From: Bob Nadler <thethirdswitch@...>
Date: 2010-07-13T05:17:25+09:00
Subject: Re: what about allowing to specify, which end belongs to which start?

On Mon, Jul 12, 2010 at 3:30 PM, Jan Lelis <prog@janlelis.de> wrote:
>> > def test
>> >  while 1
>> >    puts (1..9).each_slice(3).map do |slice|
>> >      sum = slice.inject do |acc, ele|
>> >        acc + ele
>> >      end
>> >
>> >      if sum > 6
>> >        42
>> >      else
>> >        99
>> >      end~if
>> >    end~do.join ','
>> >  end~while
>> > end
>> >
>> Hi,
>> I know it's a bit of a contrived example, and I'm not advocating a version
>> of "Ruby Golf" here, but if I saw this method in some code I was maintaining
>> I would refactor it to something like:
>>
>> def test
>>   while 1
>>     puts (1..9).each_slice(3).map do |slice|
>>       sum = slice.inject { |acc, ele| acc + ele }
>>       sum > 6 ? 42 : 99
>>     end.join(',')
>>   end
>> end
>>
>> ...or even better, move the "summing" to another method...
>>
>> def test
>>   while 1
>>     puts (1..9).each_slice(3).map do |slice|
>>       calculate_sum > 6 ? 42 : 99
>>     end.join(',')
>>   end
>> end
>>
>> def calculate_sum(items)
>>   items.inject { |acc, ele| acc + ele }
>> end
>>
>> I think most cases where the end~if syntax is "necessary" would be better off
>> (e.g. more readable) with a healthy dose of refactoring.
>>
>
> Of course, the example was made up to demonstrate the ends and not real
> world code. I would not write it in this way, either...
>
> This one is from existing code:
>
>  module ABC
>
>    # ...
>
>    def abc
>      x.each do
>        if x
>
>          case lorem
>
>          when :ipsum
>            # ...
>          when :ipsum
>            # ...
>          when :ipsum
>            # ...
>          when :ipsum
>            # ...
>          else
>            # ...
>          end
>        end
>      end
>    end
>  end
>

My general rule of thumb is to put long case statements (if I can't avoid
using them) into their own separate method. So I would refactor the code to:

module ABC

  def abc
    x.each do
      some_method_name_that_describes_what_case_statement_does(lorem) if x
    end
  end

  def some_method_name_that_describes_what_case_statement_does(value)
    case lorem

    when :ipsum
    # ...
    when :ipsum
    # ...
    when :ipsum
    # ...
    when :ipsum
    # ...
    else
    # ...
    end
  end

end

As an aside, take a look at Refactoring: Ruby Edition[1]. It covers ways of
dealing with long methods, case statements, and other situations that
cause difficulties trying
to match up "end"'s.

[1] http://www.amazon.com/Refactoring-Ruby-Jay-Fields/dp/0321603508