F12: add price transforms and rolling linear regression

- Rust core: typical_price.rs ((H+L+C)/3), median_price.rs ((H+L)/2),
  weighted_close.rs ((H+L+2C)/4) — stateless per-bar OHLC transforms — and
  linreg.rs (LinearRegression — endpoint of a rolling ordinary-least-squares
  fit) and linreg_slope.rs (LinRegSlope — slope of that fit). Each with a
  full Indicator impl, runnable doctest and reference / property / warmup /
  reset / batch==streaming tests.
- Python: PyTypicalPrice / PyMedianPrice / PyWeightedClose /
  PyLinearRegression / PyLinRegSlope PyO3 classes + module registration +
  .pyi stubs.
- Node: explicit TypicalPriceNode / MedianPriceNode / WeightedCloseNode /
  LinearRegressionNode / LinRegSlopeNode; index.d.ts and index.js updated.
- WASM: explicit WasmTypicalPrice / WasmMedianPrice / WasmWeightedClose;
  WasmLinearRegression / WasmLinRegSlope via the scalar macro.
- Wiki: a new indicators/statistics/ folder with five Indicator-*.md pages,
  a new "Statistics" family in Indicators-Overview.md and Home.md.

cargo fmt + clippy (core/wickra/data/wasm/node) clean; 454 core tests,
25 data tests and 66 doctests green.
This commit is contained in:
kingchenc
2026-05-22 19:52:04 +02:00
parent 21bbd521b3
commit 2d0ee926c5
19 changed files with 2254 additions and 12 deletions
+198
View File
@@ -0,0 +1,198 @@
//! Linear Regression (rolling least-squares endpoint).
use std::collections::VecDeque;
use crate::error::{Error, Result};
use crate::traits::Indicator;
/// Linear Regression — the endpoint of a rolling least-squares fit.
///
/// Over the last `period` inputs, indexed `x = 0, 1, …, period 1`, it fits
/// the line `y = a + b·x` by ordinary least squares and reports the line's
/// value at the most recent point:
///
/// ```text
/// b (slope) = (n·Σxy Σx·Σy) / (n·Σxx (Σx)²)
/// a (intercept) = (Σy b·Σx) / n
/// LinearReg = a + b·(period 1)
/// ```
///
/// This is TA-Lib's `LINEARREG`: a smoothed price that lags less than an SMA
/// because it extrapolates the *local trend* forward to the current bar
/// instead of averaging it away. The `Σx` terms depend only on `period`, so
/// they are computed once; each `update` is O(period).
///
/// # Example
///
/// ```
/// use wickra_core::{Indicator, LinearRegression};
///
/// let mut indicator = LinearRegression::new(14).unwrap();
/// let mut last = None;
/// for i in 0..80 {
/// last = indicator.update(f64::from(i));
/// }
/// assert!(last.is_some());
/// ```
#[derive(Debug, Clone)]
pub struct LinearRegression {
period: usize,
window: VecDeque<f64>,
sum_x: f64,
denom: f64,
}
impl LinearRegression {
/// Construct a new rolling linear regression over `period` inputs.
///
/// # Errors
/// Returns [`Error::InvalidPeriod`] if `period < 2` — a regression line is
/// undefined for fewer than two points.
pub fn new(period: usize) -> Result<Self> {
if period < 2 {
return Err(Error::InvalidPeriod {
message: "linear regression needs period >= 2",
});
}
let n = period as f64;
// Closed forms for x = 0, 1, …, period 1.
let sum_x = n * (n - 1.0) / 2.0;
let sum_xx = (n - 1.0) * n * (2.0 * n - 1.0) / 6.0;
Ok(Self {
period,
window: VecDeque::with_capacity(period),
sum_x,
denom: n * sum_xx - sum_x * sum_x,
})
}
/// Configured period.
pub const fn period(&self) -> usize {
self.period
}
/// Ordinary-least-squares `(slope, endpoint)` over the current full window.
