From: "ara.t.howard" <ara.t.howard@...>
Date: 2007-11-30T02:45:01+09:00
Subject: Re: better idiom for title on an optional list?


On Nov 29, 2007, at 10:25 AM, slothbear wrote:

> I'm still learning Ruby, and most of the time I can find a beautiful
> Ruby idiom that collapses two or more statements into one easy-to-read
> (or learn) idiom, like h[key] ||= 0.  My current project has a lot of
> places where it emits lists if they contain any items, much like this:
>
> unless items.empty?
>   puts "items\n-----"
>   items.each { |item|  puts item }
> end
>
> My header code and list code is more complicated, and sometimes there
> are lists within lists, and it all just starts to look ugly, even
> split out into smaller methods.  It would seem more Ruby-like if I
> could fold the header into the iterator somehow -- rather than what I
> have now that feels like it tests the Array for items twice.  Or maybe
> I'm trying too hard to make it terse?
>

1)

   puts "list", "----", list unless list.empty?

2) refactor you code so that this is ok

   require 'yaml'

   y 'list' => list

   this will print and empty list.  personally i think this is best  
since analysis of output is very hard when the schema keeps changing

3) same as above, but with test

   y 'list' => list unless list.empty?

4) dry it up

   def report label, list
     puts label, '---', list unless list.empty?
   end

   report 'foo', foo

5) create a list class and use it

   class List < ::Array
     def initialize label
       @label = label
     end

     def to_s
       ...
   end

   unfortunately this gets icky because ruby handles any subclass of  
array specically when given as an arg to puts...


regards.
a @ http://codeforpeople.com/
--
we can deny everything, except that we have the possibility of being  
better. simply reflect on that.
h.h. the 14th dalai lama