neure

A fast little combinational parsing library

Performance

rel is mean release, fat is mean release with lto=fat

See examples

Example

```rust use neure::*;

pub fn main() -> Result<(), Box> { let digit = neure!(['0' - '9']+); // match digit from 0 to 9 more than once let mut storer = SpanStorer::new(1); let mut ctx = CharsCtx::default().with_str("2023rust");

ctx.try_cap(0, &mut storer, digit)?;
assert_eq!(storer.spans(0)?, &vec![Span { beg: 0, len: 4 }]);

Ok(())

} ```

Performance match between crate regex

```rust use ::regex::Regex; use neure::{span::SpanStorer, *};

threadlocal! { static REGEX: Regex = Regex::new(r"^([a-z0-9.+-]+)@([\da-z.-]+).([a-z.]{2,6})$").unwrap(); }

pub fn main() -> Result<(), Box> { let test_cases = [ "plainaddress", "#@%^%#$@#$@#.com", "@example.com", "joe smith email@example.com", "”(),:;<>[ ]@example.com", "much.”more unusual”@example.com", "very.unusual.”@”.unusual.com@example.com", "email@example.com", "firstname.lastname@example.com", "email@subdomain.example.com", ];

let letter = regex!(['a' - 'z']);
let number = regex!(['0' - '9']);
let under_score = regex!('_');
let dot = regex!('.');
let plus = regex!('+');
let minus = regex!('-');
let at = neure!('@');
let prefix = neure!((group!(&letter, &number, &under_score, &dot, &plus, &minus))+);
let start = neure::start();
let domain = neure::count_if::<0, { usize::MAX }, _>(
    group!(&letter, &number, &dot, &minus),
    |ctx: &CharsCtx, char| {
        if char.1 == '.' {
            // don't match dot if we don't have more dot
            if let Ok(str) = ctx.orig_at(ctx.offset() + char.0 + 1) {
                return str.find('.').is_some();
            }
        }
        true
    },
);
let postfix = neure!((group!(&letter, &dot)){2,6});
let dot = neure!('.');
let end = neure::end();
let mut storer = SpanStorer::new(3);
let parser = |storer: &mut SpanStorer, str| -> Result<(), neure::err::Error> {
    let mut ctx = CharsCtx::new(str);

    ctx.try_mat(&start)?;
    ctx.try_cap(0, storer, &prefix)?;
    ctx.try_mat(&at)?;
    ctx.try_cap(1, storer, &domain)?;
    ctx.try_mat(&dot)?;
    ctx.try_cap(2, storer, &postfix)?;
    ctx.try_mat(&end)?;
    Ok(())
};

measure(1000, 1000, || {
    let mut count = 0;
    test_cases.iter().for_each(|test| {
        parser(&mut storer, test).is_ok().then(|| count += 1);
    });
    count
});
let mut locs = REGEX.try_with(|re| re.capture_locations()).unwrap();

measure(1000, 1000, || {
    let mut count = 0;
    test_cases.iter().for_each(|test| {
        REGEX
            .try_with(|regex| {
                regex
                    .captures_read(&mut locs, test)
                    .is_some()
                    .then(|| count += 1);
            })
            .unwrap();
    });
    count
});
Ok(())

}

pub fn measure(n: usize, size: usize, mut f: impl FnMut() -> i32) { use std::time::Instant;

let start = Instant::now();
let mut sum = 0;
for _ in 0..n {
    sum += f();
}
let time = start.elapsed();
println!(
    "Size = {size}, Cost time {} with test {} times: {} --> {}",
    time.as_secs_f64(),
    n,
    time.as_secs_f64() / n as f64,
    sum,
);

} ```

LICENSE

MPL-2.0