name × Nat
| i =>
let curr := suggestion.appendIndexAfter i;
if lctx.usesUserName curr then getUnusedNameAux (i + 1)
else (curr, i + 1)
@[export lean.local_ctx_get_unused_name_core]
def getUnusedName (lctx : LocalContext) (suggestion : Name) : Name :=
if lctx.usesUserName suggestion then (lctx.getUnusedNameAux suggestion 1).1
else suggestion
@[export lean.local_ctx_last_decl_core]
def lastDecl (lctx : LocalContext) : Option LocalDecl :=
lctx.decls.get (lctx.decls.size - 1)
@[export lean.local_ctx_rename_user_name_core]
def renameUserName (lctx : LocalContext) (fromName : Name) (toName : Name) : LocalContext :=
match lctx with
| { nameToDecl := map, decls := decls } =>
match lctx.findFromUserName fromName with
| none => lctx
| some decl =>
let decl := decl.updateUserName toName;
{ nameToDecl := map.insert decl.name decl,
decls := decls.set decl.index decl }
@[export lean.local_ctx_num_indices_core]
def numIndices (lctx : LocalContext) : Nat :=
lctx.decls.size
@[export lean.local_ctx_get_core]
def get (lctx : LocalContext) (i : Nat) : Option LocalDecl :=
lctx.decls.get i
section
universes u v
variables {m : Type u → Type v} [Monad m]
variable {β : Type u}
@[specialize] def mfoldl (lctx : LocalContext) (f : β → LocalDecl → m β) (b : β) : m β :=
lctx.decls.mfoldl (fun b decl => match decl with
| none => pure b
| some decl => f b decl)
b
@[specialize] def mfor (lctx : LocalContext) (f : LocalDecl → m β) : m PUnit :=
lctx.decls.mfor $ fun decl => match decl with
| none => pure PUnit.unit
| some decl => f decl *> pure PUnit.unit
@[specialize] def mfindDecl (lctx : LocalContext) (f : LocalDecl → m (Option β)) : m (Option β) :=
lctx.decls.mfind $ fun decl => match decl with
| none => pure none
| some decl => f decl
@[specialize] def mfindDeclRev (lctx : LocalContext) (f : LocalDecl → m (Option β)) : m (Option β) :=
lctx.decls.mfindRev $ fun decl => match decl with
| none => pure none
| some decl => f decl
@[specialize] def mfoldlFrom (lctx : LocalContext) (f : β → LocalDecl → m β) (b : β) (decl : LocalDecl) : m β :=
lctx.decls.mfoldlFrom (fun b decl => match decl with
| none => pure b
| some decl => f b decl)
b decl.index
end
@[inline] def foldl {β} (lctx : LocalContext) (f : β → LocalDecl → β) (b : β) : β :=
Id.run $ lctx.mfoldl f b
@[inline] def findDecl {β} (lctx : LocalContext) (f : LocalDecl → Option β) : Option β :=
Id.run $ lctx.mfindDecl f
@[inline] def findDeclRev {β} (lctx : LocalContext) (f : LocalDecl → Option β) : Option β :=
Id.run $ lctx.mfindDeclRev f
@[inline] def foldlFrom {β} (lctx : LocalContext) (f : β → LocalDecl → β) (b : β) (decl : LocalDecl) : β :=
Id.run $ lctx.mfoldlFrom f b decl
partial def isSubPrefixOfAux (a₁ a₂ : PArray (Option LocalDecl)) : Nat → Nat → Bool
| i, j =>
if i < a₁.size then
if j < a₂.size then
match a₁.get i with
| none => isSubPrefixOfAux (i+1) j
| some decl₁ =>
match a₂.get j with
| none => isSubPrefixOfAux i (j+1)
| some decl₂ =>
if decl₁.name == decl₂.name then isSubPrefixOfAux (i+1) (j+1) else isSubPrefixOfAux i (j+1)
else false
else true
/- Given `lctx₁` of the form `(x_1 : A_1) ... (x_n : A_n)`, then return true
iff there is a local context `B_1* (x_1 : A_1) ... B_n* (x_n : A_n)` which is a prefix
of `lctx₂` where `B_i`'s are (possibly empty) sequences of local declarations. -/
def isSubPrefixOf (lctx₁ lctx₂ : LocalContext) : Bool :=
isSubPrefixOfAux lctx₁.decls lctx₂.decls 0 0
end LocalContext
end Lean