class Tryouts::OrderedHash

def == hsh2
    return false if @order != hsh2.order
    super hsh2
end

def [] *args
  hsh = Tryouts::OrderedHash.new
  if Hash === args[0]
    hsh.replace args[0]
  elsif (args.size % 2) != 0
    raise ArgumentError, "odd number of elements for Hash"
  else
    0.step(args.size - 1, 2) do |a|
      b = a + 1
      hsh[args[a]] = args[b]
    end
  end
  hsh
end

def __class__
  Tryouts::OrderedHash
end

def class
  Hash
end

def clear
    @order = []
    super
end

def delete key
    @order.delete key
    super
end

def delete_if
    @order.clone.each { |k| 
        delete k if yield(k)
    }
    self
end

def each
    @order.each { |k| yield k,self[k] }
    self
end

def each_key
    @order.each { |k| yield k }
    self
end

def each_value
    @order.each { |k| yield self[k] }
    self
end

def each_with_index
  @order.each_with_index { |k, index| yield k, self[k], index }
  self
end

def first
  {@order.first => self[@order.first]}
end

def initialize(*a, &b)
  super
  @order = []
end

def inspect
    ary = []
    each {|k,v| ary << k.inspect + "=>" + v.inspect}
    '{' + ary.join(", ") + '}'
end

def invert
    hsh2 = Hash.new    
    @order.each { |k| hsh2[self[k]] = k }
    hsh2
end

def keys
    @order
end

def last
  {@order.last => self[@order.last]}
end

def merge hsh2
    ##self.dup update(hsh2)   ## 2009-05-12 -- delano
    update hsh2               ## dup doesn't take an argument
                              ## and there's no need for it here
end

def pop
    key = @order.last
    key ? [key,delete(key)] : nil
end

def push k,v
    unless self.include? k
        @order.push k
        orig_store(k,v)
        true
    else
        false
    end
end

def reject &block
    self.dup.delete_if &block
end

def reject! &block
    hsh2 = reject &block
    self == hsh2 ? nil : hsh2
end

def replace hsh2
    @order = hsh2.keys 
    super hsh2
end

def select
    ary = []
    each { |k,v| ary << [k,v] if yield k,v }
    ary
end

def shift
    key = @order.first
    key ? [key,delete(key)] : super
end

def store a,b
    @order.push a unless has_key? a
    super a,b
end

def store_only a,b
    store a,b
end

def to_a
    ary = []
    each { |k,v| ary << [k,v] }
    ary
end

def to_s
    self.to_a.to_s
end

def to_yaml opts = {}
  begin
    @__yaml_inline ? @__yaml_inline_meth[ opts ] : super
  rescue
    @to_yaml_style = :inline
    super
  end
end

def unshift k,v
    unless self.include? k
        @order.unshift k
        orig_store(k,v)
        true
    else
        false
    end
end

def update hsh2
    hsh2.each { |k,v| self[k] = v }
    self
end

def values
    ary = []
    @order.each { |k| ary.push self[k] }
    ary
end

def yaml_inline!() self.yaml_inline = true end

def yaml_inline= bool
  if respond_to?("to_yaml_style")
    self.to_yaml_style = :inline
  else
    unless defined? @__yaml_inline_meth
      @__yaml_inline_meth =
        lambda {|opts|
          YAML::quick_emit(object_id, opts) {|emitter|
            emitter << '{ ' << map{|kv| kv.join ': '}.join(', ') << ' }'
          }
        }
      class << self
        def to_yaml opts = {}
          begin
            @__yaml_inline ? @__yaml_inline_meth[ opts ] : super
          rescue
            @to_yaml_style = :inline
            super
          end
        end
      end
    end
  end
  @__yaml_inline = bool
end