What if the library provided a helper like this for implementing Render?
pub fn render_to<F>(f: F) -> impl maud::Render
where
F: Fn(&mut String),
{
struct Render<F>(F);
impl<F> maud::Render for Render<F>
where
F: Fn(&mut String),
{
fn render_to(&self, buffer: &mut String) {
(self.0)(buffer);
}
}
Render(f)
}This would simplify implementing Render for custom types.
As an example, let's look at custom date formatting with localization parameters:
pub struct Date { day: u8, month: Month, year: i32 }
impl Date {
pub fn render(self, local: &Local, lang: Lang) -> impl maud::Render {
struct Render<'local>(Date, &'local Local, Lang);
impl maud::Render for Render<'_> {
fn render_to(&self, buffer: &mut String) {
let Self(Date { day, month, year }, local, lang) = self;
let month_name = local.month_short_name(*month, *lang).unwrap_or_else(|| {
eprintln!("unknown month {month} for lang {lang}!");
"nul"
});
_ = write!(buffer, "{day} {month_name} {year}");
}
}
Render(self, local, lang)
}
}With the proposed helper, the implementation becomes much shorter and more ergonomic:
impl Date {
pub fn render(self, local: &Local, lang: Lang) -> impl maud::Render {
let Self { day, month, year } = self;
let month_name = local.month_short_name(month, lang).unwrap_or_else(|| {
eprintln!("unknown month {month} for lang {lang}!");
"nul"
});
render_to(move |buffer| _ = write!(buffer, "{day} {month_name} {year}"))
}
}What do you think about this idea - does it seem useful?
Alternatively, you can use the display helper, but the Display implementation would be just as verbose.
What if the library provided a helper like this for implementing
Render?This would simplify implementing
Renderfor custom types.As an example, let's look at custom date formatting with localization parameters:
With the proposed helper, the implementation becomes much shorter and more ergonomic:
What do you think about this idea - does it seem useful?
Alternatively, you can use the
displayhelper, but theDisplayimplementation would be just as verbose.