A.10.1 The Package Text_IO
Static Semantics
1
The library package
Text_IO has the following declaration:
2
with Ada.IO_Exceptions;
package Ada.Text_IO
is
3
type File_Type
is limited private;
4
type File_Mode
is (In_File, Out_File, Append_File);
5
type Count
is range 0 ..
implementation-defined;
subtype Positive_Count
is Count
range 1 .. Count'Last;
Unbounded :
constant Count := 0; --
line and page length
6
subtype Field
is Integer
range 0 ..
implementation-defined;
subtype Number_Base
is Integer
range 2 .. 16;
7
type Type_Set
is (Lower_Case, Upper_Case);
8
-- File Management
9
procedure Create (File :
in out File_Type;
Mode :
in File_Mode := Out_File;
Name :
in String := "";
Form :
in String := "");
10
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);
12
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;
14
-- Control of default input and output files
15
procedure Set_Input (File :
in File_Type);
procedure Set_Output(File :
in File_Type);
procedure Set_Error (File :
in File_Type);
16
function Standard_Input
return File_Type;
function Standard_Output
return File_Type;
function Standard_Error
return File_Type;
17
function Current_Input
return File_Type;
function Current_Output
return File_Type;
function Current_Error
return File_Type;
18
type File_Access
is access constant File_Type;
19
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;
22
-- Specification of line and page lengths
23
procedure Set_Line_Length(File :
in File_Type; To :
in Count);
procedure Set_Line_Length(To :
in Count);
24
procedure Set_Page_Length(File :
in File_Type; To :
in Count);
procedure Set_Page_Length(To :
in Count);
25
function Line_Length(File :
in File_Type)
return Count;
function Line_Length
return Count;
26
function Page_Length(File :
in File_Type)
return Count;
function Page_Length
return Count;
27
-- Column, Line, and Page Control
28
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;
31
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;
34
function End_Of_File(File :
in File_Type)
return Boolean;
function End_Of_File
return Boolean;
35
procedure Set_Col (File :
in File_Type; To :
in Positive_Count);
procedure Set_Col (To :
in Positive_Count);
36
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;
38
function Line(File :
in File_Type)
return Positive_Count;
function Line
return Positive_Count;
39
function Page(File :
in File_Type)
return Positive_Count;
function Page
return Positive_Count;
40
-- Character Input-Output
41
procedure Get(File :
in File_Type; Item :
out Character);
procedure Get(Item :
out Character);
42
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);
44
procedure Get_Immediate(File :
in File_Type;
Item :
out Character);
procedure Get_Immediate(Item :
out Character);
45
procedure Get_Immediate(File :
in File_Type;
Item :
out Character;
Available :
out Boolean);
procedure Get_Immediate(Item :
out Character;
Available :
out Boolean);
46
-- String Input-Output
47
procedure Get(File :
in File_Type; Item :
out String);
procedure Get(Item :
out String);
48
procedure Put(File :
in File_Type; Item :
in String);
procedure Put(Item :
in String);
49
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;
50
procedure Put_Line(File :
in File_Type; Item :
in String);
procedure Put_Line(Item :
in String);
51
-- 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;
57
generic
type Num
is mod <>;
package Modular_IO
is
58
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;
68
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);
76
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;
78
-- Generic package for Input-Output of Enumeration Types
79
generic
type Enum
is (<>);
package Enumeration_IO
is
80
Default_Width : Field := 0;
Default_Setting : Type_Set := Upper_Case;
81
procedure Get(File :
in File_Type;
Item :
out Enum);
procedure Get(Item :
out Enum);
82
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;
84
-- 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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