bendns' repos / aoc
heh
Diffstat (limited to 'src/util.rs')
-rw-r--r--src/util.rs146
1 files changed, 143 insertions, 3 deletions
diff --git a/src/util.rs b/src/util.rs
index b633247..a7e5dc8 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -3,8 +3,8 @@ use std::{mem::swap, str::FromStr};
pub mod prelude {
pub use super::{
- gcd, lcm, GreekTools, IterͶ, NumTupleIterTools, TupleIterTools, TupleUtils,
- UnifiedTupleUtils, Ͷ, Α, Κ, Λ, Μ,
+ gcd, lcm, GreekTools, IntoLines, IterͶ, NumTupleIterTools, Skip, TakeLine, TupleIterTools,
+ TupleUtils, UnifiedTupleUtils, Ͷ, Α, Κ, Λ, Μ,
};
pub use itertools::izip;
pub use itertools::Itertools;
@@ -17,7 +17,7 @@ pub mod prelude {
ops::Range,
};
#[allow(unused_imports)]
- pub(crate) use {super::bits, super::dang};
+ pub(crate) use {super::bits, super::dang, super::leek};
}
macro_rules! dang {
@@ -27,6 +27,13 @@ macro_rules! dang {
}
pub(crate) use dang;
+macro_rules! leek {
+ ($($allocation:ident)+) => {
+ $(std::mem::forget($allocation);)+
+ };
+}
+pub(crate) use leek;
+
pub fn lcm(n: impl IntoIterator<Item = u64>) -> u64 {
let mut x = n.into_iter();
let mut lcm = x.by_ref().next().expect("cannot compute LCM of 0 numbers");
@@ -86,6 +93,15 @@ pub trait Κ {
<T as FromStr>::Err: std::fmt::Display;
}
+impl Κ for &[u8] {
+ fn κ<T: FromStr>(self) -> impl Iterator<Item = T>
+ where
+ <T as FromStr>::Err: std::fmt::Display,
+ {
+ std::str::from_utf8(self).unwrap().κ()
+ }
+}
+
impl Κ for &str {
fn κ<T: FromStr>(self) -> impl Iterator<Item = T>
where
@@ -148,6 +164,39 @@ pub trait Μ where
<T as FromStr>::Err: std::fmt::Display;
}
+impl Μ for &[u8] {
+ fn μ(self, d: char) -> (Self, Self) {
+ self.split_once(|&x| x == d as u8).unwrap_or_else(|| {
+ panic!(
+ "{} should split at {d} fine",
+ std::str::from_utf8(self).expect("utf8")
+ )
+ })
+ }
+
+ fn μκ<T: FromStr>(self, d: char) -> impl Iterator<Item = (T, T)>
+ where
+ <T as FromStr>::Err: std::fmt::Display,
+ {
+ let (α, β) = self.μ(d);
+ α.κ::<T>().zip(β.κ::<T>())
+ }
+
+ fn μ1<T: FromStr>(self, d: char) -> impl Iterator<Item = T>
+ where
+ <T as FromStr>::Err: std::fmt::Display,
+ {
+ self.μ(d).1.κ()
+ }
+
+ fn μ0<T: FromStr>(self, d: char) -> impl Iterator<Item = T>
+ where
+ <T as FromStr>::Err: std::fmt::Display,
+ {
+ self.μ(d).0.κ()
+ }
+}
+
impl Μ for &str {
fn μ(self, d: char) -> (Self, Self) {
self.split_once(d)
@@ -302,3 +351,94 @@ fn do_bits() {
bits!(bitset[4] = true);
assert!(bits!(bitset[4]));
}
+
+pub struct Lines<'a> {
+ bytes: &'a [u8],
+}
+
+impl<'a> Iterator for Lines<'a> {
+ type Item = &'a [u8];
+
+ fn next(&mut self) -> Option<Self::Item> {
+ self.bytes.take_line()
+ }
+}
+
+impl<'a> std::iter::FusedIterator for Lines<'a> {}
+
+pub trait IntoLines {
+ fn 行(&self) -> Lines<'_>;
+}
+
+impl<T: AsRef<[u8]>> IntoLines for T {
+ fn 行(&self) -> Lines<'_> {
+ Lines {
+ bytes: self.as_ref(),
+ }
+ }
+}
+
+pub trait TakeLine<'b> {
+ fn take_line<'a>(&'a mut self) -> Option<&'b [u8]>;
+}
+
+impl<'b> TakeLine<'b> for &'b [u8] {
+ fn take_line<'a>(&'a mut self) -> Option<&'b [u8]> {
+ match memchr::memchr(b'\n', self) {
+ None if self.is_empty() => None,
+ None => {
+ let line = *self;
+ *self = b"";
+ Some(line)
+ }
+ Some(end) => {
+ let line = &self[..end];
+ *self = &self[end + 1..];
+ Some(line)
+ }
+ }
+ }
+}
+
+impl<'b> TakeLine<'b> for &'b str {
+ fn take_line<'a>(&'a mut self) -> Option<&'b [u8]> {
+ match memchr::memchr(b'\n', self.as_bytes()) {
+ None if self.is_empty() => None,
+ None => {
+ let line = self.as_bytes();
+ *self = "";
+ Some(line)
+ }
+ Some(end) => {
+ let line = self[..end].as_bytes();
+ *self = &self[end + 1..];
+ Some(line)
+ }
+ }
+ }
+}
+
+pub trait Skip {
+ fn skip(&mut self, n: usize);
+}
+
+impl Skip for &[u8] {
+ fn skip(&mut self, n: usize) {
+ *self = &self[n..];
+ }
+}
+
+impl Skip for &str {
+ fn skip(&mut self, n: usize) {
+ *self = &self[n..];
+ }
+}
+
+#[test]
+fn liney() {
+ let mut i = b"xyz\nlmaolol\nhuh".行();
+ assert_eq!(i.next(), Some(&b"xyz"[..]));
+ assert_eq!(i.next(), Some(&b"lmaolol"[..]));
+ assert_eq!(i.next(), Some(&b"huh"[..]));
+ assert_eq!(i.next(), None);
+}