Class: Kramdown::Utils::OrderedHash

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/kramdown/utils/ordered_hash.rb

Overview

A partial hash implementation which preserves the insertion order of the keys.

Note that this class is only used on Ruby 1.8 since the built-in Hash on Ruby 1.9 automatically preserves the insertion order. However, to remain compatibility only the methods defined in this class may be used when working with OrderedHash on Ruby 1.9.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ OrderedHash

Initialize the OrderedHash object.



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# File 'lib/kramdown/utils/ordered_hash.rb', line 26

def initialize
  @data =  {}
  @order = []
end

Instance Method Details

#==(other) ⇒ Object

:nodoc:



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# File 'lib/kramdown/utils/ordered_hash.rb', line 75

def ==(other) #:nodoc:
  return false unless other.kind_of?(self.class)
  @data == other.instance_variable_get(:@data) && @order == other.instance_variable_get(:@order)
end

#[](key) ⇒ Object

Return the value for the key.



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# File 'lib/kramdown/utils/ordered_hash.rb', line 37

def [](key)
  @data[key]
end

#[]=(key, val) ⇒ Object

Set the value for the key to val.



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# File 'lib/kramdown/utils/ordered_hash.rb', line 52

def []=(key, val)
  @order << key if !@data.has_key?(key)
  @data[key] = val
end

#delete(key) ⇒ Object

Delete the key.



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# File 'lib/kramdown/utils/ordered_hash.rb', line 58

def delete(key)
  @order.delete(key)
  @data.delete(key)
end

#dup ⇒ Object

:nodoc:



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# File 'lib/kramdown/utils/ordered_hash.rb', line 68

def dup #:nodoc:
  new_object = super
  new_object.instance_variable_set(:@data, @data.dup)
  new_object.instance_variable_set(:@order, @order.dup)
  new_object
end

#each ⇒ Object

Iterate over the stored keys in insertion order.



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# File 'lib/kramdown/utils/ordered_hash.rb', line 32

def each
  @order.each {|k| yield(k, @data[k])}
end

#empty? ⇒ Boolean

Return true if the hash contains no keys.

Returns:

  • (Boolean) 


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# File 'lib/kramdown/utils/ordered_hash.rb', line 47

def empty?
  @data.empty?
end

#has_key?(key) ⇒ Boolean

Return true if the hash contains the key.

Returns:

  • (Boolean) 


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# File 'lib/kramdown/utils/ordered_hash.rb', line 42

def has_key?(key)
  @data.has_key?(key)
end

#inspect ⇒ Object

:nodoc:



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# File 'lib/kramdown/utils/ordered_hash.rb', line 80

def inspect #:nodoc:
  "{" + map {|k,v| "#{k.inspect}=>#{v.inspect}"}.join(" ") + "}"
end

#merge!(other) ⇒ Object 



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# File 'lib/kramdown/utils/ordered_hash.rb', line 63

def merge!(other)
  other.each {|k,v| self[k] = v}
  self
end