Crate cew 

A personal utility crate.

Adds reexports of snafu, new piping traits (Pipe, Inspect, Lay), and reexports tracing + tracing_subscriber (as tracing_utils::subscriber) with a prelude and quick init function.

Snafu’s Whatever type is reexported as R = Result<T, Whatever>, and the R<()> is reexported as U. Use cew::e!() to call snafu::whatever!() and cew::me!() to call Err(snafu::whatever!()).

The Pipe, Inspect, and Lay traits provide functions to reduce the amount of stacked parenthesis in long method chains, like the tap crate.

The tracing_subscriber quick init should be overriden with a custom impl if needed, but it gets you started quickly.

Usage:

use cew::prelude::*;

fn main() -> cew::U {
    cew::tracing::init_filtered_w_env(
      cew::tracing::fmt_layer().without_time(),
      // What should the default level be if the environment variable is not set?
      "info,verbose_crate=warn"
    ).whatever_context("Failed to initialise tracing")?;

    info!("Traced").

    cew::me!("Error")
}

Re-exports

pub use snafu;

Modules

prelude

tracing

Macros

e

Instantiate and return a stringly-typed error message.

me

Structs

Whatever

A basic error type that you can use as a first step to better error handling.

Traits

Inspect

Run a function on a shared reference to self, but return self. Use the fallible/nullable functions [inspect_try] and [inspect_maybe] if you want to propagate errors.

Lay

Run a function that mutates self, returning self. Use the fallible/nullable functions [lay_try] and [lay_maybe] if you want to propagate errors.

OptionExt

Additions to Option.

Pipe

Apply a transformation to self, returning the result.

ResultExt

Additions to Result.

Type Aliases

R

U

Derive Macros

Snafu

The Snafu macro is the entrypoint to defining your own error types. It is designed to require little configuration for the recommended and typical usecases while still offering flexibility for unique situations.