blob: 910154d6e6f11f81406fe971d87b1e715b44c70d [file] [log] [blame]
-- --
-- --
-- A D A . W I D E _ T E X T _ I O --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2021, Free Software Foundation, Inc. --
-- --
-- This specification is derived from the Ada Reference Manual for use with --
-- GNAT. The copyright notice above, and the license provisions that follow --
-- apply solely to the contents of the part following the private keyword. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
-- Note: the generic subpackages of Wide_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 Wide_Text_IO are processed
-- and loaded.
with Ada.IO_Exceptions;
with Ada.Streams;
with Interfaces.C_Streams;
with System;
with System.File_Control_Block;
with System.WCh_Con;
package Ada.Wide_Text_IO is
type File_Type is limited private with Default_Initial_Condition;
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 .. Natural'Last;
-- The value of Count'Last must be large enough so that the assumption that
-- the Line, Column and Page counts can never exceed this value is valid.
subtype Positive_Count is Count range 1 .. Count'Last;
Unbounded : constant Count := 0;
-- Line and page length
subtype Field is Integer range 0 .. 255;
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 : File_Mode := Out_File;
Name : String := "";
Form : String := "");
procedure Open
(File : in out File_Type;
Mode : File_Mode;
Name : String;
Form : String := "");
procedure Close (File : in out File_Type);
procedure Delete (File : in out File_Type);
procedure Reset (File : in out File_Type; Mode : File_Mode);
procedure Reset (File : in out File_Type);
function Mode (File : File_Type) return File_Mode;
function Name (File : File_Type) return String;
function Form (File : File_Type) return String;
function Is_Open (File : File_Type) return Boolean;
-- Control of default input, output and error files --
procedure Set_Input (File : File_Type);
procedure Set_Output (File : File_Type);
procedure Set_Error (File : 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 parameter 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 : File_Type);
procedure Flush;
-- Specification of line and page lengths --
procedure Set_Line_Length (File : File_Type; To : Count);
procedure Set_Line_Length (To : Count);
procedure Set_Page_Length (File : File_Type; To : Count);
procedure Set_Page_Length (To : Count);
function Line_Length (File : File_Type) return Count;
function Line_Length return Count;
function Page_Length (File : File_Type) return Count;
function Page_Length return Count;
-- Column, Line, and Page Control --
procedure New_Line (File : File_Type; Spacing : Positive_Count := 1);
procedure New_Line (Spacing : Positive_Count := 1);
procedure Skip_Line (File : File_Type; Spacing : Positive_Count := 1);
procedure Skip_Line (Spacing : Positive_Count := 1);
function End_Of_Line (File : File_Type) return Boolean;
function End_Of_Line return Boolean;
procedure New_Page (File : File_Type);
procedure New_Page;
procedure Skip_Page (File : File_Type);
procedure Skip_Page;
function End_Of_Page (File : File_Type) return Boolean;
function End_Of_Page return Boolean;
function End_Of_File (File : File_Type) return Boolean;
function End_Of_File return Boolean;
procedure Set_Col (File : File_Type; To : Positive_Count);
procedure Set_Col (To : Positive_Count);
procedure Set_Line (File : File_Type; To : Positive_Count);
procedure Set_Line (To : Positive_Count);
function Col (File : File_Type) return Positive_Count;
function Col return Positive_Count;
function Line (File : File_Type) return Positive_Count;
function Line return Positive_Count;
function Page (File : File_Type) return Positive_Count;
function Page return Positive_Count;
-- Character Input-Output --
procedure Get (File : File_Type; Item : out Wide_Character);
procedure Get (Item : out Wide_Character);
procedure Put (File : File_Type; Item : Wide_Character);
procedure Put (Item : Wide_Character);
procedure Look_Ahead
(File : File_Type;
Item : out Wide_Character;
End_Of_Line : out Boolean);
procedure Look_Ahead
(Item : out Wide_Character;
End_Of_Line : out Boolean);
procedure Get_Immediate
(File : File_Type;
Item : out Wide_Character);
procedure Get_Immediate
(Item : out Wide_Character);
procedure Get_Immediate
(File : File_Type;
Item : out Wide_Character;
Available : out Boolean);
procedure Get_Immediate
(Item : out Wide_Character;
Available : out Boolean);
-- String Input-Output --
procedure Get (File : File_Type; Item : out Wide_String);
procedure Get (Item : out Wide_String);
procedure Put (File : File_Type; Item : Wide_String);
procedure Put (Item : Wide_String);
procedure Get_Line
(File : File_Type;
Item : out Wide_String;
Last : out Natural);
procedure Get_Line
(Item : out Wide_String;
Last : out Natural);
function Get_Line (File : File_Type) return Wide_String;
pragma Ada_05 (Get_Line);
function Get_Line return Wide_String;
pragma Ada_05 (Get_Line);
procedure Put_Line
(File : File_Type;
Item : Wide_String);
procedure Put_Line
(Item : Wide_String);
-- Generic packages for Input-Output --
-- The generic packages:
-- Ada.Wide_Text_IO.Integer_IO
-- Ada.Wide_Text_IO.Modular_IO
-- Ada.Wide_Text_IO.Float_IO
-- Ada.Wide_Text_IO.Fixed_IO
-- Ada.Wide_Text_IO.Decimal_IO
-- Ada.Wide_Text_IO.Enumeration_IO
-- are implemented as separate child packages in GNAT, so the
-- spec and body of these packages are to be found in separate
-- child units. This implementation detail is hidden from the
-- Ada programmer by special circuitry in the compiler that
-- treats these child packages as though they were nested in
-- Text_IO. The advantage of this special processing is that
-- the subsidiary routines needed if these generics are used
-- are not loaded when they are not used.
