Crate kinded

Kinded

Generate Rust enum kind types without boilerplate.

Get Started

use kinded::Kinded;

#[derive(Kinded)]
enum Drink {
    Mate,
    Coffee(String),
    Tea { variety: String, caffeine: bool }
}

let drink = Drink::Coffee("Espresso".to_owned());
assert_eq!(drink.kind(), DrinkKind::Coffee);

Note, the definition of DrinkKind enum is generated automatically as well as Drink::kind() method. To put it simply you get something similar to the following:

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum DrinkKind {
    Mate,
    Coffee,
    Tea
}

impl Drink {
    fn kind(&self) -> DrinkKind {
        Drink::Mate => DrinkKind::Mate,
        Drink::Coffee(..) => DrinkKind::Coffee,
        Drink::Tea { .. } => DrinkKind::Tea,
    }
}

# Kinded trait

The library provides `Kinded` trait:

```rs
pub trait Kinded {
    type Kind: PartialEq + Eq + Debug + Clone + Copy;

    fn kind(&self) -> Self::Kind;
}

From the example above, the derived implementation of Kinded for Drink resembles the following:

impl Kinded for Drink {
    type Kind = DrinkKind;

    fn kind(&self) -> DrinkKind { /* implementation */ }
}

The Kinded trait allows to build abstract functions that can be used with different enum types.

Get all kind variants

The kind type gets implementation of ::all() associated function, which returns a vector with all kind variants:

use kinded::Kinded;

#[derive(Kinded)]
enum Drink {
    Mate,
    Coffee(String),
    Tea { variety: String, caffeine: bool }
}

assert_eq!(DrinkKind::all(), [DrinkKind::Mate, DrinkKind::Coffee, DrinkKind::Tea]);

Attributes

Custom kind type name

By default the kind type name is generated by adding postfix Kind to the original enum name. This can be customized with kind = attribute:

use kinded::Kinded;

#[derive(Kinded)]
#[kinded(kind = SimpleDrink)]
enum Drink {
    Mate,
    Coffee(String),
    Tea { variety: String, caffeine: bool }
}

assert_eq!(Drink::Mate.kind(), SimpleDrink::Mate);

Derive traits

By default the kind type implements the following traits: Debug, Clone, Copy, PartialEq, Eq, From<T>, From<&T>.

Extra traits can be derived with derive(..) attribute:

use kinded::Kinded;
use std::collections::HashSet;

#[derive(Kinded)]
#[kinded(derive(Hash))]
enum Drink {
    Mate,
    Coffee(String),
    Tea { variety: String, caffeine: bool }
}

let mut drink_kinds = HashSet::new();
drink_kinds.insert(DrinkKind::Mate);

Customize Display trait

Implementation of Display trait can be customized in the serde fashion:

use kinded::Kinded;

#[derive(Kinded)]
#[kinded(display = "snake_case")]
enum Drink {
    VeryHotBlackTea,
    Milk { fat: f64 },
}

let tea = DrinkKind::VeryHotBlackTea;
assert_eq!(tea.to_string(), "very_hot_black_tea");

FromStr trait

The kind type implements FromStr trait. The implementation tries it’s best to parse, checking all the possible cases mentioned above.

use kinded::Kinded;

#[derive(Kinded)]
#[kinded(display = "snake_case")]
enum Drink {
    VeryHotBlackTea,
    Milk { fat: f64 },
}

assert_eq!(
    "VERY_HOT_BLACK_TEA".parse::<DrinkKind>().unwrap(),
    DrinkKind::VeryHotBlackTea
);

assert_eq!(
    "veryhotblacktea".parse::<DrinkKind>().unwrap(),
    DrinkKind::VeryHotBlackTea
);

The possible values are "snake_case", "camelCase", "PascalCase", "SCREAMING_SNAKE_CASE", "kebab-case", "SCREAMING-KEBAB-CASE", "Title Case", "lowercase", "UPPERCASE".

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Thank you.

License

MIT © Serhii Potapov

Structs

• ParseKindError
  An error which is returned when parsing of a kind type failures.

Traits

• Kind
• Kinded
  A trait that can be implemented by a main enum type. Typically should be derived with #[derive(kinded::Kinded)].

Derive Macros

• Kinded