1 require 'yaml'
2
3 YAML.add_builtin_type("omap") do |type, val|
4 ActiveSupport::OrderedHash[val.map(&:to_a).map(&:first)]
5 end
6
7 # OrderedHash is namespaced to prevent conflicts with other implementations
8 module ActiveSupport
9 class OrderedHash < ::Hash #:nodoc:
10 def to_yaml_type
11 "!tag:yaml.org,2002:omap"
12 end
13
14 def to_yaml(opts = {})
15 YAML.quick_emit(self, opts) do |out|
16 out.seq(taguri, to_yaml_style) do |seq|
17 each do |k, v|
18 seq.add(k => v)
19 end
20 end
21 end
22 end
23
24 # Hash is ordered in Ruby 1.9!
25 if RUBY_VERSION < '1.9'
26 def initialize(*args, &block)
27 super
28 @keys = []
29 end
30
31 def self.[](*args)
32 ordered_hash = new
33
34 if (args.length == 1 && args.first.is_a?(Array))
35 args.first.each do |key_value_pair|
36 next unless (key_value_pair.is_a?(Array))
37 ordered_hash[key_value_pair[0]] = key_value_pair[1]
38 end
39
40 return ordered_hash
41 end
42
43 unless (args.size % 2 == 0)
44 raise ArgumentError.new("odd number of arguments for Hash")
45 end
46
47 args.each_with_index do |val, ind|
48 next if (ind % 2 != 0)
49 ordered_hash[val] = args[ind + 1]
50 end
51
52 ordered_hash
53 end
54
55 def initialize_copy(other)
56 super
57 # make a deep copy of keys
58 @keys = other.keys
59 end
60
61 def []=(key, value)
62 @keys << key if !has_key?(key)
63 super
64 end
65
66 def delete(key)
67 if has_key? key
68 index = @keys.index(key)
69 @keys.delete_at index
70 end
71 super
72 end
73
74 def delete_if
75 super
76 sync_keys!
77 self
78 end
79
80 def reject!
81 super
82 sync_keys!
83 self
84 end
85
86 def reject(&block)
87 dup.reject!(&block)
88 end
89
90 def keys
91 @keys.dup
92 end
93
94 def values
95 @keys.collect { |key| self[key] }
96 end
97
98 def to_hash
99 self
100 end
101
102 def to_a
103 @keys.map { |key| [ key, self[key] ] }
104 end
105
106 def each_key
107 @keys.each { |key| yield key }
108 end
109
110 def each_value
111 @keys.each { |key| yield self[key]}
112 end
113
114 def each
115 @keys.each {|key| yield [key, self[key]]}
116 end
117
118 alias_method :each_pair, :each
119
120 def clear
121 super
122 @keys.clear
123 self
124 end
125
126 def shift
127 k = @keys.first
128 v = delete(k)
129 [k, v]
130 end
131
132 def merge!(other_hash)
133 if block_given?
134 other_hash.each { |k, v| self[k] = key?(k) ? yield(k, self[k], v) : v }
135 else
136 other_hash.each { |k, v| self[k] = v }
137 end
138 self
139 end
140
141 alias_method :update, :merge!
142
143 def merge(other_hash, &block)
144 dup.merge!(other_hash, &block)
145 end
146
147 # When replacing with another hash, the initial order of our keys must come from the other hash -ordered or not.
148 def replace(other)
149 super
150 @keys = other.keys
151 self
152 end
153
154 def invert
155 OrderedHash[self.to_a.map!{|key_value_pair| key_value_pair.reverse}]
156 end
157
158 def inspect
159 "#<OrderedHash #{super}>"
160 end
161
162 private
163 def sync_keys!
164 @keys.delete_if {|k| !has_key?(k)}
165 end
166 end
167 end
168 end