fn fit(&self) -> (f64, f64) {
let n = self.period as f64;
let mut sum_y = 0.0;
let mut sum_xy = 0.0;
for (x, &y) in self.window.iter().enumerate() {
sum_y += y;
sum_xy += x as f64 * y;
}
let slope = (n * sum_xy - self.sum_x * sum_y) / self.denom;
let intercept = (sum_y - slope * self.sum_x) / n;
(slope, intercept + slope * (n - 1.0))
}
}
impl Indicator for LinearRegression {
type Input = f64;
type Output = f64;
fn update(&mut self, value: f64) -> Option<f64> {
if self.window.len() == self.period {
self.window.pop_front();
}
self.window.push_back(value);
if self.window.len() < self.period {
return None;
}
Some(self.fit().1)
}
fn reset(&mut self) {
self.window.clear();
}
fn warmup_period(&self) -> usize {
self.period
}
fn is_ready(&self) -> bool {
self.window.len() == self.period
}
fn name(&self) -> &'static str {
"LinearRegression"
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::traits::BatchExt;
use approx::assert_relative_eq;
#[test]
fn reference_values() {
// period 3 over [1, 2, 9]: fit y = 0 + 4x, endpoint = 0 + 4·2 = 8.
let mut lr = LinearRegression::new(3).unwrap();
let out = lr.batch(&[1.0, 2.0, 9.0]);
assert!(out[0].is_none());
assert!(out[1].is_none());
assert_relative_eq!(out[2].unwrap(), 8.0, epsilon = 1e-9);
}
#[test]
fn perfect_line_returns_current_value() {
// The regression of a perfectly linear series is that line itself, so
// its endpoint equals the current value.
let prices: Vec<f64> = (0..40).map(|i| 2.0 * f64::from(i) + 5.0).collect();
let mut lr = LinearRegression::new(10).unwrap();
for (i, v) in lr.batch(&prices).into_iter().enumerate() {
if let Some(v) = v {
assert_relative_eq!(v, 2.0 * i as f64 + 5.0, epsilon = 1e-6);
}
}
}
#[test]
fn constant_series_returns_the_constant() {
let mut lr = LinearRegression::new(8).unwrap();
for v in lr.batch(&[42.0; 20]).into_iter().flatten() {
assert_relative_eq!(v, 42.0, epsilon = 1e-9);
}
}
#[test]
fn first_value_on_period_th_input() {
let mut lr = LinearRegression::new(5).unwrap();
let out = lr.batch(&[1.0, 3.0, 2.0, 5.0, 4.0, 6.0]);
for (i, v) in out.iter().enumerate().take(4) {
assert!(v.is_none(), "index {i} must be None during warmup");
}
assert!(out[4].is_some(), "first value lands at index period - 1");
assert_eq!(lr.warmup_period(), 5);
}
#[test]
fn rejects_period_below_two() {
assert!(LinearRegression::new(0).is_err());
assert!(LinearRegression::new(1).is_err());
assert!(LinearRegression::new(2).is_ok());
}
#[test]
fn reset_clears_state() {
let mut lr = LinearRegression::new(5).unwrap();
lr.batch(&[1.0, 2.0, 3.0, 4.0, 5.0]);
assert!(lr.is_ready());
lr.reset();
assert!(!lr.is_ready());
assert_eq!(lr.update(1.0), None);
}
#[test]
fn batch_equals_streaming() {
let prices: Vec<f64> = (0..60)
.map(|i| 50.0 + (f64::from(i) * 0.3).sin() * 10.0)
.collect();
let mut a = LinearRegression::new(14).unwrap();
let mut b = LinearRegression::new(14).unwrap();
assert_eq!(
a.batch(&prices),
prices.iter().map(|x| b.update(*x)).collect::<Vec<_>>()
);
}
}
@@ -0,0 +1,195 @@
//! Linear Regression Slope.
use std::collections::VecDeque;
use crate::error::{Error, Result};
use crate::traits::Indicator;
/// Linear Regression Slope — the slope of a rolling least-squares fit.
///
/// Over the last `period` inputs, indexed `x = 0, 1, …, period 1`, it fits
/// the line `y = a + b·x` by ordinary least squares and reports the slope:
///
/// ```text
/// b = (n·Σxy Σx·Σy) / (n·Σxx (Σx)²)
/// ```
///
/// This is TA-Lib's `LINEARREG_SLOPE`: a momentum-like reading of how steeply
/// price is trending over the window — positive while it rises, negative
/// while it falls, near zero when it is flat — without the band-pass quirks
/// of a difference-based oscillator. The `Σx` terms depend only on `period`,
/// so they are computed once; each `update` is O(period).
