Inheritance Ada：标记类型---从父包继承

我试图理解标记类型、代码扩展和重用。我首先创建了一个程序

传统的\u方法\u平均数\u

，它实现了一种进行计算的方法。然后，我使用标记类型的扩展并创建第二个程序

alternative\u method\u number\u of\u averages

，它实现了一种不同的方法来解决相同的问题。不同的是，现在我有了一个附加的

参数

称为

overlapple\u分数

。下面是一个简单的程序，使用第一种方法

常规方法\u平均数\u

，效果很好：

平均数的数量。广告

with Conventional_Method_Number_Of_Averages;
package Number_Of_Averages renames Conventional_Method_Number_Of_Averages;

package Conventional_Method_Number_Of_Averages is

type First_Method is tagged private;

procedure Count_Averages (Any_Method : in out First_Method; Sampling_Frequency, FFT_Size, Time_Recorded: in Float);

function Average_Is (Any_Method : in First_Method) return Float;

private
type First_Method is tagged
  record
     Number_Of_Averages : Float :=0.0;
   end record;

end Conventional_Method_Number_Of_Averages;

with Conventional_Method_Number_Of_Averages;
use Conventional_Method_Number_Of_Averages;

package Alternative_Method_Number_Of_Averages is

type Second_Method is new First_Method with private;

--override this function
procedure Count_Averages (Any_Method : in out Second_Method; Sampling_Frequency, FFT_Size, Time_Recorded, Overlap_Fraction: in Float);


private
type Second_Method is new First_Method with
  record
     Overlap_Fraction : Float :=0.5;
  end record;

end Alternative_Method_Number_Of_Averages;

常规方法\u平均数\u。ads

with Conventional_Method_Number_Of_Averages;
package Number_Of_Averages renames Conventional_Method_Number_Of_Averages;

package Conventional_Method_Number_Of_Averages is

type First_Method is tagged private;

procedure Count_Averages (Any_Method : in out First_Method; Sampling_Frequency, FFT_Size, Time_Recorded: in Float);

function Average_Is (Any_Method : in First_Method) return Float;

private
type First_Method is tagged
  record
     Number_Of_Averages : Float :=0.0;
   end record;

end Conventional_Method_Number_Of_Averages;

with Conventional_Method_Number_Of_Averages;
use Conventional_Method_Number_Of_Averages;

package Alternative_Method_Number_Of_Averages is

type Second_Method is new First_Method with private;

--override this function
procedure Count_Averages (Any_Method : in out Second_Method; Sampling_Frequency, FFT_Size, Time_Recorded, Overlap_Fraction: in Float);


private
type Second_Method is new First_Method with
  record
     Overlap_Fraction : Float :=0.5;
  end record;

end Alternative_Method_Number_Of_Averages;

常规方法\u平均数\u。adb

package body Conventional_Method_Number_Of_Averages is

procedure Count_Averages (Any_Method : in out First_Method; Sampling_Frequency, FFT_Size, Time_Recorded: in Float) is
begin
    Any_Method.Number_Of_Averages := (((Sampling_Frequency * Time_Recorded) - FFT_Size)*(2.0/FFT_Size)) + 1.0;
end Count_Averages;

function Average_Is (Any_Method : in First_Method) return Float is
begin
    return Any_Method.Number_Of_Averages;
end;

end Conventional_Method_Number_Of_Averages;

with Ada.Float_Text_IO;
with Ada.Text_IO; use Ada.Text_IO;

with Number_Of_Averages;
with Conventional_Method_Number_Of_Averages;
use type Number_Of_Averages.First_Method;
procedure Test_Number_Of_Averages is

Fs, Time_Duration, NFFT    : Float := 0.0;
Averages                   : Float := 0.0;

Good_Method : Conventional_Method_Number_Of_Averages.First_Method;

begin
   Ada.Text_IO.Put("Enter the sampling frequency ");
   Ada.Float_Text_IO.Get (Item => Fs);
   Ada.Text_IO.New_Line (1);
   Ada.Text_IO.Put("Enter the time recorded ");
   Ada.Float_Text_IO.Get (Item => Time_Duration);
   Ada.Text_IO.New_Line (1);
   Ada.Text_IO.Put("Enter the FFT size ");
   Ada.Float_Text_IO.Get (Item => NFFT);
   Ada.Text_IO.Put_Line (Ada.Text_IO.Get_Line);

