consolidate dns resolver constructors

The current convention is to return the concrete type instead of an interface so
let's go with that and have one constructor.

License: MIT
Signed-off-by: Steven Allen <steven@stebalien.com>

namesys/dns.go

@@ -21,13 +21,7 @@ type DNSResolver struct {
 }
 
 // NewDNSResolver constructs a name resolver using DNS TXT records.
-func NewDNSResolver() Resolver {
-	return &DNSResolver{lookupTXT: net.LookupTXT}
-}
-
-// newDNSResolver constructs a name resolver using DNS TXT records,
-// returning a resolver instead of NewDNSResolver's Resolver.
-func newDNSResolver() resolver {
+func NewDNSResolver() *DNSResolver {
 	return &DNSResolver{lookupTXT: net.LookupTXT}
 }
 

namesys/namesys.go

@@ -35,7 +35,7 @@ type mpns struct {
 func NewNameSystem(r routing.ValueStore, ds ds.Datastore, cachesize int) NameSystem {
 	return &mpns{
 		resolvers: map[string]resolver{
-			"dns":      newDNSResolver(),
+			"dns":      NewDNSResolver(),
 			"proquint": new(ProquintResolver),
 			"dht":      NewRoutingResolver(r, cachesize),
 		},