Package Name: ada.text_io
------------------------------------------------------------------------------
-- --
-- GNAT RUNTIME COMPONENTS --
-- --
-- A D A . T E X T _ I O --
-- --
-- S p e c --
-- --
-- $Revision: 1.40 $ --
-- --
-- This specification is adapted from the Ada Reference Manual for use with --
-- GNAT. In accordance with the copyright of that document, you can freely --
-- copy and modify this specification, provided that if you redistribute a --
-- modified version, any changes that you have made are clearly indicated. --
-- --
------------------------------------------------------------------------------
-- Note: the generic subpackages of Text_IO (Integer_IO, Float_IO, Fixed_IO,
-- Modular_IO, Decimal_IO and Enumeration_IO) appear as private children in
-- GNAT. These children are with'ed automatically if they are referenced, so
-- this rearrangement is invisible to user programs, but has the advantage
-- that only the needed parts of Text_IO are processed and loaded.
with Ada.IO_Exceptions;
with Ada.Streams;
with System;
with System.File_Control_Block;
with System.Parameters;
package Ada.Text_IO is
type File_Type is limited private;
type File_Mode is (In_File, Out_File, Append_File);
-- The following representation clause allows the use of unchecked
-- conversion for rapid translation between the File_Mode type
-- used in this package and System.File_IO.
for File_Mode use
(In_File => 0, -- System.FIle_IO.File_Mode'Pos (In_File)
Out_File => 2, -- System.File_IO.File_Mode'Pos (Out_File)
Append_File => 3); -- System.File_IO.File_Mode'Pos (Append_File)
type Count is range 0 .. System.Parameters.Count_Max;
subtype Positive_Count is Count range 1 .. Count'Last;
Unbounded : constant Count := 0;
-- Line and page length
subtype Field is Integer range 0 .. System.Parameters.Field_Max;
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, output and error 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 --
--------------------
-- Note: The paramter file is in out in the RM, but as pointed out
-- in <<95-5166.a Tucker Taft 95-6-23>> this is clearly an oversight.
procedure Flush (File : in File_Type);
procedure Flush;
--------------------------------------------
-- 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;
-----------------------------
-- Characters 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);
--------------------------
-- Strings 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);
procedure Put_Line
(File : in File_Type;
Item : in String);
procedure Put_Line
(Item : in String);
-- 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
-----------------------------------
-- Handling of Format Characters --
-----------------------------------
-- Line marks are represented by the single character Ascii.LF (16#0A#).
-- In DOS and similar systems, underlying file translation takes care
-- of translating this to and from the standard CR/LF sequences used in
-- these operating systems to mark the end of a line. On output there is
-- always a line mark at the end of the last line, but on input, this
-- line mark can be omitted, and is implied by the end of file.
-- Page marks are represented by the single character Ascii.FF (16#0C#),
-- The page mark at the end of the file may be omitted, and is normally
-- omitted on output unless an explicit New_Page call is made before
-- closing the file. No page mark is added when a file is appended to,
-- so, in accordance with the permission in (RM A.10.2(4)), there may
-- or may not be a page mark separating preexising text in the file
-- from the new text to be written.
-- A file mark is marked by the physical end of file. In DOS translation
-- mode on input, an EOF character (SUB = 16#1A#) gets translated to the
-- physical end of file, so in effect this character is recognized as
-- marking the end of file in DOS and similar systems.
LM : constant := Character'Pos (Ascii.LF);
-- Used as line mark
PM : constant := Character'Pos (Ascii.FF);
-- Used as page mark, except at end of file where it is implied
--------------------------------
-- Text_IO File Control Block --
--------------------------------
package FCB renames System.File_Control_Block;
type Text_AFCB is new FCB.AFCB with record
Page : Count := 1;
Line : Count := 1;
Col : Count := 1;
Line_Length : Count := 0;
Page_Length : Count := 0;
Before_LM : Boolean := False;
-- This flag is used to deal with the anomolies introduced by the
-- peculiar definition of End_Of_File and End_Of_Page in Ada. These
-- functions require looking ahead more than one character. Since
-- there is no convenient way of backing up more than one character,
-- what we do is to leave ourselves positioned past the LM, but set
-- this flag, so that we know that from an Ada point of view we are
-- in front of the LM, not after it. A bit of a kludge, but it works!