   Ada.Text_IO.New_Line(1);
   Ada.Text_IO.Put("Number of averages = ");
   Number_Of_Averages.Count_Averages(Good_Method, Fs, NFFT, Time_Duration);

   Averages := Conventional_Method_Number_Of_Averages.Average_Is(Good_Method);
   Ada.Float_Text_IO.Put (Item => Averages, Fore => 3, Aft  => 5, Exp  => 0);

end Test_Number_Of_Averages;

package body Alternative_Method_Number_Of_Averages is

--override this function
procedure Count_Averages (Any_Method : in out Second_Method; Sampling_Frequency, FFT_Size, Time_Recorded, Overlap_Fraction: in Float) is
begin
   Any_Method.Number_Of_Averages := ((Sampling_Frequency * Time_Recorded) - FFT_Size) / (FFT_Size - Overlap_Fraction * FFT_Size) + 1.0;
end Count_Averages;


end Alternative_Method_Number_Of_Averages;

以及测试文件测试平均值的数量。adb

package body Conventional_Method_Number_Of_Averages is

procedure Count_Averages (Any_Method : in out First_Method; Sampling_Frequency, FFT_Size, Time_Recorded: in Float) is
begin
    Any_Method.Number_Of_Averages := (((Sampling_Frequency * Time_Recorded) - FFT_Size)*(2.0/FFT_Size)) + 1.0;
end Count_Averages;

function Average_Is (Any_Method : in First_Method) return Float is
begin
    return Any_Method.Number_Of_Averages;
end;

end Conventional_Method_Number_Of_Averages;

with Ada.Float_Text_IO;
with Ada.Text_IO; use Ada.Text_IO;

with Number_Of_Averages;
with Conventional_Method_Number_Of_Averages;
use type Number_Of_Averages.First_Method;
procedure Test_Number_Of_Averages is

Fs, Time_Duration, NFFT    : Float := 0.0;
Averages                   : Float := 0.0;

Good_Method : Conventional_Method_Number_Of_Averages.First_Method;

begin
   Ada.Text_IO.Put("Enter the sampling frequency ");
   Ada.Float_Text_IO.Get (Item => Fs);
   Ada.Text_IO.New_Line (1);
   Ada.Text_IO.Put("Enter the time recorded ");
   Ada.Float_Text_IO.Get (Item => Time_Duration);
   Ada.Text_IO.New_Line (1);
   Ada.Text_IO.Put("Enter the FFT size ");
   Ada.Float_Text_IO.Get (Item => NFFT);
   Ada.Text_IO.Put_Line (Ada.Text_IO.Get_Line);

   Ada.Text_IO.New_Line(1);
   Ada.Text_IO.Put("Number of averages = ");
   Number_Of_Averages.Count_Averages(Good_Method, Fs, NFFT, Time_Duration);

   Averages := Conventional_Method_Number_Of_Averages.Average_Is(Good_Method);
   Ada.Float_Text_IO.Put (Item => Averages, Fore => 3, Aft  => 5, Exp  => 0);

end Test_Number_Of_Averages;

package body Alternative_Method_Number_Of_Averages is

--override this function
procedure Count_Averages (Any_Method : in out Second_Method; Sampling_Frequency, FFT_Size, Time_Recorded, Overlap_Fraction: in Float) is
begin
   Any_Method.Number_Of_Averages := ((Sampling_Frequency * Time_Recorded) - FFT_Size) / (FFT_Size - Overlap_Fraction * FFT_Size) + 1.0;
end Count_Averages;


end Alternative_Method_Number_Of_Averages;

上述方法可以正常工作

现在，如果我为相同的计算创建一个替代方法，我有：

其规格替代方法\u平均数\u。ads

with Conventional_Method_Number_Of_Averages;
package Number_Of_Averages renames Conventional_Method_Number_Of_Averages;

package Conventional_Method_Number_Of_Averages is

type First_Method is tagged private;

procedure Count_Averages (Any_Method : in out First_Method; Sampling_Frequency, FFT_Size, Time_Recorded: in Float);

function Average_Is (Any_Method : in First_Method) return Float;

private
type First_Method is tagged
  record
     Number_Of_Averages : Float :=0.0;
   end record;

end Conventional_Method_Number_Of_Averages;

with Conventional_Method_Number_Of_Averages;
use Conventional_Method_Number_Of_Averages;

package Alternative_Method_Number_Of_Averages is

type Second_Method is new First_Method with private;

