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|
//! Missing batteries for standard libraries.
use std::{cmp::Ordering, ops, time::Instant};
mod macros;
pub mod process;
pub mod panic_context;
pub use always_assert::{always, never};
#[inline(always)]
pub fn is_ci() -> bool {
option_env!("CI").is_some()
}
#[must_use]
pub fn timeit(label: &'static str) -> impl Drop {
let start = Instant::now();
defer(move || eprintln!("{}: {:.2?}", label, start.elapsed()))
}
/// Prints backtrace to stderr, useful for debugging.
#[cfg(feature = "backtrace")]
pub fn print_backtrace() {
let bt = backtrace::Backtrace::new();
eprintln!("{:?}", bt);
}
#[cfg(not(feature = "backtrace"))]
pub fn print_backtrace() {
eprintln!(
r#"Enable the backtrace feature.
Uncomment `default = [ "backtrace" ]` in `crates/stdx/Cargo.toml`.
"#
);
}
pub fn to_lower_snake_case(s: &str) -> String {
to_snake_case(s, char::to_ascii_lowercase)
}
pub fn to_upper_snake_case(s: &str) -> String {
to_snake_case(s, char::to_ascii_uppercase)
}
fn to_snake_case<F: Fn(&char) -> char>(s: &str, change_case: F) -> String {
let mut buf = String::with_capacity(s.len());
let mut prev = false;
for c in s.chars() {
// `&& prev` is required to not insert `_` before the first symbol.
if c.is_ascii_uppercase() && prev {
// This check is required to not translate `Weird_Case` into `weird__case`.
if !buf.ends_with('_') {
buf.push('_')
}
}
prev = true;
buf.push(change_case(&c));
}
buf
}
pub fn replace(buf: &mut String, from: char, to: &str) {
if !buf.contains(from) {
return;
}
// FIXME: do this in place.
*buf = buf.replace(from, to)
}
pub fn trim_indent(mut text: &str) -> String {
if text.starts_with('\n') {
text = &text[1..];
}
let indent = text
.lines()
.filter(|it| !it.trim().is_empty())
.map(|it| it.len() - it.trim_start().len())
.min()
.unwrap_or(0);
text.split_inclusive('\n')
.map(
|line| {
if line.len() <= indent {
line.trim_start_matches(' ')
} else {
&line[indent..]
}
},
)
.collect()
}
pub fn equal_range_by<T, F>(slice: &[T], mut key: F) -> ops::Range<usize>
where
F: FnMut(&T) -> Ordering,
{
let start = slice.partition_point(|it| key(it) == Ordering::Less);
let len = slice[start..].partition_point(|it| key(it) == Ordering::Equal);
start..start + len
}
#[must_use]
pub fn defer<F: FnOnce()>(f: F) -> impl Drop {
struct D<F: FnOnce()>(Option<F>);
impl<F: FnOnce()> Drop for D<F> {
fn drop(&mut self) {
if let Some(f) = self.0.take() {
f()
}
}
}
D(Some(f))
}
#[repr(transparent)]
pub struct JodChild(pub std::process::Child);
impl ops::Deref for JodChild {
type Target = std::process::Child;
fn deref(&self) -> &std::process::Child {
&self.0
}
}
impl ops::DerefMut for JodChild {
fn deref_mut(&mut self) -> &mut std::process::Child {
&mut self.0
}
}
impl Drop for JodChild {
fn drop(&mut self) {
let _ = self.0.kill();
let _ = self.0.wait();
}
}
impl JodChild {
pub fn into_inner(self) -> std::process::Child {
// SAFETY: repr transparent
unsafe { std::mem::transmute::<JodChild, std::process::Child>(self) }
}
}
// feature: iter_order_by
// Iterator::eq_by
pub fn iter_eq_by<I, I2, F>(this: I2, other: I, mut eq: F) -> bool
where
I: IntoIterator,
I2: IntoIterator,
F: FnMut(I2::Item, I::Item) -> bool,
{
let mut other = other.into_iter();
let mut this = this.into_iter();
loop {
let x = match this.next() {
None => return other.next().is_none(),
Some(val) => val,
};
let y = match other.next() {
None => return false,
Some(val) => val,
};
if !eq(x, y) {
return false;
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_trim_indent() {
assert_eq!(trim_indent(""), "");
assert_eq!(
trim_indent(
"
hello
world
"
),
"hello\nworld\n"
);
assert_eq!(
trim_indent(
"
hello
world"
),
"hello\nworld"
);
assert_eq!(trim_indent(" hello\n world\n"), "hello\nworld\n");
assert_eq!(
trim_indent(
"
fn main() {
return 92;
}
"
),
"fn main() {\n return 92;\n}\n"
);
}
}
|
