A.10.1 The Package Text_IO
Static Semantics
The library package
Text_IO has the following declaration:
with Ada.IO_Exceptions;
package Ada.Text_IO
with Global =>
in out synchronized is
type File_Type
is limited private;
type File_Mode
is (In_File, Out_File, Append_File);
type Count
is range 0 ..
implementation-defined;
subtype Positive_Count
is Count
range 1 .. Count'Last;
Unbounded :
constant Count := 0; --
line and page length
subtype Field
is Integer
range 0 ..
implementation-defined;
subtype Number_Base
is Integer
range 2 .. 16;
type Type_Set
is (Lower_Case, Upper_Case);
-- File Management
procedure Create (File :
in out File_Type;
Mode :
in File_Mode := Out_File;
Name :
in String := "";
Form :
in String := "");
procedure Open (File :
in out File_Type;
Mode :
in File_Mode;
Name :
in String;
Form :
in String := "");
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);
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;
function Is_Open(File :
in File_Type)
return Boolean;
-- Control of default input and output files
procedure Set_Input (File :
in File_Type);
procedure Set_Output(File :
in File_Type);
procedure Set_Error (File :
in File_Type);
function Standard_Input
return File_Type;
function Standard_Output
return File_Type;
function Standard_Error
return File_Type;
function Current_Input
return File_Type;
function Current_Output
return File_Type;
function Current_Error
return File_Type;
type File_Access
is access constant File_Type;
function Standard_Input
return File_Access;
function Standard_Output
return File_Access;
function Standard_Error
return File_Access;
function Current_Input
return File_Access;
function Current_Output
return File_Access;
function Current_Error
return File_Access;
--
Buffer control
procedure Flush (File :
in File_Type)
with Global =>
overriding in out File;
procedure Flush
with Global =>
in out all;
-- Specification of line and page lengths
procedure Set_Line_Length(File :
in File_Type; To :
in Count)
with Global =>
overriding in out File;
procedure Set_Line_Length(To :
in Count)
with Global =>
in out all;
procedure Set_Page_Length(File :
in File_Type; To :
in Count)
with Global =>
overriding in out File;
procedure Set_Page_Length(To :
in Count)
with Global =>
in out all;
function Line_Length(File :
in File_Type)
return Count;
function Line_Length
return Count
with Global =>
in all;
function Page_Length(File :
in File_Type)
return Count;
function Page_Length
return Count
with Global =>
in all;
-- Column, Line, and Page Control
procedure New_Line (File :
in File_Type;
Spacing :
in Positive_Count := 1)
with Global =>
overriding in out File;
procedure New_Line (Spacing :
in Positive_Count := 1)
with Global =>
in out all;
procedure Skip_Line (File :
in File_Type;
Spacing :
in Positive_Count := 1)
with Global =>
overriding in out File;
procedure Skip_Line (Spacing :
in Positive_Count := 1)
with Global =>
in out all;
function End_Of_Line(File :
in File_Type)
return Boolean;
function End_Of_Line
return Boolean;
procedure New_Page (File :
in File_Type)
with Global =>
overriding in out File;
procedure New_Page
with Global =>
in out all;
procedure Skip_Page (File :
in File_Type)
with Global =>
overriding in out File;
procedure Skip_Page
with Global =>
in out all;
function End_Of_Page(File :
in File_Type)
return Boolean;
function End_Of_Page
return Boolean
with Global =>
in all;
function End_Of_File(File :
in File_Type)
return Boolean;
function End_Of_File
return Boolean
with Global =>
in all;
procedure Set_Col (File :
in File_Type; To :
in Positive_Count)
with Global =>
overriding in out File;
procedure Set_Col (To :
in Positive_Count)
with Global =>
in out all;
procedure Set_Line(File :
in File_Type; To :
in Positive_Count)
with Global =>
overriding in out File;
procedure Set_Line(To :
in Positive_Count)
with Global =>
in out all;
function Col (File :
in File_Type)
return Positive_Count;
function Col
return Positive_Count
with Global =>
in all;
function Line(File :
in File_Type)
return Positive_Count;
function Line
