Remove the fmt Formatters

Formatters are not needs you can access the members just fine.
However the rdata Field access function are handy and non-trivial,
extend them and add a basic test.

dns.go

@@ -93,10 +93,7 @@
 // spaces, semicolons and the at symbol are escaped.
 package dns
 
-import (
-	"fmt"
-	"strconv"
-)
+import "strconv"
 
 const (
 	year68         = 1 << 31 // For RFC1982 (Serial Arithmetic) calculations in 32 bits.
@@ -123,8 +120,6 @@ type RR interface {
 	Header() *RR_Header
 	// String returns the text representation of the resource record.
 	String() string
-	// Formatted output
-	Format(f fmt.State, c rune)
 	// copy returns a copy of the RR
 	copy() RR
 	// len returns the length (in octets) of the uncompressed RR in wire format.

format.go

@@ -1,34 +1,15 @@
-// FORMAT
-//
-// The dns package implements String() for all RR types, but sometimes you will
-// need more flexibility. Here we define an extra set of formatting verbs that
-// can be used in the formatted I/O package fmt.
-//
-// Printing
-//
-// The verbs:
-//
-// Generic parts of RRs:
-//
-//	%N	the owner name of the RR
-//	%C	the class: IN, CH, CLASS15, etc.
-//	%D	the TTL in seconds
-//	%Y	the type: MX, A, etc.
-//
-// The rdata of each RR differs, we allow each field to be accessed as a string with
-// the Field function.
-//
 package dns
 
 import (
-	"fmt"
 	"net"
 	"reflect"
 	"strconv"
 )
 
 // Field returns the rdata field i as a string. Fields are indexed starting from 1.
-// Non existing fields will return the empty string.
+// Non existing fields will return the empty string. RR types that holds slice data,
+// for instance the NSEC type bitmap will return a single string where the types
+// are concatenated using a space.
 func Field(r RR, i int) string {
 	if i == 0 {
 		return ""
@@ -44,15 +25,17 @@ func Field(r RR, i int) string {
 	case reflect.Slice:
 		switch reflect.ValueOf(r).Elem().Type().Field(i).Tag {
 		case `dns:"a"`:
-			// println(d.Len()), Hmm store this as 16 bytes
+			// TODO(miek): We hmm store this as 16 bytes
 			if d.Len() < net.IPv6len {
-				return ""
+				return net.IPv4(byte(d.Index(0).Uint()),
+					byte(d.Index(1).Uint()),
+					byte(d.Index(2).Uint()),
+					byte(d.Index(3).Uint())).String()
 			}
-			ip := net.IPv4(byte(d.Index(12).Uint()),
+			return net.IPv4(byte(d.Index(12).Uint()),
 				byte(d.Index(13).Uint()),
 				byte(d.Index(14).Uint()),
-				byte(d.Index(15).Uint()))
-			return ip.String()
+				byte(d.Index(15).Uint())).String()
 		case `dns:"aaaa"`:
 			return net.IP{
 				byte(d.Index(0).Uint()),
@@ -72,13 +55,38 @@ func Field(r RR, i int) string {
 				byte(d.Index(14).Uint()),
 				byte(d.Index(15).Uint()),
 			}.String()
-			// []uint16 (nsec,wks)
-			// []string
+		case `dns:"nsec"`:
+			if d.Len() == 0 {
+				return ""
+			}
+			s := Type(d.Index(0).Uint()).String()
+			for i := 1; i < d.Len(); i++ {
+				s += " " + Type(d.Index(i).Uint()).String()
+			}
+			return s
+		case `dns:"wks"`:
+			if d.Len() == 0 {
+				return ""
+			}
+			s := strconv.Itoa(int(d.Index(0).Uint()))
+			for i := 0; i < d.Len(); i++ {
+				s += " " + strconv.Itoa(int(d.Index(i).Uint()))
+			}
+			return s
+		default:
+			// if it does not have a tag its a string slice
+			fallthrough
+		case `dns:"txt"`:
+			if d.Len() == 0 {
+				return ""
+			}
+			s := d.Index(0).String()
+			for i := 1; i < d.Len(); i++ {
+				s += " " + d.Index(i).String()
+			}
+			return s
 		}
-	default:
-		println("dns: unknown field kind", k.String())
 	}
-
 	return ""
 }
 
@@ -87,6 +95,7 @@ func NumField(r RR) int {
 	return reflect.ValueOf(r).Elem().NumField() - 1 // Remove RR_Header
 }
 
+/*
 func format(r RR, f fmt.State, c rune) {
 	switch c {
 	case 'N':
@@ -118,7 +127,6 @@ func format_Header(h *RR_Header, f fmt.State, c rune) {
 	case 's':
 		f.Write([]byte(h.String()))
 	default:
-		println(string(c))
 		f.Write([]byte("TODO"))
 	}
 }
@@ -198,3 +206,4 @@ func (rr *UINFO) Format(f fmt.State, c rune)      { format(rr, f, c) }
 func (rr *URI) Format(f fmt.State, c rune)        { format(rr, f, c) }
 func (rr *WKS) Format(f fmt.State, c rune)        { format(rr, f, c) }
 func (rr *X25) Format(f fmt.State, c rune)        { format(rr, f, c) }
+*/

parse_test.go

@@ -1375,9 +1375,27 @@ func TestPrintfVerbsRdata(t *testing.T) {
 	if Field(x, 2) != "mx.miek.nl." {
 		t.Errorf("should be mx.miek.nl.")
 	}
+
 	x, _ = NewRR("www.miek.nl. IN A 127.0.0.1")
-	println(Field(x, 1))
+	if Field(x, 1) != "127.0.0.1" {
+		t.Errorf("should be 127.0.0.1")
+	}
 
 	x, _ = NewRR("www.miek.nl. IN AAAA ::1")
-	println(Field(x, 1))
+	if Field(x, 1) != "::1" {
+		t.Errorf("should be ::1")
+	}
+
+	x, _ = NewRR("www.miek.nl. IN NSEC a.miek.nl. A NS SOA MX AAAA")
+	if Field(x, 1) != "a.miek.nl." {
+		t.Errorf("should be a.miek.nl.")
+	}
+	if Field(x, 2) != "A NS SOA MX AAAA" {
+		t.Errorf("should be A NS SOA MX AAAA")
+	}
+
+	x, _ = NewRR("www.miek.nl. IN TXT \"first\" \"second\"")
+	if Field(x, 1) != "first second" {
+		t.Errorf("should be first second")
+	}
 }

types.go

@@ -1394,6 +1394,7 @@ func (rr *WKS) String() (s string) {
 	if rr.Address != nil {
 		s += rr.Address.String()
 	}
+	// TODO(miek): missing protocol here.
 	for i := 0; i < len(rr.BitMap); i++ {
 		// should lookup the port
 		s += " " + strconv.Itoa(int(rr.BitMap[i]))