chore: cleanup and add tools

itertools_test.go

@@ -42,3 +42,16 @@ func TestTranspose(t *testing.T) {
 		},
 	)
 }
+
+func TestPairwise(t *testing.T) {
+	is := is.New(t)
+
+	is.Equal(
+		aoc.Pairwise([]int{1, 2, 3, 4}),
+		[][2]int{
+			{1, 2},
+			{2, 3},
+			{3, 4},
+		},
+	)
+}