--override this function
procedure Count_Averages (Any_Method : in out Second_Method; Sampling_Frequency, FFT_Size, Time_Recorded, Overlap_Fraction: in Float);


private
type Second_Method is new First_Method with
  record
     Overlap_Fraction : Float :=0.5;
  end record;

end Alternative_Method_Number_Of_Averages;

及

其主体替代方法\u平均数。adb

package body Conventional_Method_Number_Of_Averages is

procedure Count_Averages (Any_Method : in out First_Method; Sampling_Frequency, FFT_Size, Time_Recorded: in Float) is
begin
    Any_Method.Number_Of_Averages := (((Sampling_Frequency * Time_Recorded) - FFT_Size)*(2.0/FFT_Size)) + 1.0;
end Count_Averages;

function Average_Is (Any_Method : in First_Method) return Float is
begin
    return Any_Method.Number_Of_Averages;
end;

end Conventional_Method_Number_Of_Averages;

with Ada.Float_Text_IO;
with Ada.Text_IO; use Ada.Text_IO;

with Number_Of_Averages;
with Conventional_Method_Number_Of_Averages;
use type Number_Of_Averages.First_Method;
procedure Test_Number_Of_Averages is

Fs, Time_Duration, NFFT    : Float := 0.0;
Averages                   : Float := 0.0;

Good_Method : Conventional_Method_Number_Of_Averages.First_Method;

begin
   Ada.Text_IO.Put("Enter the sampling frequency ");
   Ada.Float_Text_IO.Get (Item => Fs);
   Ada.Text_IO.New_Line (1);
   Ada.Text_IO.Put("Enter the time recorded ");
   Ada.Float_Text_IO.Get (Item => Time_Duration);
   Ada.Text_IO.New_Line (1);
   Ada.Text_IO.Put("Enter the FFT size ");
   Ada.Float_Text_IO.Get (Item => NFFT);
   Ada.Text_IO.Put_Line (Ada.Text_IO.Get_Line);

   Ada.Text_IO.New_Line(1);
   Ada.Text_IO.Put("Number of averages = ");
   Number_Of_Averages.Count_Averages(Good_Method, Fs, NFFT, Time_Duration);

   Averages := Conventional_Method_Number_Of_Averages.Average_Is(Good_Method);
   Ada.Float_Text_IO.Put (Item => Averages, Fore => 3, Aft  => 5, Exp  => 0);

end Test_Number_Of_Averages;

package body Alternative_Method_Number_Of_Averages is

--override this function
procedure Count_Averages (Any_Method : in out Second_Method; Sampling_Frequency, FFT_Size, Time_Recorded, Overlap_Fraction: in Float) is
begin
   Any_Method.Number_Of_Averages := ((Sampling_Frequency * Time_Recorded) - FFT_Size) / (FFT_Size - Overlap_Fraction * FFT_Size) + 1.0;
end Count_Averages;


end Alternative_Method_Number_Of_Averages;

然后在编译规范文件时，我得到错误消息：

备选方法\u平均数\u.ads：对于在备选方法\u平均数\u.ads中定义的类型“第二种方法”，没有选择器“备选方法\u平均数”。罪魁祸首是：

     Any_Method.Number_Of_Averages := ((Sampling_Frequency * Time_Recorded) - FFT_Size) / (FFT_Size - Overlap_Fraction * FFT_Size) + 1.0;

那么如何解决这个问题呢

最后，我希望能够有这样的东西：

     Number_Of_Averages.Count_Averages(Alternative_Method, Fs, NFFT, Time_Duration, Overlap_fraction);

在测试文件中，测试\u平均值的数量\u.adb，与工作代码类似

     Number_Of_Averages.Count_Averages(Good_Method, Fs, NFFT, Time_Duration);

