pub struct Word;
impl Word {
pub fn swar_eq_ci<const N: usize>(haystack: &[u8], expected: &[u8; N]) -> bool {
let Some(h) = haystack.first_chunk::<N>() else {
return false;
};
const M64: u64 = u64::from_le_bytes([0x20; 8]);
const M32: u32 = u32::from_le_bytes([0x20; 4]);
const M16: u16 = u16::from_le_bytes([0x20; 2]);
let mut i = 0usize;
while i + 8 <= N {
let raw = u64::from_le_bytes(h[i..i + 8].try_into().unwrap()) | M64;
let exp = u64::from_le_bytes(expected[i..i + 8].try_into().unwrap());
if raw != exp {
return false;
}
i += 8;
}
if i + 4 <= N {
let raw = u32::from_le_bytes(h[i..i + 4].try_into().unwrap()) | M32;
let exp = u32::from_le_bytes(expected[i..i + 4].try_into().unwrap());
if raw != exp {
return false;
}
i += 4;
}
if i + 2 <= N {
let raw = u16::from_le_bytes(h[i..i + 2].try_into().unwrap()) | M16;
let exp = u16::from_le_bytes(expected[i..i + 2].try_into().unwrap());
if raw != exp {
return false;
}
i += 2;
}
if i < N && h[i] | 0x20 != expected[i] {
return false;
}
true
}
}
pub struct Ascii;
impl Ascii {
#[inline(always)]
pub fn fold_usize(mut acc: usize, chunk: &[u8]) -> Option<usize> {
for &b in chunk {
if !b.is_ascii_digit() {
return None;
}
acc = acc.checked_mul(10)?.checked_add((b - b'0') as usize)?;
}
Some(acc)
}
#[inline(always)]
pub fn fold_u64(mut acc: u64, chunk: &[u8]) -> Option<u64> {
for &b in chunk {
if !b.is_ascii_digit() {
return None;
}
acc = acc.checked_mul(10)?.checked_add((b - b'0') as u64)?;
}
Some(acc)
}
#[inline(always)]
pub fn parse_usize(bytes: &[u8]) -> Option<usize> {
if bytes.is_empty() {
return None;
}
Self::fold_usize(0, bytes)
}
#[inline(always)]
pub fn parse_u64(bytes: &[u8]) -> Option<u64> {
if bytes.is_empty() {
return None;
}
Self::fold_u64(0, bytes)
}
}