With IO,
     Sect; -- The Package in which the type sector is declared.
Package Randio Is

    -- Copyright 1984  RR Software, Inc., P.O. Box 1512, Madison WI 53701
    -- Permission is hereby given to distribute Object Code produced from
    -- these libraries.  All Other rights reserved.

    --
    -- JANUS/Ada Random I/O Package.
    -- Modeled on Ada Direct_IO.
    --
    -- How to use this Package
    --
    --  This Package is designed as an Ada Generic Package.  However, since
    --  Generics are not yet available in JANUS/Ada, the method for using
    --  this package is a bit awkward.  The Type Sector must imported from
    --  some other Package, by changing the With Clause, and the Subtype
    --  declaration.  Note that the name 'Sector' is used in only one place,
    --  and thus can easily be changed to any other type.  Then both the
    --  Specification and Body of RandIO must be recompiled.
    --
    --  The following classes of types must not be used as the type Sector
    --  (cannot be output or input):
    --     Limited Private Types
    --     Access Types
    --     Composite Types containing either of the above.
    --  Any other type may be output or input.
    --
    --  Io.IOResult can be tested for errors in this version.
    --
    --  Records are numbered from 1, as per the 1983 Ada Standard.

    Subtype Element_Type Is Sect.Sector; --Replace Sect.Sector with your type

    Type File_Type Is Limited Private;

    -- Many routines below have two forms, one which is compatible with
    -- current JANUS/Ada I/O, and the second which is compatible with the
    -- 1983 Ada standard.  We recommend using the Ada forms wherever
    -- possible, as the JANUS/Ada forms will be phased out.

    Type File_Mode Is (IN_File,INOUT_File,OUT_File);
    Type Count Is New Natural;
    Subtype Positive_Count Is Count Range 1 .. Count'Last;

    Procedure Open (Fyle : In Out File_Type; Name : In String;
	Mode : In IO.File_Mode);
	-- Opens a file for I/O.  JANUS/Ada version.

    Procedure Open (Fyle : In Out File_Type; Mode : In File_Mode;
	Name : In String);
	-- Opens a file for I/O.  Ada 83 version.

    Procedure Create (Fyle : In Out File_Type; Name : In String;
	Mode : In IO.File_Mode);
	-- Creates a new file for I/O.  JANUS/Ada version.

    Procedure Create (Fyle : In Out File_Type; Mode : In File_Mode;
	Name : In String);
	-- Creates a new file for I/O.  Ada 83 version.

    Procedure Close (Fyle : In Out File_Type);
	-- Closes a file.

    -- Procedure Delete (Fyle : In Out File_Type);
	-- Deletes a file.  Ada 83 version.  ** Not implemented **

    -- Procedure Delete (Name : In String);
	-- Deletes a file.  Janus/Ada version.  Use the one in I/O.

    -- Procedure Reset (File : In Out File_Type; Mode : In File_Mode);
	-- Resets a file.  Ada 83 only.  ** Not implemented **

    Function Mode (Fyle : In File_Type) Return Io.File_Mode;
	-- Returns the current mode of Fyle. Janus/Ada version.

    -- Function Mode (Fyle : In File_Type) Return File_Mode;
	-- Returns the current mode of Fyle. Ada 83 version.
	-- ** Not implemented because overloading on return types
	-- is disallowed in Janus/Ada.

    Function Name (Fyle : In File_Type) Return String;
	-- Returns the name of Fyle.

    Function Is_Open (Fyle : In File_Type) Return Boolean;
	-- Return True if the file is Open.

    Procedure Read (Fyle : In File_Type; Item : Out Element_Type; Rec : In
	positive_count);
	-- Read the record at record number positive count.  IOresult is
	-- set to 255 if it does not exist.

    Procedure Read (Fyle : In File_Type; Item : Out Element_Type);
	-- Read the record following the last one read or written.
	-- IOresult is set to 255 if it does not exist.

    Procedure Write (Fyle : In File_Type; Item : In Element_Type; Rec : In
	positive_count);
	-- Write the record at record number positive count.  IOresult is
	-- set to 255 if an error occurs.  (The disk is probably full).

    Procedure Write (Fyle : In File_Type; Item : In Element_Type);
	-- Write the record following the last one read or written.
	-- IOresult is set the same as above.

    Procedure Set_Index (Fyle : In File_Type; Rec : In Positive_Count);
	-- Set the next record to be read or written, if a number is not
	-- specified.

    Function Index (Fyle : In File_Type) Return Positive_Count;
	-- Returns the number of the next record to be read or written.

    Function Size (Fyle : In File_Type) Return Count;
	-- Returns the current size of the file, in records.

    Function End_of_File (Fyle : In File_Type) Return Boolean;
	-- Returns True if the current index points past the end of the file.

Private
    Type File_Block;
    Type File_Type Is Access File_Block;
    Type File_Block Is Record
	Fyle : File;
	Index : Positive_Count;
    End Record;
End RandIO;
 the next record to be read or written.

    Function Size (Fyle : In File_Type) Return Count;
	-- Returns the current size _Type; Item : In Element_Type);
	-- Write the record following the last one read or written.
	-- IOresult is set the same as a