add a go example

Emyrk · Emyrk · commit cc4a46285fa9 · 2024-08-23T11:27:18.000-05:00
diff --git a/coderd/util/slice/example_test.go b/coderd/util/slice/example_test.go
@@ -0,0 +1,20 @@
+package slice_test
+
+import (
+	"fmt"
+
+	"github.com/coder/coder/v2/coderd/util/slice"
+)
+
+func ExampleSymmetricDifference() {
+	// The goal of this function is to find the elements to add & remove from
+	// set 'a' to make it equal to set 'b'.
+	a := []int{1, 2, 5, 6}
+	b := []int{2, 3, 4, 5}
+	add, remove := slice.SymmetricDifference(a, b)
+	fmt.Println("Elements to add:", add)
+	fmt.Println("Elements to remove:", remove)
+	// Output:
+	// Elements to add: [3 4]
+	// Elements to remove: [1 6]
+}
diff --git a/coderd/util/slice/slice.go b/coderd/util/slice/slice.go
@@ -113,6 +113,7 @@ func Descending[T constraints.Ordered](a, b T) int {
 // In classical set theory notation, SymmetricDifference returns
 // all elements of {add} and {remove} together. It is more useful to
 // return them as their own slices.
+// Notation: A Δ B = (A\B) ∪ (B\A)
 // Example:
 //
 //	a := []int{1, 3, 4}
