To, and Fro

Automatic implimentations for Display, FromStr, and others for Enums.

Package available through cargo

cargo add to_and_fro

Implimentation

#[derive(ToAndFro)]
pub enum TestEnum {
  ValueOne,
  ValueTwo,
  ValueThree
}

TestEnum::ValueOne.to_string()  // "ValueOne"
TestEnum::from_str("ValueTwo")  //  TestEnum::ValueTwo

TestEnum::from_str("ValueFour") // anyhow::Error("Invalid variant ValueFour for enum TestEnum")

Casing

#[derive(ToAndFro)]
pub enum TestEnum {
  #[input_case("snake")]        // FromStr will parse only snake_case input
  ValueOne,
  #[output_case("kebab")]       // Display methods will produce a kebab-case output
  ValueTwo,
  ValueThree                    // Defaults to as written input, and as-written output
}

Fallback for FromStr

#[derive(ToAndFro)]
#[default("Fallback")]
pub enum TestEnum {
  Fallback,
  ValueOne,
  ValueTwo,
  ValueThree
}

TestEnum::from_str("ValueFour") // TestEnum::Fallback

Disallow field to be parsed FromStr

#[derive(ToAndFro)]
pub enum TestEnum {
  #[reject]
  ValueOne,
  ValueTwo
}

TestEnum::from_str("ValueOne")  // anyhow::Error("Invalid variant ValueOne for enum TestEnum")

List of supported cases:

• kebab (heck)
• pascal (heck)
• snake (heck)
• title (heck)
• train (heck)
• lower_camel (heck)
• upper_camel (heck)
• shouty_kebab (heck)
• shouty_snake (heck)
• upper (UPPERCASE)
• lower (lowercase)
• percent (urlencoded)

Feedback

I appreciate all feedback, in whatever forms they might take.
If you're looking to specifically make a Bug Report, or Suggest a Feature, please do so through their templates in the issues section.

Related

• Synstructure, a crate that provides helper types for matching against enum variants, and extracting bindings to each of the fields in the deriving Struct or Enum in a generic way.
• Heck, a crate that exists to provide case conversion between common cases like CamelCase and snake_case. It is intended to be unicode aware, internally consistent, and reasonably well performing.