ZIm/zed/src/util.rs
Max Brunsfeld 20542f54ef Start work on connecting to RPC endpoint
Co-Authored-By: Antonio Scandurra <me@as-cii.com>
2021-06-10 22:12:04 -07:00

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3.9 KiB
Rust
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use rand::prelude::*;
use std::cmp::Ordering;
#[derive(Copy, Clone, Eq, PartialEq, Debug, Hash)]
pub enum Bias {
Left,
Right,
}
impl PartialOrd for Bias {
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl Ord for Bias {
fn cmp(&self, other: &Self) -> Ordering {
match (self, other) {
(Self::Left, Self::Left) => Ordering::Equal,
(Self::Left, Self::Right) => Ordering::Less,
(Self::Right, Self::Right) => Ordering::Equal,
(Self::Right, Self::Left) => Ordering::Greater,
}
}
}
pub fn post_inc(value: &mut usize) -> usize {
let prev = *value;
*value += 1;
prev
}
/// Extend a sorted vector with a sorted sequence of items, maintaining the vector's sort order and
/// enforcing a maximum length. Sort the items according to the given callback. Before calling this,
/// both `vec` and `new_items` should already be sorted according to the `cmp` comparator.
pub fn extend_sorted<T, I, F>(vec: &mut Vec<T>, new_items: I, limit: usize, mut cmp: F)
where
I: IntoIterator<Item = T>,
F: FnMut(&T, &T) -> Ordering,
{
let mut start_index = 0;
for new_item in new_items {
if let Err(i) = vec[start_index..].binary_search_by(|m| cmp(m, &new_item)) {
let index = start_index + i;
if vec.len() < limit {
vec.insert(index, new_item);
} else if index < vec.len() {
vec.pop();
vec.insert(index, new_item);
}
start_index = index;
}
}
}
pub struct RandomCharIter<T: Rng>(T);
impl<T: Rng> RandomCharIter<T> {
#[cfg(test)]
pub fn new(rng: T) -> Self {
Self(rng)
}
}
impl<T: Rng> Iterator for RandomCharIter<T> {
type Item = char;
fn next(&mut self) -> Option<Self::Item> {
if self.0.gen_bool(1.0 / 5.0) {
Some('\n')
}
// two-byte greek letters
else if self.0.gen_bool(1.0 / 8.0) {
Some(std::char::from_u32(self.0.gen_range(('α' as u32)..('ω' as u32 + 1))).unwrap())
}
// three-byte characters
else if self.0.gen_bool(1.0 / 10.0) {
['✋', '✅', '❌', '❎', '⭐'].choose(&mut self.0).cloned()
}
// four-byte characters
else if self.0.gen_bool(1.0 / 12.0) {
['🍐', '🏀', '🍗', '🎉'].choose(&mut self.0).cloned()
}
// ascii letters
else {
Some(self.0.gen_range(b'a'..b'z' + 1).into())
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_extend_sorted() {
let mut vec = vec![];
extend_sorted(&mut vec, vec![21, 17, 13, 8, 1, 0], 5, |a, b| b.cmp(a));
assert_eq!(vec, &[21, 17, 13, 8, 1]);
extend_sorted(&mut vec, vec![101, 19, 17, 8, 2], 8, |a, b| b.cmp(a));
assert_eq!(vec, &[101, 21, 19, 17, 13, 8, 2, 1]);
extend_sorted(&mut vec, vec![1000, 19, 17, 9, 5], 8, |a, b| b.cmp(a));
assert_eq!(vec, &[1000, 101, 21, 19, 17, 13, 9, 8]);
}
}
// Allow surf Results to accept context like other Results do when
// using anyhow.
pub trait SurfResultExt {
fn context<C>(self, cx: C) -> Self
where
C: std::fmt::Display + Send + Sync + 'static;
fn with_context<C, F>(self, f: F) -> Self
where
C: std::fmt::Display + Send + Sync + 'static,
F: FnOnce() -> C;
}
impl<T> SurfResultExt for surf::Result<T> {
fn context<C>(self, cx: C) -> Self
where
C: std::fmt::Display + Send + Sync + 'static,
{
self.map_err(|e| surf::Error::new(e.status(), e.into_inner().context(cx)))
}
fn with_context<C, F>(self, f: F) -> Self
where
C: std::fmt::Display + Send + Sync + 'static,
F: FnOnce() -> C,
{
self.map_err(|e| surf::Error::new(e.status(), e.into_inner().context(f())))
}
}