Class: Hash

Inherits:
Object
  • Object
show all
Defined in:
lib/enumerate_hash_values/core_extensions/hash.rb

Overview

:nodoc:

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.new_empty(options = {}) ⇒ Object 



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# File 'lib/enumerate_hash_values/core_extensions/hash.rb', line 85

def new_empty(options = {})
  new_hash = allocate
  new_hash.copy_traits!(options[:traits_from]) if options[:traits_from]
  new_hash
end

Instance Method Details

#copy ⇒ Object

Shortcut to perform a shallow copy of the hash to a new instance.



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# File 'lib/enumerate_hash_values/core_extensions/hash.rb', line 51

def copy
  collect_values { |value| value }
end

#copy_traits!(hash) ⇒ Object

Copy any traits (such as defaults) from the specified hash.



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# File 'lib/enumerate_hash_values/core_extensions/hash.rb', line 56

def copy_traits!(hash)
  self.default = hash.default

  # Unfortunately, we can only transfer Hash#default_proc in Ruby 1.9 because
  # Hash#default_proc= is only defined in Ruby 1.9.
  self.default_proc = hash.default_proc if respond_to?(:default_proc=)

  self
end

#inject_into_empty(hash_class = self.class, options = {}) ⇒ Object

Shortcut to inject into an empty hash.

Raises:

  • (ArgumentError) 


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# File 'lib/enumerate_hash_values/core_extensions/hash.rb', line 67

def inject_into_empty(hash_class = self.class, options = {})
  raise ArgumentError.new("#{hash_class} is not a Hash") unless hash_class.ancestors.include?(Hash)

  # If not explicitly specified, copy traits into the new hash if it is of
  # the same class.
  copy_traits = options.has_key?(:copy_traits) ? options[:copy_traits] : (hash_class == self.class)

  new_hash_options = {}
  new_hash_options[:traits_from] = self if copy_traits
  new_hash = hash_class.new_empty(new_hash_options)

  inject(new_hash) do |hash, key_value_pair|
    yield hash, key_value_pair
  end
end