NAME
  arrayfields.rb

URIS
  http://www.codeforpeople.com/lib/ruby/
  http://rubyforge.org/projects/codeforpeople/

SYNOPSIS
    require 'arrayfields'

    a = Arrayfields.new :k, :v, :a, :b

    p a[:k]        #=> :v
    p a[:a]        #=> :b
    p a.fields     #=> [:k, :a]
    p a.values     #=> [:v, :b]
    p a            #=> [:v, :b]
    p a.to_hash    #=> {:k => :v, :a => :b} 
    p a.pairs      #=> [[:k, :v], [:a, :b]]

    a[:foo] = :bar

    p a[:foo]      #=> :bar
    p a.fields     #=> [:k, :a, :foo]

 AND

    require 'arrayfields'  

    fields = 'name', 'age'
    a = [ 'zaphod', 42 ]

    a.fields = fields

    a['name']                #=> 'zaphod'
    a[:name ]                #=> 'zaphod'
    a.indices 'name', 'age'  #=> [ 'zaphod', 42 ]

DESCRIPTION
  allow keyword access to array instances.  arrayfields works by adding only a
  few methods to arrays, namely #fields= and fields, but the #fields= method is
  hooked to extend an array on a per object basis.  in otherwords __only__ those
  arrays whose fields are set will have auto-magical keyword access bestowed on
  them - all other arrays remain unaffected.  arrays with keyword access require
  much less memory when compared to hashes/objects and yet still provide fast
  lookup and preserve data order.

LIST OF OVERRIDDEN METHODS
  Array#[]
  Array#slice
  Array#[]=
  Array#at
  Array#delete_at
  Array#fill
  Array#values_at
  Array#indices
  Array#indexes
  Array#slice!

LIST OF HASH-LIKE METHODS
  Array#each_with_field
  Array#each_pair
  Array#each_key
  Array#each_value
  Array#fetch
  Array#has_key?
  Array#member?
  Array#key?
  Array#has_value?
  Array#value?
  Array#keys
  Array#store
  Array#values
  Array#to_hash
  Array#to_h
  Array#update
  Array#replace
  Array#invert
  Array#pairs

LIST OF ADDED Array METHODS
  Array#fields=
  Array#fields

LIST OF ADDED Array CLASS METHODS
  Array.fields/Array.struct

SAMPLES
  @samples

AUTHOR
  ara.t.howard@gmail.com

HISTORY
  4.6.0
    - Array#fields getter acts as setter if arg given, eg

        a = []

        a.fields %w( a b c )
        a['c'] = 42

  4.4.0:
    - working dup method worked in, also deepcopy and clone

  4.3.0:
    - a dup like method, named 'copy' and based on clone, is added to Arrayfields objects

  4.2.0:
    - a dup impl apparently caused some confusion with both rake and rails, so
      this release undoes that impl and should be considered a critical bugfix
      release

  4.1.0:
    - improved Array.struct method, see sample/e.rb

  4.0.0:
    - added Arrayfields.new(*arbitrary_evenly_numbered_list_of_objects)
    - added #to_pairs and #pairs
    - tried but failed to recall what happend for version 3.8
    - changed Array.fields to == Arrayfields.new (used to alias Array.struct)
    - added impl of Fieldable#dup that sets fields in dupped object

  3.7.0:
    - multiton pattern clean up, thanks gavin kistner!
    - mods for ruby 1.8.6 (alias bug in 1.8.6 i think)
    - added PseudoHash class
    - added Array.struct/fields class generator

  3.6.0:
    - made string/symbol keys interchangeable

        list = [0, 1, 2]
        list.fields = %w( a b c )
        p list['a'] #=> 0
        p list[:a] #=> 0
    

  3.5.0:
    - added more hash-like methods
      - update
      - replace
      - invert

  3.4.0:
    - added FieldedArray[] ctor
    - added methods to make Arrays with fields set behave more closely to Hashes
      - each_pair 
      - each_key
      - each_value
      - fetch
      - has_key?
      - member?
      - key?
      - has_value?
      - value?
      - keys?
      - store
      - values

  3.3.0:
    - added gemspec file - thnx Assaph Mehr
    - added FieldedArray proxy class which minimizes modifications to class
      Array and allow ArrayFields to work (potientially) other arraylike object.
      thnks Sean O'Dell
    - added ArrayFields#to_hash method - this seems like an obvious one to add!
    - remedied bug where using append feature of assigning with unknow field
      appedended but did not append to acutal fields
    - added samples
    - created rubyforge accnt @ http://rubyforge.org/projects/arrayfields/ 

  3.2.0:
    - precedence fix in many methods - thnx. nobu
    - test for #slice! were not being run - corrected
    - added test for appeding via "a['new_field'] = 42"

  3.1.0:
    - added FieldSet class to reduce ram - thnx. Kirk Haines for profiliing
      memory and prompting this change

    - interface changed every so slightly so

        a.fields = 'a', 'b', 'c'

      is not allowed.  use

        a.fields = %w(a b c) 

      or

        a.fields = ['a', 'b', 'c']


  3.0.0:
    - added unit tests
