bendns' repos / ttools
[no description]
Diffstat (limited to 'src/iterator.rs')
-rw-r--r--src/iterator.rs64
1 files changed, 64 insertions, 0 deletions
diff --git a/src/iterator.rs b/src/iterator.rs
new file mode 100644
index 0000000..3d3dd26
--- /dev/null
+++ b/src/iterator.rs
@@ -0,0 +1,64 @@
+use crate::{Pick, RePick, Tupl};
+/// may add more later
+pub trait IteratorOfTuples: Iterator<Item: Tupl> {
+ /// Map the item at: (|(x, y)| (f(x), y))
+ fn map_at<const N: usize, U>(
+ self,
+ f: impl FnMut(<Self::Item as Pick<N>>::At) -> U,
+ ) -> impl Iterator<Item = <Self::Item as RePick<N, U>>::New>
+ where
+ Self::Item: RePick<N, U>;
+ /// make it just one: (|x| x.0)
+ fn just<const N: usize>(
+ self,
+ ) -> impl Iterator<Item = <Self::Item as Pick<N>>::At>
+ where
+ Self::Item: Pick<N>;
+ /// map the item to just one, then map that one: (|x| f(x.0))
+ fn map_just<const N: usize, U>(
+ self,
+ f: impl FnMut(<Self::Item as Pick<N>>::At) -> U,
+ ) -> core::iter::Map<
+ impl Iterator<Item = <Self::Item as Pick<N>>::At>,
+ impl FnMut(<Self::Item as Pick<N>>::At) -> U,
+ >
+ where
+ Self: Iterator<Item: Pick<N>> + Sized,
+ {
+ self.just().map(f)
+ }
+}
+impl<I: Iterator<Item: Tupl>> IteratorOfTuples for I {
+ #[expect(refining_impl_trait)]
+ fn map_at<const N: usize, U>(
+ self,
+ mut f: impl FnMut(<Self::Item as Pick<N>>::At) -> U,
+ ) -> core::iter::Map<
+ I,
+ impl FnMut(
+ <I as Iterator>::Item,
+ ) -> <<I as Iterator>::Item as RePick<N, U>>::New,
+ >
+ where
+ Self::Item: RePick<N, U>,
+ {
+ self.map(move |x| {
+ let (l, at, r) = x.depict();
+ let at = f(at);
+ Self::Item::unpick(l, at, r)
+ })
+ }
+
+ #[expect(refining_impl_trait)]
+ fn just<const N: usize>(
+ self,
+ ) -> core::iter::Map<
+ I,
+ impl FnMut(<I>::Item) -> <<I>::Item as Pick<N>>::At,
+ >
+ where
+ Self::Item: Pick<N>,
+ {
+ self.map(|x| x.pick())
+ }
+}