Before_LM_PM : Boolean := False;
-- This flag similarly handles the case of being physically positioned
-- after a LM-PM sequence when logically we are before the LM-PM. This
-- flag can only be set if Before_LM is also set.
Before_Wide_Character : Boolean := False;
-- This flag is always False for Text_IO files. It is used in the wide
-- character case to indicate that a wide character in the input has
-- been read by Wide_Text_IO.Look_Ahead. If it is set to True, then it
-- means that the stream is logically positioned before the character
-- but is physically positioned after it. The character involved must
-- not be in the range 16#00#-16#7F#, i.e. if the flag is set, then we
-- know the next character has a code greater than 16#7F#. The reason
-- we define this flag in the base Text_IO control block is that there
-- are routines shared between Text_IO and Wide_Text_IO, notably the
-- numeric input routines in Ada.Text_IO.Generic_Aux, which need to
-- test the flag (note that if it is set, the next character cannot
-- be a valid character in a numeric item).
end record;
type File_Type is access all Text_AFCB;
function AFCB_Allocate (Control_Block : Text_AFCB) return FCB.AFCB_Ptr;
procedure AFCB_Close (File : access Text_AFCB);
procedure AFCB_Free (File : access Text_AFCB);
procedure Read
(File : in out Text_AFCB;
Item : out Ada.Streams.Stream_Element_Array;
Last : out Ada.Streams.Stream_Element_Offset);
-- Read operation used when Text_IO file is treated directly as Stream
procedure Write
(File : in out Text_AFCB;
Item : in Ada.Streams.Stream_Element_Array);
-- Write operation used when Text_IO file is treated directly as Stream
------------------------
-- The Standard Files --
------------------------
Null_Str : aliased constant String := "";
-- Used as name and form of standard files
Standard_Err_AFCB : aliased Text_AFCB;
Standard_In_AFCB : aliased Text_AFCB;
Standard_Out_AFCB : aliased Text_AFCB;
Standard_Err : aliased File_Type := Standard_Err_AFCB'Access;
Standard_In : aliased File_Type := Standard_In_AFCB'Access;
Standard_Out : aliased File_Type := Standard_Out_AFCB'Access;
-- Standard files
Current_In : aliased File_Type := Standard_In;
Current_Out : aliased File_Type := Standard_Out;
Current_Err : aliased File_Type := Standard_Err;
-- Current files
-----------------------
-- Local Subprograms --
-----------------------
-- These subprograms are in the private part of the spec so that they can
-- be shared by the routines in the body of Ada.Text_IO.Wide_Text_IO.
-- Note: we use Integer in these declarations instead of the more accurate
-- Interfaces.C_Streams.int, because we do not want to drag in the spec of
-- this interfaces package with the spec of Ada.Text_IO, and we know that
-- in fact these types are identical
function Getc (File : File_Type) return Integer;
-- Gets next character from file, which has already been checked for
-- being in read status, and returns the character read if no error
-- occurs. The result is EOF if the end of file was read.
function Nextc (File : File_Type) return Integer;
-- Returns next character from file without skipping past it (i.e. it
-- is a combination of Getc followed by an Ungetc).
procedure Putc (ch : Integer; File : File_Type);
-- Outputs the given character to the file, which has already been
-- checked for being in output status. Device_Error is raised if the
-- character cannot be written.
procedure Terminate_Line (File : File_Type);
-- If the file is in Write_File or Append_File mode, and the current
-- line is not terminated, then a line terminator is written using
-- New_Line. Note that there is no Terminate_Page routine, because
-- the page mark at the end of the file is implied if necessary.
procedure Ungetc (ch : Integer; File : File_Type);
-- Pushes back character into stream, using ungetc. The caller has
-- checked that the file is in read status. Device_Error is raised
-- if the character cannot be pushed back. An attempt to push back
-- and end of file character (EOF) is ignored.
end Ada.Text_IO;