///
/// # Example
///
/// ```
/// use wickra_core::{Indicator, LinRegSlope};
///
/// let mut indicator = LinRegSlope::new(14).unwrap();
/// let mut last = None;
/// for i in 0..80 {
/// last = indicator.update(f64::from(i));
/// }
/// assert!(last.is_some());
/// ```
#[derive(Debug, Clone)]
pub struct LinRegSlope {
period: usize,
window: VecDeque<f64>,
sum_x: f64,
denom: f64,
}
impl LinRegSlope {
/// Construct a new rolling linear-regression slope over `period` inputs.
///
/// # Errors
/// Returns [`Error::InvalidPeriod`] if `period < 2` — a regression line is
/// undefined for fewer than two points.
pub fn new(period: usize) -> Result<Self> {
if period < 2 {
return Err(Error::InvalidPeriod {
message: "linear regression slope needs period >= 2",
});
}
let n = period as f64;
// Closed forms for x = 0, 1, …, period 1.
let sum_x = n * (n - 1.0) / 2.0;
let sum_xx = (n - 1.0) * n * (2.0 * n - 1.0) / 6.0;
Ok(Self {
period,
window: VecDeque::with_capacity(period),
sum_x,
denom: n * sum_xx - sum_x * sum_x,
})
}
/// Configured period.
pub const fn period(&self) -> usize {
self.period
}
}
impl Indicator for LinRegSlope {
type Input = f64;
type Output = f64;
fn update(&mut self, value: f64) -> Option<f64> {
if self.window.len() == self.period {
self.window.pop_front();
}
self.window.push_back(value);
if self.window.len() < self.period {
return None;
}
let n = self.period as f64;
let mut sum_y = 0.0;
let mut sum_xy = 0.0;
for (x, &y) in self.window.iter().enumerate() {
sum_y += y;
sum_xy += x as f64 * y;
}
Some((n * sum_xy - self.sum_x * sum_y) / self.denom)
}
fn reset(&mut self) {
self.window.clear();
}
fn warmup_period(&self) -> usize {
self.period
}
fn is_ready(&self) -> bool {
self.window.len() == self.period
}
fn name(&self) -> &'static str {
"LinRegSlope"
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::traits::BatchExt;
use approx::assert_relative_eq;
#[test]
fn reference_values() {
// period 3 over [1, 2, 9]: fit y = 0 + 4x, so the slope is 4.
let mut ls = LinRegSlope::new(3).unwrap();
let out = ls.batch(&[1.0, 2.0, 9.0]);
assert!(out[0].is_none());
assert!(out[1].is_none());
assert_relative_eq!(out[2].unwrap(), 4.0, epsilon = 1e-9);
}
#[test]
fn perfect_line_returns_its_step() {
// A series rising by a fixed step has exactly that slope.
let prices: Vec<f64> = (0..40).map(|i| 2.5 * f64::from(i) + 7.0).collect();
let mut ls = LinRegSlope::new(10).unwrap();
for v in ls.batch(&prices).into_iter().flatten() {
assert_relative_eq!(v, 2.5, epsilon = 1e-6);
}
}
#[test]
fn constant_series_has_zero_slope() {
let mut ls = LinRegSlope::new(8).unwrap();
for v in ls.batch(&[42.0; 20]).into_iter().flatten() {
assert_relative_eq!(v, 0.0, epsilon = 1e-9);
}
}
#[test]
fn falling_series_has_negative_slope() {
let prices: Vec<f64> = (0..30).map(|i| 100.0 - f64::from(i)).collect();
let mut ls = LinRegSlope::new(10).unwrap();
for v in ls.batch(&prices).into_iter().flatten() {
assert!(v < 0.0, "a falling series must have a negative slope");
}
}
#[test]
fn first_value_on_period_th_input() {
let mut ls = LinRegSlope::new(5).unwrap();
let out = ls.batch(&[1.0, 3.0, 2.0, 5.0, 4.0, 6.0]);
for (i, v) in out.iter().enumerate().take(4) {
assert!(v.is_none(), "index {i} must be None during warmup");
}
assert!(out[4].is_some(), "first value lands at index period - 1");
assert_eq!(ls.warmup_period(), 5);
}
#[test]
fn rejects_period_below_two() {
assert!(LinRegSlope::new(0).is_err());
assert!(LinRegSlope::new(1).is_err());
assert!(LinRegSlope::new(2).is_ok());
}
#[test]
fn reset_clears_state() {
let mut ls = LinRegSlope::new(5).unwrap();
ls.batch(&[1.0, 2.0, 3.0, 4.0, 5.0]);
assert!(ls.is_ready());
ls.reset();
assert!(!ls.is_ready());
assert_eq!(ls.update(1.0), None);
}
#[test]
fn batch_equals_streaming() {
let prices: Vec<f64> = (0..60)
.map(|i| 50.0 + (f64::from(i) * 0.3).sin() * 10.0)
.collect();
let mut a = LinRegSlope::new(14).unwrap();
let mut b = LinRegSlope::new(14).unwrap();
assert_eq!(
a.batch(&prices),
prices.iter().map(|x| b.update(*x)).collect::<Vec<_>>()
);
}
}
@@ -0,0 +1,121 @@
//! Median Price.
