Function parse_duration

cel/src/duration.rs:34–42

Parses a duration string into a [`Duration`]. Duration strings support the following grammar: DurationString -> Sign? Number Unit String? Sign -> '-' Number -> Digit+ ('.' Digit+)? Digit -> '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' Unit -> 'h' | 'm' | 's' | 'ms' | 'us' | 'ns' String -> DurationString # Examples - `1h` parses as 1 hour

(i: &str)

/// - `1ns` parses as 1 nanosecond
/// - `1.5ns` parses as 1 nanosecond (sub-nanosecond durations not supported)
pub fn parse_duration(i: &str) -> IResult<&str, Duration> {
    let (i, neg) = opt(parse_negative)(i)?;
    if i == "0" {
        return Ok((i, Duration::zero()));
    }
    let (i, duration) = many1(parse_number_unit)(i)
        .map(|(i, d)| (i, d.iter().fold(Duration::zero(), |acc, next| acc + *next)))?;
    Ok((i, duration * if neg.is_some() { -1 } else { 1 }))
}

enum Unit {
    Nanosecond,