diff --git a/src/iter.rs b/src/iter.rs
new file mode 100644
index 0000000..88be085
--- /dev/null
+++ b/src/iter.rs
@@ -0,0 +1,22 @@
+use std::convert::identity;
+
+pub(crate) fn loop_list<T: Clone>(iter: impl IntoIterator<Item = T>) -> impl Iterator<Item = T> {
+	loop_list_ex(iter, identity, identity)
+}
+
+pub(crate) fn loop_list_ex<T: Clone, U>(
+	iter: impl IntoIterator<Item = T>,
+	mut fa: impl FnMut(T) -> U,
+	mut fb: impl FnMut(T) -> U,
+) -> impl Iterator<Item = U> {
+	gen move {
+		let mut iter = iter.into_iter();
+		let Some(first) = iter.next() else { return };
+		yield fa(first.clone());
+		for item in iter {
+			yield fb(item.clone());
+			yield fa(item);
+		}
+		yield fb(first);
+	}
+}
diff --git a/src/lib.rs b/src/lib.rs
index 0873c0b..99e79e9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,12 +1,13 @@
 #![feature(gen_blocks)]
 
-use std::{convert::identity, error::Error, f32::consts::PI};
+use std::{error::Error, f32::consts::PI};
 
 use glam::{Mat4, UVec2, Vec2, Vec3, vec3};
 use rand_distr::Distribution as _;
 
 use crate::{
 	camera::OrbitalCamera,
+	iter::loop_list,
 	ray::Ray,
 	render::{
 		DEPTH_FORMAT, OUTPUT_FORMAT,
@@ -118,27 +119,6 @@ pub fn new_tripod(device: &wgpu::Device) -> Mesh {
 	)
 }
 
-fn loop_list<T: Clone>(iter: impl IntoIterator<Item = T>) -> impl Iterator<Item = T> {
-	loop_list_ex(iter, identity, identity)
-}
-
-fn loop_list_ex<T: Clone, U>(
-	iter: impl IntoIterator<Item = T>,
-	mut fa: impl FnMut(T) -> U,
-	mut fb: impl FnMut(T) -> U,
-) -> impl Iterator<Item = U> {
-	gen move {
-		let mut iter = iter.into_iter();
-		let Some(first) = iter.next() else { return };
-		yield fa(first.clone());
-		for item in iter {
-			yield fb(item.clone());
-			yield fa(item);
-		}
-		yield fb(first);
-	}
-}
-
 impl OrbitalCamera {
 	fn make_ray(&self, rng: &mut impl rand::Rng) -> Ray {
 		let off: f32 = rand_distr::StandardUniform.sample(rng);