Function binary_predicate

arrow-string/src/like.rs:413–432

(
    l: impl Iterator<Item = Option<&'a str>>,
    r: impl Iterator<Item = Option<&'a str>>,
    neg: bool,
    f: impl Fn(&'a str) -> Result<Predicate<'a>, ArrowError>,
)

}

fn binary_predicate<'a>(
    l: impl Iterator<Item = Option<&'a str>>,
    r: impl Iterator<Item = Option<&'a str>>,
    neg: bool,
    f: impl Fn(&'a str) -> Result<Predicate<'a>, ArrowError>,
) -> Result<BooleanArray, ArrowError> {
    let mut previous = None;
    l.zip(r)
        .map(|(l, r)| match (l, r) {
            (Some(l), Some(r)) => {
                let p: &Predicate = match previous {
                    Some((expr, ref predicate)) if expr == r => predicate,
                    _ => &previous.insert((r, f(r)?)).1,
                };
                Ok(Some(p.evaluate(l) != neg))
            }
            _ => Ok(None),
        })
        .collect()
}

#[cfg(test)]
mod tests {