lean4-htt/library/init/data/list/basic.lean
Mario Carneiro 26548c956c feat(init/meta/interactive): rw at *, rw at h1 h2 |- support
Now tactics supporting locations can also specify the goal among the locations by using the name `⊢` or `|-`. Also `rw at *` is implemented so that it will rewrite any hypotheses or the goal for which the whole sequence of rewrites succeeds. (This is different from `rw at h1 h2 ... hn |-`, which requires that all rewrites run to completion on each specified target.)
2017-07-28 16:47:02 +01:00

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/-
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
-/
prelude
import init.logic init.data.nat.basic init.data.bool.basic
open decidable list
universes u v w
instance (α : Type u) : inhabited (list α) :=
⟨list.nil⟩
variables {α : Type u} {β : Type v} {γ : Type w}
namespace list
protected def append : list α → list α → list α
| [] l := l
| (h :: s) t := h :: (append s t)
attribute [simp] list.append
instance : has_append (list α) :=
⟨list.append⟩
protected def mem : α → list α → Prop
| a [] := false
| a (b :: l) := a = b mem a l
instance : has_mem α (list α) :=
⟨list.mem⟩
instance decidable_mem [decidable_eq α] (a : α) : ∀ (l : list α), decidable (a ∈ l)
| [] := is_false not_false
| (b::l) :=
if h₁ : a = b then is_true (or.inl h₁)
else match decidable_mem l with
| is_true h₂ := is_true (or.inr h₂)
| is_false h₂ := is_false (not_or h₁ h₂)
end
instance : has_emptyc (list α) :=
⟨list.nil⟩
protected def erase {α} [decidable_eq α] : list αα → list α
| [] b := []
| (a::l) b := if a = b then l else a :: erase l b
protected def bag_inter {α} [decidable_eq α] : list α → list α → list α
| [] _ := []
| _ [] := []
| (a::l₁) l₂ := if a ∈ l₂ then a :: bag_inter l₁ (l₂.erase a) else bag_inter l₁ l₂
protected def diff {α} [decidable_eq α] : list α → list α → list α
| l [] := l
| l₁ (a::l₂) := if a ∈ l₁ then diff (l₁.erase a) l₂ else diff l₁ l₂
def length : list α → nat
| [] := 0
| (a :: l) := length l + 1
attribute [simp] length
def empty : list α → bool
| [] := tt
| (_ :: _) := ff
open option nat
def nth : list α → nat → option α
| [] n := none
| (a :: l) 0 := some a
| (a :: l) (n+1) := nth l n
attribute [simp] nth
def nth_le : Π (l : list α) (n), n < l.length → α
| [] n h := absurd h (not_lt_zero n)
| (a :: l) 0 h := a
| (a :: l) (n+1) h := nth_le l n (le_of_succ_le_succ h)
attribute [simp] nth_le
def head [inhabited α] : list αα
| [] := default α
| (a :: l) := a
attribute [simp] head
def tail : list α → list α
| [] := []
| (a :: l) := l
attribute [simp] tail
def reverse_core : list α → list α → list α
| [] r := r
| (a::l) r := reverse_core l (a::r)
def reverse : list α → list α :=
λ l, reverse_core l []
def map (f : α → β) : list α → list β
| [] := []
| (a :: l) := f a :: map l
attribute [simp] map
def map₂ (f : α → β → γ) : list α → list β → list γ
| [] _ := []
| _ [] := []
| (x::xs) (y::ys) := f x y :: map₂ xs ys
attribute [simp] map₂
def join : list (list α) → list α
| [] := []
| (l :: ls) := l ++ join ls
def filter_map (f : α → option β) : list α → list β
| [] := []
| (a::l) :=
match f a with
| none := filter_map l
| some b := b :: filter_map l
end
def filter (p : α → Prop) [decidable_pred p] : list α → list α
| [] := []
| (a::l) := if p a then a :: filter l else filter l
def partition (p : α → Prop) [decidable_pred p] : list α → list α × list α
| [] := ([], [])
| (a::l) := let (l₁, l₂) := partition l in if p a then (a :: l₁, l₂) else (l₁, a :: l₂)
def drop_while (p : α → Prop) [decidable_pred p] : list α → list α
