Ada HashMap in HashMap

Question

我不知道，这是否叫做赛跑，但我想要一个HashMap(字符串，长，短，字符串)；

侏儒编译器抱怨：

main.adb:20:13: warning: possible infinite recursion
main.adb:20:13: warning: Storage_Error may be raised at run time
main.adb:24:13: warning: possible infinite recursion
main.adb:24:13: warning: Storage_Error may be raised at run time

在这里写"=“函数的正确方法是什么？

main.adb

with Ada.Containers.Indefinite_Hashed_Maps;
with Ada.Strings.Hash;
with Ada.Text_IO;

procedure Main is
   subtype Short is Short_Integer;
   subtype Long is Long_Integer;

   function Hash (X : String) return Ada.Containers.Hash_Type is
      (Ada.Strings.Hash (X));

   function Hash (X : Short) return Ada.Containers.Hash_Type is
      (Ada.Containers.Hash_Type'Mod (X));

   function Hash (X : Long) return Ada.Containers.Hash_Type is
      (Ada.Containers.Hash_Type'Mod (X));

   package Short_String_Map is new Ada.Containers.Indefinite_Hashed_Maps (Short, String, Hash, "=");
   function "=" (Left, Right : Short_String_Map.Map) return Boolean is
      (Left = Right);

   package Long_Short_Map is new Ada.Containers.Indefinite_Hashed_Maps (Long, Short_String_Map.Map, Hash, "=");
   function "=" (Left, Right : Long_Short_Map.Map) return Boolean is
      (Left = Right);

   package String_Long_Map is new Ada.Containers.Indefinite_Hashed_Maps (String, Long_Short_Map.Map, Hash, "=");
begin
   --  Map(String, Long, Short, String);
   null;
end Main;

Answer 1

而不是

function "=" (Left, Right : Short_String_Map.Map) return Boolean is
    (Left = Right);

写

function "=" (Left, Right : Short_String_Map.Map) return Boolean is
    (Short_String_Map."=" (Left, Right));

或者，更好的(我认为)：

function "=" (Left, Right : Short_String_Map.Map) return Boolean 
    renames Short_String_Map."=";     

问题是，您编写它的方式，= in Left = Right指的是您刚才根据可见性规则在上面的行上定义的"="。当然，这意味着您刚刚定义了一个无限递归函数。要使用在"="中定义的Short_String_Map，您必须使用像Short_String_Map."="(Left,Right)这样的语法来显式显示您所指的"="。