ok
Direktori : /opt/alt/ruby25/lib64/ruby/2.5.0/ |
Current File : //opt/alt/ruby25/lib64/ruby/2.5.0/ostruct.rb |
# frozen_string_literal: true # # = ostruct.rb: OpenStruct implementation # # Author:: Yukihiro Matsumoto # Documentation:: Gavin Sinclair # # OpenStruct allows the creation of data objects with arbitrary attributes. # See OpenStruct for an example. # # # An OpenStruct is a data structure, similar to a Hash, that allows the # definition of arbitrary attributes with their accompanying values. This is # accomplished by using Ruby's metaprogramming to define methods on the class # itself. # # == Examples # # require "ostruct" # # person = OpenStruct.new # person.name = "John Smith" # person.age = 70 # # person.name # => "John Smith" # person.age # => 70 # person.address # => nil # # An OpenStruct employs a Hash internally to store the attributes and values # and can even be initialized with one: # # australia = OpenStruct.new(:country => "Australia", :capital => "Canberra") # # => #<OpenStruct country="Australia", capital="Canberra"> # # Hash keys with spaces or characters that could normally not be used for # method calls (e.g. <code>()[]*</code>) will not be immediately available # on the OpenStruct object as a method for retrieval or assignment, but can # still be reached through the Object#send method. # # measurements = OpenStruct.new("length (in inches)" => 24) # measurements.send("length (in inches)") # => 24 # # message = OpenStruct.new(:queued? => true) # message.queued? # => true # message.send("queued?=", false) # message.queued? # => false # # Removing the presence of an attribute requires the execution of the # delete_field method as setting the property value to +nil+ will not # remove the attribute. # # first_pet = OpenStruct.new(:name => "Rowdy", :owner => "John Smith") # second_pet = OpenStruct.new(:name => "Rowdy") # # first_pet.owner = nil # first_pet # => #<OpenStruct name="Rowdy", owner=nil> # first_pet == second_pet # => false # # first_pet.delete_field(:owner) # first_pet # => #<OpenStruct name="Rowdy"> # first_pet == second_pet # => true # # # == Implementation # # An OpenStruct utilizes Ruby's method lookup structure to find and define the # necessary methods for properties. This is accomplished through the methods # method_missing and define_singleton_method. # # This should be a consideration if there is a concern about the performance of # the objects that are created, as there is much more overhead in the setting # of these properties compared to using a Hash or a Struct. # class OpenStruct # # Creates a new OpenStruct object. By default, the resulting OpenStruct # object will have no attributes. # # The optional +hash+, if given, will generate attributes and values # (can be a Hash, an OpenStruct or a Struct). # For example: # # require "ostruct" # hash = { "country" => "Australia", :capital => "Canberra" } # data = OpenStruct.new(hash) # # data # => #<OpenStruct country="Australia", capital="Canberra"> # def initialize(hash=nil) @table = {} if hash hash.each_pair do |k, v| k = k.to_sym @table[k] = v end end end # Duplicates an OpenStruct object's Hash table. def initialize_copy(orig) # :nodoc: super @table = @table.dup end # # Converts the OpenStruct to a hash with keys representing # each attribute (as symbols) and their corresponding values. # # require "ostruct" # data = OpenStruct.new("country" => "Australia", :capital => "Canberra") # data.to_h # => {:country => "Australia", :capital => "Canberra" } # def to_h @table.dup end # # :call-seq: # ostruct.each_pair {|name, value| block } -> ostruct # ostruct.each_pair -> Enumerator # # Yields all attributes (as symbols) along with the corresponding values # or returns an enumerator if no block is given. # # require "ostruct" # data = OpenStruct.new("country" => "Australia", :capital => "Canberra") # data.each_pair.to_a # => [[:country, "Australia"], [:capital, "Canberra"]] # def each_pair return to_enum(__method__) { @table.size } unless block_given? @table.each_pair{|p| yield p} self end # # Provides marshalling support for use by the Marshal library. # def marshal_dump @table end # # Provides marshalling support for use by the Marshal library. # def marshal_load(x) @table = x end # # Used internally to check if the OpenStruct is able to be # modified before granting access to the internal Hash table to be modified. # def modifiable? # :nodoc: begin @modifiable = true rescue raise RuntimeError, "can't modify frozen #{self.class}", caller(3) end @table end private :modifiable? # ::Kernel.warn("do not use OpenStruct#modifiable", uplevel: 1) alias modifiable modifiable? # :nodoc: protected :modifiable # # Used internally to defined properties on the # OpenStruct. It does this by using the metaprogramming function # define_singleton_method for both the getter method and the setter method. # def new_ostruct_member!