use crate::ohlcv::Candle;
use crate::traits::Indicator;
/// Median Price — the bar's `(high + low) / 2`.
///
/// The midpoint of the bar's range, ignoring where it opened or closed. It is
/// the price series Bill Williams' [`AwesomeOscillator`](crate::AwesomeOscillator)
/// is built on, and a smoother stand-in for the close when feeding other
/// indicators. As a stateless per-bar transform it emits a value from the
/// very first candle.
///
/// # Example
///
/// ```
/// use wickra_core::{Candle, Indicator, MedianPrice};
///
/// let mut indicator = MedianPrice::new();
/// let mut last = None;
/// for i in 0..80 {
/// let base = 100.0 + f64::from(i);
/// let candle =
/// Candle::new(base, base + 2.0, base - 2.0, base + 1.0, 10.0, i64::from(i)).unwrap();
/// last = indicator.update(candle);
/// }
/// assert!(last.is_some());
/// ```
#[derive(Debug, Clone, Default)]
pub struct MedianPrice {
has_emitted: bool,
}
impl MedianPrice {
/// Construct a new Median Price transform.
pub const fn new() -> Self {
Self { has_emitted: false }
}
}
impl Indicator for MedianPrice {
type Input = Candle;
type Output = f64;
fn update(&mut self, candle: Candle) -> Option<f64> {
self.has_emitted = true;
Some(candle.median_price())
}
fn reset(&mut self) {
self.has_emitted = false;
}
fn warmup_period(&self) -> usize {
1
}
fn is_ready(&self) -> bool {
self.has_emitted
}
fn name(&self) -> &'static str {
"MedianPrice"
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::traits::BatchExt;
use approx::assert_relative_eq;
fn candle(open: f64, high: f64, low: f64, close: f64, ts: i64) -> Candle {
Candle::new(open, high, low, close, 1.0, ts).unwrap()
}
#[test]
fn reference_value() {
// (high + low) / 2 = (12 + 8) / 2 = 10.
