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use crate::common::{ConvertCasing, LIFETIME_TICK_PREFIX};
use convert_case::Case;
/// Types convertible to the letter casing corresponding to names of
/// [lifetimes](https://doc.rust-lang.org/rust-by-example/scope/lifetime.html).
pub trait ToLifetimeName {
/// The resulting type, coming out of the conversion.
type Output;
/// Converts self to the letter casing of
/// [lifetime](https://doc.rust-lang.org/rust-by-example/scope/lifetime.html) names
/// (`'snake_case`). Adheres to the
/// [general conversion rules](crate#general-rules-for-conversions).
///
/// # Examples
///
/// Usage with [`syn::Ident`]:
///
/// ```
/// # use caseidae::ToLifetimeName;
/// # use syn::Ident;
/// # use proc_macro2::Span;
/// let enum_name = Ident::new("HeroAbility", Span::call_site());
/// let lifetime = enum_name.to_lifetime_name();
/// assert_eq!(lifetime.to_string(), "'hero_ability");
/// ```
///
/// Note that the output of the conversion (here the `lifetime` variable) is of type
/// [`syn::Lifetime`].
///
/// Usage with strings:
///
/// ```
/// # use caseidae::ToLifetimeName;
/// assert_eq!("PIZZA_DIAMETER".to_lifetime_name(), "'pizza_diameter");
/// assert_eq!(String::from("AlexAndDerMurder").to_lifetime_name(), "'alex_and_der_murder");
/// assert_eq!(String::from("'already_a_lifetime").to_lifetime_name(), "'already_a_lifetime");
/// ```
///
/// # Panics
///
/// Whether this method panics depends on the implementator, see their documentation for that.
/// However, implementations from this crate never panic.
fn to_lifetime_name(&self) -> Self::Output;
}
impl ToLifetimeName for str {
type Output = <Self as ToOwned>::Owned;
fn to_lifetime_name(&self) -> Self::Output {
format!("{LIFETIME_TICK_PREFIX}{}", self.convert_casing(Case::Snake))
}
}
#[cfg(feature = "syn")]
impl ToLifetimeName for syn::Ident {
type Output = syn::Lifetime;
/// See the [trait method documentation](ToLifetimeName::to_lifetime_name).
///
/// The resulting [`Lifetime`](syn::Lifetime) has the same span as self.
fn to_lifetime_name(&self) -> Self::Output {
syn::Lifetime::new(self.to_string().to_lifetime_name().as_str(), self.span())
}
}