From: Morton Goldberg <m_goldberg@...>
Date: 2006-08-14T03:52:10+09:00
Subject: Re: Search objects

I'm assuming that you are just implementing this for its educational  
value and not seriously considering implementing a data base with  
this approach. Ruby has built-in and third-party libraries to help  
you implement a data bases application.

I've modified your posting just enough to make a shallow scratch on  
the surface of what can be done to organize and search data. I hope  
it's enough to help you along. Although you said you didn't want to  
consider regular expressions yet, I use them because it makes life  
much simpler to use at least simple regexes.

#! /usr/bin/ruby -w

class Composer

    @@composers = []

    def Composer.find(attrib, regex)
       @@composers.select do |c|
          c.respond_to?(attrib) &&
          c.send(attrib) =~ regex
       end
    end

    def initialize( lname, country )
        @lname    = lname
        @country  = country
        @@composers << self
    end

    attr_accessor :lname, :country
    alias :to_s :inspect

end

Composer.new("Beethoven", "Germany")
Composer.new("DeFalla", "Spain")
Composer.new("Debussy", "France")
Composer.new("Bach", "Germany")
Composer.new("Rodrigo", "Spain")
Composer.new("Ravel", "France")

puts Composer.find(:country, /^Ger/)
puts Composer.find(:lname, /^R/)
# =>
# #<Composer:0x24a18 @country="Germany", @lname="Beethoven">
# #<Composer:0x24964 @country="Germany", @lname="Bach">
# #<Composer:0x24928 @country="Spain", @lname="Rodrigo">
# #<Composer:0x248ec @country="France", @lname="Ravel">

Regards, Morton


On Aug 13, 2006, at 1:54 PM, Dark Ambient wrote:

> I can use some help here:
>
> I've set up this class and objects and would like to "search" it
> similar to the way I would search a database.  At this point I'm not
> concerned with adding regex for more liberal searches.
> Any suggestions ?
>
>
>
> class Composer
>    def initialize( lname, country )
>        @lname    = lname
>        @country  = country
>    end
>        attr_accessor(:lname, :country)
> end
>
> comp1 = Composer.new("Beethoven", "Germany")
> comp2 = Composer.new("DeFalla", "Spain")
> comp3 = Composer.new("Debussy", "France")
>