文章摘要
这篇文章主要介绍了Ruby模块系统中不同方法调用的基本规则和操作。文章重点讲解了模块方法（module method）、私有方法（private method）以及如何将私有方法绑定到模块函数（module_function）。通过示例代码，展示了如何在模块中定义这些方法，以及在模块外类中包含模块后，如何通过实例调用这些方法。
文章的核心内容可以概括为：
1. 模块方法（module_method）可以被模块直接调用，但不能通过对象调用。
2. 私有方法（private method）需要通过绑定到模块函数（module_function）的方式来调用，否则无法通过对象调用。
3. 当试图调用无法被调用的模块方法或私有方法时，会抛出NoMethodError，并给出相应的错误提示。
文章通过代码示例详细演示了这些规则的应用场景，帮助读者理解模块化编程中方法调用的灵活性和限制。
# test.rb
module MyModule
def public_meth
p “a public method, if the module is included to a class , can be call as object.public_meth”
end
def module_method
p “a module method,can be called as module_name.module_method. but can not be call as object.module_method”
end
private
def private_method_to_module_function
p “a private_method, but can be call as module_name.module_method, because it was assigned to module_function”
end
def private_method
p “I am a private method”
end
module_function :module_method, :private_method_to_module_function
end
# test.rb
module MyModule
def public_meth
p “a public method, if the module is included to a class , can be call as object.public_meth”
end
def module_method
p “a module method,can be called as module_name.module_method. but can not be call as object.module_method”
end
private
def private_method_to_module_function
p “a private_method, but can be call as module_name.module_method, because it was assigned to module_function”
end
def private_method
p “I am a private method”
end
module_function :module_method, :private_method_to_module_function
end
MyModule.module_method
MyModule.private_method_to_module_function
begin
MyModule.public_meth
rescue
p “public method can not be called by module_name.public_meth”
end
begin
MyModule.private_method
rescue NoMethodError
p “private method can not be called by module_name.module_method”
end
class MyClass
include MyModule
end
obj=MyClass.new
obj.public_meth
begin
obj.private_method
rescue NoMethodError
p “private method in module can not be call by object.method_name”
end
begin
obj.module_method
rescue NoMethodError
p “module method can not be called by object.method_name, for object, module method is private instance method”
end
#调用
ruby test.rb
“a module method,can be called as module_name.module_method. but can not be call as object.module_method”
“a private_method, but can be call as module_name.module_method, because it was assigned to module_function”
“public method can not be called by module_name.public_meth”
“private method can not be called by module_name.module_method”
“a public method, if the module is included to a class , can be call as object.public_meth”
“private method in module can not be call by object.method_name”
“module method can not be called by object.method_name, for object, module method is private instance method”
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