checking in some WIP

* added some netx funcs
* added netx/dnsx
* currently updating docs and adding *x funcs to sprigx

netx/dnsx/funcs_test.go

@@ -0,0 +1,29 @@
+package dnsx
+
+import (
+	`net/netip`
+	"testing"
+)
+
+func TestPtr(t *testing.T) {
+
+	var err error
+	var ptr string
+	var ip netip.Addr
+	var ipStr string = "::ffff:192.168.0.1"
+	var ptrStr string = "1.0.0.0.8.a.0.c.f.f.f.f.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa."
+
+	if ip, err = AddrFromPtr(ptrStr); err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("PTR -> Addr: %s -> %s", ptrStr, ip.String())
+	if ip.String() != ipStr {
+		t.Fatalf("expect IP %v, got %v", ipStr, ip.String())
+	}
+
+	ptr = AddrToPtr(ip)
+	if ptr != ptrStr {
+		t.Fatalf("expect PTR %v, got %v", ptrStr, ptr)
+	}
+	t.Logf("Addr -> PTR: %s -> %s", ip.String(), ptr)
+}