add Order instance for AtLeast2

modules/pan/src/main/scala/collections.scala

@@ -72,6 +72,11 @@ object collections:
     /** Define equality the same way as for the underlying, unrefined value. */
     given eqForAtLeast2[C[*], E](using Eq[C[E]]): Eq[AtLeast2[C, E]] = Eq.by(es => es: C[E])
 
+    /** Define order the same way as for the underlying, unrefined value. */
+    given orderForAtLeast2[C[*], A](using Order[C[A]]): Order[AtLeast2[C, A]] =
+      Order.by: xs =>
+        xs: C[A]
+
     /** Simply concatenate the elements from the left list to the head of the right list. */
     given semigroupKForAtLeast2List: SemigroupK[AtLeast2List] = new:
       override def combineK[A](xs: AtLeast2List[A], ys: AtLeast2List[A]): AtLeast2List[A] =

modules/pan/src/test/scala/TestAtLeast2.scala

@@ -100,4 +100,13 @@ class TestAtLeast2
     forAll: (xs: AtLeast2[Set, Int]) =>
       xs.toNes shouldEqual NonEmptySet.fromSetUnsafe(xs.toSortedSet)
 
+  test("When syntax is imported, AtLeast2[Set, A] may be represented as simply Set[A]."):
+    assertCompiles("AtLeast2.unsafe(Set(1, 2))") // Precondition: we can build the collection.
+    assertTypeError(
+      "AtLeast2.unsafe(Set(1, 2)).toSet"
+    ) // Test: without syntax import, .toNes is unavailable.
+    assertCompiles(
+      "import AtLeast2.syntax.toSet; AtLeast2.unsafe(Set(1, 2)).toSet"
+    ) // Test: with syntax import, .toNes becomes available.
+
 end TestAtLeast2