* lib/resolv.rb (Resolv::DNS::Name#subdomain_of?): new method.

(Resolv::DNS::Name#inspect): ditto.
  Suggested by Sam Roberts.  [ruby-talk:129086]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@7915 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Tue Feb  8 00:19:02 2005  Tanaka Akira  <akr@m17n.org>
+
+	* lib/resolv.rb (Resolv::DNS::Name#subdomain_of?): new method.
+	  (Resolv::DNS::Name#inspect): ditto.
+	  Suggested by Sam Roberts.  [ruby-talk:129086]
+
 Mon Feb  7 23:14:11 2005  Tanaka Akira  <akr@m17n.org>
 
 	* io.c (io_getc): flush rb_stdout before read fro stdin, which is

lib/resolv.rb

@@ -978,15 +978,38 @@ class Resolv
         @absolute = absolute
       end
 
+      def inspect
+        "#<#{self.class}: #{self.to_s}#{@absolute ? '.' : ''}>"
+      end
+
       def absolute?
         return @absolute
       end
 
       def ==(other)
+        return false unless Name === other
         return @labels == other.to_a && @absolute == other.absolute?
       end
       alias eql? ==
 
+      # tests subdomain-of relation.
+      #
+      #   domain = Resolv::DNS::Name.create("y.z")
+      #   p Resolv::DNS::Name.create("w.x.y.z").subdomain_of?(domain) #=> true
+      #   p Resolv::DNS::Name.create("x.y.z").subdomain_of?(domain) #=> true
+      #   p Resolv::DNS::Name.create("y.z").subdomain_of?(domain) #=> false
+      #   p Resolv::DNS::Name.create("z").subdomain_of?(domain) #=> false
+      #   p Resolv::DNS::Name.create("x.y.z.").subdomain_of?(domain) #=> false
+      #   p Resolv::DNS::Name.create("w.z").subdomain_of?(domain) #=> false
+      #
+      def subdomain_of?(other)
+        raise ArgumentError, "not a domain name: #{other.inspect}" unless Name === other
+        return false if @absolute != other.absolute?
+        other_len = other.length
+        return false if @labels.length <= other_len
+        return @labels[-other_len, other_len] == other.to_a
+      end
+
       def hash
         return @labels.hash ^ @absolute.hash
       end
@@ -1003,6 +1026,14 @@ class Resolv
         return @labels[i]
       end
 
+      # returns the domain name as a string.
+      #
+      # The domain name doesn't have a trailing dot even if the name object is
+      # absolute.
+      #
+      #   p Resolv::DNS::Name.create("x.y.z.").to_s #=> "x.y.z"
+      #   p Resolv::DNS::Name.create("x.y.z").to_s #=> "x.y.z"
+      #
       def to_s
         return @labels.join('.')
       end