| [] := []
| (a::l) := if p a then drop_while l else a::l
def span (p : α → Prop) [decidable_pred p] : list α → list α × list α
| [] := ([], [])
| (a::xs) := if p a then let (l, r) := span xs in (a :: l, r) else ([], a::xs)
def find_index (p : α → Prop) [decidable_pred p] : list α → nat
| [] := 0
| (a::l) := if p a then 0 else succ (find_index l)
def index_of [decidable_eq α] (a : α) : list α → nat := find_index (eq a)
def remove_all [decidable_eq α] (xs ys : list α) : list α :=
filter (∉ ys) xs
def update_nth : list αα → list α
| (x::xs) 0 a := a :: xs
| (x::xs) (i+1) a := x :: update_nth xs i a
| [] _ _ := []
def remove_nth : list α → list α
| [] _ := []
| (x::xs) 0 := xs
| (x::xs) (i+1) := x :: remove_nth xs i
def drop : → list α → list α
| 0 a := a
| (succ n) [] := []
| (succ n) (x::r) := drop n r
attribute [simp] drop
def take : → list α → list α
| 0 a := []
| (succ n) [] := []
| (succ n) (x :: r) := x :: take n r
attribute [simp] take
def foldl (f : α → β → α) : α → list β → α
| a [] := a
| a (b :: l) := foldl (f a b) l
attribute [simp] foldl
def foldr (f : α → β → β) (b : β) : list α → β
| [] := b
| (a :: l) := f a (foldr l)
attribute [simp] foldr
def any (l : list α) (p : α → bool) : bool :=
foldr (λ a r, p a || r) ff l
def all (l : list α) (p : α → bool) : bool :=
foldr (λ a r, p a && r) tt l
def bor (l : list bool) : bool := any l id
def band (l : list bool) : bool := all l id
def zip_with (f : α → β → γ) : list α → list β → list γ
| (x::xs) (y::ys) := f x y :: zip_with xs ys
| _ _ := []
def zip : list α → list β → list (prod α β) :=
zip_with prod.mk
def unzip : list (α × β) → list α × list β
| [] := ([], [])
| ((a, b) :: t) := match unzip t with (al, bl) := (a::al, b::bl) end
protected def insert [decidable_eq α] (a : α) (l : list α) : list α :=
if a ∈ l then l else a :: l
instance [decidable_eq α] : has_insert α (list α) :=
⟨list.insert⟩
protected def union [decidable_eq α] (l₁ l₂ : list α) : list α :=
foldr insert l₂ l₁
instance [decidable_eq α] : has_union (list α) :=
⟨list.union⟩
protected def inter [decidable_eq α] (l₁ l₂ : list α) : list α :=
filter (∈ l₂) l₁
instance [decidable_eq α] : has_inter (list α) :=
⟨list.inter⟩
def repeat (a : α) : → list α
| 0 := []
| (succ n) := a :: repeat n
attribute [simp] repeat
def range_core : → list → list
| 0 l := l
| (succ n) l := range_core n (n :: l)
def range (n : ) : list :=
range_core n []
def iota : → list
| 0 := []
| (succ n) := succ n :: iota n
def enum_from : → list α → list ( × α)
| n [] := nil
| n (x :: xs) := (n, x) :: enum_from (n + 1) xs
def enum : list α → list ( × α) := enum_from 0
def last : Π l : list α, l ≠ [] → α
| [] h := absurd rfl h
| [a] h := a
| (a::b::l) h := last (b::l) (λ h, list.no_confusion h)
attribute [simp] last
def ilast [inhabited α] : list αα
| [] := arbitrary α
| [a] := a
| [a, b] := b
| (a::b::l) := ilast l
def init : list α → list α
| [] := []
| [a] := []
| (a::l) := a::init l
def intersperse (sep : α) : list α → list α
| [] := []
| [x] := [x]
| (x::xs) := x::sep::intersperse xs
def intercalate (sep : list α) (xs : list (list α)) : list α :=
join (intersperse sep xs)
@[inline] def bind {α : Type u} {β : Type v} (a : list α) (b : α → list β) : list β :=
join (map b a)
@[inline] def ret {α : Type u} (a : α) : list α :=
[a]
end list
namespace bin_tree
private def to_list_aux : bin_tree α → list α → list α
| empty as := as
| (leaf a) as := a::as
| (node l r) as := to_list_aux l (to_list_aux r as)
def to_list (t : bin_tree α) : list α :=
to_list_aux t []
end bin_tree