let mut mp = MedianPrice::new();
assert_relative_eq!(
mp.update(candle(10.0, 12.0, 8.0, 11.0, 0)).unwrap(),
10.0,
epsilon = 1e-12
);
}
#[test]
fn emits_from_first_candle() {
let mut mp = MedianPrice::new();
assert_eq!(mp.warmup_period(), 1);
assert!(!mp.is_ready());
assert!(mp.update(candle(10.0, 11.0, 9.0, 10.0, 0)).is_some());
assert!(mp.is_ready());
}
#[test]
fn reset_clears_state() {
let mut mp = MedianPrice::new();
mp.update(candle(10.0, 11.0, 9.0, 10.0, 0));
assert!(mp.is_ready());
mp.reset();
assert!(!mp.is_ready());
}
#[test]
fn batch_equals_streaming() {
let candles: Vec<Candle> = (0..40)
.map(|i| {
let base = 100.0 + i as f64;
candle(base, base + 2.0, base - 2.0, base + 1.0, i)
})
.collect();
let mut a = MedianPrice::new();
let mut b = MedianPrice::new();
assert_eq!(
a.batch(&candles),
candles.iter().map(|x| b.update(*x)).collect::<Vec<_>>()
);
}
}
+10
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@@ -30,8 +30,11 @@ mod historical_volatility;
mod hma;
mod kama;
mod keltner;
mod linreg;
mod linreg_slope;
mod macd;
mod mass_index;
mod median_price;
mod mfi;
mod mom;
mod natr;
@@ -53,12 +56,14 @@ mod tema;
mod trima;
mod trix;
mod tsi;
mod typical_price;
mod ulcer_index;
mod ultimate_oscillator;
mod vortex;
mod vpt;
mod vwap;
mod vwma;
mod weighted_close;
mod williams_r;
mod wma;
mod zlema;
@@ -89,8 +94,11 @@ pub use historical_volatility::HistoricalVolatility;
pub use hma::Hma;
pub use kama::Kama;
pub use keltner::{Keltner, KeltnerOutput};
pub use linreg::LinearRegression;
pub use linreg_slope::LinRegSlope;
pub use macd::{MacdIndicator, MacdOutput};
pub use mass_index::MassIndex;
pub use median_price::MedianPrice;
pub use mfi::Mfi;
pub use mom::Mom;
pub use natr::Natr;
@@ -112,12 +120,14 @@ pub use tema::Tema;
pub use trima::Trima;
pub use trix::Trix;
pub use tsi::Tsi;
pub use typical_price::TypicalPrice;
pub use ulcer_index::UlcerIndex;
pub use ultimate_oscillator::UltimateOscillator;
pub use vortex::{Vortex, VortexOutput};
pub use vpt::VolumePriceTrend;
pub use vwap::{RollingVwap, Vwap};
pub use vwma::Vwma;
pub use weighted_close::WeightedClose;
pub use williams_r::WilliamsR;
pub use wma::Wma;
pub use zlema::Zlema;
@@ -0,0 +1,121 @@
//! Typical Price.
use crate::ohlcv::Candle;
use crate::traits::Indicator;
/// Typical Price — the bar's `(high + low + close) / 3`.
///
/// A single representative price per bar that weights the close no more
/// heavily than the two extremes. It is the price series that
/// [`Cci`](crate::Cci) and [`Mfi`](crate::Mfi) are built on, and a common
/// input to feed other indicators in place of the raw close. As a stateless
/// per-bar transform it emits a value from the very first candle.
///
/// # Example
///
/// ```
/// use wickra_core::{Candle, Indicator, TypicalPrice};
///
/// let mut indicator = TypicalPrice::new();
/// let mut last = None;
/// for i in 0..80 {
/// let base = 100.0 + f64::from(i);
/// let candle =
/// Candle::new(base, base + 2.0, base - 2.0, base + 1.0, 10.0, i64::from(i)).unwrap();
/// last = indicator.update(candle);
/// }
/// assert!(last.is_some());
/// ```
#[derive(Debug, Clone, Default)]
pub struct TypicalPrice {
has_emitted: bool,
}
impl TypicalPrice {
/// Construct a new Typical Price transform.
pub const fn new() -> Self {
Self { has_emitted: false }
}
}
impl Indicator for TypicalPrice {
type Input = Candle;
type Output = f64;
fn update(&mut self, candle: Candle) -> Option<f64> {
self.has_emitted = true;
Some(candle.typical_price())
}
fn reset(&mut self) {
self.has_emitted = false;
}
fn warmup_period(&self) -> usize {
1
}
fn is_ready(&self) -> bool {
self.has_emitted
}
fn name(&self) -> &'static str {
"TypicalPrice"
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::traits::BatchExt;
use approx::assert_relative_eq;
fn candle(open: f64, high: f64, low: f64, close: f64, ts: i64) -> Candle {
Candle::new(open, high, low, close, 1.0, ts).unwrap()
}
#[test]
fn reference_value() {
// (high + low + close) / 3 = (12 + 6 + 9) / 3 = 9.
