From: Bertram Scharpf <lists@...>
Date: 2007-02-15T03:49:42+09:00
Subject: Re: Justification for Array#join behaviour?

Hi,

Am Mittwoch, 14. Feb 2007, 16:52:00 +0900 schrieb Farrel Lifson:
> What is the justification for [1,2,[3,4]].join(',') being '1,2,3,4'
> instead of '1,2,34'? According to ruby-doc.org join "Returns a string
> created by converting each element of the array to a string, separated
> by sep.". Why should an element be recursively joined if it's also an
> array?

You would have to ask for the objects type:

  class Array
    def deep_join sep
      map { |x|
        case x
          when Array then x.deep_join sep
          else            x.to_s
        end
      }.join sep
    end
  end

I don't look at this as a smart programming style actually.

The object-oriented approach is to redefine `to_s'.

Bertram


-- 
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de