From: Martin DeMello <martindemello@...>
Date: 2005-02-16T06:39:53+09:00
Subject: Re: Ruby as a domain specific language?

cnmaclean@hotmail.com wrote:
> In our current (proprietary) language, it's something like this:
> 
> Define File 1234
>         Name = "My File"
>         Parent = 5678
>         DataItem = "DataItem 1", Decimal, 10 bytes
>         DataItem = "DataItem 2", Hex, 10 bytes

Ruby would let you come fairly close:

#-----------------------------------------------------------------------#

class DataFile
  def initialize(file_id, &block)
    @file_id = file_id
    $registry[file_id] = self
    @data = []
    instance_eval(&block)
  end
  
  def name(name)
    @name = name
  end

  def parent(pid)
    @parent = pid
  end

  def data_item(*args)
    p args
    @data << args
  end
end

def define(klass, *args, &block)
  klass.new(*args, &block)
end

$registry = {}

define(DataFile, 1234) {
  name  "My File"
  parent 5678
  data_item "DataItem 1", :Decimal, "10 bytes"
  data_item "DataItem 2", :Hex, "10 bytes"
}

p $registry

#-----------------------------------------------------------------------#

If you don't like the string quoting in "10 bytes" you can do

class Fixnum
  def bytes
    self
  end
end

and then write 10.bytes

martin