运算符重载和Ruby风格的运算符重载程序大概意思是，重新定义，文件类的比较方法。只要目录和文件名一样，就说这两个文件类一样。ruby的
class DocumentPointer attr_reader :folder, :name def initialize( folder, name ) @folder = folder @name = name end def ==(other) return true if other.equal?(self) return false unless other.instance_of?(self.class) folder == other.folder && name == other.name endend
class DocumentPointer attr_reader :folder, :name def initialize( folder, name ) @folder = folder @name = name end def ==(other) return false unless other.respond_to?(:folder) return false unless other.respond_to?(:name) folder == other.folder && name == other.name endend
当我们用的时候
#Asymmetryclass ContractIdentifier < DocumentIdentifierenddoc_id = DocumentIdentifier.new( 'contracts', 'Book Deal' )con_id = ContractIdentifier.new( 'contracts', 'Book Deal' )puts "They are equal!" if doc_id == con_id
会出现子类没有父类方法的问题，在contractIdentifier里没有重载操作符。那么
class VersionedIdentifier < DocumentIdentifier attr_reader :version def initialize(folder, name, version) super(folder, name) Well-Behaved Equality 147 @version = version end def ==(other) if other.instance_of? VersionedIdentifier other.folder == folder && other.name == name && other.version == version elsif other.instance_of? DocumentIdentifier other.folder == folder && other.name == name else false end endend
想想我的影子，我会在你身后给你一个拥抱;
