From: ara.t.howard@...
Date: 2005-12-08T12:11:25+09:00
Subject: Re: They say I write Ruby like Perl

On Thu, 8 Dec 2005, Steve Litt wrote:

> Hi all,
>
> I wrote some hierarchy handling classes in Node.rb
> (http://www.troubleshooters.com/projects/Node.rb/index.htm), and I've been
> told I write Ruby in Perl style. In future software, what could I do to write
> in a more Ruby-like fashion?

here are some thoughts:

     class Node < Object
             def initialize(nam, type, value)
                     super()
                     @name = nam
                     @type = type
                     @value = value
                     @attribs = {}
                     @parent = nil
                     @prevsibling = nil
                     @nextsibling = nil
                     @firstchild = nil
                     @lastchild = nil
             end

             attr_reader :name, :type, :value
             attr_writer :name, :type, :value
             attr_reader :parent, :prevsibling, :nextsibling, :firstchild, :lastchild

             def setAttributes(attribs) @attribs = attribs; end
             def getAttributes() return @attribs; end
             def hasAttributes() return @attribs != nil; end
             def setAttribute(key, value) @attribs[key] = value; end
             def getAttribute(key) return @attribs[key]; end
             def hasAttribute(key) return @attribs[key] != nil; end

i would condensed into

   class Node

     ATTRIBUTES = %w(
       name type value attribs parent prevsibling nextsibling firstchild lastchild
     ).each{|a| attr_accessor a; alias_method "#{ a }?", a}

     def initialize name, type, value, attribs = {}
       @name, @type, @value, @attribs = name, type, value, attribs
     end

don't bother with access control - sometimes it's needed (object available on
the web) but sometimes it's not.  with it you are saying "my code has no
mistakes - you will not need access to these vars" by saying 'read_only'.  i've
probably fixed about 50 bugs in code where i had to subvert the access control
by doing

   obj.instance_var_set "@broken", "fixed"

because of this kind of design.  don't use it where it's not critical.

dont' use get/set/has - use attr, attr=, attr?

         def setParent(parent)
                 @parent = parent
                 node = self
                 while node.prevsibling
                         node = node.prevsibling
                 end
                 @parent.firstchild = node
                 node = self
                 while node.nextsibling
                         node = node.nextsibling
                 end
                 @parent.lastchild = node
                 @parent
         end

could be

       def parent= parent
         parent.firstchild = oldest
         parent.lastchild = youngest
         @parent = parent
       end
       def oldest
         node = self
         node = node.prevsibling while node.prevsibling
         node
       end
       def youngest
         node = self
         node = node.nextsibling while node.nextsibling
         node
       end

which isn't shorter - until the next time you write that code.

food for thought.

cheers.

-a
-- 
===============================================================================
| ara [dot] t [dot] howard [at] noaa [dot] gov
| all happiness comes from the desire for others to be happy.  all misery
| comes from the desire for oneself to be happy.
| -- bodhicaryavatara
===============================================================================