[英]variable is not properly set after renaming into heir
I know how to fix it (see my solution @bottom) but don't understand why this compilation error occurs, as in my mind, renamed attributes should be created by the Precursor into default_create.我知道如何修复它(请参阅我的解决方案@bottom)但不明白为什么会发生此编译错误,因为在我看来,重命名的属性应该由 Precursor 创建到 default_create 中。 Why isn't that so?
为什么不是这样?
inherit
ANY
redefine
default_create
end
feature {NONE} -- Initialization
default_create
do
create current_day
create current_month
create current_year
Precursor
end
feature -- Access
current_day,
current_month,
current_year: ENERGY_UNIT
end
inherit
NRJ_ENTITY
end
inherit
NRJ_ENTITY
end
inherit
NRJ_GENERATOR
rename
current_day as current_day_generation,
current_month as current_month_generation,
current_year as current_year_generation
redefine
default_create
select
current_day_generation,
current_month_generation,
current_year_generation
end
NRJ_CONSUMER
rename
current_day as current_day_consumption,
current_month as current_month_consumption,
current_year as current_year_consumption
redefine
default_create
end
feature {NONE} -- Initialize
default_create
do
Precursor {NRJ_GENERATOR}
Precursor {NRJ_CONSUMER}
end
end结尾
default_create
do
create current_day_consumption
create current_month_consumption
create current_year_consumption
Precursor {NRJ_CONSUMER}
Precursor {NRJ_GENERATOR}
end
Class NRJ_GENERATOR_CONSUMER
has two versions of every attribute from NRJ_ENTITY
.类
NRJ_GENERATOR_CONSUMER
具有从每个属性的两个版本NRJ_ENTITY
。 For example, current_day
has versions current_day_generation
and current_day_consumption
.例如,
current_day
有current_day_generation
和current_day_consumption
版本。 The code in NRJ_ENTITY
works only with one version of current_day
, possibly renamed. NRJ_ENTITY
的代码仅适用于current_day
一个版本,可能已重命名。 It has no idea about the second version.它不知道第二个版本。 In order to tell which version of the replicated attribute (or a feature, in general) should be used, the class with the replication should
select
exactly one suitable version.为了确定应该使用哪个版本的复制属性(或一般特征),具有复制的类应该
select
一个合适的版本。
In the example, the selected version is current_day_generation
.在示例中,所选版本为
current_day_generation
。 Therefore, default_create
inherited from NRJ_ENTITY
initializes it and not the other attribute.因此,从
NRJ_ENTITY
继承的default_create
初始化它而不是其他属性。 In other words, with replication,换句话说,通过复制,
create current_day
is not automatically translated into不会自动翻译成
create current_day_generation
create current_day_consumption
but just into但只是进入
create current_day_generation -- The selected version.
This explains why you need the fix you are referring to.这解释了为什么您需要所指的修复程序。
Also, note that the instructions Precursor {NRJ_CONSUMER}
and Precursor {NRJ_GENERATOR}
call exactly the same version of default_create
defined in NRJ_ENTITY
, so one of the calls can be safely removed.另请注意,指令
Precursor {NRJ_CONSUMER}
和Precursor {NRJ_GENERATOR}
调用NRJ_ENTITY
定义的default_create
的完全相同版本,因此可以安全地删除其中一个调用。
Summary: Inherited code deals only with selected versions of replicated features.总结:继承的代码只处理复制功能的选定版本。
Corollary: Non-selected versions of replicated attributes have to be explicitly initialized in the class where they are replicated.推论:复制属性的非选择版本必须在复制它们的类中显式初始化。
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