Class: Newstile::Utils::OrderedHash

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

Overview

A very simple class mimicking the most used methods of a Hash. The difference to a normal Hash is that a OrderedHash retains the insertion order of the keys.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(hash = {}) ⇒ OrderedHash

Initialize the OrderedHash object, optionally with an hash. If the optional hash is used, there is no special order imposed on the keys (additionally set keys will be stored in insertion order). An OrderedHash object may be used instead of a hash to provide the initial data.



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# File 'lib/newstile/utils/ordered_hash.rb', line 40

def initialize(hash = {})
  if hash.kind_of?(OrderedHash)
    @data, @order = hash.instance_eval { [@data.dup, @order.dup] }
  else
    @data = hash || {}
    @order = @data.keys
  end
end

Instance Attribute Details

#data ⇒ Object (readonly)

Direct access to the hash with the key-value pairs. May not be used to modify the data!



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# File 'lib/newstile/utils/ordered_hash.rb', line 34

def data
  @data
end

Instance Method Details

#[](key) ⇒ Object

Return the value for the key.



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# File 'lib/newstile/utils/ordered_hash.rb', line 55

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

#[]=(key, val) ⇒ Object

Set the value for the key to val.



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# File 'lib/newstile/utils/ordered_hash.rb', line 60

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/newstile/utils/ordered_hash.rb', line 66

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

#each ⇒ Object

Iterate over the stored keys in insertion order.



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# File 'lib/newstile/utils/ordered_hash.rb', line 50

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

#inspect ⇒ Object

:nodoc:



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# File 'lib/newstile/utils/ordered_hash.rb', line 71

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