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
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;
-- Specification of line and page lengths
procedure Set_Line_Length(File :
in File_Type; To :
in Count);
procedure Set_Line_Length(To :
in Count);
procedure Set_Page_Length(File :
in File_Type; To :
in Count);
procedure Set_Page_Length(To :
in Count);
function Line_Length(File :
in File_Type)
return Count;
function Line_Length
return Count;
function Page_Length(File :
in File_Type)
return Count;
function Page_Length
return Count;
-- Column, Line, and Page Control
procedure New_Line (File :
in File_Type;
Spacing :
in Positive_Count := 1);
procedure New_Line (Spacing :
in Positive_Count := 1);
procedure Skip_Line (File :
in File_Type;
Spacing :
in Positive_Count := 1);
procedure Skip_Line (Spacing :
in Positive_Count := 1);
function End_Of_Line(File :
in File_Type)
return Boolean;
function End_Of_Line
return Boolean;
procedure New_Page (File :
in File_Type);
procedure New_Page;
procedure Skip_Page (File :
in File_Type);
procedure Skip_Page;
function End_Of_Page(File :
in File_Type)
return Boolean;
function End_Of_Page
return Boolean;
function End_Of_File(File :
in File_Type)
return Boolean;
function End_Of_File
return Boolean;
procedure Set_Col (File :
in File_Type; To :
in Positive_Count);
procedure Set_Col (To :
in Positive_Count);
procedure Set_Line(File :
in File_Type; To :
in Positive_Count);
procedure Set_Line(To :
in Positive_Count);
function Col (File :
in File_Type)
return Positive_Count;
function Col
return Positive_Count;
function Line(File :
in File_Type)
return Positive_Count;
function Line
return Positive_Count;
function Page(File :
in File_Type)
return Positive_Count;
function Page
return Positive_Count;
-- Character Input-Output
procedure Get(File :
in File_Type; Item :
out Character);
procedure Get(Item :
out Character);
procedure Put(File :
in File_Type; Item :
in Character);
procedure Put(Item :
in Character);
procedure Look_Ahead (File :
in File_Type;
Item :
out Character;
End_Of_Line :
out Boolean);
procedure Look_Ahead (Item :
out Character;
End_Of_Line :
out Boolean);
procedure Get_Immediate(File :
in File_Type;
Item :
out Character);
procedure Get_Immediate(Item :
out Character);
procedure Get_Immediate(File :
in File_Type;
Item :
out Character;
Available :
out Boolean);
procedure Get_Immediate(Item :
out Character;
Available :
out Boolean);
-- String Input-Output
procedure Get(File :
in File_Type; Item :
out String);
procedure Get(Item :
out String);
procedure Put(File :
in File_Type; Item :
in String);
procedure Put(Item :
in String);
procedure Get_Line(File :
in File_Type;
Item :
out String;
Last :
out Natural);
procedure Get_Line(Item :
out String; Last :
out Natural);
{
AI95-00301-01}
function Get_Line(File :
in File_Type)
return String;
function Get_Line
return String;
procedure Put_Line(File :
in File_Type; Item :
in String);
procedure Put_Line(Item :
in String);
-- 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);
procedure Get(Item :
out Num;
Width :
in Field := 0);
procedure Put(File :
in File_Type;
Item :
in Num;
Width :
in Field := Default_Width;
Base :
in Number_Base := Default_Base);
procedure Put(Item :
in Num;
Width :
in Field := Default_Width;
Base :
in Number_Base := Default_Base);
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive);
procedure Put(To :
out String;
Item :
in Num;
Base :
in Number_Base := Default_Base);
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);
procedure Get(Item :
out Num;
Width :
in Field := 0);
procedure Put(File :
in File_Type;
Item :
in Num;
Width :
in Field := Default_Width;
Base :
in Number_Base := Default_Base);
procedure Put(Item :
in Num;
Width :
in Field := Default_Width;
Base :
in Number_Base := Default_Base);
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive);
procedure Put(To :
out String;
Item :
in Num;
Base :
in Number_Base := Default_Base);
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);
procedure Get(Item :
out Num;
Width :
in Field := 0);
procedure Put(File :
in File_Type;
Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp);
procedure Put(Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp);
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive);
procedure Put(To :
out String;
Item :
in Num;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp);
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);
procedure Get(Item :
out Num;
Width :
in Field := 0);
procedure Put(File :
in File_Type;
Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp);
procedure Put(Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp);
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive);
procedure Put(To :
out String;
Item :
in Num;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp);
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);
procedure Get(Item :
out Num;
Width :
in Field := 0);
procedure Put(File :
in File_Type;
Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp);
procedure Put(Item :
in Num;
Fore :
in Field := Default_Fore;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp);
procedure Get(From :
in String;
Item :
out Num;
Last :
out Positive);
procedure Put(To :
out String;
Item :
in Num;
Aft :
in Field := Default_Aft;
Exp :
in Field := Default_Exp);
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);
procedure Get(Item :
out Enum);
procedure Put(File :
in File_Type;
Item :
in Enum;
Width :
in Field := Default_Width;
Set :
in Type_Set := Default_Setting);
procedure Put(Item :
in Enum;
Width :
in Field := Default_Width;
Set :
in Type_Set := Default_Setting);
procedure Get(From :
in String;
Item :
out Enum;
Last :
out Positive);
procedure Put(To :
out String;
Item :
in Enum;
Set :
in Type_Set := Default_Setting);
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;
private
... --
not specified by the language
end Ada.Text_IO;
Incompatibilities With Ada 83
{
incompatibilities with Ada 83}
Append_File
is a new element of enumeration type File_Mode.
Extensions to Ada 83
{
extensions to Ada 83}
Get_Immediate,
Look_Ahead, the subprograms for dealing with standard error, the type
File_Access and its associated subprograms, and the generic packages
Modular_IO and Decimal_IO are new in Ada 95.
Incompatibilities With Ada 95
{
AI95-00360-01}
{
incompatibilities with Ada 95}
Amendment
Correction: Text_IO.File_Type 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.
Wording Changes from Ada 95
{
8652/0051}
{
AI95-00057-01}
Corrigendum: Corrected the parameter mode of Flush; otherwise
it could not be used on Standard_Output.
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