let mut tp = TypicalPrice::new();
assert_relative_eq!(
tp.update(candle(9.0, 12.0, 6.0, 9.0, 0)).unwrap(),
9.0,
epsilon = 1e-12
);
}
#[test]
fn emits_from_first_candle() {
let mut tp = TypicalPrice::new();
assert_eq!(tp.warmup_period(), 1);
assert!(!tp.is_ready());
assert!(tp.update(candle(10.0, 11.0, 9.0, 10.0, 0)).is_some());
assert!(tp.is_ready());
}
#[test]
fn reset_clears_state() {
let mut tp = TypicalPrice::new();
tp.update(candle(10.0, 11.0, 9.0, 10.0, 0));
assert!(tp.is_ready());
tp.reset();
assert!(!tp.is_ready());
}
#[test]
fn batch_equals_streaming() {
let candles: Vec<Candle> = (0..40)
.map(|i| {
let base = 100.0 + i as f64;
candle(base, base + 2.0, base - 2.0, base + 1.0, i)
})
.collect();
let mut a = TypicalPrice::new();
let mut b = TypicalPrice::new();
assert_eq!(
a.batch(&candles),
candles.iter().map(|x| b.update(*x)).collect::<Vec<_>>()
);
}
}
@@ -0,0 +1,120 @@
//! Weighted Close.
use crate::ohlcv::Candle;
use crate::traits::Indicator;
/// Weighted Close — the bar's `(high + low + 2·close) / 4`.
///
/// A representative per-bar price that, unlike the [`TypicalPrice`](crate::TypicalPrice),
/// gives the close double weight — useful when the closing print matters more
/// than the extremes for your strategy. As a stateless per-bar transform it
/// emits a value from the very first candle.
///
/// # Example
///
/// ```
/// use wickra_core::{Candle, Indicator, WeightedClose};
///
/// let mut indicator = WeightedClose::new();
/// let mut last = None;
/// for i in 0..80 {
/// let base = 100.0 + f64::from(i);
/// let candle =
/// Candle::new(base, base + 2.0, base - 2.0, base + 1.0, 10.0, i64::from(i)).unwrap();
/// last = indicator.update(candle);
/// }
/// assert!(last.is_some());
/// ```
#[derive(Debug, Clone, Default)]
pub struct WeightedClose {
has_emitted: bool,
}
impl WeightedClose {
/// Construct a new Weighted Close transform.
pub const fn new() -> Self {
Self { has_emitted: false }
}
}
impl Indicator for WeightedClose {
type Input = Candle;
type Output = f64;
fn update(&mut self, candle: Candle) -> Option<f64> {
self.has_emitted = true;
Some(candle.weighted_close())
}
fn reset(&mut self) {
self.has_emitted = false;
}
fn warmup_period(&self) -> usize {
1
}
fn is_ready(&self) -> bool {
self.has_emitted
}
fn name(&self) -> &'static str {
"WeightedClose"
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::traits::BatchExt;
use approx::assert_relative_eq;
fn candle(open: f64, high: f64, low: f64, close: f64, ts: i64) -> Candle {
Candle::new(open, high, low, close, 1.0, ts).unwrap()
}
#[test]
fn reference_value() {
// (high + low + 2·close) / 4 = (12 + 8 + 2·11) / 4 = 42 / 4 = 10.5.
let mut wc = WeightedClose::new();
assert_relative_eq!(
wc.update(candle(10.0, 12.0, 8.0, 11.0, 0)).unwrap(),
10.5,
epsilon = 1e-12
);
}
#[test]
fn emits_from_first_candle() {
let mut wc = WeightedClose::new();
assert_eq!(wc.warmup_period(), 1);
assert!(!wc.is_ready());
assert!(wc.update(candle(10.0, 11.0, 9.0, 10.0, 0)).is_some());
assert!(wc.is_ready());
}
#[test]
fn reset_clears_state() {
let mut wc = WeightedClose::new();
wc.update(candle(10.0, 11.0, 9.0, 10.0, 0));
assert!(wc.is_ready());
wc.reset();
assert!(!wc.is_ready());
}
#[test]
fn batch_equals_streaming() {
let candles: Vec<Candle> = (0..40)
.map(|i| {
let base = 100.0 + i as f64;
candle(base, base + 2.0, base - 2.0, base + 1.0, i)
})
.collect();
let mut a = WeightedClose::new();
let mut b = WeightedClose::new();
assert_eq!(
a.batch(&candles),
candles.iter().map(|x| b.update(*x)).collect::<Vec<_>>()
);
}
}