Question

我学习埃菲尔，我知道在C我可以做这样的事情来设置头文件，例如::

#define USER_ACTIVE     0
#define WHEN_SOMETHING  1
#define WHERE_HAND      2
#define WHERE_ACTIVE    3
#define WHERE_GOOD      4

并且还有例如：

typedef struct something {
   int user;
   int where;
   int somethingelse
}something;

甚至是集合函数指针：

typedef struct decisions {
  void (*init)(struct something *s, int who, double factor);
}decisions;

对于几乎所有普通的编程语言而言，它都是同一个故事..我一直在寻找fx here，除了它没有很好的翻译，因为我很难掌握如何这样做..所以这种语言有“正常”的方式吗？或所有必须做意大利面风格？

谢谢

Answer 1

这个例子可以翻译成：

class MY_CONSTANTS feature
    user_active: INTEGER = 0
    when_something: INTEGER = 1
    where_hand: INTEGER = 2
    where_active: INTEGER = 3
    where_good: INTEGER = 4
end

class SOMETHING
feature -- Access
    user: INTEGER
    where: INTEGER
    somethingelse: INTEGER
feature -- Modification
    set_user (u: like user) do user := u end
    set_where (w: like where) do where := w end
    set_somethingelse (s: like somethingelse) do somethingelse := s end
end

deferred class DECISION feature
    init (s: SOMETHING; who: INTEGER; factor: REAL_64) deferred end
end

class DECISION_1 inherit DECISION feature
    init (s: SOMETHING; who: INTEGER; factor: REAL_64)
        do
            ...
        end
end

class DECISION_2 inherit DECISION feature
    init (s: SOMETHING; who: INTEGER; factor: REAL_64)
        do
            ...
        end
end

class MY_CLASS inherit
    MY_CONSTANTS
... -- user_active, when_something, etc. can be used here
feature
    something: SOMETHING
    decision: DECISION
...
           -- Somewhere in the code
        create something
        if ... then
            create {DECISION_1} decision
        else
            create {DECISION_2} decision
        end
        ...
        decision.init (something, ..., ...)
    ...
end

在Eiffel中设置头文件？

1 个答案: