没有候选解释与ADA中实际的泛型编码问题相匹配

Question

由于使用put的print语句而导致代码无法编译。将邮政编码放在下面。

--  createlis.ads
generic
size: integer;
type itemtype is private;

package createlis is

procedure addtolist( ad : in itemtype );

procedure printlist;

procedure printlist1(pt: in integer );

procedure deletelist(pt: in integer );

procedure listlength;

end createlis;

--  createlis.adb

with ada.text_io; use ada.text_io;

package body createlis is

len: integer;
list: array(1..size) of itemtype;

procedure addtolist( ad : in itemtype ) is 
begin
if len < size then
len := len +1;
list(len) := ad;
end if;
end addtolist;

procedure printlist is 
begin
for i in 1..len loop
put((list(i)));
put(" , ");
end loop;
end printlist;


procedure printlist1( pt: in integer ) is 
begin
put((list(pt)));
end printlist1;


procedure deletelist( pt: in integer) is
begin
for k in pt..(len-1) loop
list(k) := list(k+1);
end loop;
len := len - 1;
end deletelist;

procedure listlength is
i : integer;
begin
i := 0;
for x in 1..size loop
i := i + 1;
end loop;
put("the array is ");
put(integer'image(i));
put(" numbers.");

end listlength;

end createlis;

--  main.adb
with Ada.Text_IO; use Ada.Text_IO;
with createlis; 
procedure main is

package iio is new ada.text_io.integer_io(integer); use iio;
package iii is new ada.text_io.float_io(float); use iii;

size: integer;

begin

put("enter size for option c: ");
get(size);

declare

package clist is new createlis(size, integer); use clist;

begin
clist.printlist;
clist.addtolist(12);
clist.addtolist(3);
clist.addtolist(7);
clist.printlist;
new_line;
clist.printlist1(2);
new_line;
clist.listlength;
new_line;
clist.deletelist(2);
clist.printlist;

end;

declare

package blist is new createlis(size, float); use blist;

begin

blist.printlist;
blist.addtolist(12.7);
blist.addtolist(3.5);
blist.addtolist(7.6);
blist.printlist;
new_line;
blist.listlength;
new_line;
blist.deletelist(2);
blist.printlist;
end;
end main;

Answer 1

Text_IO不包含Integer和Float的Put函数。虽然它包含通用包Integer_IO和Float_IO，但你不能直接使用它们，因为你的通用包可以采用这两种类型。

这意味着你必须在实例化时告诉你的泛型包如何放置itemtype，例如:

generic
size: integer;
type itemtype is private;
with procedure Put (Value : itemtype);
package createlis is
-- ...

然后在main中定义putters:

procedure Put_Integer (Value : Integer) is
begin
iio.Put (Value);
end Put_Integer;
procedure Put_Float (Value : Float) is
begin
iii.Put (Value);
end Put_Float;

并在泛型包的实例化中使用它们:

package clist is new createlis 
(size, integer, Put_Integer); use clist;
-- ...
package blist is new createlis
(size, float, Put_Float); use blist;

你不能直接给iio/iii中的过程作为通用参数，因为它们使用默认值的附加参数。