Make OStream#write accept multiple arguments

lib/iruby/ostream.rb

@@ -25,26 +25,38 @@ def read(*args)
     alias_method :next, :read
     alias_method :readline, :read
 
-    def write(s)
-      raise 'I/O operation on closed file' unless @session
-      @session.send(:publish, :stream, name: @name, text: s.to_s)
-      nil
+    def write(*obj)
+      str = build_string { |sio| sio.write(*obj) }
+      session_send(str)
     end
     alias_method :<<, :write
     alias_method :print, :write
 
-    def printf(*fmt)
-      write sprintf(*fmt)
+    def printf(format, *obj)
+      str = build_string { |sio| sio.printf(format, *obj) }
+      session_send(str)
     end
 
-    def puts(*lines)
-      lines = [''] if lines.empty?
-      lines.each { |s| write("#{s}\n")}
-      nil
+    def puts(*obj)
+      str = build_string { |sio| sio.puts(*obj) }
+      session_send(str)
     end
 
     def writelines(lines)
       lines.each { |s| write(s) }
     end
+
+    private
+
+    def build_string
+      StringIO.open { |sio| yield(sio); sio.string }
+    end
+
+    def session_send(str)
+      raise 'I/O operation on closed file' unless @session
+
+      @session.send(:publish, :stream, name: @name, text: str)
+      nil
+    end
   end
 end