Trait TryMapFn 

pub trait TryMapFn<In, Out, Err>: FnMut(In) -> Result<Out, Err> { }

Fallible variant of MapFn, with the error type as a third parameter.

use spate_core::deser::RecFamily;
use spate_core::ops::TryMapFn;
use std::num::ParseIntError;

struct LogEvent<'buf> {
    line: &'buf str,
}
struct LogF;
impl RecFamily for LogF {
    type Rec<'buf> = LogEvent<'buf>;
}

fn numeric_only<'a>(ev: LogEvent<'a>) -> Result<LogEvent<'a>, ParseIntError> {
    ev.line.parse::<u32>()?;
    Ok(ev)
}

fn try_stage<F, G, E>(g: G) -> G
where
    F: RecFamily,
    G: for<'buf> TryMapFn<F::Rec<'buf>, F::Rec<'buf>, E>,
    E: std::fmt::Display,
{
    g
}

let _ = try_stage::<LogF, _, ParseIntError>(numeric_only);

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<G, In, Out, Err> TryMapFn<In, Out, Err> for G

where G: FnMut(In) -> Result<Out, Err>,