class ActiveSupport::OrderedHash

ActiveSupport::OrderedHash implements a hash that preserves insertion order.

oh = ActiveSupport::OrderedHash.new
oh[:a] = 1
oh[:b] = 2
oh.keys # => [:a, :b], this order is guaranteed

Also, maps the omap feature for YAML files (See yaml.org/type/omap.html) to support ordered items when loading from yaml.

ActiveSupport::OrderedHash is namespaced to prevent conflicts with other implementations.

encode_with(coder) Show source

# File activesupport/lib/active_support/ordered_hash.rb, line 27
def encode_with(coder)
  coder.represent_seq '!omap', map { |k,v| { k => v } }
end

extractable_options?() Show source

# File activesupport/lib/active_support/ordered_hash.rb, line 44
def extractable_options?
  true
end

Returns true to make sure that this hash is extractable via Array#extract_options!

nested_under_indifferent_access() Show source

# File activesupport/lib/active_support/ordered_hash.rb, line 39
def nested_under_indifferent_access
  self
end

reject(*args, &block) Show source

# File activesupport/lib/active_support/ordered_hash.rb, line 35
def reject(*args, &block)
  dup.tap { |hash| hash.reject!(*args, &block) }
end

select(*args, &block) Show source

# File activesupport/lib/active_support/ordered_hash.rb, line 31
def select(*args, &block)
  dup.tap { |hash| hash.select!(*args, &block) }
end

to_yaml_type() Show source

# File activesupport/lib/active_support/ordered_hash.rb, line 23
def to_yaml_type
  "!tag:yaml.org,2002:omap"
end