-- 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;
-- The following procedures have a File_Type formal of mode IN OUT because
-- they may close the original file. The Close operation may raise an
-- exception, but in that case we want any assignment to the formal to
-- be effective anyway, so it must be passed by reference (or the caller
-- will be left with a dangling pointer).
pragma Export_Procedure
(Internal => Close,
External => "",
Mechanism => Reference);
pragma Export_Procedure
(Internal => Delete,
External => "",
Mechanism => Reference);
pragma Export_Procedure
(Internal => Reset,
External => "",
Parameter_Types => (File_Type),
Mechanism => Reference);
pragma Export_Procedure
(Internal => Reset,
External => "",
Parameter_Types => (File_Type, File_Mode),
Mechanism => (File => Reference));
package WCh_Con renames System.WCh_Con;
-- 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 preexisting 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
-- Wide_Text_IO File Control Block --
Default_WCEM : WCh_Con.WC_Encoding_Method := WCh_Con.WCEM_UTF8;
-- This gets modified during initialization (see body) using
-- the default value established in the call to Set_Globals.
package FCB renames System.File_Control_Block;
type Wide_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;
Self : aliased File_Type;
-- Set to point to the containing Text_AFCB block. This is used to
-- implement the Current_{Error,Input,Output} functions which return
-- a File_Access, the file access value returned is a pointer to
-- the Self field of the corresponding file.
Before_LM : Boolean := False;
-- This flag is used to deal with the anomalies 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 odd, 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.
WC_Method : WCh_Con.WC_Encoding_Method := Default_WCEM;
-- Encoding method to be used for this file
Before_Wide_Character : Boolean := False;
-- This flag is set 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#, and the
-- value of this character is saved in Saved_Wide_Character.
Saved_Wide_Character : Wide_Character;
-- This field is valid only if Before_Wide_Character is set. It
-- contains a wide character read by Look_Ahead. If Look_Ahead
-- reads a character in the range 16#0000# to 16#007F#, then it
-- can use ungetc to put it back, but ungetc cannot be called
-- more than once, so for characters above this range, we don't
-- try to back up the file. Instead we save the character in this
-- field and set the flag Before_Wide_Character to indicate that
-- we are logically positioned before this character even though
-- the stream is physically positioned after it.
end record;
type File_Type is access all Wide_Text_AFCB;
function AFCB_Allocate (Control_Block : Wide_Text_AFCB) return FCB.AFCB_Ptr;
procedure AFCB_Close (File : not null access Wide_Text_AFCB);
procedure AFCB_Free (File : not null access Wide_Text_AFCB);
procedure Read
(File : in out Wide_Text_AFCB;
Item : out Ada.Streams.Stream_Element_Array;
Last : out Ada.Streams.Stream_Element_Offset);
-- Read operation used when Wide_Text_IO file is treated as a Stream
procedure Write
(File : in out Wide_Text_AFCB;
Item : Ada.Streams.Stream_Element_Array);
-- Write operation used when Wide_Text_IO file is treated as a Stream
-- The Standard Files --
Standard_Err_AFCB : aliased Wide_Text_AFCB;
Standard_In_AFCB : aliased Wide_Text_AFCB;
Standard_Out_AFCB : aliased Wide_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
procedure Initialize_Standard_Files;
-- Initializes the file control blocks for the standard files. Called from
-- the elaboration routine for this package, and from Reset_Standard_Files
-- in package Ada.Wide_Text_IO.Reset_Standard_Files.
-- Local Subprograms --
-- These subprograms are in the private part of the spec so that they can
-- be shared by the children of Ada.Wide_Text_IO.
function Getc (File : File_Type) return;
-- 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.
procedure Get_Character (File : File_Type; Item : out Character);
-- This is essentially a copy of the normal Get routine from Text_IO. It
-- obtains a single character from the input file File, and places it in
-- Item. This character may be the leading character of a Wide_Character
-- sequence, but that is up to the caller to deal with.
function Get_Wide_Char
(C : Character;
File : File_Type) return Wide_Character;
-- This function is shared by Get and Get_Immediate to extract a wide
-- character value from the given File. The first byte has already been
-- read and is passed in C. The wide character value is returned as the
-- result, and the file pointer is bumped past the character.
function Nextc (File : File_Type) return;
-- Returns next character from file without skipping past it (i.e. it is a
-- combination of Getc followed by an Ungetc).
end Ada.Wide_Text_IO;