vendor/rails/activesupport/lib/active_support/ordered_hash.rb

   1 # OrderedHash is namespaced to prevent conflicts with other implementations
   2 module ActiveSupport
   3   # Hash is ordered in Ruby 1.9!
   4   if RUBY_VERSION >= '1.9'
   5     OrderedHash = ::Hash
   6   else
   7     class OrderedHash < Hash #:nodoc:
   8       def initialize(*args, &block)
   9         super
  10         @keys = []
  11       end
  12
  13       def initialize_copy(other)
  14         super
  15         # make a deep copy of keys
  16         @keys = other.keys
  17       end
  18
  19       def []=(key, value)
  20         @keys << key if !has_key?(key)
  21         super
  22       end
  23
  24       def delete(key)
  25         if has_key? key
  26           index = @keys.index(key)
  27           @keys.delete_at index
  28         end
  29         super
  30       end
  31
  32       def delete_if
  33         super
  34         sync_keys!
  35         self
  36       end
  37
  38       def reject!
  39         super
  40         sync_keys!
  41         self
  42       end
  43
  44       def reject(&block)
  45         dup.reject!(&block)
  46       end
  47
  48       def keys
  49         @keys.dup
  50       end
  51
  52       def values
  53         @keys.collect { |key| self[key] }
  54       end
  55
  56       def to_hash
  57         self
  58       end
  59
  60       def each_key
  61         @keys.each { |key| yield key }
  62       end
  63
  64       def each_value
  65         @keys.each { |key| yield self[key]}
  66       end
  67
  68       def each
  69         @keys.each {|key| yield [key, self[key]]}
  70       end
  71
  72       alias_method :each_pair, :each
  73
  74       def clear
  75         super
  76         @keys.clear
  77         self
  78       end
  79
  80       def shift
  81         k = @keys.first
  82         v = delete(k)
  83         [k, v]
  84       end
  85
  86       def merge!(other_hash)
  87         other_hash.each {|k,v| self[k] = v }
  88         self
  89       end
  90
  91       def merge(other_hash)
  92         dup.merge!(other_hash)
  93       end
  94
  95       def inspect
  96         "#<OrderedHash #{super}>"
  97       end
  98
  99     private
 100
 101       def sync_keys!
 102         @keys.delete_if {|k| !has_key?(k)}
 103       end
 104     end
 105   end
 106 end