#bool #toggle

condition

Commonly used synonyms for true and false

1 unstable release

0.1.0 Feb 10, 2020

#9 in #eventually-support

MIT license

5KB
73 lines

Overview

Provides a trait for easier expression (and consumption) if features, toggles, checkboxes, settings, options, or any other so-called bivalent pair.

Conditions typically come in pairs (e.g, {Deny, Allow}, {No, Yes}, etc.)

A derive macro is available in the prelude module. If the macro is not desired to be in scope, simply use the crate instead.

Custom Derive

Currently the custom derive macro is applicable to enums with two fields only. The first field will be treated as the false state, while the second field will be treated as the true state.

Roadmap

Currently planned:

  • #[true] and #[false] attributes to permit changing the order, as well as having multiple names for true or false.
  • Automatic FromStr generation for parsing.

lib.rs:

This library provides condition::Condition a trait for easier expression (and consumption) of features, toggles, checkboxes, settings, options, or any other bivalent pair.

NOTE: This crate will eventually support no-std, but does not at this time

Conditions typically come in pairs. (e.g., {Allow, Deny}, {Yes, No}, {With, Without}. This library provides several types by default. To import them, use the prelude module. If you only want to use the trait, simply import it.

Use impl Condition anywhere you might take a boolean value. Then, use any type that implements this condition.

Within the function, branch off of the condition provided

use condition::prelude::*;

#[derive(Condition)]
enum Answer {
  No,
  Yes
}

pub fn verbose(v: impl Condition) { assert!(v.is(false)); }

/* ... */

use Answer::No;
verbose(No);

Dependencies

~1.5MB
~33K SLoC