(name) # :nodoc: name = name.to_sym unless singleton_class.method_defined?(name) define_singleton_method(name) { @table[name] } define_singleton_method("#{name}=") {|x| modifiable?[name] = x} end name end private :new_ostruct_member! # ::Kernel.warn("do not use OpenStruct#new_ostruct_member", uplevel: 1) alias new_ostruct_member new_ostruct_member! # :nodoc: protected :new_ostruct_member def freeze @table.each_key {|key| new_ostruct_member!(key)} super end def respond_to_missing?(mid, include_private = false) # :nodoc: mname = mid.to_s.chomp("=").to_sym @table&.key?(mname) || super end def method_missing(mid, *args) # :nodoc: len = args.length if mname = mid[/.*(?==\z)/m] if len != 1 raise ArgumentError, "wrong number of arguments (#{len} for 1)", caller(1) end modifiable?[new_ostruct_member!(mname)] = args[0] elsif len == 0 # and /\A[a-z_]\w*\z/ =~ mid # if @table.key?(mid) new_ostruct_member!(mid) unless frozen? @table[mid] end else begin super rescue NoMethodError => err err.backtrace.shift raise end end end # # :call-seq: # ostruct[name] -> object # # Returns the value of an attribute. # # require "ostruct" # person = OpenStruct.new("name" => "John Smith", "age" => 70) # person[:age] # => 70, same as person.age # def [](name) @table[name.to_sym] end # # :call-seq: # ostruct[name] = obj -> obj # # Sets the value of an attribute. # # require "ostruct" # person = OpenStruct.new("name" => "John Smith", "age" => 70) # person[:age] = 42 # equivalent to person.age = 42 # person.age # => 42 # def []=(name, value) modifiable?[new_ostruct_member!(name)] = value end # # :call-seq: # ostruct.dig(name, ...) -> object # # Extracts the nested value specified by the sequence of +name+ # objects by calling +dig+ at each step, returning +nil+ if any # intermediate step is +nil+. # # require "ostruct" # address = OpenStruct.new("city" => "Anytown NC", "zip" => 12345) # person = OpenStruct.new("name" => "John Smith", "address" => address) # # person.dig(:address, "zip") # => 12345 # person.dig(:business_address, "zip") # => nil # # data = OpenStruct.new(:array => [1, [2, 3]]) # # data.dig(:array, 1, 0) # => 2 # data.dig(:array, 0, 0) # TypeError: Integer does not have #dig method # def dig(name, *names) begin name = name.to_sym rescue NoMethodError raise TypeError, "#{name} is not a symbol nor a string" end @table.dig(name, *names) end # # Removes the named field from the object. Returns the value that the field # contained if it was defined. # # require "ostruct" # # person = OpenStruct.new(name: "John", age: 70, pension: 300) # # person.delete_field("age") # => 70 # person # => #<OpenStruct name="John", pension=300> # # Setting the value to +nil+ will not remove the attribute: # # person.pension = nil # person # => #<OpenStruct name="John", pension=nil> # def delete_field(name) sym = name.to_sym begin singleton_class.__send__(:remove_method, sym, "#{sym}=") rescue NameError end @table.delete(sym) do raise NameError.new("no field `#{sym}' in #{self}", sym) end end InspectKey = :__inspect_key__ # :nodoc: # # Returns a string containing a detailed summary of the keys and values. # def inspect ids = (Thread.current[InspectKey] ||= []) if ids.include?(object_id) detail = ' ...' else ids << object_id begin detail = @table.map do |key, value| " #{key}=#{value.inspect}" end.join(',') ensure ids.pop end end ['#<', self.class, detail, '>'].join end alias :to_s :inspect attr_reader :table # :nodoc: protected :table alias table! table # # Compares this object and +other+ for equality. An OpenStruct is equal to # +other+ when +other+ is an OpenStruct and the two objects' Hash tables are # equal. # # require "ostruct" # first_pet = OpenStruct.new("name" => "Rowdy") # second_pet = OpenStruct.new(:name => "Rowdy") # third_pet = OpenStruct.new("name" => "Rowdy", :age => nil) # # first_pet == second_pet # => true # first_pet == third_pet # => false # def ==(other) return false unless other.kind_of?(OpenStruct) @table == other.table! end # # Compares this object and +other+ for equality. An OpenStruct is eql? to # +other+ when +other+ is an OpenStruct and the two objects' Hash tables are # eql?. # def eql?(other) return false unless other.kind_of?(OpenStruct) @table.eql?(other.table!) end # Computes a hash code for this OpenStruct. # Two OpenStruct objects with the same content will have the same hash code # (and will compare using #eql?). # # See also Object#hash. def hash @table.hash end end