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Text File | 2000-07-19 | 17KB | 419 lines

------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME COMPONENTS -- -- -- -- A D A . T E X T _ I O -- -- -- -- S p e c -- -- -- -- $Revision: 1.50 $ -- -- -- Copyright (C) 1992-2000 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 2, 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 -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- -- -- ------------------------------------------------------------------------------ -- 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; package Ada.Text_IO is pragma Elaborate_Body (Text_IO); 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 .. Natural'Last; -- The value of Count'Last must be large enough so that the assumption -- enough so that the assumption that the Line, Column and Page -- counts can never exceed this value is a valid assumption. subtype Positive_Count is Count range 1 .. Count'Last; Unbounded : constant Count := 0; -- Line and page length subtype Field is Integer range 0 .. 255; -- Note: if for any reason, there is a need to increase this value, -- then it will be necessary to change the corresponding value in -- System.Img_Real in file s-imgrea.adb. 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 parameter file is IN OUT in the RM, but this is clearly -- an oversight, and was intended to be IN, see AI95-00057. 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; type File_Type is access all Text_AFCB; 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; Self : aliased File_Type; -- Set to point to the containing Text_AFCB block. This is used to -- implement the Current_{Error,Input,Ouput} 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 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. end record; 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;