Trait Tldr

Source

pub trait Tldr<T = String> {
    type Error;

    // Provided methods
    fn who(&self, _ctx: &TldrContext) -> TldrResult<T, Self::Error> { ... }
    fn what(&self, _ctx: &TldrContext) -> TldrResult<T, Self::Error> { ... }
    fn when(&self, _ctx: &TldrContext) -> TldrResult<T, Self::Error> { ... }
    fn where(&self, _ctx: &TldrContext) -> TldrResult<T, Self::Error> { ... }
    fn why(&self, _ctx: &TldrContext) -> TldrResult<T, Self::Error> { ... }
    fn whence(&self, _ctx: &TldrContext) -> TldrResult<T, Self::Error> { ... }
    fn how(&self, _ctx: &TldrContext) -> TldrResult<T, Self::Error> { ... }
}

Expand description

A trait for generating a TL;DR summary.

§Examples

Implementing the Tldr trait for a custom type is simple:

struct Rectangle {
    width: u32,
    height: u32,
}

impl Tldr<String> for Rectangle {
    type Error = Box<dyn Error>;

    fn what(&self, _ctx: &TldrContext) -> TldrResult<String> {
        Ok(Some(format!("A rectangle with a width of {} and a height of {}.", self.width, self.height)))
    }
}

Generally, you’d want to match on the context language to provide a localized response:

struct Rectangle {
    width: u32,
    height: u32,
}

impl Tldr<String> for Rectangle {
    type Error = Box<dyn Error>;

    fn what(&self, ctx: &TldrContext) -> TldrResult<String> {
        use TldrLanguage::*;
        Ok(match ctx.language {
            English => Some(format!("A rectangle with a width of {} and a height of {}.", self.width, self.height)),
            _ => None,
        })
    }
}