return Positive_Count
with Global =>
in all;
function Page(File :
in File_Type)
return Positive_Count;
function Page
return Positive_Count
with Global =>
in all;
-- Character Input-Output
procedure Get(File :
in File_Type; Item :
out Character)
with Global =>
overriding in out File;
procedure Get(Item :
out Character)
with Global =>
in out all;
procedure Put(File :
in File_Type; Item :
in Character)
with Global =>
overriding in out File;
procedure Put(Item :
in Character)
with Global =>
in out all;
procedure Look_Ahead (File :
in File_Type;
Item :
out Character;
End_Of_Line :
out Boolean)
with Global =>
overriding in out File;
procedure Look_Ahead (Item :
out Character;
End_Of_Line :
out Boolean)
with Global =>
in out all;
procedure Get_Immediate(File :
in File_Type;
Item :
out Character)
with Global =>
overriding in out File;
procedure Get_Immediate(Item :
out Character)
with Global =>
in out all;
procedure Get_Immediate(File :
in File_Type;
Item :
out Character;
Available :
out Boolean)
with Global =>
overriding in out File;
procedure Get_Immediate(Item :
out Character;
Available :
out Boolean)
with Global =>
in out all;
-- String Input-Output
procedure Get(File :
in File_Type; Item :
out String)
with Global =>
overriding in out File;
procedure Get(Item :
out String)
with Global =>
in out all;
procedure Put(File :
in File_Type; Item :
in String)
with Global =>
overriding in out File;
procedure Put(Item :
in String)
with Global =>
in out all;
procedure Get_Line(File :
in File_Type;
Item :
out String;
Last :
out Natural)
with Global =>
overriding in out File;
procedure Get_Line(Item :
out String; Last :
out Natural)
with Global =>
in out all;
function Get_Line(File :
in File_Type)
return String
with Global =>
overriding in out File;
function Get_Line
return String
with Global =>
in out all;
procedure Put_Line(File :
in File_Type; Item :
in String)
with Global =>
overriding in out File;
procedure Put_Line(Item :
in String)
with Global =>
in out all;
-- Generic packages for Input-Output of Integer Types
generic
type Num
is range <>;
package Integer_IO
is
Default_Width : Field := Num'Width;
Default_Base : Number_Base := 10;
procedure Get(File :
in File_Type;
Item :
out Num;
Width :
in Field := 0)
with Global =>
overriding in out File;
procedure Get(Item :
out Num;
Width :
in Field := 0)
with Global =>
in out all;
procedure Put(File :
in File_Type;
Item :
in Num;
Width :
in Field := Default_Width;
Base :
in Number_Base := Default_Base)
with Global =>
overriding in out File;
procedure Put(Item :
in Num;
Width :
in Field := Default_Width;
Base :
in Number_Base := Default_Base)
with Global =>
in out all;
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive)
with Nonblocking;
procedure Put(To :
out String;
Item :
in Num;
Base :
in Number_Base := Default_Base)
with Nonblocking;
end Integer_IO;
generic
type Num
is mod <>;
package Modular_IO
is
Default_Width : Field := Num'Width;
Default_Base : Number_Base := 10;
procedure Get(File :
in File_Type;
Item :
out Num;
Width :
in Field := 0)
with Global =>
overriding in out File;
procedure Get(Item :
out Num;
Width :
in Field := 0)
with Global =>
in out all;
procedure Put(File :
in File_Type;
Item :
in Num;
Width :
in Field := Default_Width;
Base :
in Number_Base := Default_Base)
with Global =>
overriding in out File;
procedure Put(Item :
in Num;
Width :
in Field := Default_Width;
Base :
in Number_Base := Default_Base)
with Global =>
in out all;
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive)
with Nonblocking;
procedure Put(To :
out String;
Item :
in Num;
Base :
in Number_Base := Default_Base)
with Nonblocking;
end Modular_IO;
-- Generic packages for Input-Output of Real Types
generic
type Num
is digits <>;
package Float_IO
is
Default_Fore : Field := 2;
Default_Aft : Field := Num'Digits-1;
Default_Exp : Field := 3;
procedure Get(File :
in File_Type;
Item :
out Num;
Width :
in Field := 0)
with Global =>
overriding in out File;
procedure Get(Item :
out Num;
Width :
in Field := 0)
with Global =>
in out all;
