The Package Text_IO
Author: JTC1/SC22/WG9/ARG, by Randall Brukardt, ARG Editor

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# A.10.1 The Package Text_IO

#### Static Semantics

1
The library package Text_IO has the following declaration:
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with Ada.IO_Exceptions;
package Ada.Text_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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type Count is range 0 .. implementation-defined;
subtype Positive_Count is Count range 1 .. Count'Last;
Unbounded : constant Count := 0; -- line and page length
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subtype Field is Integer range 0 .. implementation-defined;
subtype Number_Base is Integer range 2 .. 16;
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type Type_Set is (Lower_Case, Upper_Case);
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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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-- Control of default input and output files
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procedure Set_Input (File : in File_Type);
procedure Set_Output(File : in File_Type);
procedure Set_Error (File : in File_Type);
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function Standard_Input return File_Type;
function Standard_Output return File_Type;
function Standard_Error return File_Type;
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function Current_Input return File_Type;
function Current_Output return File_Type;
function Current_Error return File_Type;
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type File_Access is access constant File_Type;
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function Standard_Input return File_Access;
function Standard_Output return File_Access;
function Standard_Error return File_Access;
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function Current_Input return File_Access;
function Current_Output return File_Access;
function Current_Error return File_Access;
21/1
--Buffer control
procedure Flush (File : in File_Type);
procedure Flush;
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-- Specification of line and page lengths
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procedure Set_Line_Length(File : in File_Type; To : in Count);
procedure Set_Line_Length(To : in Count);
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procedure Set_Page_Length(File : in File_Type; To : in Count);
procedure Set_Page_Length(To : in Count);
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function Line_Length(File : in File_Type) return Count;
function Line_Length return Count;
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function Page_Length(File : in File_Type) return Count;
function Page_Length return Count;
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-- Column, Line, and Page Control
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procedure New_Line (File : in File_Type;
Spacing : in Positive_Count := 1);
procedure New_Line (Spacing : in Positive_Count := 1);
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procedure Skip_Line (File : in File_Type;
Spacing : in Positive_Count := 1);
procedure Skip_Line (Spacing : in Positive_Count := 1);
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function End_Of_Line(File : in File_Type) return Boolean;
function End_Of_Line return Boolean;
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procedure New_Page (File : in File_Type);
procedure New_Page;
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procedure Skip_Page (File : in File_Type);
procedure Skip_Page;
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function End_Of_Page(File : in File_Type) return Boolean;
function End_Of_Page return Boolean;
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function End_Of_File(File : in File_Type) return Boolean;
function End_Of_File return Boolean;
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procedure Set_Col (File : in File_Type; To : in Positive_Count);
procedure Set_Col (To : in Positive_Count);
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procedure Set_Line(File : in File_Type; To : in Positive_Count);
procedure Set_Line(To : in Positive_Count);
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function Col (File : in File_Type) return Positive_Count;
function Col return Positive_Count;
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function Line(File : in File_Type) return Positive_Count;
function Line return Positive_Count;
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function Page(File : in File_Type) return Positive_Count;
function Page return Positive_Count;
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-- Character Input-Output
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procedure Get(File : in File_Type; Item : out Character);
procedure Get(Item : out Character);
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procedure Put(File : in File_Type; Item : in Character);
procedure Put(Item : in Character);
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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);
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procedure Get_Immediate(File : in File_Type;
Item : out Character);
procedure Get_Immediate(Item : out Character);
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procedure Get_Immediate(File : in File_Type;
Item : out Character;
Available : out Boolean);
procedure Get_Immediate(Item : out Character;
Available : out Boolean);
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-- String Input-Output
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procedure Get(File : in File_Type; Item : out String);
procedure Get(Item : out String);
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procedure Put(File : in File_Type; Item : in String);
procedure Put(Item : in String);
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procedure Get_Line(File : in File_Type;
Item : out String;
Last : out Natural);
procedure Get_Line(Item : out String; Last : out Natural);
49.1/2
function Get_Line(File : in File_Type) return String;
function Get_Line return String;
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procedure Put_Line(File : in File_Type; Item : in String);
procedure Put_Line(Item : in String);
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-- Generic packages for Input-Output of Integer Types
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generic
type Num is range <>;
package Integer_IO is
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Default_Width : Field := Num'Width;
Default_Base : Number_Base := 10;
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procedure Get(File : in File_Type;
Item : out Num;
Width : in Field := 0);
procedure Get(Item : out Num;
Width : in Field := 0);
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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);
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end Integer_IO;
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generic
type Num is mod <>;
package Modular_IO is
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Default_Width : Field := Num'Width;
Default_Base : Number_Base := 10;
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procedure Get(File : in File_Type;
Item : out Num;
Width : in Field := 0);
procedure Get(Item : out Num;
Width : in Field := 0);
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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);
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end Modular_IO;
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-- Generic packages for Input-Output of Real Types
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generic
type Num is digits <>;
package Float_IO is
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Default_Fore : Field := 2;
Default_Aft : Field := Num'Digits-1;
Default_Exp : Field := 3;
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procedure Get(File : in File_Type;
Item : out Num;
Width : in Field := 0);
procedure Get(Item : out Num;
Width : in Field := 0);
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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);
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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;
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generic
type Num is delta <>;
package Fixed_IO is
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Default_Fore : Field := Num'Fore;
Default_Aft : Field := Num'Aft;
Default_Exp : Field := 0;
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procedure Get(File : in File_Type;
Item : out Num;
Width : in Field := 0);
procedure Get(Item : out Num;
Width : in Field := 0);
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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);
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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;
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generic
type Num is delta <> digits <>;
package Decimal_IO is
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Default_Fore : Field := Num'Fore;
Default_Aft : Field := Num'Aft;
Default_Exp : Field := 0;
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procedure Get(File : in File_Type;
Item : out Num;
Width : in Field := 0);
procedure Get(Item : out Num;
Width : in Field := 0);
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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);
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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;
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-- Generic package for Input-Output of Enumeration Types
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generic
type Enum is (<>);
package Enumeration_IO is
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Default_Width : Field := 0;
Default_Setting : Type_Set := Upper_Case;
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procedure Get(File : in File_Type;
Item : out Enum);
procedure Get(Item : out Enum);
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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);
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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;
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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;
Layout_Error : exception renames IO_Exceptions.Layout_Error;
private
... -- not specified by the language
end Ada.Text_IO;
86/2
The type File_Type needs finalization (see 7.6).

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