ruff/crates/ruff_formatter/shared_traits.rs
2023-06-01 12:20:49 +02:00

108 lines
2.8 KiB
Rust

/// Used to get an object that knows how to format this object.
pub trait AsFormat<Context> {
type Format<'a>: ruff_formatter::Format<Context>
where
Self: 'a;
/// Returns an object that is able to format this object.
fn format(&self) -> Self::Format<'_>;
}
/// Implement [`AsFormat`] for references to types that implement [`AsFormat`].
impl<T, C> AsFormat<C> for &T
where
T: AsFormat<C>,
{
type Format<'a> = T::Format<'a> where Self: 'a;
fn format(&self) -> Self::Format<'_> {
AsFormat::format(&**self)
}
}
/// Used to convert this object into an object that can be formatted.
///
/// The difference to [`AsFormat`] is that this trait takes ownership of `self`.
pub trait IntoFormat<Context> {
type Format: ruff_formatter::Format<Context>;
fn into_format(self) -> Self::Format;
}
/// Implement [`IntoFormat`] for [`Option`] when `T` implements [`IntoFormat`]
///
/// Allows to call format on optional AST fields without having to unwrap the
/// field first.
impl<T, Context> IntoFormat<Context> for Option<T>
where
T: IntoFormat<Context>,
{
type Format = Option<T::Format>;
fn into_format(self) -> Self::Format {
self.map(IntoFormat::into_format)
}
}
/// Implement [`IntoFormat`] for references to types that implement [`AsFormat`].
impl<'a, T, C> IntoFormat<C> for &'a T
where
T: AsFormat<C>,
{
type Format = T::Format<'a>;
fn into_format(self) -> Self::Format {
AsFormat::format(self)
}
}
/// Formatting specific [`Iterator`] extensions
pub trait FormattedIterExt {
/// Converts every item to an object that knows how to format it.
fn formatted<Context>(self) -> FormattedIter<Self, Self::Item, Context>
where
Self: Iterator + Sized,
Self::Item: IntoFormat<Context>,
{
FormattedIter {
inner: self,
options: std::marker::PhantomData,
}
}
}
impl<I> FormattedIterExt for I where I: std::iter::Iterator {}
pub struct FormattedIter<Iter, Item, Context>
where
Iter: Iterator<Item = Item>,
{
inner: Iter,
options: std::marker::PhantomData<Context>,
}
impl<Iter, Item, Context> std::iter::Iterator for FormattedIter<Iter, Item, Context>
where
Iter: Iterator<Item = Item>,
Item: IntoFormat<Context>,
{
type Item = Item::Format;
fn next(&mut self) -> Option<Self::Item> {
Some(self.inner.next()?.into_format())
}
}
impl<Iter, Item, Context> std::iter::FusedIterator for FormattedIter<Iter, Item, Context>
where
Iter: std::iter::FusedIterator<Item = Item>,
Item: IntoFormat<Context>,
{
}
impl<Iter, Item, Context> std::iter::ExactSizeIterator for FormattedIter<Iter, Item, Context>
where
Iter: Iterator<Item = Item> + std::iter::ExactSizeIterator,
Item: IntoFormat<Context>,
{
}