procedure Put(File :
in File_Type;
Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp)
with Global =>
overriding in out File;
procedure Put(Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp)
with Global =>
in out all;
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive)
with Nonblocking;
procedure Put(To :
out String;
Item :
in Num;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp)
with Nonblocking;
end Float_IO;
generic
type Num
is delta <>;
package Fixed_IO
is
Default_Fore : Field := Num'Fore;
Default_Aft : Field := Num'Aft;
Default_Exp : Field := 0;
procedure Get(File :
in File_Type;
Item :
out Num;
Width :
in Field := 0)
with Global =>
overriding in out File;
procedure Get(Item :
out Num;
Width :
in Field := 0)
with Global =>
in out all;
procedure Put(File :
in File_Type;
Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp)
with Global =>
overriding in out File;
procedure Put(Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp)
with Global =>
in out all;
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive)
with Nonblocking;
procedure Put(To :
out String;
Item :
in Num;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp)
with Nonblocking;
end Fixed_IO;
generic
type Num
is delta <>
digits <>;
package Decimal_IO
is
Default_Fore : Field := Num'Fore;
Default_Aft : Field := Num'Aft;
Default_Exp : Field := 0;
procedure Get(File :
in File_Type;
Item :
out Num;
Width :
in Field := 0)
with Global =>
overriding in out File;
procedure Get(Item :
out Num;
Width :
in Field := 0)
with Global =>
in out all;
procedure Put(File :
in File_Type;
Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp)
with Global =>
overriding in out File;
procedure Put(Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp)
with Global =>
in out all;
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive)
with Nonblocking;
procedure Put(To :
out String;
Item :
in Num;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp)
with Nonblocking;
end Decimal_IO;
-- Generic package for Input-Output of Enumeration Types
generic
type Enum
is (<>);
package Enumeration_IO
is
Default_Width : Field := 0;
Default_Setting : Type_Set := Upper_Case;
procedure Get(File :
in File_Type;
Item :
out Enum)
with Global =>
overriding in out File;
procedure Get(Item :
out Enum)
with Global =>
in out all;
procedure Put(File :
in File_Type;
Item :
in Enum;
Width :
in Field := Default_Width;
Set :
in Type_Set := Default_Setting)
with Global =>
overriding in out File;
procedure Put(Item :
in Enum;
Width :
in Field := Default_Width;
Set :
in Type_Set := Default_Setting)
with Global =>
in out all;
procedure Get(From :
in String;
Item :
out Enum;
Last :
out Positive)
with Nonblocking;
procedure Put(To :
out String;
Item :
in Enum;
Set :
in Type_Set := Default_Setting)
with Nonblocking;
end Enumeration_IO;
-- Exceptions
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;
Layout_Error :
exception renames IO_Exceptions.Layout_Error;
package Wide_File_Names
is
-- File management
procedure Create (File :
in out File_Type;
Mode :
in File_Mode := Out_File;
Name :
in Wide_String := "";
Form :
in Wide_String := "");
procedure Open (File :
in out File_Type;
Mode :
in File_Mode;
Name :
in Wide_String;
Form :
in Wide_String := "");
function Name (File :
in File_Type)
return Wide_String;
function Form (File :
in File_Type)
return Wide_String;
end Wide_File_Names;
package Wide_Wide_File_Names
is
-- File management
procedure Create (File :
in out File_Type;
Mode :
in File_Mode := Out_File;
Name :
in Wide_Wide_String := "";
Form :
in Wide_Wide_String := "");
procedure Open (File :
in out File_Type;
Mode :
in File_Mode;
Name :
in Wide_Wide_String;
Form :
in Wide_Wide_String := "");
function Name (File :
in File_Type)
return Wide_Wide_String;
function Form (File :
in File_Type)
return Wide_Wide_String;
end Wide_Wide_File_Names;
private
... -- not specified by the language
end Ada.Text_IO;
The type File_Type needs finalization
(see
7.6).
Ada 2005 and 2012 Editions sponsored in part by Ada-Europe
