A.8.1 The Generic Package Sequential_IO
Static Semantics
1
The generic library
package Sequential_IO has the following declaration:
2
with Ada.IO_Exceptions;
generic
type Element_Type(<>)
is private;
package Ada.Sequential_IO
is
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type File_Type
is limited private;
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type File_Mode
is (In_File, Out_File, Append_File);
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-- File management
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procedure Create(File :
in out File_Type;
Mode :
in File_Mode := Out_File;
Name :
in String := "";
Form :
in String := "");
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procedure Open (File :
in out File_Type;
Mode :
in File_Mode;
Name :
in String;
Form :
in String := "");
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procedure Close (File :
in out File_Type);
procedure Delete(File :
in out File_Type);
procedure Reset (File :
in out File_Type; Mode :
in File_Mode);
procedure Reset (File :
in out File_Type);
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function Mode (File :
in File_Type)
return File_Mode;
function Name (File :
in File_Type)
return String;
function Form (File :
in File_Type)
return String;
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function Is_Open(File :
in File_Type)
return Boolean;
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-- Input and output operations
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procedure Read (File :
in File_Type; Item :
out Element_Type);
procedure Write (File :
in File_Type; Item :
in Element_Type);
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function End_Of_File(File :
in File_Type)
return Boolean;
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-- Exceptions
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Status_Error :
exception renames IO_Exceptions.Status_Error;
Mode_Error :
exception renames IO_Exceptions.Mode_Error;
Name_Error :
exception renames IO_Exceptions.Name_Error;
Use_Error :
exception renames IO_Exceptions.Use_Error;
Device_Error :
exception renames IO_Exceptions.Device_Error;
End_Error :
exception renames IO_Exceptions.End_Error;
Data_Error :
exception renames IO_Exceptions.Data_Error;
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private
... -- not specified by the language
end Ada.Sequential_IO;
17/2
{
AI95-00360-01}
The type File_Type needs finalization
(see 7.6) in every instantiation of Sequential_IO.Incompatibilities With Ada 83
17.a
The new enumeration element
Append_File may introduce upward incompatibilities. It is possible that
a program based on the assumption that File_Mode'Last = Out_File will
be illegal (e.g., case statement choice coverage) or execute with a different
effect in Ada 95.
17.a.1/2
This paragraph
was deleted.Implementation Note:
{
8652/0097}
{
AI95-00115-01}
{
AI95-00344-01}
File_Type
cannot be implemented as a (directly) controlled type, as Ada.Sequential_IO
can be instantiated at any nesting depth. File_Type could have a component
of a controlled type, as long as that type is declared in some other
(non-generic) package.
Incompatibilities With Ada 95
17.b/2
{
AI95-00360-01}
Amendment Correction:
File_Type in an instance of Sequential_IO is defined to need finalization.
If the restriction No_Nested_Finalization (see D.7)
applies to the partition, and File_Type does not have a controlled part,
it will not be allowed in local objects in Ada 2005 whereas it would
be allowed in original Ada 95. Such code is not portable, as another
Ada compiler may have a controlled part in File_Type, and thus would
be illegal.
Ada 2005 and 2012 Editions sponsored in part by Ada-Europe
