#boolean #traits #create #left #right #extension #maybe

eitherable

Extension trait to create the either type from booleans. (and maybe other types)

1 unstable release

0.1.0 Sep 30, 2023

#13 in #maybe

MIT/Apache

5KB

eitherable

Info

This crate extends bool with a simple way to create the Either type, from the either crate.

It is a simple convenience trait and method, and also a way for me to learn about how crates.io and cargo work.

Why is this not in the either crate

The either crate emphasies that the two sides of Either, Left nd Right, have no element of truthiness or falsiness. However, the trait here immediately assigns Left to be the truthy value. So this is not quite suitable for the either crate.

The reason I chose Left to be the truthy value is simple: it retains the dame order as the if statement. The two following statements are equivalent.

let fst_example = if my_cond { Either::Left(left) } else { Either::Right(right) };
let snd_example = my_cond.either(left, right);

If you think Right should be the truthy value, you can .flip().

Usage

Dependency

Add the library as a dependency to your project by inserting

eitherable = "0.1.0"

into the [dependencies] section of your Cargo.toml file.

Example

use eitherable::*;
    
let x = true;
assert_eq!(x.either(1, "right"), Either::Left(1));
    
let x = false;
assert_eq!(x.either(1, "right"), Either::Right("right"));

let x = true;
assert_eq!(x.either_else(|| 1,|| "right"), Either::Left(1));

let x = false;
assert_eq!(x.either_else(|| 1,|| "right"), Either::Right("right"));

Dependencies

~45KB