Documentation

Init.Data.ByteArray.Lemmas

@[simp]
theorem ByteArray.data_extract {a : ByteArray} {b e : Nat} :
(a.extract b e).data = a.data.extract b e
@[simp]
theorem ByteArray.extract_same {b : ByteArray} {i : Nat} :
@[simp]
theorem ByteArray.data_append {l l' : ByteArray} :
(l ++ l').data = l.data ++ l'.data
@[simp]
@[simp]
@[simp]
theorem ByteArray.size_append {a b : ByteArray} :
(a ++ b).size = a.size + b.size
@[simp]
theorem ByteArray.getElem_append_left {i : Nat} {a b : ByteArray} {h : i < (a ++ b).size} (hlt : i < a.size) :
(a ++ b)[i] = a[i]
theorem ByteArray.getElem_append_right {i : Nat} {a b : ByteArray} {h : i < (a ++ b).size} (hle : a.size i) :
(a ++ b)[i] = b[i - a.size]
@[simp]
@[simp]
theorem ByteArray.size_extract {a : ByteArray} {b e : Nat} :
(a.extract b e).size = min e a.size - b
@[simp]
@[simp]
theorem ByteArray.extract_add_left {b : ByteArray} {i j : Nat} :
b.extract (i + j) i = empty
theorem ByteArray.append_right_inj {ys₁ ys₂ : ByteArray} (xs : ByteArray) :
xs ++ ys₁ = xs ++ ys₂ ys₁ = ys₂
@[simp]
theorem ByteArray.extract_append_extract {a : ByteArray} {i j k : Nat} :
a.extract i j ++ a.extract j k = a.extract (min i j) (max j k)
theorem ByteArray.extract_eq_extract_append_extract {a : ByteArray} {i k : Nat} (j : Nat) (hi : i j) (hk : j k) :
a.extract i k = a.extract i j ++ a.extract j k
theorem ByteArray.append_inj_left {xs₁ xs₂ ys₁ ys₂ : ByteArray} (h : xs₁ ++ ys₁ = xs₂ ++ ys₂) (hl : xs₁.size = xs₂.size) :
xs₁ = xs₂
theorem ByteArray.extract_append_eq_right {a b : ByteArray} {i j : Nat} (hi : i = a.size) (hj : j = a.size + b.size) :
(a ++ b).extract i j = b
theorem ByteArray.extract_append_eq_left {a b : ByteArray} {i : Nat} (hi : i = a.size) :
(a ++ b).extract 0 i = a
theorem ByteArray.extract_append_size_add {a b : ByteArray} {i j : Nat} :
(a ++ b).extract (a.size + i) (a.size + j) = b.extract i j
theorem ByteArray.extract_append {as bs : ByteArray} {i j : Nat} :
(as ++ bs).extract i j = as.extract i j ++ bs.extract (i - as.size) (j - as.size)
theorem ByteArray.extract_append_size_add' {a b : ByteArray} {i j k : Nat} (h : k = a.size) :
(a ++ b).extract (k + i) (k + j) = b.extract i j
theorem ByteArray.extract_extract {a : ByteArray} {i j k l : Nat} :
(a.extract i j).extract k l = a.extract (i + k) (min (i + l) j)
theorem ByteArray.getElem_extract_aux {i : Nat} {xs : ByteArray} {start stop : Nat} (h : i < (xs.extract start stop).size) :
start + i < xs.size
theorem ByteArray.getElem_extract {i : Nat} {b : ByteArray} {start stop : Nat} (h : i < (b.extract start stop).size) :
(b.extract start stop)[i] = b[start + i]
theorem ByteArray.extract_eq_extract_left {a : ByteArray} {i i' j : Nat} :
a.extract i j = a.extract i' j min j a.size - i = min j a.size - i'
theorem ByteArray.extract_add_one {a : ByteArray} {i : Nat} (ha : i + 1 a.size) :
a.extract i (i + 1) = [a[i]].toByteArray
theorem ByteArray.extract_add_two {a : ByteArray} {i : Nat} (ha : i + 2 a.size) :
a.extract i (i + 2) = [a[i], a[i + 1]].toByteArray
theorem ByteArray.extract_add_three {a : ByteArray} {i : Nat} (ha : i + 3 a.size) :
a.extract i (i + 3) = [a[i], a[i + 1], a[i + 2]].toByteArray
theorem ByteArray.extract_add_four {a : ByteArray} {i : Nat} (ha : i + 4 a.size) :
a.extract i (i + 4) = [a[i], a[i + 1], a[i + 2], a[i + 3]].toByteArray
theorem ByteArray.append_assoc {a b c : ByteArray} :
a ++ b ++ c = a ++ (b ++ c)
theorem ByteArray.copySlice_eq_append {src : ByteArray} {srcOff : Nat} {dest : ByteArray} {destOff len : Nat} {exact : Bool} :
src.copySlice srcOff dest destOff len exact = dest.extract 0 destOff ++ src.extract srcOff (srcOff + len) ++ dest.extract (destOff + min len (src.data.size - srcOff)) dest.data.size
@[simp]
theorem ByteArray.data_set {as : ByteArray} {i : Nat} {h : i < as.size} {a : UInt8} :
(as.set i a h).data = as.data.set i a
theorem ByteArray.set_eq_push_extract_append_extract {as : ByteArray} {i : Nat} (h : i < as.size) {a : UInt8} :
as.set i a h = (as.extract 0 i).push a ++ as.extract (i + 1) as.size