From: Mikael Brockman <mikael@...>
Date: 2004-10-11T05:03:25+09:00
Subject: Re: Putting some code out to DRY

"trans.  (T. Onoma)" <transami@runbox.com> writes:

> Notice the three lines of duplication. Any ideas on DRYing this up?
>     
>     def each
>       seed = @start
>       if @step
>         @step.times do
>           yield(seed)
>           @skip.times { seed = seed.succ }          
>           break if @halt.call(seed) if @halt
>         end
>       else
>         loop do
>           yield(seed)
>           @skip.times { seed = seed.succ }
>           break if @halt.call(seed) if @halt
>         end
>       end
>     end

You could let @step default to $infinity, where $infinity is something
like this:

| $infinity = Object.new
| class << $infinity
|   def times; loop { yield }; end
|   # other infinity methods omitted because YAGNI
| end

That would let you define #each as simply

| def each
|   seed = @start
|   @step.times do
|     yield(seed)
|     @skip.times { seed = seed.succ }
|     break if @halt.call(seed) if @halt
|   end
| end