99 lines
2.9 KiB
Text
99 lines
2.9 KiB
Text
/-
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Copyright (c) 2017 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Authors: Leonardo de Moura
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-/
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universes u w
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def buffer (α : Type u) := Σ n, array α n
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def mk_buffer {α : Type u} : buffer α :=
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⟨0, {data := λ i, fin.elim0 i}⟩
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def array.to_buffer {α : Type u} {n : nat} (a : array α n) : buffer α :=
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⟨n, a⟩
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namespace buffer
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variables {α : Type u} {β : Type w}
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def nil : buffer α :=
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mk_buffer
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def size (b : buffer α) : nat :=
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b.1
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def to_array (b : buffer α) : array α (b^.size) :=
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b.2
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def push_back : buffer α → α → buffer α
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| ⟨n, a⟩ v := ⟨n+1, a^.push_back v⟩
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def pop_back : buffer α → buffer α
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| ⟨0, a⟩ := ⟨0, a⟩
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| ⟨n+1, a⟩ := ⟨n, a^.pop_back⟩
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def read : Π (b : buffer α), fin b^.size → α
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| ⟨n, a⟩ i := a^.read i
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def write : Π (b : buffer α), fin b^.size → α → buffer α
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| ⟨n, a⟩ i v := ⟨n, a^.write i v⟩
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def read' [inhabited α] : buffer α → nat → α
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| ⟨n, a⟩ i := a^.read' i
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def write' : buffer α → nat → α → buffer α
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| ⟨n, a⟩ i v := ⟨n, a^.write' i v⟩
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def to_list (b : buffer α) : list α :=
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b^.to_array^.to_list
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def append_list {α : Type u} : buffer α → list α → buffer α
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| b [] := b
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| b (v::vs) := append_list (b^.push_back v) vs
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def append_string (b : buffer char) (s : string) : buffer char :=
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b^.append_list s^.reverse
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def append_array {α : Type u} {n : nat} (nz : n > 0) : buffer α → array α n → ∀ i : nat, i < n → buffer α
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| ⟨m, b⟩ a 0 _ :=
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let i : fin n := ⟨n - 1, array.lt_aux_2 nz⟩ in
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⟨m+1, b^.push_back (a^.read i)⟩
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| ⟨m, b⟩ a (j+1) h :=
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let i : fin n := ⟨n - 2 - j, array.lt_aux_3 h⟩ in
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append_array ⟨m+1, b^.push_back (a^.read i)⟩ a j (array.lt_aux_1 h)
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protected def append {α : Type u} : buffer α → buffer α → buffer α
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| b ⟨0, a⟩ := b
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| b ⟨n+1, a⟩ := append_array (nat.zero_lt_succ _) b a n (nat.lt_succ_self _)
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def iterate : Π b : buffer α, β → (fin b^.size → α → β → β) → β
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| ⟨_, a⟩ b f := a^.iterate b f
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def foreach : Π b : buffer α, (fin b^.size → α → α) → buffer α
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| ⟨n, a⟩ f := ⟨n, a^.foreach f⟩
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def map (f : α → α) : buffer α → buffer α
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| ⟨n, a⟩ := ⟨n, a^.map f⟩
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def foldl : buffer α → β → (α → β → β) → β
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| ⟨_, a⟩ b f := a^.foldl b f
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def rev_iterate : Π (b : buffer α), β → (fin b^.size → α → β → β) → β
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| ⟨_, a⟩ b f := a^.rev_iterate b f
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instance : has_append (buffer α) :=
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⟨buffer.append⟩
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instance [has_to_string α] : has_to_string (buffer α) :=
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⟨to_string ∘ to_list⟩
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meta instance [has_to_format α] : has_to_format (buffer α) :=
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⟨to_fmt ∘ to_list⟩
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meta instance [has_to_tactic_format α] : has_to_tactic_format (buffer α) :=
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⟨tactic.pp ∘ to_list⟩
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end buffer
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def list.to_buffer {α : Type u} (l : list α) : buffer α :=
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mk_buffer^.append_list l
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