From: "ara.t.howard" <ara.t.howard@...>
Date: 2010-10-29T08:32:24+09:00
Subject: [ANN] map-1.5.0

NAME
  map.rb

SYNOPSIS
  the ruby container you've always wanted: a string/symbol indifferent
ordered
  hash that works in all rubies

  maps are rad ordered hashes that are both ordered, string/symbol
  indifferent, and have all sorts of sweetness like recursive
convertsion,
  more robust implementation than HashWithIndifferentAccess, support
for
  struct like (map.foo) access, and support for option/keyword access
which
  avoids several nasty classes of errors in many ruby libraries

INSTALL
  gem install map

URI
  http://github.com/ahoward/map

DESCRIPTION

# maps are always ordered.  constructing them in an ordered fashion
builds
# them that way, although the normal hash contructor is also supported
#
  m = Map[:k, :v, :key, :val]
  m = Map(:k, :v, :key, :val)

  m = Map[[:k, :v], [:key, :val]]
  m = Map[{:k => :v, :key => :val}]


  m = Map.new
  m[:a] = 0
  m[:b] = 1
  m[:c] = 2

  p m.keys #=> ['a','b','c']  ### always ordered!
  p m.keys #=> [0,1,2]        ### always ordered!

# maps don't care between symbol and string keys
#
  p m[:a]  #=> 0
  p m["a"] #=> 0

# many functions operate in a way one would expect from an ordered
container
#
  m.update(:k2 => :v2)
  m.update(:k2, :v2)

# maps keep mapiness for even deep operations
#
  m.update :nested => {:hashes => {:are => :converted}}

# maps can give back clever little struct objects
#
  m = Map(:foo => {:bar => 42})
  s = m.struct
  p s.foo.bar #=> 42

# because option parsing is such a common use case for needing string/
symbol
# indifference map.rb comes out of the box for option support
#
  def foo(*args, &block)
    opts = Map.options(args)
    a = opts.getopt(:a)
    b = opts.getopt(:b, :default => false)
  end


  opts = Map.options(:a => 42, :b => nil, :c => false)
  opts.getopt(:a)                    #=> 42
  opts.getopt(:b)                    #=> nil
  opts.getopt(:b, :default => 42)    #=> 42
  opts.getopt(:c)                    #=> false
  opts.getopt(:d, :default => false) #=> false

# this avoids such bugs as
#
  options = {:read_only => true}
  read_only = options[:read_only] || true  # should be false but is
true

# with options this becomes
#
  options = Map.options(:read_only => true)
  read_only = options.getopt(:read_only, :default => false) #=> true

# tons more goodness, see test/map_test.rb
#

USAGE
  again, see test/map_test.rb


enjoy.