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| author | Jari Vetoniemi <jari.vetoniemi@indooratlas.com> | 2020-03-16 18:49:26 +0900 | 
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| committer | Jari Vetoniemi <jari.vetoniemi@indooratlas.com> | 2020-03-30 00:39:06 +0900 | 
| commit | fcbf63e62c627deae76c1b8cb8c0876c536ed811 (patch) | |
| tree | 64cb17de3f41a2b6fef2368028fbd00349946994 /jni/ruby/lib/ostruct.rb | |
Fresh start
Diffstat (limited to 'jni/ruby/lib/ostruct.rb')
| -rw-r--r-- | jni/ruby/lib/ostruct.rb | 286 | 
1 files changed, 286 insertions, 0 deletions
| diff --git a/jni/ruby/lib/ostruct.rb b/jni/ruby/lib/ostruct.rb new file mode 100644 index 0000000..f51eb7b --- /dev/null +++ b/jni/ruby/lib/ostruct.rb @@ -0,0 +1,286 @@ +# +# = 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.pension = 300 +# +#   puts person.name     # -> "John Smith" +#   puts person.age      # -> 70 +#   puts person.address  # -> nil +# +# An OpenStruct employs a Hash internally to store the methods and values and +# can even be initialized with one: +# +#   australia = OpenStruct.new(:country => "Australia", :population => 20_000_000) +#   p australia   # -> <OpenStruct country="Australia" population=20000000> +# +# Hash keys with spaces or characters that would normally not be able to use for +# method calls (e.g. ()[]*) will not be immediately available on the +# OpenStruct object as a method for retrieval or assignment, but can be still be +# reached through the Object#send method. +# +#   measurements = OpenStruct.new("length (in inches)" => 24) +#   measurements.send("length (in inches)")  # -> 24 +# +#   data_point = OpenStruct.new(:queued? => true) +#   data_point.queued?                       # -> true +#   data_point.send("queued?=",false) +#   data_point.queued?                       # -> false +# +# Removing the presence of a method requires the execution the delete_field +# method as setting the property value to +nil+ will not remove the method. +# +#   first_pet = OpenStruct.new(:name => 'Rowdy', :owner => 'John Smith') +#   first_pet.owner = nil +#   second_pet = OpenStruct.new(:name => 'Rowdy') +# +#   first_pet == second_pet   # -> false +# +#   first_pet.delete_field(:owner) +#   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 method +# method_missing and define_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", :population => 20_000_000 } +  #   data = OpenStruct.new(hash) +  # +  #   p data        # -> <OpenStruct country="Australia" population=20000000> +  # +  def initialize(hash=nil) +    @table = {} +    if hash +      hash.each_pair do |k, v| +        k = k.to_sym +        @table[k] = v +        new_ostruct_member(k) +      end +    end +  end + +  # Duplicate an OpenStruct object members. +  def initialize_copy(orig) +    super +    @table = @table.dup +    @table.each_key{|key| new_ostruct_member(key)} +  end + +  # +  # Converts the OpenStruct to a hash with keys representing +  # each attribute (as symbols) and their corresponding values +  # Example: +  # +  #   require 'ostruct' +  #   data = OpenStruct.new("country" => "Australia", :population => 20_000_000) +  #   data.to_h   # => {:country => "Australia", :population => 20000000 } +  # +  def to_h +    @table.dup +  end + +  # +  # Yields all attributes (as a symbol) along with the corresponding values +  # or returns an enumerator if not block is given. +  # Example: +  # +  #   require 'ostruct' +  #   data = OpenStruct.new("country" => "Australia", :population => 20_000_000) +  #   data.each_pair.to_a  # => [[:country, "Australia"], [:population, 20000000]] +  # +  def each_pair +    return to_enum(__method__) { @table.size } unless block_given? +    @table.each_pair{|p| yield p} +  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 +    @table.each_key{|key| new_ostruct_member(key)} +  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 +    begin +      @modifiable = true +    rescue +      raise RuntimeError, "can't modify frozen #{self.class}", caller(3) +    end +    @table +  end +  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) +    name = name.to_sym +    unless respond_to?(name) +      define_singleton_method(name) { @table[name] } +      define_singleton_method("#{name}=") { |x| modifiable[name] = x } +    end +    name +  end +  protected :new_ostruct_member + +  def method_missing(mid, *args) # :nodoc: +    mname = mid.id2name +    len = args.length +    if mname.chomp!('=') +      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 +      @table[mid] +    else +      err = NoMethodError.new "undefined method `#{mid}' for #{self}", mid, args +      err.set_backtrace caller(1) +      raise err +    end +  end + +  # Returns the value of a member. +  # +  #   person = OpenStruct.new('name' => 'John Smith', 'age' => 70) +  #   person[:age] # => 70, same as ostruct.age +  # +  def [](name) +    @table[name.to_sym] +  end + +  # +  # Sets the value of a member. +  # +  #   person = OpenStruct.new('name' => 'John Smith', 'age' => 70) +  #   person[:age] = 42 # => equivalent to ostruct.age = 42 +  #   person.age # => 42 +  # +  def []=(name, value) +    modifiable[new_ostruct_member(name)] = value +  end + +  # +  # Remove the named field from the object. Returns the value that the field +  # contained if it was defined. +  # +  #   require 'ostruct' +  # +  #   person = OpenStruct.new('name' => 'John Smith', 'age' => 70) +  # +  #   person.delete_field('name')  # => 'John Smith' +  # +  def delete_field(name) +    sym = name.to_sym +    singleton_class.__send__(:remove_method, sym, "#{sym}=") +    @table.delete sym +  end + +  InspectKey = :__inspect_key__ # :nodoc: + +  # +  # Returns a string containing a detailed summary of the keys and values. +  # +  def inspect +    str = "#<#{self.class}" + +    ids = (Thread.current[InspectKey] ||= []) +    if ids.include?(object_id) +      return str << ' ...>' +    end + +    ids << object_id +    begin +      first = true +      for k,v in @table +        str << "," unless first +        first = false +        str << " #{k}=#{v.inspect}" +      end +      return str << '>' +    ensure +      ids.pop +    end +  end +  alias :to_s :inspect + +  attr_reader :table # :nodoc: +  protected :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. +  # +  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 + +  # Compute a hash-code for this OpenStruct. +  # Two hashes with the same content will have the same hash code +  # (and will be eql?). +  def hash +    @table.hash +  end +end | 