非常感谢

更新

因此，现在对于替代方法的实施，我将替代方法\u平均数\u.ads/adb重命名为传统方法\u平均数\u-替代方法\u平均数\u.ads/adb。测试文件为：

   with Ada.Float_Text_IO;
   with Ada.Text_IO; use Ada.Text_IO;

   with Number_Of_Averages;
   with Conventional_Method_Number_Of_Averages;
   use type Number_Of_Averages.First_Method;

   with Conventional_Method_Number_Of_Averages.Alternative_Method_Number_Of_Averages;

   procedure Test_Number_Of_Averages is

   Fs, Time_Duration, NFFT    : Float := 0.0;
   Averages1                   : Float := 0.0;
   Averages2                   : Float := 0.0;

   Good_Method                 : Conventional_Method_Number_Of_Averages.First_Method;
   Alternative_Method          : Conventional_Method_Number_Of_Averages.Alternative_Method_Number_Of_Averages.Second_Method;

   begin
   Ada.Text_IO.Put("Enter the sampling frequency ");
   Ada.Float_Text_IO.Get (Item => Fs);
   Ada.Text_IO.New_Line (1);
   Ada.Text_IO.Put("Enter the time recorded ");
   Ada.Float_Text_IO.Get (Item => Time_Duration);
   Ada.Text_IO.New_Line (1);
   Ada.Text_IO.Put("Enter the FFT size ");
   Ada.Float_Text_IO.Get (Item => NFFT);
   Ada.Text_IO.Put_Line (Ada.Text_IO.Get_Line);

   Ada.Text_IO.New_Line(1);
   Ada.Text_IO.Put("Number of averages = ");
   Number_Of_Averages.Count_Averages(Good_Method, Fs, NFFT, Time_Duration);

   Averages1 := Conventional_Method_Number_Of_Averages.Average_Is(Good_Method);
   Ada.Float_Text_IO.Put (Item => Averages1, Fore => 3, Aft  => 5, Exp  => 0);

   Ada.Text_IO.New_Line(1);
   Ada.Text_IO.Put("Number of averages = ");

   Number_Of_Averages.Alternative_Method_Number_Of_Averages.Count_Averages(Alternative_Method, Fs, NFFT, Time_Duration); 
   Averages2 := Conventional_Method_Number_Of_Averages.Alternative_Method_Number_Of_Averages.Average_Is(Alternative_Method); 
   Ada.Float_Text_IO.Put (Item => Averages2, Fore => 3, Aft  => 5, Exp  => 0);

   end Test_Number_Of_Averages;

---

当Fs=48000，Time_Duration=60，NFFT=8192时，两种方法都返回702.125。尽管如此，第二种方法始终返回702.125，而与

重叠部分

参数无关。如何在调用函数中指定

Overlap\u分数

，同时仍保持使用它的私有性，即通过让函数使用存储在记录中的

Overlap\u分数

的值。

在

替代方法\u平均数\u

的正文中，您试图使用

平均数\u

，它是父类型的私有成员。既然是私人的， 你看不见它

使用包时，只能看到规范的公共部分

子包在其自己的公共部分中可以看到父包的公共部分，在其自己的私有部分中可以看到父包的私有部分

还有私有child，它们在自己的规范中可以看到整个父对象

要查看

平均数的数量

，您可以将完整的类型声明移动到公共部分，或者将

替代方法

作为

常规方法

的子包

有关更多详细信息，请参阅：

---

另一方面，只有当类型扩展使用与父类中相同的参数配置文件实现子程序时，才会发生重写。在您的示例中，

Second\u方法

重载了

Count\u平均值

，即添加一个名称相同但配置文件不同的新子程序<代码>计数\u平均值仍然从具有较短参数配置文件的父级继承。

@egilhh。谢谢如何使替代方法的平均数成为常规平均数的子包？我更愿意将平均数保密。1投赞成票。将包名称更改为：“包常规方法平均数。替代方法平均数为”。您可能还需要更改文件名。@谢谢。我做了必要的修改，但是替代方法的结果是零，这是不对的（尽管公式是好的）。我已经更新了帖子。我没有看到为替代方法计算平均值的调用，因此Average只会返回默认值Number of of of the the the of the of the the the of the of the the the the Averages，即0.0。@egilhh Yes您是对的。我把

平均值的个数。可选方法平均值的个数。计数平均值（可选方法，Fs，NFFT，时间持续时间）但我得到的值是相同的702.125，与
重叠部分
的值无关。因此，仍有一些问题无法解决。