core_exts.rb

##  Like a Symbol#to_proc but for array
class Array
  def to_proc
    lambda {|object| 
      self.map{|symbol| object.send(symbol.to_sym)}
    }
  end
end


## Some class
class Person
  attr_accessor :id, :name
  
  def initialize()
    @id = 1
    @name = 'John'
  end 
end


## Usage
crowd = []
5.times{ crowd << Person.new }

puts crowd.collect(&[:id, :name]).inspect
puts crowd.collect(&['name', 'id']).inspect
=>
[[1, "John"], [1, "John"], [1, "John"], [1, "John"], [1, "John"]]
[["John", 1], ["John", 1], ["John", 1], ["John", 1], ["John", 1]]


## A different implementation that empower you to call symbol#to_proc method with parameters
# http://www.sanityinc.com/articles/adding-array-to-proc-to-ruby