DEFINITION MODULE ByteItems;
(*====================================================================
    Version  : 1.0  Sat, Mar 4, 1989  C. Lins
    Compiler : JPI TopSpeed Modula-2
    Component: Generic Item Structure Utility - BYTE Items

    INTRODUCTION
    This module provides support for generic data items, restricted
    to types compatible with BYTE.  Assignment, equality testing, and
    relational operations are all provided by the language.

    REVISION HISTORY
    v1.0  Sat, Mar 4, 1989  C. Lins
      Initial JPI implementation.

    Proprietary Notices
      Copyright (C) 1989 Charles A. Lins. All rights reserved. 
====================================================================*)

FROM SYSTEM IMPORT
    (*--Type*) BYTE;


TYPE  Item	= BYTE; 	    (*-- The BYTE item data type *)
CONST NullItem	= VAL(BYTE, 0C);    (*-- The ╘null╒ value *)


TYPE  AssignProc  = PROCEDURE (    Item    (*-- in    *))
				 : Item    (*-- out   *);

TYPE  EqualProc   = PROCEDURE (    Item    (*-- in    *),
				   Item    (*-- in    *))
				 : BOOLEAN (*-- out   *);


    (*---------------------------------*)
    (*--	 ITERATORS	     --*)

TYPE  AccessProc     = PROCEDURE (    Item     (*-- in	  *));
TYPE  ChangeProc     = PROCEDURE (VAR Item     (*-- inout *));


TYPE  Continue	     = BOOLEAN;
TYPE  LoopAccessProc = PROCEDURE (    Item     (*-- in	  *))
				    : Continue (*-- out   *);

TYPE  LoopChangeProc = PROCEDURE (VAR Item     (*-- inout *))
				    : Continue (*-- out   *);

END ByteItems.