require 'rdoc/method_attr'

##
# An attribute created by \#attr, \#attr_reader, \#attr_writer or
# \#attr_accessor

class RDoc::Attr < RDoc::MethodAttr

  MARSHAL_VERSION = 1 # :nodoc:

  ##
  # Is the attribute readable ('R'), writable ('W') or both ('RW')?

  attr_accessor :rw

  ##
  # Creates a new Attr with body +text+, +name+, read/write status +rw+ and
  # +comment+.  +singleton+ marks this as a class attribute.

  def initialize(text, name, rw, comment, singleton = false)
    super text, name

    @rw = rw
    @singleton = singleton
    self.comment = comment
  end

  ##
  # Attributes are equal when their names, singleton and rw are identical

  def == other
    self.class == other.class and
      self.name == other.name and
      self.rw == other.rw and
      self.singleton == other.singleton
  end

  ##
  # Add +an_alias+ as an attribute in +context+.

  def add_alias(an_alias, context)
    new_attr = self.class.new(self.text, an_alias.new_name, self.rw,
                              self.comment, self.singleton)

    new_attr.record_location an_alias.file
    new_attr.visibility = self.visibility
    new_attr.is_alias_for = self
    @aliases << new_attr
    context.add_attribute new_attr
    new_attr
  end

  ##
  # The #aref prefix for attributes

  def aref_prefix
    'attribute'
  end

  ##
  # Returns attr_reader, attr_writer or attr_accessor as appropriate.

  def definition
    case @rw
    when 'RW' then 'attr_accessor'
    when 'R'  then 'attr_reader'
    when 'W'  then 'attr_writer'
    end
  end

  ##
  # Dumps this Attr for use by ri.  See also #marshal_load

  def marshal_dump
    [ MARSHAL_VERSION,
      @name,
      full_name,
      @rw,
      @visibility,
      parse(@comment),
      singleton,
    ]
  end

  ##
  # Loads this Attr from +array+.  For a loaded Attr the following
  # methods will return cached values:
  #
  # * #full_name
  # * #parent_name

  def marshal_load array
    @name       = array[1]
    @full_name  = array[2]
    @rw         = array[3]
    @visibility = array[4]
    @comment    = array[5]
    @singleton  = array[6] || false # MARSHAL_VERSION == 0

    @parent_name = @full_name
  end

  def to_s # :nodoc:
    "#{definition} #{name} in: #{parent}"
  end

end