Function prometheus_http_query::functions::delta

pub fn delta(vector: RangeVector) -> InstantVector

Apply the PromQL delta function.

use prometheus_http_query::{Selector, RangeVector};
use prometheus_http_query::functions::delta;
use std::convert::TryInto;

fn main() -> Result<(), prometheus_http_query::Error> {
    let vector: RangeVector = Selector::new()
        .metric("some_metric")?
        .with("some_label", "some_value")
        .range("5m")?
        .try_into()?;

    let result = delta(vector);

    assert_eq!(&result.to_string(), "delta(some_metric{some_label=\"some_value\"}[5m])");

    Ok(())
}