From: Paul Brannan <pbrannan@...>
Date: 2001-11-01T03:56:23+09:00
Subject: [ruby-talk:24010] Re: RubyGems Discussion

On Thu, 1 Nov 2001, Jim Freeze wrote:

> On Wed, 31 Oct 2001, Paul Brannan wrote:
>
> > Another possibility (and I do this with config files) is to put a set of
> > constants in the Ruby file.  You can even temporarily overload [], so you
> > end up with something that looks a LOT like an INI file:

Reading this a second time, it sounds like I'm saying that my config files
have sections.  Actually, they are sectionless, and the section idea was
just something I was thinking about out-load; see below.

> > [section]
> > CONSTANT1 = value1
> > CONSTANT2 = value2
> >
> How do you overload [] to get the above affect?

I do not think it is possible to do this in Ruby 1.6.x.  But I think it
should be possible in 1.7.1 using Array#allocate.  I get a segmentation
fault when I try this, though:

  class Array
    def self.allocate
    end
  end

  [1, 2, 3]

With Ruby 1.6.x, I can prefix the [] with an "X" to get a similar effect.
Here's something I did to get nifty-looking tables in Ruby:

  class Foo
    Rows = Array.new
    def self.[](name, *args)
      Rows.push([name, args])
    end

    X = self
    _ = ' '

    Header =
     [ _,    :x, :y, :z, :a, :b ]
    X[ :foo,  1,  _,  3,  _,  5 ]
    X[ :foo,  _,  2,  _,  4,  _ ]
  end

  puts Foo::Header.join("\t")
  puts Foo::Rows.map { |row| row.join("\t") }

Paul